xref: /openbmc/linux/drivers/mtd/nand/raw/nand_base.c (revision 5ef12cb4a3a78ffb331c03a795a15eea4ae35155)
1 /*
2  *  Overview:
3  *   This is the generic MTD driver for NAND flash devices. It should be
4  *   capable of working with almost all NAND chips currently available.
5  *
6  *	Additional technical information is available on
7  *	http://www.linux-mtd.infradead.org/doc/nand.html
8  *
9  *  Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
10  *		  2002-2006 Thomas Gleixner (tglx@linutronix.de)
11  *
12  *  Credits:
13  *	David Woodhouse for adding multichip support
14  *
15  *	Aleph One Ltd. and Toby Churchill Ltd. for supporting the
16  *	rework for 2K page size chips
17  *
18  *  TODO:
19  *	Enable cached programming for 2k page size chips
20  *	Check, if mtd->ecctype should be set to MTD_ECC_HW
21  *	if we have HW ECC support.
22  *	BBT table is not serialized, has to be fixed
23  *
24  * This program is free software; you can redistribute it and/or modify
25  * it under the terms of the GNU General Public License version 2 as
26  * published by the Free Software Foundation.
27  *
28  */
29 
30 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31 
32 #include <linux/module.h>
33 #include <linux/delay.h>
34 #include <linux/errno.h>
35 #include <linux/err.h>
36 #include <linux/sched.h>
37 #include <linux/slab.h>
38 #include <linux/mm.h>
39 #include <linux/nmi.h>
40 #include <linux/types.h>
41 #include <linux/mtd/mtd.h>
42 #include <linux/mtd/rawnand.h>
43 #include <linux/mtd/nand_ecc.h>
44 #include <linux/mtd/nand_bch.h>
45 #include <linux/interrupt.h>
46 #include <linux/bitops.h>
47 #include <linux/io.h>
48 #include <linux/mtd/partitions.h>
49 #include <linux/of.h>
50 
51 static int nand_get_device(struct mtd_info *mtd, int new_state);
52 
53 static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
54 			     struct mtd_oob_ops *ops);
55 
56 /* Define default oob placement schemes for large and small page devices */
57 static int nand_ooblayout_ecc_sp(struct mtd_info *mtd, int section,
58 				 struct mtd_oob_region *oobregion)
59 {
60 	struct nand_chip *chip = mtd_to_nand(mtd);
61 	struct nand_ecc_ctrl *ecc = &chip->ecc;
62 
63 	if (section > 1)
64 		return -ERANGE;
65 
66 	if (!section) {
67 		oobregion->offset = 0;
68 		if (mtd->oobsize == 16)
69 			oobregion->length = 4;
70 		else
71 			oobregion->length = 3;
72 	} else {
73 		if (mtd->oobsize == 8)
74 			return -ERANGE;
75 
76 		oobregion->offset = 6;
77 		oobregion->length = ecc->total - 4;
78 	}
79 
80 	return 0;
81 }
82 
83 static int nand_ooblayout_free_sp(struct mtd_info *mtd, int section,
84 				  struct mtd_oob_region *oobregion)
85 {
86 	if (section > 1)
87 		return -ERANGE;
88 
89 	if (mtd->oobsize == 16) {
90 		if (section)
91 			return -ERANGE;
92 
93 		oobregion->length = 8;
94 		oobregion->offset = 8;
95 	} else {
96 		oobregion->length = 2;
97 		if (!section)
98 			oobregion->offset = 3;
99 		else
100 			oobregion->offset = 6;
101 	}
102 
103 	return 0;
104 }
105 
106 const struct mtd_ooblayout_ops nand_ooblayout_sp_ops = {
107 	.ecc = nand_ooblayout_ecc_sp,
108 	.free = nand_ooblayout_free_sp,
109 };
110 EXPORT_SYMBOL_GPL(nand_ooblayout_sp_ops);
111 
112 static int nand_ooblayout_ecc_lp(struct mtd_info *mtd, int section,
113 				 struct mtd_oob_region *oobregion)
114 {
115 	struct nand_chip *chip = mtd_to_nand(mtd);
116 	struct nand_ecc_ctrl *ecc = &chip->ecc;
117 
118 	if (section || !ecc->total)
119 		return -ERANGE;
120 
121 	oobregion->length = ecc->total;
122 	oobregion->offset = mtd->oobsize - oobregion->length;
123 
124 	return 0;
125 }
126 
127 static int nand_ooblayout_free_lp(struct mtd_info *mtd, int section,
128 				  struct mtd_oob_region *oobregion)
129 {
130 	struct nand_chip *chip = mtd_to_nand(mtd);
131 	struct nand_ecc_ctrl *ecc = &chip->ecc;
132 
133 	if (section)
134 		return -ERANGE;
135 
136 	oobregion->length = mtd->oobsize - ecc->total - 2;
137 	oobregion->offset = 2;
138 
139 	return 0;
140 }
141 
142 const struct mtd_ooblayout_ops nand_ooblayout_lp_ops = {
143 	.ecc = nand_ooblayout_ecc_lp,
144 	.free = nand_ooblayout_free_lp,
145 };
146 EXPORT_SYMBOL_GPL(nand_ooblayout_lp_ops);
147 
148 /*
149  * Support the old "large page" layout used for 1-bit Hamming ECC where ECC
150  * are placed at a fixed offset.
151  */
152 static int nand_ooblayout_ecc_lp_hamming(struct mtd_info *mtd, int section,
153 					 struct mtd_oob_region *oobregion)
154 {
155 	struct nand_chip *chip = mtd_to_nand(mtd);
156 	struct nand_ecc_ctrl *ecc = &chip->ecc;
157 
158 	if (section)
159 		return -ERANGE;
160 
161 	switch (mtd->oobsize) {
162 	case 64:
163 		oobregion->offset = 40;
164 		break;
165 	case 128:
166 		oobregion->offset = 80;
167 		break;
168 	default:
169 		return -EINVAL;
170 	}
171 
172 	oobregion->length = ecc->total;
173 	if (oobregion->offset + oobregion->length > mtd->oobsize)
174 		return -ERANGE;
175 
176 	return 0;
177 }
178 
179 static int nand_ooblayout_free_lp_hamming(struct mtd_info *mtd, int section,
180 					  struct mtd_oob_region *oobregion)
181 {
182 	struct nand_chip *chip = mtd_to_nand(mtd);
183 	struct nand_ecc_ctrl *ecc = &chip->ecc;
184 	int ecc_offset = 0;
185 
186 	if (section < 0 || section > 1)
187 		return -ERANGE;
188 
189 	switch (mtd->oobsize) {
190 	case 64:
191 		ecc_offset = 40;
192 		break;
193 	case 128:
194 		ecc_offset = 80;
195 		break;
196 	default:
197 		return -EINVAL;
198 	}
199 
200 	if (section == 0) {
201 		oobregion->offset = 2;
202 		oobregion->length = ecc_offset - 2;
203 	} else {
204 		oobregion->offset = ecc_offset + ecc->total;
205 		oobregion->length = mtd->oobsize - oobregion->offset;
206 	}
207 
208 	return 0;
209 }
210 
211 static const struct mtd_ooblayout_ops nand_ooblayout_lp_hamming_ops = {
212 	.ecc = nand_ooblayout_ecc_lp_hamming,
213 	.free = nand_ooblayout_free_lp_hamming,
214 };
215 
216 static int check_offs_len(struct mtd_info *mtd,
217 					loff_t ofs, uint64_t len)
218 {
219 	struct nand_chip *chip = mtd_to_nand(mtd);
220 	int ret = 0;
221 
222 	/* Start address must align on block boundary */
223 	if (ofs & ((1ULL << chip->phys_erase_shift) - 1)) {
224 		pr_debug("%s: unaligned address\n", __func__);
225 		ret = -EINVAL;
226 	}
227 
228 	/* Length must align on block boundary */
229 	if (len & ((1ULL << chip->phys_erase_shift) - 1)) {
230 		pr_debug("%s: length not block aligned\n", __func__);
231 		ret = -EINVAL;
232 	}
233 
234 	return ret;
235 }
236 
237 /**
238  * nand_release_device - [GENERIC] release chip
239  * @mtd: MTD device structure
240  *
241  * Release chip lock and wake up anyone waiting on the device.
242  */
243 static void nand_release_device(struct mtd_info *mtd)
244 {
245 	struct nand_chip *chip = mtd_to_nand(mtd);
246 
247 	/* Release the controller and the chip */
248 	spin_lock(&chip->controller->lock);
249 	chip->controller->active = NULL;
250 	chip->state = FL_READY;
251 	wake_up(&chip->controller->wq);
252 	spin_unlock(&chip->controller->lock);
253 }
254 
255 /**
256  * nand_read_byte - [DEFAULT] read one byte from the chip
257  * @mtd: MTD device structure
258  *
259  * Default read function for 8bit buswidth
260  */
261 static uint8_t nand_read_byte(struct mtd_info *mtd)
262 {
263 	struct nand_chip *chip = mtd_to_nand(mtd);
264 	return readb(chip->IO_ADDR_R);
265 }
266 
267 /**
268  * nand_read_byte16 - [DEFAULT] read one byte endianness aware from the chip
269  * @mtd: MTD device structure
270  *
271  * Default read function for 16bit buswidth with endianness conversion.
272  *
273  */
274 static uint8_t nand_read_byte16(struct mtd_info *mtd)
275 {
276 	struct nand_chip *chip = mtd_to_nand(mtd);
277 	return (uint8_t) cpu_to_le16(readw(chip->IO_ADDR_R));
278 }
279 
280 /**
281  * nand_read_word - [DEFAULT] read one word from the chip
282  * @mtd: MTD device structure
283  *
284  * Default read function for 16bit buswidth without endianness conversion.
285  */
286 static u16 nand_read_word(struct mtd_info *mtd)
287 {
288 	struct nand_chip *chip = mtd_to_nand(mtd);
289 	return readw(chip->IO_ADDR_R);
290 }
291 
292 /**
293  * nand_select_chip - [DEFAULT] control CE line
294  * @mtd: MTD device structure
295  * @chipnr: chipnumber to select, -1 for deselect
296  *
297  * Default select function for 1 chip devices.
298  */
299 static void nand_select_chip(struct mtd_info *mtd, int chipnr)
300 {
301 	struct nand_chip *chip = mtd_to_nand(mtd);
302 
303 	switch (chipnr) {
304 	case -1:
305 		chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0 | NAND_CTRL_CHANGE);
306 		break;
307 	case 0:
308 		break;
309 
310 	default:
311 		BUG();
312 	}
313 }
314 
315 /**
316  * nand_write_byte - [DEFAULT] write single byte to chip
317  * @mtd: MTD device structure
318  * @byte: value to write
319  *
320  * Default function to write a byte to I/O[7:0]
321  */
322 static void nand_write_byte(struct mtd_info *mtd, uint8_t byte)
323 {
324 	struct nand_chip *chip = mtd_to_nand(mtd);
325 
326 	chip->write_buf(mtd, &byte, 1);
327 }
328 
329 /**
330  * nand_write_byte16 - [DEFAULT] write single byte to a chip with width 16
331  * @mtd: MTD device structure
332  * @byte: value to write
333  *
334  * Default function to write a byte to I/O[7:0] on a 16-bit wide chip.
335  */
336 static void nand_write_byte16(struct mtd_info *mtd, uint8_t byte)
337 {
338 	struct nand_chip *chip = mtd_to_nand(mtd);
339 	uint16_t word = byte;
340 
341 	/*
342 	 * It's not entirely clear what should happen to I/O[15:8] when writing
343 	 * a byte. The ONFi spec (Revision 3.1; 2012-09-19, Section 2.16) reads:
344 	 *
345 	 *    When the host supports a 16-bit bus width, only data is
346 	 *    transferred at the 16-bit width. All address and command line
347 	 *    transfers shall use only the lower 8-bits of the data bus. During
348 	 *    command transfers, the host may place any value on the upper
349 	 *    8-bits of the data bus. During address transfers, the host shall
350 	 *    set the upper 8-bits of the data bus to 00h.
351 	 *
352 	 * One user of the write_byte callback is nand_set_features. The
353 	 * four parameters are specified to be written to I/O[7:0], but this is
354 	 * neither an address nor a command transfer. Let's assume a 0 on the
355 	 * upper I/O lines is OK.
356 	 */
357 	chip->write_buf(mtd, (uint8_t *)&word, 2);
358 }
359 
360 /**
361  * nand_write_buf - [DEFAULT] write buffer to chip
362  * @mtd: MTD device structure
363  * @buf: data buffer
364  * @len: number of bytes to write
365  *
366  * Default write function for 8bit buswidth.
367  */
368 static void nand_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
369 {
370 	struct nand_chip *chip = mtd_to_nand(mtd);
371 
372 	iowrite8_rep(chip->IO_ADDR_W, buf, len);
373 }
374 
375 /**
376  * nand_read_buf - [DEFAULT] read chip data into buffer
377  * @mtd: MTD device structure
378  * @buf: buffer to store date
379  * @len: number of bytes to read
380  *
381  * Default read function for 8bit buswidth.
382  */
383 static void nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
384 {
385 	struct nand_chip *chip = mtd_to_nand(mtd);
386 
387 	ioread8_rep(chip->IO_ADDR_R, buf, len);
388 }
389 
390 /**
391  * nand_write_buf16 - [DEFAULT] write buffer to chip
392  * @mtd: MTD device structure
393  * @buf: data buffer
394  * @len: number of bytes to write
395  *
396  * Default write function for 16bit buswidth.
397  */
398 static void nand_write_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
399 {
400 	struct nand_chip *chip = mtd_to_nand(mtd);
401 	u16 *p = (u16 *) buf;
402 
403 	iowrite16_rep(chip->IO_ADDR_W, p, len >> 1);
404 }
405 
406 /**
407  * nand_read_buf16 - [DEFAULT] read chip data into buffer
408  * @mtd: MTD device structure
409  * @buf: buffer to store date
410  * @len: number of bytes to read
411  *
412  * Default read function for 16bit buswidth.
413  */
414 static void nand_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
415 {
416 	struct nand_chip *chip = mtd_to_nand(mtd);
417 	u16 *p = (u16 *) buf;
418 
419 	ioread16_rep(chip->IO_ADDR_R, p, len >> 1);
420 }
421 
422 /**
423  * nand_block_bad - [DEFAULT] Read bad block marker from the chip
424  * @mtd: MTD device structure
425  * @ofs: offset from device start
426  *
427  * Check, if the block is bad.
428  */
429 static int nand_block_bad(struct mtd_info *mtd, loff_t ofs)
430 {
431 	int page, page_end, res;
432 	struct nand_chip *chip = mtd_to_nand(mtd);
433 	u8 bad;
434 
435 	if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
436 		ofs += mtd->erasesize - mtd->writesize;
437 
438 	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
439 	page_end = page + (chip->bbt_options & NAND_BBT_SCAN2NDPAGE ? 2 : 1);
440 
441 	for (; page < page_end; page++) {
442 		res = chip->ecc.read_oob(mtd, chip, page);
443 		if (res)
444 			return res;
445 
446 		bad = chip->oob_poi[chip->badblockpos];
447 
448 		if (likely(chip->badblockbits == 8))
449 			res = bad != 0xFF;
450 		else
451 			res = hweight8(bad) < chip->badblockbits;
452 		if (res)
453 			return res;
454 	}
455 
456 	return 0;
457 }
458 
459 /**
460  * nand_default_block_markbad - [DEFAULT] mark a block bad via bad block marker
461  * @mtd: MTD device structure
462  * @ofs: offset from device start
463  *
464  * This is the default implementation, which can be overridden by a hardware
465  * specific driver. It provides the details for writing a bad block marker to a
466  * block.
467  */
468 static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
469 {
470 	struct nand_chip *chip = mtd_to_nand(mtd);
471 	struct mtd_oob_ops ops;
472 	uint8_t buf[2] = { 0, 0 };
473 	int ret = 0, res, i = 0;
474 
475 	memset(&ops, 0, sizeof(ops));
476 	ops.oobbuf = buf;
477 	ops.ooboffs = chip->badblockpos;
478 	if (chip->options & NAND_BUSWIDTH_16) {
479 		ops.ooboffs &= ~0x01;
480 		ops.len = ops.ooblen = 2;
481 	} else {
482 		ops.len = ops.ooblen = 1;
483 	}
484 	ops.mode = MTD_OPS_PLACE_OOB;
485 
486 	/* Write to first/last page(s) if necessary */
487 	if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
488 		ofs += mtd->erasesize - mtd->writesize;
489 	do {
490 		res = nand_do_write_oob(mtd, ofs, &ops);
491 		if (!ret)
492 			ret = res;
493 
494 		i++;
495 		ofs += mtd->writesize;
496 	} while ((chip->bbt_options & NAND_BBT_SCAN2NDPAGE) && i < 2);
497 
498 	return ret;
499 }
500 
501 /**
502  * nand_block_markbad_lowlevel - mark a block bad
503  * @mtd: MTD device structure
504  * @ofs: offset from device start
505  *
506  * This function performs the generic NAND bad block marking steps (i.e., bad
507  * block table(s) and/or marker(s)). We only allow the hardware driver to
508  * specify how to write bad block markers to OOB (chip->block_markbad).
509  *
510  * We try operations in the following order:
511  *
512  *  (1) erase the affected block, to allow OOB marker to be written cleanly
513  *  (2) write bad block marker to OOB area of affected block (unless flag
514  *      NAND_BBT_NO_OOB_BBM is present)
515  *  (3) update the BBT
516  *
517  * Note that we retain the first error encountered in (2) or (3), finish the
518  * procedures, and dump the error in the end.
519 */
520 static int nand_block_markbad_lowlevel(struct mtd_info *mtd, loff_t ofs)
521 {
522 	struct nand_chip *chip = mtd_to_nand(mtd);
523 	int res, ret = 0;
524 
525 	if (!(chip->bbt_options & NAND_BBT_NO_OOB_BBM)) {
526 		struct erase_info einfo;
527 
528 		/* Attempt erase before marking OOB */
529 		memset(&einfo, 0, sizeof(einfo));
530 		einfo.addr = ofs;
531 		einfo.len = 1ULL << chip->phys_erase_shift;
532 		nand_erase_nand(mtd, &einfo, 0);
533 
534 		/* Write bad block marker to OOB */
535 		nand_get_device(mtd, FL_WRITING);
536 		ret = chip->block_markbad(mtd, ofs);
537 		nand_release_device(mtd);
538 	}
539 
540 	/* Mark block bad in BBT */
541 	if (chip->bbt) {
542 		res = nand_markbad_bbt(mtd, ofs);
543 		if (!ret)
544 			ret = res;
545 	}
546 
547 	if (!ret)
548 		mtd->ecc_stats.badblocks++;
549 
550 	return ret;
551 }
552 
553 /**
554  * nand_check_wp - [GENERIC] check if the chip is write protected
555  * @mtd: MTD device structure
556  *
557  * Check, if the device is write protected. The function expects, that the
558  * device is already selected.
559  */
560 static int nand_check_wp(struct mtd_info *mtd)
561 {
562 	struct nand_chip *chip = mtd_to_nand(mtd);
563 	u8 status;
564 	int ret;
565 
566 	/* Broken xD cards report WP despite being writable */
567 	if (chip->options & NAND_BROKEN_XD)
568 		return 0;
569 
570 	/* Check the WP bit */
571 	ret = nand_status_op(chip, &status);
572 	if (ret)
573 		return ret;
574 
575 	return status & NAND_STATUS_WP ? 0 : 1;
576 }
577 
578 /**
579  * nand_block_isreserved - [GENERIC] Check if a block is marked reserved.
580  * @mtd: MTD device structure
581  * @ofs: offset from device start
582  *
583  * Check if the block is marked as reserved.
584  */
585 static int nand_block_isreserved(struct mtd_info *mtd, loff_t ofs)
586 {
587 	struct nand_chip *chip = mtd_to_nand(mtd);
588 
589 	if (!chip->bbt)
590 		return 0;
591 	/* Return info from the table */
592 	return nand_isreserved_bbt(mtd, ofs);
593 }
594 
595 /**
596  * nand_block_checkbad - [GENERIC] Check if a block is marked bad
597  * @mtd: MTD device structure
598  * @ofs: offset from device start
599  * @allowbbt: 1, if its allowed to access the bbt area
600  *
601  * Check, if the block is bad. Either by reading the bad block table or
602  * calling of the scan function.
603  */
604 static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int allowbbt)
605 {
606 	struct nand_chip *chip = mtd_to_nand(mtd);
607 
608 	if (!chip->bbt)
609 		return chip->block_bad(mtd, ofs);
610 
611 	/* Return info from the table */
612 	return nand_isbad_bbt(mtd, ofs, allowbbt);
613 }
614 
615 /**
616  * panic_nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
617  * @mtd: MTD device structure
618  * @timeo: Timeout
619  *
620  * Helper function for nand_wait_ready used when needing to wait in interrupt
621  * context.
622  */
623 static void panic_nand_wait_ready(struct mtd_info *mtd, unsigned long timeo)
624 {
625 	struct nand_chip *chip = mtd_to_nand(mtd);
626 	int i;
627 
628 	/* Wait for the device to get ready */
629 	for (i = 0; i < timeo; i++) {
630 		if (chip->dev_ready(mtd))
631 			break;
632 		touch_softlockup_watchdog();
633 		mdelay(1);
634 	}
635 }
636 
637 /**
638  * nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
639  * @mtd: MTD device structure
640  *
641  * Wait for the ready pin after a command, and warn if a timeout occurs.
642  */
643 void nand_wait_ready(struct mtd_info *mtd)
644 {
645 	struct nand_chip *chip = mtd_to_nand(mtd);
646 	unsigned long timeo = 400;
647 
648 	if (in_interrupt() || oops_in_progress)
649 		return panic_nand_wait_ready(mtd, timeo);
650 
651 	/* Wait until command is processed or timeout occurs */
652 	timeo = jiffies + msecs_to_jiffies(timeo);
653 	do {
654 		if (chip->dev_ready(mtd))
655 			return;
656 		cond_resched();
657 	} while (time_before(jiffies, timeo));
658 
659 	if (!chip->dev_ready(mtd))
660 		pr_warn_ratelimited("timeout while waiting for chip to become ready\n");
661 }
662 EXPORT_SYMBOL_GPL(nand_wait_ready);
663 
664 /**
665  * nand_wait_status_ready - [GENERIC] Wait for the ready status after commands.
666  * @mtd: MTD device structure
667  * @timeo: Timeout in ms
668  *
669  * Wait for status ready (i.e. command done) or timeout.
670  */
671 static void nand_wait_status_ready(struct mtd_info *mtd, unsigned long timeo)
672 {
673 	register struct nand_chip *chip = mtd_to_nand(mtd);
674 	int ret;
675 
676 	timeo = jiffies + msecs_to_jiffies(timeo);
677 	do {
678 		u8 status;
679 
680 		ret = nand_read_data_op(chip, &status, sizeof(status), true);
681 		if (ret)
682 			return;
683 
684 		if (status & NAND_STATUS_READY)
685 			break;
686 		touch_softlockup_watchdog();
687 	} while (time_before(jiffies, timeo));
688 };
689 
690 /**
691  * nand_soft_waitrdy - Poll STATUS reg until RDY bit is set to 1
692  * @chip: NAND chip structure
693  * @timeout_ms: Timeout in ms
694  *
695  * Poll the STATUS register using ->exec_op() until the RDY bit becomes 1.
696  * If that does not happen whitin the specified timeout, -ETIMEDOUT is
697  * returned.
698  *
699  * This helper is intended to be used when the controller does not have access
700  * to the NAND R/B pin.
701  *
702  * Be aware that calling this helper from an ->exec_op() implementation means
703  * ->exec_op() must be re-entrant.
704  *
705  * Return 0 if the NAND chip is ready, a negative error otherwise.
706  */
707 int nand_soft_waitrdy(struct nand_chip *chip, unsigned long timeout_ms)
708 {
709 	const struct nand_sdr_timings *timings;
710 	u8 status = 0;
711 	int ret;
712 
713 	if (!chip->exec_op)
714 		return -ENOTSUPP;
715 
716 	/* Wait tWB before polling the STATUS reg. */
717 	timings = nand_get_sdr_timings(&chip->data_interface);
718 	ndelay(PSEC_TO_NSEC(timings->tWB_max));
719 
720 	ret = nand_status_op(chip, NULL);
721 	if (ret)
722 		return ret;
723 
724 	timeout_ms = jiffies + msecs_to_jiffies(timeout_ms);
725 	do {
726 		ret = nand_read_data_op(chip, &status, sizeof(status), true);
727 		if (ret)
728 			break;
729 
730 		if (status & NAND_STATUS_READY)
731 			break;
732 
733 		/*
734 		 * Typical lowest execution time for a tR on most NANDs is 10us,
735 		 * use this as polling delay before doing something smarter (ie.
736 		 * deriving a delay from the timeout value, timeout_ms/ratio).
737 		 */
738 		udelay(10);
739 	} while	(time_before(jiffies, timeout_ms));
740 
741 	/*
742 	 * We have to exit READ_STATUS mode in order to read real data on the
743 	 * bus in case the WAITRDY instruction is preceding a DATA_IN
744 	 * instruction.
745 	 */
746 	nand_exit_status_op(chip);
747 
748 	if (ret)
749 		return ret;
750 
751 	return status & NAND_STATUS_READY ? 0 : -ETIMEDOUT;
752 };
753 EXPORT_SYMBOL_GPL(nand_soft_waitrdy);
754 
755 /**
756  * nand_command - [DEFAULT] Send command to NAND device
757  * @mtd: MTD device structure
758  * @command: the command to be sent
759  * @column: the column address for this command, -1 if none
760  * @page_addr: the page address for this command, -1 if none
761  *
762  * Send command to NAND device. This function is used for small page devices
763  * (512 Bytes per page).
764  */
765 static void nand_command(struct mtd_info *mtd, unsigned int command,
766 			 int column, int page_addr)
767 {
768 	register struct nand_chip *chip = mtd_to_nand(mtd);
769 	int ctrl = NAND_CTRL_CLE | NAND_CTRL_CHANGE;
770 
771 	/* Write out the command to the device */
772 	if (command == NAND_CMD_SEQIN) {
773 		int readcmd;
774 
775 		if (column >= mtd->writesize) {
776 			/* OOB area */
777 			column -= mtd->writesize;
778 			readcmd = NAND_CMD_READOOB;
779 		} else if (column < 256) {
780 			/* First 256 bytes --> READ0 */
781 			readcmd = NAND_CMD_READ0;
782 		} else {
783 			column -= 256;
784 			readcmd = NAND_CMD_READ1;
785 		}
786 		chip->cmd_ctrl(mtd, readcmd, ctrl);
787 		ctrl &= ~NAND_CTRL_CHANGE;
788 	}
789 	if (command != NAND_CMD_NONE)
790 		chip->cmd_ctrl(mtd, command, ctrl);
791 
792 	/* Address cycle, when necessary */
793 	ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE;
794 	/* Serially input address */
795 	if (column != -1) {
796 		/* Adjust columns for 16 bit buswidth */
797 		if (chip->options & NAND_BUSWIDTH_16 &&
798 				!nand_opcode_8bits(command))
799 			column >>= 1;
800 		chip->cmd_ctrl(mtd, column, ctrl);
801 		ctrl &= ~NAND_CTRL_CHANGE;
802 	}
803 	if (page_addr != -1) {
804 		chip->cmd_ctrl(mtd, page_addr, ctrl);
805 		ctrl &= ~NAND_CTRL_CHANGE;
806 		chip->cmd_ctrl(mtd, page_addr >> 8, ctrl);
807 		if (chip->options & NAND_ROW_ADDR_3)
808 			chip->cmd_ctrl(mtd, page_addr >> 16, ctrl);
809 	}
810 	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
811 
812 	/*
813 	 * Program and erase have their own busy handlers status and sequential
814 	 * in needs no delay
815 	 */
816 	switch (command) {
817 
818 	case NAND_CMD_NONE:
819 	case NAND_CMD_PAGEPROG:
820 	case NAND_CMD_ERASE1:
821 	case NAND_CMD_ERASE2:
822 	case NAND_CMD_SEQIN:
823 	case NAND_CMD_STATUS:
824 	case NAND_CMD_READID:
825 	case NAND_CMD_SET_FEATURES:
826 		return;
827 
828 	case NAND_CMD_RESET:
829 		if (chip->dev_ready)
830 			break;
831 		udelay(chip->chip_delay);
832 		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
833 			       NAND_CTRL_CLE | NAND_CTRL_CHANGE);
834 		chip->cmd_ctrl(mtd,
835 			       NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
836 		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
837 		nand_wait_status_ready(mtd, 250);
838 		return;
839 
840 		/* This applies to read commands */
841 	case NAND_CMD_READ0:
842 		/*
843 		 * READ0 is sometimes used to exit GET STATUS mode. When this
844 		 * is the case no address cycles are requested, and we can use
845 		 * this information to detect that we should not wait for the
846 		 * device to be ready.
847 		 */
848 		if (column == -1 && page_addr == -1)
849 			return;
850 
851 	default:
852 		/*
853 		 * If we don't have access to the busy pin, we apply the given
854 		 * command delay
855 		 */
856 		if (!chip->dev_ready) {
857 			udelay(chip->chip_delay);
858 			return;
859 		}
860 	}
861 	/*
862 	 * Apply this short delay always to ensure that we do wait tWB in
863 	 * any case on any machine.
864 	 */
865 	ndelay(100);
866 
867 	nand_wait_ready(mtd);
868 }
869 
870 static void nand_ccs_delay(struct nand_chip *chip)
871 {
872 	/*
873 	 * The controller already takes care of waiting for tCCS when the RNDIN
874 	 * or RNDOUT command is sent, return directly.
875 	 */
876 	if (!(chip->options & NAND_WAIT_TCCS))
877 		return;
878 
879 	/*
880 	 * Wait tCCS_min if it is correctly defined, otherwise wait 500ns
881 	 * (which should be safe for all NANDs).
882 	 */
883 	if (chip->setup_data_interface)
884 		ndelay(chip->data_interface.timings.sdr.tCCS_min / 1000);
885 	else
886 		ndelay(500);
887 }
888 
889 /**
890  * nand_command_lp - [DEFAULT] Send command to NAND large page device
891  * @mtd: MTD device structure
892  * @command: the command to be sent
893  * @column: the column address for this command, -1 if none
894  * @page_addr: the page address for this command, -1 if none
895  *
896  * Send command to NAND device. This is the version for the new large page
897  * devices. We don't have the separate regions as we have in the small page
898  * devices. We must emulate NAND_CMD_READOOB to keep the code compatible.
899  */
900 static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
901 			    int column, int page_addr)
902 {
903 	register struct nand_chip *chip = mtd_to_nand(mtd);
904 
905 	/* Emulate NAND_CMD_READOOB */
906 	if (command == NAND_CMD_READOOB) {
907 		column += mtd->writesize;
908 		command = NAND_CMD_READ0;
909 	}
910 
911 	/* Command latch cycle */
912 	if (command != NAND_CMD_NONE)
913 		chip->cmd_ctrl(mtd, command,
914 			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
915 
916 	if (column != -1 || page_addr != -1) {
917 		int ctrl = NAND_CTRL_CHANGE | NAND_NCE | NAND_ALE;
918 
919 		/* Serially input address */
920 		if (column != -1) {
921 			/* Adjust columns for 16 bit buswidth */
922 			if (chip->options & NAND_BUSWIDTH_16 &&
923 					!nand_opcode_8bits(command))
924 				column >>= 1;
925 			chip->cmd_ctrl(mtd, column, ctrl);
926 			ctrl &= ~NAND_CTRL_CHANGE;
927 
928 			/* Only output a single addr cycle for 8bits opcodes. */
929 			if (!nand_opcode_8bits(command))
930 				chip->cmd_ctrl(mtd, column >> 8, ctrl);
931 		}
932 		if (page_addr != -1) {
933 			chip->cmd_ctrl(mtd, page_addr, ctrl);
934 			chip->cmd_ctrl(mtd, page_addr >> 8,
935 				       NAND_NCE | NAND_ALE);
936 			if (chip->options & NAND_ROW_ADDR_3)
937 				chip->cmd_ctrl(mtd, page_addr >> 16,
938 					       NAND_NCE | NAND_ALE);
939 		}
940 	}
941 	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
942 
943 	/*
944 	 * Program and erase have their own busy handlers status, sequential
945 	 * in and status need no delay.
946 	 */
947 	switch (command) {
948 
949 	case NAND_CMD_NONE:
950 	case NAND_CMD_CACHEDPROG:
951 	case NAND_CMD_PAGEPROG:
952 	case NAND_CMD_ERASE1:
953 	case NAND_CMD_ERASE2:
954 	case NAND_CMD_SEQIN:
955 	case NAND_CMD_STATUS:
956 	case NAND_CMD_READID:
957 	case NAND_CMD_SET_FEATURES:
958 		return;
959 
960 	case NAND_CMD_RNDIN:
961 		nand_ccs_delay(chip);
962 		return;
963 
964 	case NAND_CMD_RESET:
965 		if (chip->dev_ready)
966 			break;
967 		udelay(chip->chip_delay);
968 		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
969 			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
970 		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
971 			       NAND_NCE | NAND_CTRL_CHANGE);
972 		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
973 		nand_wait_status_ready(mtd, 250);
974 		return;
975 
976 	case NAND_CMD_RNDOUT:
977 		/* No ready / busy check necessary */
978 		chip->cmd_ctrl(mtd, NAND_CMD_RNDOUTSTART,
979 			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
980 		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
981 			       NAND_NCE | NAND_CTRL_CHANGE);
982 
983 		nand_ccs_delay(chip);
984 		return;
985 
986 	case NAND_CMD_READ0:
987 		/*
988 		 * READ0 is sometimes used to exit GET STATUS mode. When this
989 		 * is the case no address cycles are requested, and we can use
990 		 * this information to detect that READSTART should not be
991 		 * issued.
992 		 */
993 		if (column == -1 && page_addr == -1)
994 			return;
995 
996 		chip->cmd_ctrl(mtd, NAND_CMD_READSTART,
997 			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
998 		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
999 			       NAND_NCE | NAND_CTRL_CHANGE);
1000 
1001 		/* This applies to read commands */
1002 	default:
1003 		/*
1004 		 * If we don't have access to the busy pin, we apply the given
1005 		 * command delay.
1006 		 */
1007 		if (!chip->dev_ready) {
1008 			udelay(chip->chip_delay);
1009 			return;
1010 		}
1011 	}
1012 
1013 	/*
1014 	 * Apply this short delay always to ensure that we do wait tWB in
1015 	 * any case on any machine.
1016 	 */
1017 	ndelay(100);
1018 
1019 	nand_wait_ready(mtd);
1020 }
1021 
1022 /**
1023  * panic_nand_get_device - [GENERIC] Get chip for selected access
1024  * @chip: the nand chip descriptor
1025  * @mtd: MTD device structure
1026  * @new_state: the state which is requested
1027  *
1028  * Used when in panic, no locks are taken.
1029  */
1030 static void panic_nand_get_device(struct nand_chip *chip,
1031 		      struct mtd_info *mtd, int new_state)
1032 {
1033 	/* Hardware controller shared among independent devices */
1034 	chip->controller->active = chip;
1035 	chip->state = new_state;
1036 }
1037 
1038 /**
1039  * nand_get_device - [GENERIC] Get chip for selected access
1040  * @mtd: MTD device structure
1041  * @new_state: the state which is requested
1042  *
1043  * Get the device and lock it for exclusive access
1044  */
1045 static int
1046 nand_get_device(struct mtd_info *mtd, int new_state)
1047 {
1048 	struct nand_chip *chip = mtd_to_nand(mtd);
1049 	spinlock_t *lock = &chip->controller->lock;
1050 	wait_queue_head_t *wq = &chip->controller->wq;
1051 	DECLARE_WAITQUEUE(wait, current);
1052 retry:
1053 	spin_lock(lock);
1054 
1055 	/* Hardware controller shared among independent devices */
1056 	if (!chip->controller->active)
1057 		chip->controller->active = chip;
1058 
1059 	if (chip->controller->active == chip && chip->state == FL_READY) {
1060 		chip->state = new_state;
1061 		spin_unlock(lock);
1062 		return 0;
1063 	}
1064 	if (new_state == FL_PM_SUSPENDED) {
1065 		if (chip->controller->active->state == FL_PM_SUSPENDED) {
1066 			chip->state = FL_PM_SUSPENDED;
1067 			spin_unlock(lock);
1068 			return 0;
1069 		}
1070 	}
1071 	set_current_state(TASK_UNINTERRUPTIBLE);
1072 	add_wait_queue(wq, &wait);
1073 	spin_unlock(lock);
1074 	schedule();
1075 	remove_wait_queue(wq, &wait);
1076 	goto retry;
1077 }
1078 
1079 /**
1080  * panic_nand_wait - [GENERIC] wait until the command is done
1081  * @mtd: MTD device structure
1082  * @chip: NAND chip structure
1083  * @timeo: timeout
1084  *
1085  * Wait for command done. This is a helper function for nand_wait used when
1086  * we are in interrupt context. May happen when in panic and trying to write
1087  * an oops through mtdoops.
1088  */
1089 static void panic_nand_wait(struct mtd_info *mtd, struct nand_chip *chip,
1090 			    unsigned long timeo)
1091 {
1092 	int i;
1093 	for (i = 0; i < timeo; i++) {
1094 		if (chip->dev_ready) {
1095 			if (chip->dev_ready(mtd))
1096 				break;
1097 		} else {
1098 			int ret;
1099 			u8 status;
1100 
1101 			ret = nand_read_data_op(chip, &status, sizeof(status),
1102 						true);
1103 			if (ret)
1104 				return;
1105 
1106 			if (status & NAND_STATUS_READY)
1107 				break;
1108 		}
1109 		mdelay(1);
1110 	}
1111 }
1112 
1113 /**
1114  * nand_wait - [DEFAULT] wait until the command is done
1115  * @mtd: MTD device structure
1116  * @chip: NAND chip structure
1117  *
1118  * Wait for command done. This applies to erase and program only.
1119  */
1120 static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
1121 {
1122 
1123 	unsigned long timeo = 400;
1124 	u8 status;
1125 	int ret;
1126 
1127 	/*
1128 	 * Apply this short delay always to ensure that we do wait tWB in any
1129 	 * case on any machine.
1130 	 */
1131 	ndelay(100);
1132 
1133 	ret = nand_status_op(chip, NULL);
1134 	if (ret)
1135 		return ret;
1136 
1137 	if (in_interrupt() || oops_in_progress)
1138 		panic_nand_wait(mtd, chip, timeo);
1139 	else {
1140 		timeo = jiffies + msecs_to_jiffies(timeo);
1141 		do {
1142 			if (chip->dev_ready) {
1143 				if (chip->dev_ready(mtd))
1144 					break;
1145 			} else {
1146 				ret = nand_read_data_op(chip, &status,
1147 							sizeof(status), true);
1148 				if (ret)
1149 					return ret;
1150 
1151 				if (status & NAND_STATUS_READY)
1152 					break;
1153 			}
1154 			cond_resched();
1155 		} while (time_before(jiffies, timeo));
1156 	}
1157 
1158 	ret = nand_read_data_op(chip, &status, sizeof(status), true);
1159 	if (ret)
1160 		return ret;
1161 
1162 	/* This can happen if in case of timeout or buggy dev_ready */
1163 	WARN_ON(!(status & NAND_STATUS_READY));
1164 	return status;
1165 }
1166 
1167 static bool nand_supports_get_features(struct nand_chip *chip, int addr)
1168 {
1169 	return (chip->parameters.supports_set_get_features &&
1170 		test_bit(addr, chip->parameters.get_feature_list));
1171 }
1172 
1173 static bool nand_supports_set_features(struct nand_chip *chip, int addr)
1174 {
1175 	return (chip->parameters.supports_set_get_features &&
1176 		test_bit(addr, chip->parameters.set_feature_list));
1177 }
1178 
1179 /**
1180  * nand_get_features - wrapper to perform a GET_FEATURE
1181  * @chip: NAND chip info structure
1182  * @addr: feature address
1183  * @subfeature_param: the subfeature parameters, a four bytes array
1184  *
1185  * Returns 0 for success, a negative error otherwise. Returns -ENOTSUPP if the
1186  * operation cannot be handled.
1187  */
1188 int nand_get_features(struct nand_chip *chip, int addr,
1189 		      u8 *subfeature_param)
1190 {
1191 	struct mtd_info *mtd = nand_to_mtd(chip);
1192 
1193 	if (!nand_supports_get_features(chip, addr))
1194 		return -ENOTSUPP;
1195 
1196 	return chip->get_features(mtd, chip, addr, subfeature_param);
1197 }
1198 EXPORT_SYMBOL_GPL(nand_get_features);
1199 
1200 /**
1201  * nand_set_features - wrapper to perform a SET_FEATURE
1202  * @chip: NAND chip info structure
1203  * @addr: feature address
1204  * @subfeature_param: the subfeature parameters, a four bytes array
1205  *
1206  * Returns 0 for success, a negative error otherwise. Returns -ENOTSUPP if the
1207  * operation cannot be handled.
1208  */
1209 int nand_set_features(struct nand_chip *chip, int addr,
1210 		      u8 *subfeature_param)
1211 {
1212 	struct mtd_info *mtd = nand_to_mtd(chip);
1213 
1214 	if (!nand_supports_set_features(chip, addr))
1215 		return -ENOTSUPP;
1216 
1217 	return chip->set_features(mtd, chip, addr, subfeature_param);
1218 }
1219 EXPORT_SYMBOL_GPL(nand_set_features);
1220 
1221 /**
1222  * nand_reset_data_interface - Reset data interface and timings
1223  * @chip: The NAND chip
1224  * @chipnr: Internal die id
1225  *
1226  * Reset the Data interface and timings to ONFI mode 0.
1227  *
1228  * Returns 0 for success or negative error code otherwise.
1229  */
1230 static int nand_reset_data_interface(struct nand_chip *chip, int chipnr)
1231 {
1232 	struct mtd_info *mtd = nand_to_mtd(chip);
1233 	int ret;
1234 
1235 	if (!chip->setup_data_interface)
1236 		return 0;
1237 
1238 	/*
1239 	 * The ONFI specification says:
1240 	 * "
1241 	 * To transition from NV-DDR or NV-DDR2 to the SDR data
1242 	 * interface, the host shall use the Reset (FFh) command
1243 	 * using SDR timing mode 0. A device in any timing mode is
1244 	 * required to recognize Reset (FFh) command issued in SDR
1245 	 * timing mode 0.
1246 	 * "
1247 	 *
1248 	 * Configure the data interface in SDR mode and set the
1249 	 * timings to timing mode 0.
1250 	 */
1251 
1252 	onfi_fill_data_interface(chip, NAND_SDR_IFACE, 0);
1253 	ret = chip->setup_data_interface(mtd, chipnr, &chip->data_interface);
1254 	if (ret)
1255 		pr_err("Failed to configure data interface to SDR timing mode 0\n");
1256 
1257 	return ret;
1258 }
1259 
1260 /**
1261  * nand_setup_data_interface - Setup the best data interface and timings
1262  * @chip: The NAND chip
1263  * @chipnr: Internal die id
1264  *
1265  * Find and configure the best data interface and NAND timings supported by
1266  * the chip and the driver.
1267  * First tries to retrieve supported timing modes from ONFI information,
1268  * and if the NAND chip does not support ONFI, relies on the
1269  * ->onfi_timing_mode_default specified in the nand_ids table.
1270  *
1271  * Returns 0 for success or negative error code otherwise.
1272  */
1273 static int nand_setup_data_interface(struct nand_chip *chip, int chipnr)
1274 {
1275 	struct mtd_info *mtd = nand_to_mtd(chip);
1276 	u8 tmode_param[ONFI_SUBFEATURE_PARAM_LEN] = {
1277 		chip->onfi_timing_mode_default,
1278 	};
1279 	int ret;
1280 
1281 	if (!chip->setup_data_interface)
1282 		return 0;
1283 
1284 	/* Change the mode on the chip side (if supported by the NAND chip) */
1285 	if (nand_supports_set_features(chip, ONFI_FEATURE_ADDR_TIMING_MODE)) {
1286 		chip->select_chip(mtd, chipnr);
1287 		ret = nand_set_features(chip, ONFI_FEATURE_ADDR_TIMING_MODE,
1288 					tmode_param);
1289 		chip->select_chip(mtd, -1);
1290 		if (ret)
1291 			return ret;
1292 	}
1293 
1294 	/* Change the mode on the controller side */
1295 	ret = chip->setup_data_interface(mtd, chipnr, &chip->data_interface);
1296 	if (ret)
1297 		return ret;
1298 
1299 	/* Check the mode has been accepted by the chip, if supported */
1300 	if (!nand_supports_get_features(chip, ONFI_FEATURE_ADDR_TIMING_MODE))
1301 		return 0;
1302 
1303 	memset(tmode_param, 0, ONFI_SUBFEATURE_PARAM_LEN);
1304 	chip->select_chip(mtd, chipnr);
1305 	ret = nand_get_features(chip, ONFI_FEATURE_ADDR_TIMING_MODE,
1306 				tmode_param);
1307 	chip->select_chip(mtd, -1);
1308 	if (ret)
1309 		goto err_reset_chip;
1310 
1311 	if (tmode_param[0] != chip->onfi_timing_mode_default) {
1312 		pr_warn("timing mode %d not acknowledged by the NAND chip\n",
1313 			chip->onfi_timing_mode_default);
1314 		goto err_reset_chip;
1315 	}
1316 
1317 	return 0;
1318 
1319 err_reset_chip:
1320 	/*
1321 	 * Fallback to mode 0 if the chip explicitly did not ack the chosen
1322 	 * timing mode.
1323 	 */
1324 	nand_reset_data_interface(chip, chipnr);
1325 	chip->select_chip(mtd, chipnr);
1326 	nand_reset_op(chip);
1327 	chip->select_chip(mtd, -1);
1328 
1329 	return ret;
1330 }
1331 
1332 /**
1333  * nand_init_data_interface - find the best data interface and timings
1334  * @chip: The NAND chip
1335  *
1336  * Find the best data interface and NAND timings supported by the chip
1337  * and the driver.
1338  * First tries to retrieve supported timing modes from ONFI information,
1339  * and if the NAND chip does not support ONFI, relies on the
1340  * ->onfi_timing_mode_default specified in the nand_ids table. After this
1341  * function nand_chip->data_interface is initialized with the best timing mode
1342  * available.
1343  *
1344  * Returns 0 for success or negative error code otherwise.
1345  */
1346 static int nand_init_data_interface(struct nand_chip *chip)
1347 {
1348 	struct mtd_info *mtd = nand_to_mtd(chip);
1349 	int modes, mode, ret;
1350 
1351 	if (!chip->setup_data_interface)
1352 		return 0;
1353 
1354 	/*
1355 	 * First try to identify the best timings from ONFI parameters and
1356 	 * if the NAND does not support ONFI, fallback to the default ONFI
1357 	 * timing mode.
1358 	 */
1359 	modes = onfi_get_async_timing_mode(chip);
1360 	if (modes == ONFI_TIMING_MODE_UNKNOWN) {
1361 		if (!chip->onfi_timing_mode_default)
1362 			return 0;
1363 
1364 		modes = GENMASK(chip->onfi_timing_mode_default, 0);
1365 	}
1366 
1367 
1368 	for (mode = fls(modes) - 1; mode >= 0; mode--) {
1369 		ret = onfi_fill_data_interface(chip, NAND_SDR_IFACE, mode);
1370 		if (ret)
1371 			continue;
1372 
1373 		/*
1374 		 * Pass NAND_DATA_IFACE_CHECK_ONLY to only check if the
1375 		 * controller supports the requested timings.
1376 		 */
1377 		ret = chip->setup_data_interface(mtd,
1378 						 NAND_DATA_IFACE_CHECK_ONLY,
1379 						 &chip->data_interface);
1380 		if (!ret) {
1381 			chip->onfi_timing_mode_default = mode;
1382 			break;
1383 		}
1384 	}
1385 
1386 	return 0;
1387 }
1388 
1389 /**
1390  * nand_fill_column_cycles - fill the column cycles of an address
1391  * @chip: The NAND chip
1392  * @addrs: Array of address cycles to fill
1393  * @offset_in_page: The offset in the page
1394  *
1395  * Fills the first or the first two bytes of the @addrs field depending
1396  * on the NAND bus width and the page size.
1397  *
1398  * Returns the number of cycles needed to encode the column, or a negative
1399  * error code in case one of the arguments is invalid.
1400  */
1401 static int nand_fill_column_cycles(struct nand_chip *chip, u8 *addrs,
1402 				   unsigned int offset_in_page)
1403 {
1404 	struct mtd_info *mtd = nand_to_mtd(chip);
1405 
1406 	/* Make sure the offset is less than the actual page size. */
1407 	if (offset_in_page > mtd->writesize + mtd->oobsize)
1408 		return -EINVAL;
1409 
1410 	/*
1411 	 * On small page NANDs, there's a dedicated command to access the OOB
1412 	 * area, and the column address is relative to the start of the OOB
1413 	 * area, not the start of the page. Asjust the address accordingly.
1414 	 */
1415 	if (mtd->writesize <= 512 && offset_in_page >= mtd->writesize)
1416 		offset_in_page -= mtd->writesize;
1417 
1418 	/*
1419 	 * The offset in page is expressed in bytes, if the NAND bus is 16-bit
1420 	 * wide, then it must be divided by 2.
1421 	 */
1422 	if (chip->options & NAND_BUSWIDTH_16) {
1423 		if (WARN_ON(offset_in_page % 2))
1424 			return -EINVAL;
1425 
1426 		offset_in_page /= 2;
1427 	}
1428 
1429 	addrs[0] = offset_in_page;
1430 
1431 	/*
1432 	 * Small page NANDs use 1 cycle for the columns, while large page NANDs
1433 	 * need 2
1434 	 */
1435 	if (mtd->writesize <= 512)
1436 		return 1;
1437 
1438 	addrs[1] = offset_in_page >> 8;
1439 
1440 	return 2;
1441 }
1442 
1443 static int nand_sp_exec_read_page_op(struct nand_chip *chip, unsigned int page,
1444 				     unsigned int offset_in_page, void *buf,
1445 				     unsigned int len)
1446 {
1447 	struct mtd_info *mtd = nand_to_mtd(chip);
1448 	const struct nand_sdr_timings *sdr =
1449 		nand_get_sdr_timings(&chip->data_interface);
1450 	u8 addrs[4];
1451 	struct nand_op_instr instrs[] = {
1452 		NAND_OP_CMD(NAND_CMD_READ0, 0),
1453 		NAND_OP_ADDR(3, addrs, PSEC_TO_NSEC(sdr->tWB_max)),
1454 		NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tR_max),
1455 				 PSEC_TO_NSEC(sdr->tRR_min)),
1456 		NAND_OP_DATA_IN(len, buf, 0),
1457 	};
1458 	struct nand_operation op = NAND_OPERATION(instrs);
1459 	int ret;
1460 
1461 	/* Drop the DATA_IN instruction if len is set to 0. */
1462 	if (!len)
1463 		op.ninstrs--;
1464 
1465 	if (offset_in_page >= mtd->writesize)
1466 		instrs[0].ctx.cmd.opcode = NAND_CMD_READOOB;
1467 	else if (offset_in_page >= 256 &&
1468 		 !(chip->options & NAND_BUSWIDTH_16))
1469 		instrs[0].ctx.cmd.opcode = NAND_CMD_READ1;
1470 
1471 	ret = nand_fill_column_cycles(chip, addrs, offset_in_page);
1472 	if (ret < 0)
1473 		return ret;
1474 
1475 	addrs[1] = page;
1476 	addrs[2] = page >> 8;
1477 
1478 	if (chip->options & NAND_ROW_ADDR_3) {
1479 		addrs[3] = page >> 16;
1480 		instrs[1].ctx.addr.naddrs++;
1481 	}
1482 
1483 	return nand_exec_op(chip, &op);
1484 }
1485 
1486 static int nand_lp_exec_read_page_op(struct nand_chip *chip, unsigned int page,
1487 				     unsigned int offset_in_page, void *buf,
1488 				     unsigned int len)
1489 {
1490 	const struct nand_sdr_timings *sdr =
1491 		nand_get_sdr_timings(&chip->data_interface);
1492 	u8 addrs[5];
1493 	struct nand_op_instr instrs[] = {
1494 		NAND_OP_CMD(NAND_CMD_READ0, 0),
1495 		NAND_OP_ADDR(4, addrs, 0),
1496 		NAND_OP_CMD(NAND_CMD_READSTART, PSEC_TO_NSEC(sdr->tWB_max)),
1497 		NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tR_max),
1498 				 PSEC_TO_NSEC(sdr->tRR_min)),
1499 		NAND_OP_DATA_IN(len, buf, 0),
1500 	};
1501 	struct nand_operation op = NAND_OPERATION(instrs);
1502 	int ret;
1503 
1504 	/* Drop the DATA_IN instruction if len is set to 0. */
1505 	if (!len)
1506 		op.ninstrs--;
1507 
1508 	ret = nand_fill_column_cycles(chip, addrs, offset_in_page);
1509 	if (ret < 0)
1510 		return ret;
1511 
1512 	addrs[2] = page;
1513 	addrs[3] = page >> 8;
1514 
1515 	if (chip->options & NAND_ROW_ADDR_3) {
1516 		addrs[4] = page >> 16;
1517 		instrs[1].ctx.addr.naddrs++;
1518 	}
1519 
1520 	return nand_exec_op(chip, &op);
1521 }
1522 
1523 /**
1524  * nand_read_page_op - Do a READ PAGE operation
1525  * @chip: The NAND chip
1526  * @page: page to read
1527  * @offset_in_page: offset within the page
1528  * @buf: buffer used to store the data
1529  * @len: length of the buffer
1530  *
1531  * This function issues a READ PAGE operation.
1532  * This function does not select/unselect the CS line.
1533  *
1534  * Returns 0 on success, a negative error code otherwise.
1535  */
1536 int nand_read_page_op(struct nand_chip *chip, unsigned int page,
1537 		      unsigned int offset_in_page, void *buf, unsigned int len)
1538 {
1539 	struct mtd_info *mtd = nand_to_mtd(chip);
1540 
1541 	if (len && !buf)
1542 		return -EINVAL;
1543 
1544 	if (offset_in_page + len > mtd->writesize + mtd->oobsize)
1545 		return -EINVAL;
1546 
1547 	if (chip->exec_op) {
1548 		if (mtd->writesize > 512)
1549 			return nand_lp_exec_read_page_op(chip, page,
1550 							 offset_in_page, buf,
1551 							 len);
1552 
1553 		return nand_sp_exec_read_page_op(chip, page, offset_in_page,
1554 						 buf, len);
1555 	}
1556 
1557 	chip->cmdfunc(mtd, NAND_CMD_READ0, offset_in_page, page);
1558 	if (len)
1559 		chip->read_buf(mtd, buf, len);
1560 
1561 	return 0;
1562 }
1563 EXPORT_SYMBOL_GPL(nand_read_page_op);
1564 
1565 /**
1566  * nand_read_param_page_op - Do a READ PARAMETER PAGE operation
1567  * @chip: The NAND chip
1568  * @page: parameter page to read
1569  * @buf: buffer used to store the data
1570  * @len: length of the buffer
1571  *
1572  * This function issues a READ PARAMETER PAGE operation.
1573  * This function does not select/unselect the CS line.
1574  *
1575  * Returns 0 on success, a negative error code otherwise.
1576  */
1577 static int nand_read_param_page_op(struct nand_chip *chip, u8 page, void *buf,
1578 				   unsigned int len)
1579 {
1580 	struct mtd_info *mtd = nand_to_mtd(chip);
1581 	unsigned int i;
1582 	u8 *p = buf;
1583 
1584 	if (len && !buf)
1585 		return -EINVAL;
1586 
1587 	if (chip->exec_op) {
1588 		const struct nand_sdr_timings *sdr =
1589 			nand_get_sdr_timings(&chip->data_interface);
1590 		struct nand_op_instr instrs[] = {
1591 			NAND_OP_CMD(NAND_CMD_PARAM, 0),
1592 			NAND_OP_ADDR(1, &page, PSEC_TO_NSEC(sdr->tWB_max)),
1593 			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tR_max),
1594 					 PSEC_TO_NSEC(sdr->tRR_min)),
1595 			NAND_OP_8BIT_DATA_IN(len, buf, 0),
1596 		};
1597 		struct nand_operation op = NAND_OPERATION(instrs);
1598 
1599 		/* Drop the DATA_IN instruction if len is set to 0. */
1600 		if (!len)
1601 			op.ninstrs--;
1602 
1603 		return nand_exec_op(chip, &op);
1604 	}
1605 
1606 	chip->cmdfunc(mtd, NAND_CMD_PARAM, page, -1);
1607 	for (i = 0; i < len; i++)
1608 		p[i] = chip->read_byte(mtd);
1609 
1610 	return 0;
1611 }
1612 
1613 /**
1614  * nand_change_read_column_op - Do a CHANGE READ COLUMN operation
1615  * @chip: The NAND chip
1616  * @offset_in_page: offset within the page
1617  * @buf: buffer used to store the data
1618  * @len: length of the buffer
1619  * @force_8bit: force 8-bit bus access
1620  *
1621  * This function issues a CHANGE READ COLUMN operation.
1622  * This function does not select/unselect the CS line.
1623  *
1624  * Returns 0 on success, a negative error code otherwise.
1625  */
1626 int nand_change_read_column_op(struct nand_chip *chip,
1627 			       unsigned int offset_in_page, void *buf,
1628 			       unsigned int len, bool force_8bit)
1629 {
1630 	struct mtd_info *mtd = nand_to_mtd(chip);
1631 
1632 	if (len && !buf)
1633 		return -EINVAL;
1634 
1635 	if (offset_in_page + len > mtd->writesize + mtd->oobsize)
1636 		return -EINVAL;
1637 
1638 	/* Small page NANDs do not support column change. */
1639 	if (mtd->writesize <= 512)
1640 		return -ENOTSUPP;
1641 
1642 	if (chip->exec_op) {
1643 		const struct nand_sdr_timings *sdr =
1644 			nand_get_sdr_timings(&chip->data_interface);
1645 		u8 addrs[2] = {};
1646 		struct nand_op_instr instrs[] = {
1647 			NAND_OP_CMD(NAND_CMD_RNDOUT, 0),
1648 			NAND_OP_ADDR(2, addrs, 0),
1649 			NAND_OP_CMD(NAND_CMD_RNDOUTSTART,
1650 				    PSEC_TO_NSEC(sdr->tCCS_min)),
1651 			NAND_OP_DATA_IN(len, buf, 0),
1652 		};
1653 		struct nand_operation op = NAND_OPERATION(instrs);
1654 		int ret;
1655 
1656 		ret = nand_fill_column_cycles(chip, addrs, offset_in_page);
1657 		if (ret < 0)
1658 			return ret;
1659 
1660 		/* Drop the DATA_IN instruction if len is set to 0. */
1661 		if (!len)
1662 			op.ninstrs--;
1663 
1664 		instrs[3].ctx.data.force_8bit = force_8bit;
1665 
1666 		return nand_exec_op(chip, &op);
1667 	}
1668 
1669 	chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset_in_page, -1);
1670 	if (len)
1671 		chip->read_buf(mtd, buf, len);
1672 
1673 	return 0;
1674 }
1675 EXPORT_SYMBOL_GPL(nand_change_read_column_op);
1676 
1677 /**
1678  * nand_read_oob_op - Do a READ OOB operation
1679  * @chip: The NAND chip
1680  * @page: page to read
1681  * @offset_in_oob: offset within the OOB area
1682  * @buf: buffer used to store the data
1683  * @len: length of the buffer
1684  *
1685  * This function issues a READ OOB operation.
1686  * This function does not select/unselect the CS line.
1687  *
1688  * Returns 0 on success, a negative error code otherwise.
1689  */
1690 int nand_read_oob_op(struct nand_chip *chip, unsigned int page,
1691 		     unsigned int offset_in_oob, void *buf, unsigned int len)
1692 {
1693 	struct mtd_info *mtd = nand_to_mtd(chip);
1694 
1695 	if (len && !buf)
1696 		return -EINVAL;
1697 
1698 	if (offset_in_oob + len > mtd->oobsize)
1699 		return -EINVAL;
1700 
1701 	if (chip->exec_op)
1702 		return nand_read_page_op(chip, page,
1703 					 mtd->writesize + offset_in_oob,
1704 					 buf, len);
1705 
1706 	chip->cmdfunc(mtd, NAND_CMD_READOOB, offset_in_oob, page);
1707 	if (len)
1708 		chip->read_buf(mtd, buf, len);
1709 
1710 	return 0;
1711 }
1712 EXPORT_SYMBOL_GPL(nand_read_oob_op);
1713 
1714 static int nand_exec_prog_page_op(struct nand_chip *chip, unsigned int page,
1715 				  unsigned int offset_in_page, const void *buf,
1716 				  unsigned int len, bool prog)
1717 {
1718 	struct mtd_info *mtd = nand_to_mtd(chip);
1719 	const struct nand_sdr_timings *sdr =
1720 		nand_get_sdr_timings(&chip->data_interface);
1721 	u8 addrs[5] = {};
1722 	struct nand_op_instr instrs[] = {
1723 		/*
1724 		 * The first instruction will be dropped if we're dealing
1725 		 * with a large page NAND and adjusted if we're dealing
1726 		 * with a small page NAND and the page offset is > 255.
1727 		 */
1728 		NAND_OP_CMD(NAND_CMD_READ0, 0),
1729 		NAND_OP_CMD(NAND_CMD_SEQIN, 0),
1730 		NAND_OP_ADDR(0, addrs, PSEC_TO_NSEC(sdr->tADL_min)),
1731 		NAND_OP_DATA_OUT(len, buf, 0),
1732 		NAND_OP_CMD(NAND_CMD_PAGEPROG, PSEC_TO_NSEC(sdr->tWB_max)),
1733 		NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tPROG_max), 0),
1734 	};
1735 	struct nand_operation op = NAND_OPERATION(instrs);
1736 	int naddrs = nand_fill_column_cycles(chip, addrs, offset_in_page);
1737 	int ret;
1738 	u8 status;
1739 
1740 	if (naddrs < 0)
1741 		return naddrs;
1742 
1743 	addrs[naddrs++] = page;
1744 	addrs[naddrs++] = page >> 8;
1745 	if (chip->options & NAND_ROW_ADDR_3)
1746 		addrs[naddrs++] = page >> 16;
1747 
1748 	instrs[2].ctx.addr.naddrs = naddrs;
1749 
1750 	/* Drop the last two instructions if we're not programming the page. */
1751 	if (!prog) {
1752 		op.ninstrs -= 2;
1753 		/* Also drop the DATA_OUT instruction if empty. */
1754 		if (!len)
1755 			op.ninstrs--;
1756 	}
1757 
1758 	if (mtd->writesize <= 512) {
1759 		/*
1760 		 * Small pages need some more tweaking: we have to adjust the
1761 		 * first instruction depending on the page offset we're trying
1762 		 * to access.
1763 		 */
1764 		if (offset_in_page >= mtd->writesize)
1765 			instrs[0].ctx.cmd.opcode = NAND_CMD_READOOB;
1766 		else if (offset_in_page >= 256 &&
1767 			 !(chip->options & NAND_BUSWIDTH_16))
1768 			instrs[0].ctx.cmd.opcode = NAND_CMD_READ1;
1769 	} else {
1770 		/*
1771 		 * Drop the first command if we're dealing with a large page
1772 		 * NAND.
1773 		 */
1774 		op.instrs++;
1775 		op.ninstrs--;
1776 	}
1777 
1778 	ret = nand_exec_op(chip, &op);
1779 	if (!prog || ret)
1780 		return ret;
1781 
1782 	ret = nand_status_op(chip, &status);
1783 	if (ret)
1784 		return ret;
1785 
1786 	return status;
1787 }
1788 
1789 /**
1790  * nand_prog_page_begin_op - starts a PROG PAGE operation
1791  * @chip: The NAND chip
1792  * @page: page to write
1793  * @offset_in_page: offset within the page
1794  * @buf: buffer containing the data to write to the page
1795  * @len: length of the buffer
1796  *
1797  * This function issues the first half of a PROG PAGE operation.
1798  * This function does not select/unselect the CS line.
1799  *
1800  * Returns 0 on success, a negative error code otherwise.
1801  */
1802 int nand_prog_page_begin_op(struct nand_chip *chip, unsigned int page,
1803 			    unsigned int offset_in_page, const void *buf,
1804 			    unsigned int len)
1805 {
1806 	struct mtd_info *mtd = nand_to_mtd(chip);
1807 
1808 	if (len && !buf)
1809 		return -EINVAL;
1810 
1811 	if (offset_in_page + len > mtd->writesize + mtd->oobsize)
1812 		return -EINVAL;
1813 
1814 	if (chip->exec_op)
1815 		return nand_exec_prog_page_op(chip, page, offset_in_page, buf,
1816 					      len, false);
1817 
1818 	chip->cmdfunc(mtd, NAND_CMD_SEQIN, offset_in_page, page);
1819 
1820 	if (buf)
1821 		chip->write_buf(mtd, buf, len);
1822 
1823 	return 0;
1824 }
1825 EXPORT_SYMBOL_GPL(nand_prog_page_begin_op);
1826 
1827 /**
1828  * nand_prog_page_end_op - ends a PROG PAGE operation
1829  * @chip: The NAND chip
1830  *
1831  * This function issues the second half of a PROG PAGE operation.
1832  * This function does not select/unselect the CS line.
1833  *
1834  * Returns 0 on success, a negative error code otherwise.
1835  */
1836 int nand_prog_page_end_op(struct nand_chip *chip)
1837 {
1838 	struct mtd_info *mtd = nand_to_mtd(chip);
1839 	int ret;
1840 	u8 status;
1841 
1842 	if (chip->exec_op) {
1843 		const struct nand_sdr_timings *sdr =
1844 			nand_get_sdr_timings(&chip->data_interface);
1845 		struct nand_op_instr instrs[] = {
1846 			NAND_OP_CMD(NAND_CMD_PAGEPROG,
1847 				    PSEC_TO_NSEC(sdr->tWB_max)),
1848 			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tPROG_max), 0),
1849 		};
1850 		struct nand_operation op = NAND_OPERATION(instrs);
1851 
1852 		ret = nand_exec_op(chip, &op);
1853 		if (ret)
1854 			return ret;
1855 
1856 		ret = nand_status_op(chip, &status);
1857 		if (ret)
1858 			return ret;
1859 	} else {
1860 		chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1861 		ret = chip->waitfunc(mtd, chip);
1862 		if (ret < 0)
1863 			return ret;
1864 
1865 		status = ret;
1866 	}
1867 
1868 	if (status & NAND_STATUS_FAIL)
1869 		return -EIO;
1870 
1871 	return 0;
1872 }
1873 EXPORT_SYMBOL_GPL(nand_prog_page_end_op);
1874 
1875 /**
1876  * nand_prog_page_op - Do a full PROG PAGE operation
1877  * @chip: The NAND chip
1878  * @page: page to write
1879  * @offset_in_page: offset within the page
1880  * @buf: buffer containing the data to write to the page
1881  * @len: length of the buffer
1882  *
1883  * This function issues a full PROG PAGE operation.
1884  * This function does not select/unselect the CS line.
1885  *
1886  * Returns 0 on success, a negative error code otherwise.
1887  */
1888 int nand_prog_page_op(struct nand_chip *chip, unsigned int page,
1889 		      unsigned int offset_in_page, const void *buf,
1890 		      unsigned int len)
1891 {
1892 	struct mtd_info *mtd = nand_to_mtd(chip);
1893 	int status;
1894 
1895 	if (!len || !buf)
1896 		return -EINVAL;
1897 
1898 	if (offset_in_page + len > mtd->writesize + mtd->oobsize)
1899 		return -EINVAL;
1900 
1901 	if (chip->exec_op) {
1902 		status = nand_exec_prog_page_op(chip, page, offset_in_page, buf,
1903 						len, true);
1904 	} else {
1905 		chip->cmdfunc(mtd, NAND_CMD_SEQIN, offset_in_page, page);
1906 		chip->write_buf(mtd, buf, len);
1907 		chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1908 		status = chip->waitfunc(mtd, chip);
1909 	}
1910 
1911 	if (status & NAND_STATUS_FAIL)
1912 		return -EIO;
1913 
1914 	return 0;
1915 }
1916 EXPORT_SYMBOL_GPL(nand_prog_page_op);
1917 
1918 /**
1919  * nand_change_write_column_op - Do a CHANGE WRITE COLUMN operation
1920  * @chip: The NAND chip
1921  * @offset_in_page: offset within the page
1922  * @buf: buffer containing the data to send to the NAND
1923  * @len: length of the buffer
1924  * @force_8bit: force 8-bit bus access
1925  *
1926  * This function issues a CHANGE WRITE COLUMN operation.
1927  * This function does not select/unselect the CS line.
1928  *
1929  * Returns 0 on success, a negative error code otherwise.
1930  */
1931 int nand_change_write_column_op(struct nand_chip *chip,
1932 				unsigned int offset_in_page,
1933 				const void *buf, unsigned int len,
1934 				bool force_8bit)
1935 {
1936 	struct mtd_info *mtd = nand_to_mtd(chip);
1937 
1938 	if (len && !buf)
1939 		return -EINVAL;
1940 
1941 	if (offset_in_page + len > mtd->writesize + mtd->oobsize)
1942 		return -EINVAL;
1943 
1944 	/* Small page NANDs do not support column change. */
1945 	if (mtd->writesize <= 512)
1946 		return -ENOTSUPP;
1947 
1948 	if (chip->exec_op) {
1949 		const struct nand_sdr_timings *sdr =
1950 			nand_get_sdr_timings(&chip->data_interface);
1951 		u8 addrs[2];
1952 		struct nand_op_instr instrs[] = {
1953 			NAND_OP_CMD(NAND_CMD_RNDIN, 0),
1954 			NAND_OP_ADDR(2, addrs, PSEC_TO_NSEC(sdr->tCCS_min)),
1955 			NAND_OP_DATA_OUT(len, buf, 0),
1956 		};
1957 		struct nand_operation op = NAND_OPERATION(instrs);
1958 		int ret;
1959 
1960 		ret = nand_fill_column_cycles(chip, addrs, offset_in_page);
1961 		if (ret < 0)
1962 			return ret;
1963 
1964 		instrs[2].ctx.data.force_8bit = force_8bit;
1965 
1966 		/* Drop the DATA_OUT instruction if len is set to 0. */
1967 		if (!len)
1968 			op.ninstrs--;
1969 
1970 		return nand_exec_op(chip, &op);
1971 	}
1972 
1973 	chip->cmdfunc(mtd, NAND_CMD_RNDIN, offset_in_page, -1);
1974 	if (len)
1975 		chip->write_buf(mtd, buf, len);
1976 
1977 	return 0;
1978 }
1979 EXPORT_SYMBOL_GPL(nand_change_write_column_op);
1980 
1981 /**
1982  * nand_readid_op - Do a READID operation
1983  * @chip: The NAND chip
1984  * @addr: address cycle to pass after the READID command
1985  * @buf: buffer used to store the ID
1986  * @len: length of the buffer
1987  *
1988  * This function sends a READID command and reads back the ID returned by the
1989  * NAND.
1990  * This function does not select/unselect the CS line.
1991  *
1992  * Returns 0 on success, a negative error code otherwise.
1993  */
1994 int nand_readid_op(struct nand_chip *chip, u8 addr, void *buf,
1995 		   unsigned int len)
1996 {
1997 	struct mtd_info *mtd = nand_to_mtd(chip);
1998 	unsigned int i;
1999 	u8 *id = buf;
2000 
2001 	if (len && !buf)
2002 		return -EINVAL;
2003 
2004 	if (chip->exec_op) {
2005 		const struct nand_sdr_timings *sdr =
2006 			nand_get_sdr_timings(&chip->data_interface);
2007 		struct nand_op_instr instrs[] = {
2008 			NAND_OP_CMD(NAND_CMD_READID, 0),
2009 			NAND_OP_ADDR(1, &addr, PSEC_TO_NSEC(sdr->tADL_min)),
2010 			NAND_OP_8BIT_DATA_IN(len, buf, 0),
2011 		};
2012 		struct nand_operation op = NAND_OPERATION(instrs);
2013 
2014 		/* Drop the DATA_IN instruction if len is set to 0. */
2015 		if (!len)
2016 			op.ninstrs--;
2017 
2018 		return nand_exec_op(chip, &op);
2019 	}
2020 
2021 	chip->cmdfunc(mtd, NAND_CMD_READID, addr, -1);
2022 
2023 	for (i = 0; i < len; i++)
2024 		id[i] = chip->read_byte(mtd);
2025 
2026 	return 0;
2027 }
2028 EXPORT_SYMBOL_GPL(nand_readid_op);
2029 
2030 /**
2031  * nand_status_op - Do a STATUS operation
2032  * @chip: The NAND chip
2033  * @status: out variable to store the NAND status
2034  *
2035  * This function sends a STATUS command and reads back the status returned by
2036  * the NAND.
2037  * This function does not select/unselect the CS line.
2038  *
2039  * Returns 0 on success, a negative error code otherwise.
2040  */
2041 int nand_status_op(struct nand_chip *chip, u8 *status)
2042 {
2043 	struct mtd_info *mtd = nand_to_mtd(chip);
2044 
2045 	if (chip->exec_op) {
2046 		const struct nand_sdr_timings *sdr =
2047 			nand_get_sdr_timings(&chip->data_interface);
2048 		struct nand_op_instr instrs[] = {
2049 			NAND_OP_CMD(NAND_CMD_STATUS,
2050 				    PSEC_TO_NSEC(sdr->tADL_min)),
2051 			NAND_OP_8BIT_DATA_IN(1, status, 0),
2052 		};
2053 		struct nand_operation op = NAND_OPERATION(instrs);
2054 
2055 		if (!status)
2056 			op.ninstrs--;
2057 
2058 		return nand_exec_op(chip, &op);
2059 	}
2060 
2061 	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
2062 	if (status)
2063 		*status = chip->read_byte(mtd);
2064 
2065 	return 0;
2066 }
2067 EXPORT_SYMBOL_GPL(nand_status_op);
2068 
2069 /**
2070  * nand_exit_status_op - Exit a STATUS operation
2071  * @chip: The NAND chip
2072  *
2073  * This function sends a READ0 command to cancel the effect of the STATUS
2074  * command to avoid reading only the status until a new read command is sent.
2075  *
2076  * This function does not select/unselect the CS line.
2077  *
2078  * Returns 0 on success, a negative error code otherwise.
2079  */
2080 int nand_exit_status_op(struct nand_chip *chip)
2081 {
2082 	struct mtd_info *mtd = nand_to_mtd(chip);
2083 
2084 	if (chip->exec_op) {
2085 		struct nand_op_instr instrs[] = {
2086 			NAND_OP_CMD(NAND_CMD_READ0, 0),
2087 		};
2088 		struct nand_operation op = NAND_OPERATION(instrs);
2089 
2090 		return nand_exec_op(chip, &op);
2091 	}
2092 
2093 	chip->cmdfunc(mtd, NAND_CMD_READ0, -1, -1);
2094 
2095 	return 0;
2096 }
2097 EXPORT_SYMBOL_GPL(nand_exit_status_op);
2098 
2099 /**
2100  * nand_erase_op - Do an erase operation
2101  * @chip: The NAND chip
2102  * @eraseblock: block to erase
2103  *
2104  * This function sends an ERASE command and waits for the NAND to be ready
2105  * before returning.
2106  * This function does not select/unselect the CS line.
2107  *
2108  * Returns 0 on success, a negative error code otherwise.
2109  */
2110 int nand_erase_op(struct nand_chip *chip, unsigned int eraseblock)
2111 {
2112 	struct mtd_info *mtd = nand_to_mtd(chip);
2113 	unsigned int page = eraseblock <<
2114 			    (chip->phys_erase_shift - chip->page_shift);
2115 	int ret;
2116 	u8 status;
2117 
2118 	if (chip->exec_op) {
2119 		const struct nand_sdr_timings *sdr =
2120 			nand_get_sdr_timings(&chip->data_interface);
2121 		u8 addrs[3] = {	page, page >> 8, page >> 16 };
2122 		struct nand_op_instr instrs[] = {
2123 			NAND_OP_CMD(NAND_CMD_ERASE1, 0),
2124 			NAND_OP_ADDR(2, addrs, 0),
2125 			NAND_OP_CMD(NAND_CMD_ERASE2,
2126 				    PSEC_TO_MSEC(sdr->tWB_max)),
2127 			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tBERS_max), 0),
2128 		};
2129 		struct nand_operation op = NAND_OPERATION(instrs);
2130 
2131 		if (chip->options & NAND_ROW_ADDR_3)
2132 			instrs[1].ctx.addr.naddrs++;
2133 
2134 		ret = nand_exec_op(chip, &op);
2135 		if (ret)
2136 			return ret;
2137 
2138 		ret = nand_status_op(chip, &status);
2139 		if (ret)
2140 			return ret;
2141 	} else {
2142 		chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
2143 		chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
2144 
2145 		ret = chip->waitfunc(mtd, chip);
2146 		if (ret < 0)
2147 			return ret;
2148 
2149 		status = ret;
2150 	}
2151 
2152 	if (status & NAND_STATUS_FAIL)
2153 		return -EIO;
2154 
2155 	return 0;
2156 }
2157 EXPORT_SYMBOL_GPL(nand_erase_op);
2158 
2159 /**
2160  * nand_set_features_op - Do a SET FEATURES operation
2161  * @chip: The NAND chip
2162  * @feature: feature id
2163  * @data: 4 bytes of data
2164  *
2165  * This function sends a SET FEATURES command and waits for the NAND to be
2166  * ready before returning.
2167  * This function does not select/unselect the CS line.
2168  *
2169  * Returns 0 on success, a negative error code otherwise.
2170  */
2171 static int nand_set_features_op(struct nand_chip *chip, u8 feature,
2172 				const void *data)
2173 {
2174 	struct mtd_info *mtd = nand_to_mtd(chip);
2175 	const u8 *params = data;
2176 	int i, ret;
2177 	u8 status;
2178 
2179 	if (chip->exec_op) {
2180 		const struct nand_sdr_timings *sdr =
2181 			nand_get_sdr_timings(&chip->data_interface);
2182 		struct nand_op_instr instrs[] = {
2183 			NAND_OP_CMD(NAND_CMD_SET_FEATURES, 0),
2184 			NAND_OP_ADDR(1, &feature, PSEC_TO_NSEC(sdr->tADL_min)),
2185 			NAND_OP_8BIT_DATA_OUT(ONFI_SUBFEATURE_PARAM_LEN, data,
2186 					      PSEC_TO_NSEC(sdr->tWB_max)),
2187 			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tFEAT_max), 0),
2188 		};
2189 		struct nand_operation op = NAND_OPERATION(instrs);
2190 
2191 		ret = nand_exec_op(chip, &op);
2192 		if (ret)
2193 			return ret;
2194 
2195 		ret = nand_status_op(chip, &status);
2196 		if (ret)
2197 			return ret;
2198 	} else {
2199 		chip->cmdfunc(mtd, NAND_CMD_SET_FEATURES, feature, -1);
2200 		for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
2201 			chip->write_byte(mtd, params[i]);
2202 
2203 		ret = chip->waitfunc(mtd, chip);
2204 		if (ret < 0)
2205 			return ret;
2206 
2207 		status = ret;
2208 	}
2209 
2210 	if (status & NAND_STATUS_FAIL)
2211 		return -EIO;
2212 
2213 	return 0;
2214 }
2215 
2216 /**
2217  * nand_get_features_op - Do a GET FEATURES operation
2218  * @chip: The NAND chip
2219  * @feature: feature id
2220  * @data: 4 bytes of data
2221  *
2222  * This function sends a GET FEATURES command and waits for the NAND to be
2223  * ready before returning.
2224  * This function does not select/unselect the CS line.
2225  *
2226  * Returns 0 on success, a negative error code otherwise.
2227  */
2228 static int nand_get_features_op(struct nand_chip *chip, u8 feature,
2229 				void *data)
2230 {
2231 	struct mtd_info *mtd = nand_to_mtd(chip);
2232 	u8 *params = data;
2233 	int i;
2234 
2235 	if (chip->exec_op) {
2236 		const struct nand_sdr_timings *sdr =
2237 			nand_get_sdr_timings(&chip->data_interface);
2238 		struct nand_op_instr instrs[] = {
2239 			NAND_OP_CMD(NAND_CMD_GET_FEATURES, 0),
2240 			NAND_OP_ADDR(1, &feature, PSEC_TO_NSEC(sdr->tWB_max)),
2241 			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tFEAT_max),
2242 					 PSEC_TO_NSEC(sdr->tRR_min)),
2243 			NAND_OP_8BIT_DATA_IN(ONFI_SUBFEATURE_PARAM_LEN,
2244 					     data, 0),
2245 		};
2246 		struct nand_operation op = NAND_OPERATION(instrs);
2247 
2248 		return nand_exec_op(chip, &op);
2249 	}
2250 
2251 	chip->cmdfunc(mtd, NAND_CMD_GET_FEATURES, feature, -1);
2252 	for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
2253 		params[i] = chip->read_byte(mtd);
2254 
2255 	return 0;
2256 }
2257 
2258 /**
2259  * nand_reset_op - Do a reset operation
2260  * @chip: The NAND chip
2261  *
2262  * This function sends a RESET command and waits for the NAND to be ready
2263  * before returning.
2264  * This function does not select/unselect the CS line.
2265  *
2266  * Returns 0 on success, a negative error code otherwise.
2267  */
2268 int nand_reset_op(struct nand_chip *chip)
2269 {
2270 	struct mtd_info *mtd = nand_to_mtd(chip);
2271 
2272 	if (chip->exec_op) {
2273 		const struct nand_sdr_timings *sdr =
2274 			nand_get_sdr_timings(&chip->data_interface);
2275 		struct nand_op_instr instrs[] = {
2276 			NAND_OP_CMD(NAND_CMD_RESET, PSEC_TO_NSEC(sdr->tWB_max)),
2277 			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tRST_max), 0),
2278 		};
2279 		struct nand_operation op = NAND_OPERATION(instrs);
2280 
2281 		return nand_exec_op(chip, &op);
2282 	}
2283 
2284 	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
2285 
2286 	return 0;
2287 }
2288 EXPORT_SYMBOL_GPL(nand_reset_op);
2289 
2290 /**
2291  * nand_read_data_op - Read data from the NAND
2292  * @chip: The NAND chip
2293  * @buf: buffer used to store the data
2294  * @len: length of the buffer
2295  * @force_8bit: force 8-bit bus access
2296  *
2297  * This function does a raw data read on the bus. Usually used after launching
2298  * another NAND operation like nand_read_page_op().
2299  * This function does not select/unselect the CS line.
2300  *
2301  * Returns 0 on success, a negative error code otherwise.
2302  */
2303 int nand_read_data_op(struct nand_chip *chip, void *buf, unsigned int len,
2304 		      bool force_8bit)
2305 {
2306 	struct mtd_info *mtd = nand_to_mtd(chip);
2307 
2308 	if (!len || !buf)
2309 		return -EINVAL;
2310 
2311 	if (chip->exec_op) {
2312 		struct nand_op_instr instrs[] = {
2313 			NAND_OP_DATA_IN(len, buf, 0),
2314 		};
2315 		struct nand_operation op = NAND_OPERATION(instrs);
2316 
2317 		instrs[0].ctx.data.force_8bit = force_8bit;
2318 
2319 		return nand_exec_op(chip, &op);
2320 	}
2321 
2322 	if (force_8bit) {
2323 		u8 *p = buf;
2324 		unsigned int i;
2325 
2326 		for (i = 0; i < len; i++)
2327 			p[i] = chip->read_byte(mtd);
2328 	} else {
2329 		chip->read_buf(mtd, buf, len);
2330 	}
2331 
2332 	return 0;
2333 }
2334 EXPORT_SYMBOL_GPL(nand_read_data_op);
2335 
2336 /**
2337  * nand_write_data_op - Write data from the NAND
2338  * @chip: The NAND chip
2339  * @buf: buffer containing the data to send on the bus
2340  * @len: length of the buffer
2341  * @force_8bit: force 8-bit bus access
2342  *
2343  * This function does a raw data write on the bus. Usually used after launching
2344  * another NAND operation like nand_write_page_begin_op().
2345  * This function does not select/unselect the CS line.
2346  *
2347  * Returns 0 on success, a negative error code otherwise.
2348  */
2349 int nand_write_data_op(struct nand_chip *chip, const void *buf,
2350 		       unsigned int len, bool force_8bit)
2351 {
2352 	struct mtd_info *mtd = nand_to_mtd(chip);
2353 
2354 	if (!len || !buf)
2355 		return -EINVAL;
2356 
2357 	if (chip->exec_op) {
2358 		struct nand_op_instr instrs[] = {
2359 			NAND_OP_DATA_OUT(len, buf, 0),
2360 		};
2361 		struct nand_operation op = NAND_OPERATION(instrs);
2362 
2363 		instrs[0].ctx.data.force_8bit = force_8bit;
2364 
2365 		return nand_exec_op(chip, &op);
2366 	}
2367 
2368 	if (force_8bit) {
2369 		const u8 *p = buf;
2370 		unsigned int i;
2371 
2372 		for (i = 0; i < len; i++)
2373 			chip->write_byte(mtd, p[i]);
2374 	} else {
2375 		chip->write_buf(mtd, buf, len);
2376 	}
2377 
2378 	return 0;
2379 }
2380 EXPORT_SYMBOL_GPL(nand_write_data_op);
2381 
2382 /**
2383  * struct nand_op_parser_ctx - Context used by the parser
2384  * @instrs: array of all the instructions that must be addressed
2385  * @ninstrs: length of the @instrs array
2386  * @subop: Sub-operation to be passed to the NAND controller
2387  *
2388  * This structure is used by the core to split NAND operations into
2389  * sub-operations that can be handled by the NAND controller.
2390  */
2391 struct nand_op_parser_ctx {
2392 	const struct nand_op_instr *instrs;
2393 	unsigned int ninstrs;
2394 	struct nand_subop subop;
2395 };
2396 
2397 /**
2398  * nand_op_parser_must_split_instr - Checks if an instruction must be split
2399  * @pat: the parser pattern element that matches @instr
2400  * @instr: pointer to the instruction to check
2401  * @start_offset: this is an in/out parameter. If @instr has already been
2402  *		  split, then @start_offset is the offset from which to start
2403  *		  (either an address cycle or an offset in the data buffer).
2404  *		  Conversely, if the function returns true (ie. instr must be
2405  *		  split), this parameter is updated to point to the first
2406  *		  data/address cycle that has not been taken care of.
2407  *
2408  * Some NAND controllers are limited and cannot send X address cycles with a
2409  * unique operation, or cannot read/write more than Y bytes at the same time.
2410  * In this case, split the instruction that does not fit in a single
2411  * controller-operation into two or more chunks.
2412  *
2413  * Returns true if the instruction must be split, false otherwise.
2414  * The @start_offset parameter is also updated to the offset at which the next
2415  * bundle of instruction must start (if an address or a data instruction).
2416  */
2417 static bool
2418 nand_op_parser_must_split_instr(const struct nand_op_parser_pattern_elem *pat,
2419 				const struct nand_op_instr *instr,
2420 				unsigned int *start_offset)
2421 {
2422 	switch (pat->type) {
2423 	case NAND_OP_ADDR_INSTR:
2424 		if (!pat->ctx.addr.maxcycles)
2425 			break;
2426 
2427 		if (instr->ctx.addr.naddrs - *start_offset >
2428 		    pat->ctx.addr.maxcycles) {
2429 			*start_offset += pat->ctx.addr.maxcycles;
2430 			return true;
2431 		}
2432 		break;
2433 
2434 	case NAND_OP_DATA_IN_INSTR:
2435 	case NAND_OP_DATA_OUT_INSTR:
2436 		if (!pat->ctx.data.maxlen)
2437 			break;
2438 
2439 		if (instr->ctx.data.len - *start_offset >
2440 		    pat->ctx.data.maxlen) {
2441 			*start_offset += pat->ctx.data.maxlen;
2442 			return true;
2443 		}
2444 		break;
2445 
2446 	default:
2447 		break;
2448 	}
2449 
2450 	return false;
2451 }
2452 
2453 /**
2454  * nand_op_parser_match_pat - Checks if a pattern matches the instructions
2455  *			      remaining in the parser context
2456  * @pat: the pattern to test
2457  * @ctx: the parser context structure to match with the pattern @pat
2458  *
2459  * Check if @pat matches the set or a sub-set of instructions remaining in @ctx.
2460  * Returns true if this is the case, false ortherwise. When true is returned,
2461  * @ctx->subop is updated with the set of instructions to be passed to the
2462  * controller driver.
2463  */
2464 static bool
2465 nand_op_parser_match_pat(const struct nand_op_parser_pattern *pat,
2466 			 struct nand_op_parser_ctx *ctx)
2467 {
2468 	unsigned int instr_offset = ctx->subop.first_instr_start_off;
2469 	const struct nand_op_instr *end = ctx->instrs + ctx->ninstrs;
2470 	const struct nand_op_instr *instr = ctx->subop.instrs;
2471 	unsigned int i, ninstrs;
2472 
2473 	for (i = 0, ninstrs = 0; i < pat->nelems && instr < end; i++) {
2474 		/*
2475 		 * The pattern instruction does not match the operation
2476 		 * instruction. If the instruction is marked optional in the
2477 		 * pattern definition, we skip the pattern element and continue
2478 		 * to the next one. If the element is mandatory, there's no
2479 		 * match and we can return false directly.
2480 		 */
2481 		if (instr->type != pat->elems[i].type) {
2482 			if (!pat->elems[i].optional)
2483 				return false;
2484 
2485 			continue;
2486 		}
2487 
2488 		/*
2489 		 * Now check the pattern element constraints. If the pattern is
2490 		 * not able to handle the whole instruction in a single step,
2491 		 * we have to split it.
2492 		 * The last_instr_end_off value comes back updated to point to
2493 		 * the position where we have to split the instruction (the
2494 		 * start of the next subop chunk).
2495 		 */
2496 		if (nand_op_parser_must_split_instr(&pat->elems[i], instr,
2497 						    &instr_offset)) {
2498 			ninstrs++;
2499 			i++;
2500 			break;
2501 		}
2502 
2503 		instr++;
2504 		ninstrs++;
2505 		instr_offset = 0;
2506 	}
2507 
2508 	/*
2509 	 * This can happen if all instructions of a pattern are optional.
2510 	 * Still, if there's not at least one instruction handled by this
2511 	 * pattern, this is not a match, and we should try the next one (if
2512 	 * any).
2513 	 */
2514 	if (!ninstrs)
2515 		return false;
2516 
2517 	/*
2518 	 * We had a match on the pattern head, but the pattern may be longer
2519 	 * than the instructions we're asked to execute. We need to make sure
2520 	 * there's no mandatory elements in the pattern tail.
2521 	 */
2522 	for (; i < pat->nelems; i++) {
2523 		if (!pat->elems[i].optional)
2524 			return false;
2525 	}
2526 
2527 	/*
2528 	 * We have a match: update the subop structure accordingly and return
2529 	 * true.
2530 	 */
2531 	ctx->subop.ninstrs = ninstrs;
2532 	ctx->subop.last_instr_end_off = instr_offset;
2533 
2534 	return true;
2535 }
2536 
2537 #if IS_ENABLED(CONFIG_DYNAMIC_DEBUG) || defined(DEBUG)
2538 static void nand_op_parser_trace(const struct nand_op_parser_ctx *ctx)
2539 {
2540 	const struct nand_op_instr *instr;
2541 	char *prefix = "      ";
2542 	unsigned int i;
2543 
2544 	pr_debug("executing subop:\n");
2545 
2546 	for (i = 0; i < ctx->ninstrs; i++) {
2547 		instr = &ctx->instrs[i];
2548 
2549 		if (instr == &ctx->subop.instrs[0])
2550 			prefix = "    ->";
2551 
2552 		switch (instr->type) {
2553 		case NAND_OP_CMD_INSTR:
2554 			pr_debug("%sCMD      [0x%02x]\n", prefix,
2555 				 instr->ctx.cmd.opcode);
2556 			break;
2557 		case NAND_OP_ADDR_INSTR:
2558 			pr_debug("%sADDR     [%d cyc: %*ph]\n", prefix,
2559 				 instr->ctx.addr.naddrs,
2560 				 instr->ctx.addr.naddrs < 64 ?
2561 				 instr->ctx.addr.naddrs : 64,
2562 				 instr->ctx.addr.addrs);
2563 			break;
2564 		case NAND_OP_DATA_IN_INSTR:
2565 			pr_debug("%sDATA_IN  [%d B%s]\n", prefix,
2566 				 instr->ctx.data.len,
2567 				 instr->ctx.data.force_8bit ?
2568 				 ", force 8-bit" : "");
2569 			break;
2570 		case NAND_OP_DATA_OUT_INSTR:
2571 			pr_debug("%sDATA_OUT [%d B%s]\n", prefix,
2572 				 instr->ctx.data.len,
2573 				 instr->ctx.data.force_8bit ?
2574 				 ", force 8-bit" : "");
2575 			break;
2576 		case NAND_OP_WAITRDY_INSTR:
2577 			pr_debug("%sWAITRDY  [max %d ms]\n", prefix,
2578 				 instr->ctx.waitrdy.timeout_ms);
2579 			break;
2580 		}
2581 
2582 		if (instr == &ctx->subop.instrs[ctx->subop.ninstrs - 1])
2583 			prefix = "      ";
2584 	}
2585 }
2586 #else
2587 static void nand_op_parser_trace(const struct nand_op_parser_ctx *ctx)
2588 {
2589 	/* NOP */
2590 }
2591 #endif
2592 
2593 /**
2594  * nand_op_parser_exec_op - exec_op parser
2595  * @chip: the NAND chip
2596  * @parser: patterns description provided by the controller driver
2597  * @op: the NAND operation to address
2598  * @check_only: when true, the function only checks if @op can be handled but
2599  *		does not execute the operation
2600  *
2601  * Helper function designed to ease integration of NAND controller drivers that
2602  * only support a limited set of instruction sequences. The supported sequences
2603  * are described in @parser, and the framework takes care of splitting @op into
2604  * multiple sub-operations (if required) and pass them back to the ->exec()
2605  * callback of the matching pattern if @check_only is set to false.
2606  *
2607  * NAND controller drivers should call this function from their own ->exec_op()
2608  * implementation.
2609  *
2610  * Returns 0 on success, a negative error code otherwise. A failure can be
2611  * caused by an unsupported operation (none of the supported patterns is able
2612  * to handle the requested operation), or an error returned by one of the
2613  * matching pattern->exec() hook.
2614  */
2615 int nand_op_parser_exec_op(struct nand_chip *chip,
2616 			   const struct nand_op_parser *parser,
2617 			   const struct nand_operation *op, bool check_only)
2618 {
2619 	struct nand_op_parser_ctx ctx = {
2620 		.subop.instrs = op->instrs,
2621 		.instrs = op->instrs,
2622 		.ninstrs = op->ninstrs,
2623 	};
2624 	unsigned int i;
2625 
2626 	while (ctx.subop.instrs < op->instrs + op->ninstrs) {
2627 		int ret;
2628 
2629 		for (i = 0; i < parser->npatterns; i++) {
2630 			const struct nand_op_parser_pattern *pattern;
2631 
2632 			pattern = &parser->patterns[i];
2633 			if (!nand_op_parser_match_pat(pattern, &ctx))
2634 				continue;
2635 
2636 			nand_op_parser_trace(&ctx);
2637 
2638 			if (check_only)
2639 				break;
2640 
2641 			ret = pattern->exec(chip, &ctx.subop);
2642 			if (ret)
2643 				return ret;
2644 
2645 			break;
2646 		}
2647 
2648 		if (i == parser->npatterns) {
2649 			pr_debug("->exec_op() parser: pattern not found!\n");
2650 			return -ENOTSUPP;
2651 		}
2652 
2653 		/*
2654 		 * Update the context structure by pointing to the start of the
2655 		 * next subop.
2656 		 */
2657 		ctx.subop.instrs = ctx.subop.instrs + ctx.subop.ninstrs;
2658 		if (ctx.subop.last_instr_end_off)
2659 			ctx.subop.instrs -= 1;
2660 
2661 		ctx.subop.first_instr_start_off = ctx.subop.last_instr_end_off;
2662 	}
2663 
2664 	return 0;
2665 }
2666 EXPORT_SYMBOL_GPL(nand_op_parser_exec_op);
2667 
2668 static bool nand_instr_is_data(const struct nand_op_instr *instr)
2669 {
2670 	return instr && (instr->type == NAND_OP_DATA_IN_INSTR ||
2671 			 instr->type == NAND_OP_DATA_OUT_INSTR);
2672 }
2673 
2674 static bool nand_subop_instr_is_valid(const struct nand_subop *subop,
2675 				      unsigned int instr_idx)
2676 {
2677 	return subop && instr_idx < subop->ninstrs;
2678 }
2679 
2680 static int nand_subop_get_start_off(const struct nand_subop *subop,
2681 				    unsigned int instr_idx)
2682 {
2683 	if (instr_idx)
2684 		return 0;
2685 
2686 	return subop->first_instr_start_off;
2687 }
2688 
2689 /**
2690  * nand_subop_get_addr_start_off - Get the start offset in an address array
2691  * @subop: The entire sub-operation
2692  * @instr_idx: Index of the instruction inside the sub-operation
2693  *
2694  * During driver development, one could be tempted to directly use the
2695  * ->addr.addrs field of address instructions. This is wrong as address
2696  * instructions might be split.
2697  *
2698  * Given an address instruction, returns the offset of the first cycle to issue.
2699  */
2700 int nand_subop_get_addr_start_off(const struct nand_subop *subop,
2701 				  unsigned int instr_idx)
2702 {
2703 	if (!nand_subop_instr_is_valid(subop, instr_idx) ||
2704 	    subop->instrs[instr_idx].type != NAND_OP_ADDR_INSTR)
2705 		return -EINVAL;
2706 
2707 	return nand_subop_get_start_off(subop, instr_idx);
2708 }
2709 EXPORT_SYMBOL_GPL(nand_subop_get_addr_start_off);
2710 
2711 /**
2712  * nand_subop_get_num_addr_cyc - Get the remaining address cycles to assert
2713  * @subop: The entire sub-operation
2714  * @instr_idx: Index of the instruction inside the sub-operation
2715  *
2716  * During driver development, one could be tempted to directly use the
2717  * ->addr->naddrs field of a data instruction. This is wrong as instructions
2718  * might be split.
2719  *
2720  * Given an address instruction, returns the number of address cycle to issue.
2721  */
2722 int nand_subop_get_num_addr_cyc(const struct nand_subop *subop,
2723 				unsigned int instr_idx)
2724 {
2725 	int start_off, end_off;
2726 
2727 	if (!nand_subop_instr_is_valid(subop, instr_idx) ||
2728 	    subop->instrs[instr_idx].type != NAND_OP_ADDR_INSTR)
2729 		return -EINVAL;
2730 
2731 	start_off = nand_subop_get_addr_start_off(subop, instr_idx);
2732 
2733 	if (instr_idx == subop->ninstrs - 1 &&
2734 	    subop->last_instr_end_off)
2735 		end_off = subop->last_instr_end_off;
2736 	else
2737 		end_off = subop->instrs[instr_idx].ctx.addr.naddrs;
2738 
2739 	return end_off - start_off;
2740 }
2741 EXPORT_SYMBOL_GPL(nand_subop_get_num_addr_cyc);
2742 
2743 /**
2744  * nand_subop_get_data_start_off - Get the start offset in a data array
2745  * @subop: The entire sub-operation
2746  * @instr_idx: Index of the instruction inside the sub-operation
2747  *
2748  * During driver development, one could be tempted to directly use the
2749  * ->data->buf.{in,out} field of data instructions. This is wrong as data
2750  * instructions might be split.
2751  *
2752  * Given a data instruction, returns the offset to start from.
2753  */
2754 int nand_subop_get_data_start_off(const struct nand_subop *subop,
2755 				  unsigned int instr_idx)
2756 {
2757 	if (!nand_subop_instr_is_valid(subop, instr_idx) ||
2758 	    !nand_instr_is_data(&subop->instrs[instr_idx]))
2759 		return -EINVAL;
2760 
2761 	return nand_subop_get_start_off(subop, instr_idx);
2762 }
2763 EXPORT_SYMBOL_GPL(nand_subop_get_data_start_off);
2764 
2765 /**
2766  * nand_subop_get_data_len - Get the number of bytes to retrieve
2767  * @subop: The entire sub-operation
2768  * @instr_idx: Index of the instruction inside the sub-operation
2769  *
2770  * During driver development, one could be tempted to directly use the
2771  * ->data->len field of a data instruction. This is wrong as data instructions
2772  * might be split.
2773  *
2774  * Returns the length of the chunk of data to send/receive.
2775  */
2776 int nand_subop_get_data_len(const struct nand_subop *subop,
2777 			    unsigned int instr_idx)
2778 {
2779 	int start_off = 0, end_off;
2780 
2781 	if (!nand_subop_instr_is_valid(subop, instr_idx) ||
2782 	    !nand_instr_is_data(&subop->instrs[instr_idx]))
2783 		return -EINVAL;
2784 
2785 	start_off = nand_subop_get_data_start_off(subop, instr_idx);
2786 
2787 	if (instr_idx == subop->ninstrs - 1 &&
2788 	    subop->last_instr_end_off)
2789 		end_off = subop->last_instr_end_off;
2790 	else
2791 		end_off = subop->instrs[instr_idx].ctx.data.len;
2792 
2793 	return end_off - start_off;
2794 }
2795 EXPORT_SYMBOL_GPL(nand_subop_get_data_len);
2796 
2797 /**
2798  * nand_reset - Reset and initialize a NAND device
2799  * @chip: The NAND chip
2800  * @chipnr: Internal die id
2801  *
2802  * Save the timings data structure, then apply SDR timings mode 0 (see
2803  * nand_reset_data_interface for details), do the reset operation, and
2804  * apply back the previous timings.
2805  *
2806  * Returns 0 on success, a negative error code otherwise.
2807  */
2808 int nand_reset(struct nand_chip *chip, int chipnr)
2809 {
2810 	struct mtd_info *mtd = nand_to_mtd(chip);
2811 	struct nand_data_interface saved_data_intf = chip->data_interface;
2812 	int ret;
2813 
2814 	ret = nand_reset_data_interface(chip, chipnr);
2815 	if (ret)
2816 		return ret;
2817 
2818 	/*
2819 	 * The CS line has to be released before we can apply the new NAND
2820 	 * interface settings, hence this weird ->select_chip() dance.
2821 	 */
2822 	chip->select_chip(mtd, chipnr);
2823 	ret = nand_reset_op(chip);
2824 	chip->select_chip(mtd, -1);
2825 	if (ret)
2826 		return ret;
2827 
2828 	/*
2829 	 * A nand_reset_data_interface() put both the NAND chip and the NAND
2830 	 * controller in timings mode 0. If the default mode for this chip is
2831 	 * also 0, no need to proceed to the change again. Plus, at probe time,
2832 	 * nand_setup_data_interface() uses ->set/get_features() which would
2833 	 * fail anyway as the parameter page is not available yet.
2834 	 */
2835 	if (!chip->onfi_timing_mode_default)
2836 		return 0;
2837 
2838 	chip->data_interface = saved_data_intf;
2839 	ret = nand_setup_data_interface(chip, chipnr);
2840 	if (ret)
2841 		return ret;
2842 
2843 	return 0;
2844 }
2845 EXPORT_SYMBOL_GPL(nand_reset);
2846 
2847 /**
2848  * nand_check_erased_buf - check if a buffer contains (almost) only 0xff data
2849  * @buf: buffer to test
2850  * @len: buffer length
2851  * @bitflips_threshold: maximum number of bitflips
2852  *
2853  * Check if a buffer contains only 0xff, which means the underlying region
2854  * has been erased and is ready to be programmed.
2855  * The bitflips_threshold specify the maximum number of bitflips before
2856  * considering the region is not erased.
2857  * Note: The logic of this function has been extracted from the memweight
2858  * implementation, except that nand_check_erased_buf function exit before
2859  * testing the whole buffer if the number of bitflips exceed the
2860  * bitflips_threshold value.
2861  *
2862  * Returns a positive number of bitflips less than or equal to
2863  * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the
2864  * threshold.
2865  */
2866 static int nand_check_erased_buf(void *buf, int len, int bitflips_threshold)
2867 {
2868 	const unsigned char *bitmap = buf;
2869 	int bitflips = 0;
2870 	int weight;
2871 
2872 	for (; len && ((uintptr_t)bitmap) % sizeof(long);
2873 	     len--, bitmap++) {
2874 		weight = hweight8(*bitmap);
2875 		bitflips += BITS_PER_BYTE - weight;
2876 		if (unlikely(bitflips > bitflips_threshold))
2877 			return -EBADMSG;
2878 	}
2879 
2880 	for (; len >= sizeof(long);
2881 	     len -= sizeof(long), bitmap += sizeof(long)) {
2882 		unsigned long d = *((unsigned long *)bitmap);
2883 		if (d == ~0UL)
2884 			continue;
2885 		weight = hweight_long(d);
2886 		bitflips += BITS_PER_LONG - weight;
2887 		if (unlikely(bitflips > bitflips_threshold))
2888 			return -EBADMSG;
2889 	}
2890 
2891 	for (; len > 0; len--, bitmap++) {
2892 		weight = hweight8(*bitmap);
2893 		bitflips += BITS_PER_BYTE - weight;
2894 		if (unlikely(bitflips > bitflips_threshold))
2895 			return -EBADMSG;
2896 	}
2897 
2898 	return bitflips;
2899 }
2900 
2901 /**
2902  * nand_check_erased_ecc_chunk - check if an ECC chunk contains (almost) only
2903  *				 0xff data
2904  * @data: data buffer to test
2905  * @datalen: data length
2906  * @ecc: ECC buffer
2907  * @ecclen: ECC length
2908  * @extraoob: extra OOB buffer
2909  * @extraooblen: extra OOB length
2910  * @bitflips_threshold: maximum number of bitflips
2911  *
2912  * Check if a data buffer and its associated ECC and OOB data contains only
2913  * 0xff pattern, which means the underlying region has been erased and is
2914  * ready to be programmed.
2915  * The bitflips_threshold specify the maximum number of bitflips before
2916  * considering the region as not erased.
2917  *
2918  * Note:
2919  * 1/ ECC algorithms are working on pre-defined block sizes which are usually
2920  *    different from the NAND page size. When fixing bitflips, ECC engines will
2921  *    report the number of errors per chunk, and the NAND core infrastructure
2922  *    expect you to return the maximum number of bitflips for the whole page.
2923  *    This is why you should always use this function on a single chunk and
2924  *    not on the whole page. After checking each chunk you should update your
2925  *    max_bitflips value accordingly.
2926  * 2/ When checking for bitflips in erased pages you should not only check
2927  *    the payload data but also their associated ECC data, because a user might
2928  *    have programmed almost all bits to 1 but a few. In this case, we
2929  *    shouldn't consider the chunk as erased, and checking ECC bytes prevent
2930  *    this case.
2931  * 3/ The extraoob argument is optional, and should be used if some of your OOB
2932  *    data are protected by the ECC engine.
2933  *    It could also be used if you support subpages and want to attach some
2934  *    extra OOB data to an ECC chunk.
2935  *
2936  * Returns a positive number of bitflips less than or equal to
2937  * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the
2938  * threshold. In case of success, the passed buffers are filled with 0xff.
2939  */
2940 int nand_check_erased_ecc_chunk(void *data, int datalen,
2941 				void *ecc, int ecclen,
2942 				void *extraoob, int extraooblen,
2943 				int bitflips_threshold)
2944 {
2945 	int data_bitflips = 0, ecc_bitflips = 0, extraoob_bitflips = 0;
2946 
2947 	data_bitflips = nand_check_erased_buf(data, datalen,
2948 					      bitflips_threshold);
2949 	if (data_bitflips < 0)
2950 		return data_bitflips;
2951 
2952 	bitflips_threshold -= data_bitflips;
2953 
2954 	ecc_bitflips = nand_check_erased_buf(ecc, ecclen, bitflips_threshold);
2955 	if (ecc_bitflips < 0)
2956 		return ecc_bitflips;
2957 
2958 	bitflips_threshold -= ecc_bitflips;
2959 
2960 	extraoob_bitflips = nand_check_erased_buf(extraoob, extraooblen,
2961 						  bitflips_threshold);
2962 	if (extraoob_bitflips < 0)
2963 		return extraoob_bitflips;
2964 
2965 	if (data_bitflips)
2966 		memset(data, 0xff, datalen);
2967 
2968 	if (ecc_bitflips)
2969 		memset(ecc, 0xff, ecclen);
2970 
2971 	if (extraoob_bitflips)
2972 		memset(extraoob, 0xff, extraooblen);
2973 
2974 	return data_bitflips + ecc_bitflips + extraoob_bitflips;
2975 }
2976 EXPORT_SYMBOL(nand_check_erased_ecc_chunk);
2977 
2978 /**
2979  * nand_read_page_raw - [INTERN] read raw page data without ecc
2980  * @mtd: mtd info structure
2981  * @chip: nand chip info structure
2982  * @buf: buffer to store read data
2983  * @oob_required: caller requires OOB data read to chip->oob_poi
2984  * @page: page number to read
2985  *
2986  * Not for syndrome calculating ECC controllers, which use a special oob layout.
2987  */
2988 int nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
2989 		       uint8_t *buf, int oob_required, int page)
2990 {
2991 	int ret;
2992 
2993 	ret = nand_read_page_op(chip, page, 0, buf, mtd->writesize);
2994 	if (ret)
2995 		return ret;
2996 
2997 	if (oob_required) {
2998 		ret = nand_read_data_op(chip, chip->oob_poi, mtd->oobsize,
2999 					false);
3000 		if (ret)
3001 			return ret;
3002 	}
3003 
3004 	return 0;
3005 }
3006 EXPORT_SYMBOL(nand_read_page_raw);
3007 
3008 /**
3009  * nand_read_page_raw_syndrome - [INTERN] read raw page data without ecc
3010  * @mtd: mtd info structure
3011  * @chip: nand chip info structure
3012  * @buf: buffer to store read data
3013  * @oob_required: caller requires OOB data read to chip->oob_poi
3014  * @page: page number to read
3015  *
3016  * We need a special oob layout and handling even when OOB isn't used.
3017  */
3018 static int nand_read_page_raw_syndrome(struct mtd_info *mtd,
3019 				       struct nand_chip *chip, uint8_t *buf,
3020 				       int oob_required, int page)
3021 {
3022 	int eccsize = chip->ecc.size;
3023 	int eccbytes = chip->ecc.bytes;
3024 	uint8_t *oob = chip->oob_poi;
3025 	int steps, size, ret;
3026 
3027 	ret = nand_read_page_op(chip, page, 0, NULL, 0);
3028 	if (ret)
3029 		return ret;
3030 
3031 	for (steps = chip->ecc.steps; steps > 0; steps--) {
3032 		ret = nand_read_data_op(chip, buf, eccsize, false);
3033 		if (ret)
3034 			return ret;
3035 
3036 		buf += eccsize;
3037 
3038 		if (chip->ecc.prepad) {
3039 			ret = nand_read_data_op(chip, oob, chip->ecc.prepad,
3040 						false);
3041 			if (ret)
3042 				return ret;
3043 
3044 			oob += chip->ecc.prepad;
3045 		}
3046 
3047 		ret = nand_read_data_op(chip, oob, eccbytes, false);
3048 		if (ret)
3049 			return ret;
3050 
3051 		oob += eccbytes;
3052 
3053 		if (chip->ecc.postpad) {
3054 			ret = nand_read_data_op(chip, oob, chip->ecc.postpad,
3055 						false);
3056 			if (ret)
3057 				return ret;
3058 
3059 			oob += chip->ecc.postpad;
3060 		}
3061 	}
3062 
3063 	size = mtd->oobsize - (oob - chip->oob_poi);
3064 	if (size) {
3065 		ret = nand_read_data_op(chip, oob, size, false);
3066 		if (ret)
3067 			return ret;
3068 	}
3069 
3070 	return 0;
3071 }
3072 
3073 /**
3074  * nand_read_page_swecc - [REPLACEABLE] software ECC based page read function
3075  * @mtd: mtd info structure
3076  * @chip: nand chip info structure
3077  * @buf: buffer to store read data
3078  * @oob_required: caller requires OOB data read to chip->oob_poi
3079  * @page: page number to read
3080  */
3081 static int nand_read_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
3082 				uint8_t *buf, int oob_required, int page)
3083 {
3084 	int i, eccsize = chip->ecc.size, ret;
3085 	int eccbytes = chip->ecc.bytes;
3086 	int eccsteps = chip->ecc.steps;
3087 	uint8_t *p = buf;
3088 	uint8_t *ecc_calc = chip->ecc.calc_buf;
3089 	uint8_t *ecc_code = chip->ecc.code_buf;
3090 	unsigned int max_bitflips = 0;
3091 
3092 	chip->ecc.read_page_raw(mtd, chip, buf, 1, page);
3093 
3094 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
3095 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
3096 
3097 	ret = mtd_ooblayout_get_eccbytes(mtd, ecc_code, chip->oob_poi, 0,
3098 					 chip->ecc.total);
3099 	if (ret)
3100 		return ret;
3101 
3102 	eccsteps = chip->ecc.steps;
3103 	p = buf;
3104 
3105 	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
3106 		int stat;
3107 
3108 		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
3109 		if (stat < 0) {
3110 			mtd->ecc_stats.failed++;
3111 		} else {
3112 			mtd->ecc_stats.corrected += stat;
3113 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
3114 		}
3115 	}
3116 	return max_bitflips;
3117 }
3118 
3119 /**
3120  * nand_read_subpage - [REPLACEABLE] ECC based sub-page read function
3121  * @mtd: mtd info structure
3122  * @chip: nand chip info structure
3123  * @data_offs: offset of requested data within the page
3124  * @readlen: data length
3125  * @bufpoi: buffer to store read data
3126  * @page: page number to read
3127  */
3128 static int nand_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
3129 			uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi,
3130 			int page)
3131 {
3132 	int start_step, end_step, num_steps, ret;
3133 	uint8_t *p;
3134 	int data_col_addr, i, gaps = 0;
3135 	int datafrag_len, eccfrag_len, aligned_len, aligned_pos;
3136 	int busw = (chip->options & NAND_BUSWIDTH_16) ? 2 : 1;
3137 	int index, section = 0;
3138 	unsigned int max_bitflips = 0;
3139 	struct mtd_oob_region oobregion = { };
3140 
3141 	/* Column address within the page aligned to ECC size (256bytes) */
3142 	start_step = data_offs / chip->ecc.size;
3143 	end_step = (data_offs + readlen - 1) / chip->ecc.size;
3144 	num_steps = end_step - start_step + 1;
3145 	index = start_step * chip->ecc.bytes;
3146 
3147 	/* Data size aligned to ECC ecc.size */
3148 	datafrag_len = num_steps * chip->ecc.size;
3149 	eccfrag_len = num_steps * chip->ecc.bytes;
3150 
3151 	data_col_addr = start_step * chip->ecc.size;
3152 	/* If we read not a page aligned data */
3153 	p = bufpoi + data_col_addr;
3154 	ret = nand_read_page_op(chip, page, data_col_addr, p, datafrag_len);
3155 	if (ret)
3156 		return ret;
3157 
3158 	/* Calculate ECC */
3159 	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size)
3160 		chip->ecc.calculate(mtd, p, &chip->ecc.calc_buf[i]);
3161 
3162 	/*
3163 	 * The performance is faster if we position offsets according to
3164 	 * ecc.pos. Let's make sure that there are no gaps in ECC positions.
3165 	 */
3166 	ret = mtd_ooblayout_find_eccregion(mtd, index, &section, &oobregion);
3167 	if (ret)
3168 		return ret;
3169 
3170 	if (oobregion.length < eccfrag_len)
3171 		gaps = 1;
3172 
3173 	if (gaps) {
3174 		ret = nand_change_read_column_op(chip, mtd->writesize,
3175 						 chip->oob_poi, mtd->oobsize,
3176 						 false);
3177 		if (ret)
3178 			return ret;
3179 	} else {
3180 		/*
3181 		 * Send the command to read the particular ECC bytes take care
3182 		 * about buswidth alignment in read_buf.
3183 		 */
3184 		aligned_pos = oobregion.offset & ~(busw - 1);
3185 		aligned_len = eccfrag_len;
3186 		if (oobregion.offset & (busw - 1))
3187 			aligned_len++;
3188 		if ((oobregion.offset + (num_steps * chip->ecc.bytes)) &
3189 		    (busw - 1))
3190 			aligned_len++;
3191 
3192 		ret = nand_change_read_column_op(chip,
3193 						 mtd->writesize + aligned_pos,
3194 						 &chip->oob_poi[aligned_pos],
3195 						 aligned_len, false);
3196 		if (ret)
3197 			return ret;
3198 	}
3199 
3200 	ret = mtd_ooblayout_get_eccbytes(mtd, chip->ecc.code_buf,
3201 					 chip->oob_poi, index, eccfrag_len);
3202 	if (ret)
3203 		return ret;
3204 
3205 	p = bufpoi + data_col_addr;
3206 	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size) {
3207 		int stat;
3208 
3209 		stat = chip->ecc.correct(mtd, p, &chip->ecc.code_buf[i],
3210 					 &chip->ecc.calc_buf[i]);
3211 		if (stat == -EBADMSG &&
3212 		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
3213 			/* check for empty pages with bitflips */
3214 			stat = nand_check_erased_ecc_chunk(p, chip->ecc.size,
3215 						&chip->ecc.code_buf[i],
3216 						chip->ecc.bytes,
3217 						NULL, 0,
3218 						chip->ecc.strength);
3219 		}
3220 
3221 		if (stat < 0) {
3222 			mtd->ecc_stats.failed++;
3223 		} else {
3224 			mtd->ecc_stats.corrected += stat;
3225 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
3226 		}
3227 	}
3228 	return max_bitflips;
3229 }
3230 
3231 /**
3232  * nand_read_page_hwecc - [REPLACEABLE] hardware ECC based page read function
3233  * @mtd: mtd info structure
3234  * @chip: nand chip info structure
3235  * @buf: buffer to store read data
3236  * @oob_required: caller requires OOB data read to chip->oob_poi
3237  * @page: page number to read
3238  *
3239  * Not for syndrome calculating ECC controllers which need a special oob layout.
3240  */
3241 static int nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
3242 				uint8_t *buf, int oob_required, int page)
3243 {
3244 	int i, eccsize = chip->ecc.size, ret;
3245 	int eccbytes = chip->ecc.bytes;
3246 	int eccsteps = chip->ecc.steps;
3247 	uint8_t *p = buf;
3248 	uint8_t *ecc_calc = chip->ecc.calc_buf;
3249 	uint8_t *ecc_code = chip->ecc.code_buf;
3250 	unsigned int max_bitflips = 0;
3251 
3252 	ret = nand_read_page_op(chip, page, 0, NULL, 0);
3253 	if (ret)
3254 		return ret;
3255 
3256 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
3257 		chip->ecc.hwctl(mtd, NAND_ECC_READ);
3258 
3259 		ret = nand_read_data_op(chip, p, eccsize, false);
3260 		if (ret)
3261 			return ret;
3262 
3263 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
3264 	}
3265 
3266 	ret = nand_read_data_op(chip, chip->oob_poi, mtd->oobsize, false);
3267 	if (ret)
3268 		return ret;
3269 
3270 	ret = mtd_ooblayout_get_eccbytes(mtd, ecc_code, chip->oob_poi, 0,
3271 					 chip->ecc.total);
3272 	if (ret)
3273 		return ret;
3274 
3275 	eccsteps = chip->ecc.steps;
3276 	p = buf;
3277 
3278 	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
3279 		int stat;
3280 
3281 		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
3282 		if (stat == -EBADMSG &&
3283 		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
3284 			/* check for empty pages with bitflips */
3285 			stat = nand_check_erased_ecc_chunk(p, eccsize,
3286 						&ecc_code[i], eccbytes,
3287 						NULL, 0,
3288 						chip->ecc.strength);
3289 		}
3290 
3291 		if (stat < 0) {
3292 			mtd->ecc_stats.failed++;
3293 		} else {
3294 			mtd->ecc_stats.corrected += stat;
3295 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
3296 		}
3297 	}
3298 	return max_bitflips;
3299 }
3300 
3301 /**
3302  * nand_read_page_hwecc_oob_first - [REPLACEABLE] hw ecc, read oob first
3303  * @mtd: mtd info structure
3304  * @chip: nand chip info structure
3305  * @buf: buffer to store read data
3306  * @oob_required: caller requires OOB data read to chip->oob_poi
3307  * @page: page number to read
3308  *
3309  * Hardware ECC for large page chips, require OOB to be read first. For this
3310  * ECC mode, the write_page method is re-used from ECC_HW. These methods
3311  * read/write ECC from the OOB area, unlike the ECC_HW_SYNDROME support with
3312  * multiple ECC steps, follows the "infix ECC" scheme and reads/writes ECC from
3313  * the data area, by overwriting the NAND manufacturer bad block markings.
3314  */
3315 static int nand_read_page_hwecc_oob_first(struct mtd_info *mtd,
3316 	struct nand_chip *chip, uint8_t *buf, int oob_required, int page)
3317 {
3318 	int i, eccsize = chip->ecc.size, ret;
3319 	int eccbytes = chip->ecc.bytes;
3320 	int eccsteps = chip->ecc.steps;
3321 	uint8_t *p = buf;
3322 	uint8_t *ecc_code = chip->ecc.code_buf;
3323 	uint8_t *ecc_calc = chip->ecc.calc_buf;
3324 	unsigned int max_bitflips = 0;
3325 
3326 	/* Read the OOB area first */
3327 	ret = nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
3328 	if (ret)
3329 		return ret;
3330 
3331 	ret = nand_read_page_op(chip, page, 0, NULL, 0);
3332 	if (ret)
3333 		return ret;
3334 
3335 	ret = mtd_ooblayout_get_eccbytes(mtd, ecc_code, chip->oob_poi, 0,
3336 					 chip->ecc.total);
3337 	if (ret)
3338 		return ret;
3339 
3340 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
3341 		int stat;
3342 
3343 		chip->ecc.hwctl(mtd, NAND_ECC_READ);
3344 
3345 		ret = nand_read_data_op(chip, p, eccsize, false);
3346 		if (ret)
3347 			return ret;
3348 
3349 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
3350 
3351 		stat = chip->ecc.correct(mtd, p, &ecc_code[i], NULL);
3352 		if (stat == -EBADMSG &&
3353 		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
3354 			/* check for empty pages with bitflips */
3355 			stat = nand_check_erased_ecc_chunk(p, eccsize,
3356 						&ecc_code[i], eccbytes,
3357 						NULL, 0,
3358 						chip->ecc.strength);
3359 		}
3360 
3361 		if (stat < 0) {
3362 			mtd->ecc_stats.failed++;
3363 		} else {
3364 			mtd->ecc_stats.corrected += stat;
3365 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
3366 		}
3367 	}
3368 	return max_bitflips;
3369 }
3370 
3371 /**
3372  * nand_read_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page read
3373  * @mtd: mtd info structure
3374  * @chip: nand chip info structure
3375  * @buf: buffer to store read data
3376  * @oob_required: caller requires OOB data read to chip->oob_poi
3377  * @page: page number to read
3378  *
3379  * The hw generator calculates the error syndrome automatically. Therefore we
3380  * need a special oob layout and handling.
3381  */
3382 static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
3383 				   uint8_t *buf, int oob_required, int page)
3384 {
3385 	int ret, i, eccsize = chip->ecc.size;
3386 	int eccbytes = chip->ecc.bytes;
3387 	int eccsteps = chip->ecc.steps;
3388 	int eccpadbytes = eccbytes + chip->ecc.prepad + chip->ecc.postpad;
3389 	uint8_t *p = buf;
3390 	uint8_t *oob = chip->oob_poi;
3391 	unsigned int max_bitflips = 0;
3392 
3393 	ret = nand_read_page_op(chip, page, 0, NULL, 0);
3394 	if (ret)
3395 		return ret;
3396 
3397 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
3398 		int stat;
3399 
3400 		chip->ecc.hwctl(mtd, NAND_ECC_READ);
3401 
3402 		ret = nand_read_data_op(chip, p, eccsize, false);
3403 		if (ret)
3404 			return ret;
3405 
3406 		if (chip->ecc.prepad) {
3407 			ret = nand_read_data_op(chip, oob, chip->ecc.prepad,
3408 						false);
3409 			if (ret)
3410 				return ret;
3411 
3412 			oob += chip->ecc.prepad;
3413 		}
3414 
3415 		chip->ecc.hwctl(mtd, NAND_ECC_READSYN);
3416 
3417 		ret = nand_read_data_op(chip, oob, eccbytes, false);
3418 		if (ret)
3419 			return ret;
3420 
3421 		stat = chip->ecc.correct(mtd, p, oob, NULL);
3422 
3423 		oob += eccbytes;
3424 
3425 		if (chip->ecc.postpad) {
3426 			ret = nand_read_data_op(chip, oob, chip->ecc.postpad,
3427 						false);
3428 			if (ret)
3429 				return ret;
3430 
3431 			oob += chip->ecc.postpad;
3432 		}
3433 
3434 		if (stat == -EBADMSG &&
3435 		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
3436 			/* check for empty pages with bitflips */
3437 			stat = nand_check_erased_ecc_chunk(p, chip->ecc.size,
3438 							   oob - eccpadbytes,
3439 							   eccpadbytes,
3440 							   NULL, 0,
3441 							   chip->ecc.strength);
3442 		}
3443 
3444 		if (stat < 0) {
3445 			mtd->ecc_stats.failed++;
3446 		} else {
3447 			mtd->ecc_stats.corrected += stat;
3448 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
3449 		}
3450 	}
3451 
3452 	/* Calculate remaining oob bytes */
3453 	i = mtd->oobsize - (oob - chip->oob_poi);
3454 	if (i) {
3455 		ret = nand_read_data_op(chip, oob, i, false);
3456 		if (ret)
3457 			return ret;
3458 	}
3459 
3460 	return max_bitflips;
3461 }
3462 
3463 /**
3464  * nand_transfer_oob - [INTERN] Transfer oob to client buffer
3465  * @mtd: mtd info structure
3466  * @oob: oob destination address
3467  * @ops: oob ops structure
3468  * @len: size of oob to transfer
3469  */
3470 static uint8_t *nand_transfer_oob(struct mtd_info *mtd, uint8_t *oob,
3471 				  struct mtd_oob_ops *ops, size_t len)
3472 {
3473 	struct nand_chip *chip = mtd_to_nand(mtd);
3474 	int ret;
3475 
3476 	switch (ops->mode) {
3477 
3478 	case MTD_OPS_PLACE_OOB:
3479 	case MTD_OPS_RAW:
3480 		memcpy(oob, chip->oob_poi + ops->ooboffs, len);
3481 		return oob + len;
3482 
3483 	case MTD_OPS_AUTO_OOB:
3484 		ret = mtd_ooblayout_get_databytes(mtd, oob, chip->oob_poi,
3485 						  ops->ooboffs, len);
3486 		BUG_ON(ret);
3487 		return oob + len;
3488 
3489 	default:
3490 		BUG();
3491 	}
3492 	return NULL;
3493 }
3494 
3495 /**
3496  * nand_setup_read_retry - [INTERN] Set the READ RETRY mode
3497  * @mtd: MTD device structure
3498  * @retry_mode: the retry mode to use
3499  *
3500  * Some vendors supply a special command to shift the Vt threshold, to be used
3501  * when there are too many bitflips in a page (i.e., ECC error). After setting
3502  * a new threshold, the host should retry reading the page.
3503  */
3504 static int nand_setup_read_retry(struct mtd_info *mtd, int retry_mode)
3505 {
3506 	struct nand_chip *chip = mtd_to_nand(mtd);
3507 
3508 	pr_debug("setting READ RETRY mode %d\n", retry_mode);
3509 
3510 	if (retry_mode >= chip->read_retries)
3511 		return -EINVAL;
3512 
3513 	if (!chip->setup_read_retry)
3514 		return -EOPNOTSUPP;
3515 
3516 	return chip->setup_read_retry(mtd, retry_mode);
3517 }
3518 
3519 /**
3520  * nand_do_read_ops - [INTERN] Read data with ECC
3521  * @mtd: MTD device structure
3522  * @from: offset to read from
3523  * @ops: oob ops structure
3524  *
3525  * Internal function. Called with chip held.
3526  */
3527 static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
3528 			    struct mtd_oob_ops *ops)
3529 {
3530 	int chipnr, page, realpage, col, bytes, aligned, oob_required;
3531 	struct nand_chip *chip = mtd_to_nand(mtd);
3532 	int ret = 0;
3533 	uint32_t readlen = ops->len;
3534 	uint32_t oobreadlen = ops->ooblen;
3535 	uint32_t max_oobsize = mtd_oobavail(mtd, ops);
3536 
3537 	uint8_t *bufpoi, *oob, *buf;
3538 	int use_bufpoi;
3539 	unsigned int max_bitflips = 0;
3540 	int retry_mode = 0;
3541 	bool ecc_fail = false;
3542 
3543 	chipnr = (int)(from >> chip->chip_shift);
3544 	chip->select_chip(mtd, chipnr);
3545 
3546 	realpage = (int)(from >> chip->page_shift);
3547 	page = realpage & chip->pagemask;
3548 
3549 	col = (int)(from & (mtd->writesize - 1));
3550 
3551 	buf = ops->datbuf;
3552 	oob = ops->oobbuf;
3553 	oob_required = oob ? 1 : 0;
3554 
3555 	while (1) {
3556 		unsigned int ecc_failures = mtd->ecc_stats.failed;
3557 
3558 		bytes = min(mtd->writesize - col, readlen);
3559 		aligned = (bytes == mtd->writesize);
3560 
3561 		if (!aligned)
3562 			use_bufpoi = 1;
3563 		else if (chip->options & NAND_USE_BOUNCE_BUFFER)
3564 			use_bufpoi = !virt_addr_valid(buf) ||
3565 				     !IS_ALIGNED((unsigned long)buf,
3566 						 chip->buf_align);
3567 		else
3568 			use_bufpoi = 0;
3569 
3570 		/* Is the current page in the buffer? */
3571 		if (realpage != chip->pagebuf || oob) {
3572 			bufpoi = use_bufpoi ? chip->data_buf : buf;
3573 
3574 			if (use_bufpoi && aligned)
3575 				pr_debug("%s: using read bounce buffer for buf@%p\n",
3576 						 __func__, buf);
3577 
3578 read_retry:
3579 			/*
3580 			 * Now read the page into the buffer.  Absent an error,
3581 			 * the read methods return max bitflips per ecc step.
3582 			 */
3583 			if (unlikely(ops->mode == MTD_OPS_RAW))
3584 				ret = chip->ecc.read_page_raw(mtd, chip, bufpoi,
3585 							      oob_required,
3586 							      page);
3587 			else if (!aligned && NAND_HAS_SUBPAGE_READ(chip) &&
3588 				 !oob)
3589 				ret = chip->ecc.read_subpage(mtd, chip,
3590 							col, bytes, bufpoi,
3591 							page);
3592 			else
3593 				ret = chip->ecc.read_page(mtd, chip, bufpoi,
3594 							  oob_required, page);
3595 			if (ret < 0) {
3596 				if (use_bufpoi)
3597 					/* Invalidate page cache */
3598 					chip->pagebuf = -1;
3599 				break;
3600 			}
3601 
3602 			/* Transfer not aligned data */
3603 			if (use_bufpoi) {
3604 				if (!NAND_HAS_SUBPAGE_READ(chip) && !oob &&
3605 				    !(mtd->ecc_stats.failed - ecc_failures) &&
3606 				    (ops->mode != MTD_OPS_RAW)) {
3607 					chip->pagebuf = realpage;
3608 					chip->pagebuf_bitflips = ret;
3609 				} else {
3610 					/* Invalidate page cache */
3611 					chip->pagebuf = -1;
3612 				}
3613 				memcpy(buf, chip->data_buf + col, bytes);
3614 			}
3615 
3616 			if (unlikely(oob)) {
3617 				int toread = min(oobreadlen, max_oobsize);
3618 
3619 				if (toread) {
3620 					oob = nand_transfer_oob(mtd,
3621 						oob, ops, toread);
3622 					oobreadlen -= toread;
3623 				}
3624 			}
3625 
3626 			if (chip->options & NAND_NEED_READRDY) {
3627 				/* Apply delay or wait for ready/busy pin */
3628 				if (!chip->dev_ready)
3629 					udelay(chip->chip_delay);
3630 				else
3631 					nand_wait_ready(mtd);
3632 			}
3633 
3634 			if (mtd->ecc_stats.failed - ecc_failures) {
3635 				if (retry_mode + 1 < chip->read_retries) {
3636 					retry_mode++;
3637 					ret = nand_setup_read_retry(mtd,
3638 							retry_mode);
3639 					if (ret < 0)
3640 						break;
3641 
3642 					/* Reset failures; retry */
3643 					mtd->ecc_stats.failed = ecc_failures;
3644 					goto read_retry;
3645 				} else {
3646 					/* No more retry modes; real failure */
3647 					ecc_fail = true;
3648 				}
3649 			}
3650 
3651 			buf += bytes;
3652 			max_bitflips = max_t(unsigned int, max_bitflips, ret);
3653 		} else {
3654 			memcpy(buf, chip->data_buf + col, bytes);
3655 			buf += bytes;
3656 			max_bitflips = max_t(unsigned int, max_bitflips,
3657 					     chip->pagebuf_bitflips);
3658 		}
3659 
3660 		readlen -= bytes;
3661 
3662 		/* Reset to retry mode 0 */
3663 		if (retry_mode) {
3664 			ret = nand_setup_read_retry(mtd, 0);
3665 			if (ret < 0)
3666 				break;
3667 			retry_mode = 0;
3668 		}
3669 
3670 		if (!readlen)
3671 			break;
3672 
3673 		/* For subsequent reads align to page boundary */
3674 		col = 0;
3675 		/* Increment page address */
3676 		realpage++;
3677 
3678 		page = realpage & chip->pagemask;
3679 		/* Check, if we cross a chip boundary */
3680 		if (!page) {
3681 			chipnr++;
3682 			chip->select_chip(mtd, -1);
3683 			chip->select_chip(mtd, chipnr);
3684 		}
3685 	}
3686 	chip->select_chip(mtd, -1);
3687 
3688 	ops->retlen = ops->len - (size_t) readlen;
3689 	if (oob)
3690 		ops->oobretlen = ops->ooblen - oobreadlen;
3691 
3692 	if (ret < 0)
3693 		return ret;
3694 
3695 	if (ecc_fail)
3696 		return -EBADMSG;
3697 
3698 	return max_bitflips;
3699 }
3700 
3701 /**
3702  * nand_read_oob_std - [REPLACEABLE] the most common OOB data read function
3703  * @mtd: mtd info structure
3704  * @chip: nand chip info structure
3705  * @page: page number to read
3706  */
3707 int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip, int page)
3708 {
3709 	return nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
3710 }
3711 EXPORT_SYMBOL(nand_read_oob_std);
3712 
3713 /**
3714  * nand_read_oob_syndrome - [REPLACEABLE] OOB data read function for HW ECC
3715  *			    with syndromes
3716  * @mtd: mtd info structure
3717  * @chip: nand chip info structure
3718  * @page: page number to read
3719  */
3720 int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
3721 			   int page)
3722 {
3723 	int length = mtd->oobsize;
3724 	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
3725 	int eccsize = chip->ecc.size;
3726 	uint8_t *bufpoi = chip->oob_poi;
3727 	int i, toread, sndrnd = 0, pos, ret;
3728 
3729 	ret = nand_read_page_op(chip, page, chip->ecc.size, NULL, 0);
3730 	if (ret)
3731 		return ret;
3732 
3733 	for (i = 0; i < chip->ecc.steps; i++) {
3734 		if (sndrnd) {
3735 			int ret;
3736 
3737 			pos = eccsize + i * (eccsize + chunk);
3738 			if (mtd->writesize > 512)
3739 				ret = nand_change_read_column_op(chip, pos,
3740 								 NULL, 0,
3741 								 false);
3742 			else
3743 				ret = nand_read_page_op(chip, page, pos, NULL,
3744 							0);
3745 
3746 			if (ret)
3747 				return ret;
3748 		} else
3749 			sndrnd = 1;
3750 		toread = min_t(int, length, chunk);
3751 
3752 		ret = nand_read_data_op(chip, bufpoi, toread, false);
3753 		if (ret)
3754 			return ret;
3755 
3756 		bufpoi += toread;
3757 		length -= toread;
3758 	}
3759 	if (length > 0) {
3760 		ret = nand_read_data_op(chip, bufpoi, length, false);
3761 		if (ret)
3762 			return ret;
3763 	}
3764 
3765 	return 0;
3766 }
3767 EXPORT_SYMBOL(nand_read_oob_syndrome);
3768 
3769 /**
3770  * nand_write_oob_std - [REPLACEABLE] the most common OOB data write function
3771  * @mtd: mtd info structure
3772  * @chip: nand chip info structure
3773  * @page: page number to write
3774  */
3775 int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip, int page)
3776 {
3777 	return nand_prog_page_op(chip, page, mtd->writesize, chip->oob_poi,
3778 				 mtd->oobsize);
3779 }
3780 EXPORT_SYMBOL(nand_write_oob_std);
3781 
3782 /**
3783  * nand_write_oob_syndrome - [REPLACEABLE] OOB data write function for HW ECC
3784  *			     with syndrome - only for large page flash
3785  * @mtd: mtd info structure
3786  * @chip: nand chip info structure
3787  * @page: page number to write
3788  */
3789 int nand_write_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
3790 			    int page)
3791 {
3792 	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
3793 	int eccsize = chip->ecc.size, length = mtd->oobsize;
3794 	int ret, i, len, pos, sndcmd = 0, steps = chip->ecc.steps;
3795 	const uint8_t *bufpoi = chip->oob_poi;
3796 
3797 	/*
3798 	 * data-ecc-data-ecc ... ecc-oob
3799 	 * or
3800 	 * data-pad-ecc-pad-data-pad .... ecc-pad-oob
3801 	 */
3802 	if (!chip->ecc.prepad && !chip->ecc.postpad) {
3803 		pos = steps * (eccsize + chunk);
3804 		steps = 0;
3805 	} else
3806 		pos = eccsize;
3807 
3808 	ret = nand_prog_page_begin_op(chip, page, pos, NULL, 0);
3809 	if (ret)
3810 		return ret;
3811 
3812 	for (i = 0; i < steps; i++) {
3813 		if (sndcmd) {
3814 			if (mtd->writesize <= 512) {
3815 				uint32_t fill = 0xFFFFFFFF;
3816 
3817 				len = eccsize;
3818 				while (len > 0) {
3819 					int num = min_t(int, len, 4);
3820 
3821 					ret = nand_write_data_op(chip, &fill,
3822 								 num, false);
3823 					if (ret)
3824 						return ret;
3825 
3826 					len -= num;
3827 				}
3828 			} else {
3829 				pos = eccsize + i * (eccsize + chunk);
3830 				ret = nand_change_write_column_op(chip, pos,
3831 								  NULL, 0,
3832 								  false);
3833 				if (ret)
3834 					return ret;
3835 			}
3836 		} else
3837 			sndcmd = 1;
3838 		len = min_t(int, length, chunk);
3839 
3840 		ret = nand_write_data_op(chip, bufpoi, len, false);
3841 		if (ret)
3842 			return ret;
3843 
3844 		bufpoi += len;
3845 		length -= len;
3846 	}
3847 	if (length > 0) {
3848 		ret = nand_write_data_op(chip, bufpoi, length, false);
3849 		if (ret)
3850 			return ret;
3851 	}
3852 
3853 	return nand_prog_page_end_op(chip);
3854 }
3855 EXPORT_SYMBOL(nand_write_oob_syndrome);
3856 
3857 /**
3858  * nand_do_read_oob - [INTERN] NAND read out-of-band
3859  * @mtd: MTD device structure
3860  * @from: offset to read from
3861  * @ops: oob operations description structure
3862  *
3863  * NAND read out-of-band data from the spare area.
3864  */
3865 static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
3866 			    struct mtd_oob_ops *ops)
3867 {
3868 	unsigned int max_bitflips = 0;
3869 	int page, realpage, chipnr;
3870 	struct nand_chip *chip = mtd_to_nand(mtd);
3871 	struct mtd_ecc_stats stats;
3872 	int readlen = ops->ooblen;
3873 	int len;
3874 	uint8_t *buf = ops->oobbuf;
3875 	int ret = 0;
3876 
3877 	pr_debug("%s: from = 0x%08Lx, len = %i\n",
3878 			__func__, (unsigned long long)from, readlen);
3879 
3880 	stats = mtd->ecc_stats;
3881 
3882 	len = mtd_oobavail(mtd, ops);
3883 
3884 	chipnr = (int)(from >> chip->chip_shift);
3885 	chip->select_chip(mtd, chipnr);
3886 
3887 	/* Shift to get page */
3888 	realpage = (int)(from >> chip->page_shift);
3889 	page = realpage & chip->pagemask;
3890 
3891 	while (1) {
3892 		if (ops->mode == MTD_OPS_RAW)
3893 			ret = chip->ecc.read_oob_raw(mtd, chip, page);
3894 		else
3895 			ret = chip->ecc.read_oob(mtd, chip, page);
3896 
3897 		if (ret < 0)
3898 			break;
3899 
3900 		len = min(len, readlen);
3901 		buf = nand_transfer_oob(mtd, buf, ops, len);
3902 
3903 		if (chip->options & NAND_NEED_READRDY) {
3904 			/* Apply delay or wait for ready/busy pin */
3905 			if (!chip->dev_ready)
3906 				udelay(chip->chip_delay);
3907 			else
3908 				nand_wait_ready(mtd);
3909 		}
3910 
3911 		max_bitflips = max_t(unsigned int, max_bitflips, ret);
3912 
3913 		readlen -= len;
3914 		if (!readlen)
3915 			break;
3916 
3917 		/* Increment page address */
3918 		realpage++;
3919 
3920 		page = realpage & chip->pagemask;
3921 		/* Check, if we cross a chip boundary */
3922 		if (!page) {
3923 			chipnr++;
3924 			chip->select_chip(mtd, -1);
3925 			chip->select_chip(mtd, chipnr);
3926 		}
3927 	}
3928 	chip->select_chip(mtd, -1);
3929 
3930 	ops->oobretlen = ops->ooblen - readlen;
3931 
3932 	if (ret < 0)
3933 		return ret;
3934 
3935 	if (mtd->ecc_stats.failed - stats.failed)
3936 		return -EBADMSG;
3937 
3938 	return max_bitflips;
3939 }
3940 
3941 /**
3942  * nand_read_oob - [MTD Interface] NAND read data and/or out-of-band
3943  * @mtd: MTD device structure
3944  * @from: offset to read from
3945  * @ops: oob operation description structure
3946  *
3947  * NAND read data and/or out-of-band data.
3948  */
3949 static int nand_read_oob(struct mtd_info *mtd, loff_t from,
3950 			 struct mtd_oob_ops *ops)
3951 {
3952 	int ret;
3953 
3954 	ops->retlen = 0;
3955 
3956 	if (ops->mode != MTD_OPS_PLACE_OOB &&
3957 	    ops->mode != MTD_OPS_AUTO_OOB &&
3958 	    ops->mode != MTD_OPS_RAW)
3959 		return -ENOTSUPP;
3960 
3961 	nand_get_device(mtd, FL_READING);
3962 
3963 	if (!ops->datbuf)
3964 		ret = nand_do_read_oob(mtd, from, ops);
3965 	else
3966 		ret = nand_do_read_ops(mtd, from, ops);
3967 
3968 	nand_release_device(mtd);
3969 	return ret;
3970 }
3971 
3972 
3973 /**
3974  * nand_write_page_raw - [INTERN] raw page write function
3975  * @mtd: mtd info structure
3976  * @chip: nand chip info structure
3977  * @buf: data buffer
3978  * @oob_required: must write chip->oob_poi to OOB
3979  * @page: page number to write
3980  *
3981  * Not for syndrome calculating ECC controllers, which use a special oob layout.
3982  */
3983 int nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
3984 			const uint8_t *buf, int oob_required, int page)
3985 {
3986 	int ret;
3987 
3988 	ret = nand_prog_page_begin_op(chip, page, 0, buf, mtd->writesize);
3989 	if (ret)
3990 		return ret;
3991 
3992 	if (oob_required) {
3993 		ret = nand_write_data_op(chip, chip->oob_poi, mtd->oobsize,
3994 					 false);
3995 		if (ret)
3996 			return ret;
3997 	}
3998 
3999 	return nand_prog_page_end_op(chip);
4000 }
4001 EXPORT_SYMBOL(nand_write_page_raw);
4002 
4003 /**
4004  * nand_write_page_raw_syndrome - [INTERN] raw page write function
4005  * @mtd: mtd info structure
4006  * @chip: nand chip info structure
4007  * @buf: data buffer
4008  * @oob_required: must write chip->oob_poi to OOB
4009  * @page: page number to write
4010  *
4011  * We need a special oob layout and handling even when ECC isn't checked.
4012  */
4013 static int nand_write_page_raw_syndrome(struct mtd_info *mtd,
4014 					struct nand_chip *chip,
4015 					const uint8_t *buf, int oob_required,
4016 					int page)
4017 {
4018 	int eccsize = chip->ecc.size;
4019 	int eccbytes = chip->ecc.bytes;
4020 	uint8_t *oob = chip->oob_poi;
4021 	int steps, size, ret;
4022 
4023 	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
4024 	if (ret)
4025 		return ret;
4026 
4027 	for (steps = chip->ecc.steps; steps > 0; steps--) {
4028 		ret = nand_write_data_op(chip, buf, eccsize, false);
4029 		if (ret)
4030 			return ret;
4031 
4032 		buf += eccsize;
4033 
4034 		if (chip->ecc.prepad) {
4035 			ret = nand_write_data_op(chip, oob, chip->ecc.prepad,
4036 						 false);
4037 			if (ret)
4038 				return ret;
4039 
4040 			oob += chip->ecc.prepad;
4041 		}
4042 
4043 		ret = nand_write_data_op(chip, oob, eccbytes, false);
4044 		if (ret)
4045 			return ret;
4046 
4047 		oob += eccbytes;
4048 
4049 		if (chip->ecc.postpad) {
4050 			ret = nand_write_data_op(chip, oob, chip->ecc.postpad,
4051 						 false);
4052 			if (ret)
4053 				return ret;
4054 
4055 			oob += chip->ecc.postpad;
4056 		}
4057 	}
4058 
4059 	size = mtd->oobsize - (oob - chip->oob_poi);
4060 	if (size) {
4061 		ret = nand_write_data_op(chip, oob, size, false);
4062 		if (ret)
4063 			return ret;
4064 	}
4065 
4066 	return nand_prog_page_end_op(chip);
4067 }
4068 /**
4069  * nand_write_page_swecc - [REPLACEABLE] software ECC based page write function
4070  * @mtd: mtd info structure
4071  * @chip: nand chip info structure
4072  * @buf: data buffer
4073  * @oob_required: must write chip->oob_poi to OOB
4074  * @page: page number to write
4075  */
4076 static int nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
4077 				 const uint8_t *buf, int oob_required,
4078 				 int page)
4079 {
4080 	int i, eccsize = chip->ecc.size, ret;
4081 	int eccbytes = chip->ecc.bytes;
4082 	int eccsteps = chip->ecc.steps;
4083 	uint8_t *ecc_calc = chip->ecc.calc_buf;
4084 	const uint8_t *p = buf;
4085 
4086 	/* Software ECC calculation */
4087 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
4088 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
4089 
4090 	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi, 0,
4091 					 chip->ecc.total);
4092 	if (ret)
4093 		return ret;
4094 
4095 	return chip->ecc.write_page_raw(mtd, chip, buf, 1, page);
4096 }
4097 
4098 /**
4099  * nand_write_page_hwecc - [REPLACEABLE] hardware ECC based page write function
4100  * @mtd: mtd info structure
4101  * @chip: nand chip info structure
4102  * @buf: data buffer
4103  * @oob_required: must write chip->oob_poi to OOB
4104  * @page: page number to write
4105  */
4106 static int nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
4107 				  const uint8_t *buf, int oob_required,
4108 				  int page)
4109 {
4110 	int i, eccsize = chip->ecc.size, ret;
4111 	int eccbytes = chip->ecc.bytes;
4112 	int eccsteps = chip->ecc.steps;
4113 	uint8_t *ecc_calc = chip->ecc.calc_buf;
4114 	const uint8_t *p = buf;
4115 
4116 	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
4117 	if (ret)
4118 		return ret;
4119 
4120 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
4121 		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
4122 
4123 		ret = nand_write_data_op(chip, p, eccsize, false);
4124 		if (ret)
4125 			return ret;
4126 
4127 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
4128 	}
4129 
4130 	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi, 0,
4131 					 chip->ecc.total);
4132 	if (ret)
4133 		return ret;
4134 
4135 	ret = nand_write_data_op(chip, chip->oob_poi, mtd->oobsize, false);
4136 	if (ret)
4137 		return ret;
4138 
4139 	return nand_prog_page_end_op(chip);
4140 }
4141 
4142 
4143 /**
4144  * nand_write_subpage_hwecc - [REPLACEABLE] hardware ECC based subpage write
4145  * @mtd:	mtd info structure
4146  * @chip:	nand chip info structure
4147  * @offset:	column address of subpage within the page
4148  * @data_len:	data length
4149  * @buf:	data buffer
4150  * @oob_required: must write chip->oob_poi to OOB
4151  * @page: page number to write
4152  */
4153 static int nand_write_subpage_hwecc(struct mtd_info *mtd,
4154 				struct nand_chip *chip, uint32_t offset,
4155 				uint32_t data_len, const uint8_t *buf,
4156 				int oob_required, int page)
4157 {
4158 	uint8_t *oob_buf  = chip->oob_poi;
4159 	uint8_t *ecc_calc = chip->ecc.calc_buf;
4160 	int ecc_size      = chip->ecc.size;
4161 	int ecc_bytes     = chip->ecc.bytes;
4162 	int ecc_steps     = chip->ecc.steps;
4163 	uint32_t start_step = offset / ecc_size;
4164 	uint32_t end_step   = (offset + data_len - 1) / ecc_size;
4165 	int oob_bytes       = mtd->oobsize / ecc_steps;
4166 	int step, ret;
4167 
4168 	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
4169 	if (ret)
4170 		return ret;
4171 
4172 	for (step = 0; step < ecc_steps; step++) {
4173 		/* configure controller for WRITE access */
4174 		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
4175 
4176 		/* write data (untouched subpages already masked by 0xFF) */
4177 		ret = nand_write_data_op(chip, buf, ecc_size, false);
4178 		if (ret)
4179 			return ret;
4180 
4181 		/* mask ECC of un-touched subpages by padding 0xFF */
4182 		if ((step < start_step) || (step > end_step))
4183 			memset(ecc_calc, 0xff, ecc_bytes);
4184 		else
4185 			chip->ecc.calculate(mtd, buf, ecc_calc);
4186 
4187 		/* mask OOB of un-touched subpages by padding 0xFF */
4188 		/* if oob_required, preserve OOB metadata of written subpage */
4189 		if (!oob_required || (step < start_step) || (step > end_step))
4190 			memset(oob_buf, 0xff, oob_bytes);
4191 
4192 		buf += ecc_size;
4193 		ecc_calc += ecc_bytes;
4194 		oob_buf  += oob_bytes;
4195 	}
4196 
4197 	/* copy calculated ECC for whole page to chip->buffer->oob */
4198 	/* this include masked-value(0xFF) for unwritten subpages */
4199 	ecc_calc = chip->ecc.calc_buf;
4200 	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi, 0,
4201 					 chip->ecc.total);
4202 	if (ret)
4203 		return ret;
4204 
4205 	/* write OOB buffer to NAND device */
4206 	ret = nand_write_data_op(chip, chip->oob_poi, mtd->oobsize, false);
4207 	if (ret)
4208 		return ret;
4209 
4210 	return nand_prog_page_end_op(chip);
4211 }
4212 
4213 
4214 /**
4215  * nand_write_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page write
4216  * @mtd: mtd info structure
4217  * @chip: nand chip info structure
4218  * @buf: data buffer
4219  * @oob_required: must write chip->oob_poi to OOB
4220  * @page: page number to write
4221  *
4222  * The hw generator calculates the error syndrome automatically. Therefore we
4223  * need a special oob layout and handling.
4224  */
4225 static int nand_write_page_syndrome(struct mtd_info *mtd,
4226 				    struct nand_chip *chip,
4227 				    const uint8_t *buf, int oob_required,
4228 				    int page)
4229 {
4230 	int i, eccsize = chip->ecc.size;
4231 	int eccbytes = chip->ecc.bytes;
4232 	int eccsteps = chip->ecc.steps;
4233 	const uint8_t *p = buf;
4234 	uint8_t *oob = chip->oob_poi;
4235 	int ret;
4236 
4237 	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
4238 	if (ret)
4239 		return ret;
4240 
4241 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
4242 		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
4243 
4244 		ret = nand_write_data_op(chip, p, eccsize, false);
4245 		if (ret)
4246 			return ret;
4247 
4248 		if (chip->ecc.prepad) {
4249 			ret = nand_write_data_op(chip, oob, chip->ecc.prepad,
4250 						 false);
4251 			if (ret)
4252 				return ret;
4253 
4254 			oob += chip->ecc.prepad;
4255 		}
4256 
4257 		chip->ecc.calculate(mtd, p, oob);
4258 
4259 		ret = nand_write_data_op(chip, oob, eccbytes, false);
4260 		if (ret)
4261 			return ret;
4262 
4263 		oob += eccbytes;
4264 
4265 		if (chip->ecc.postpad) {
4266 			ret = nand_write_data_op(chip, oob, chip->ecc.postpad,
4267 						 false);
4268 			if (ret)
4269 				return ret;
4270 
4271 			oob += chip->ecc.postpad;
4272 		}
4273 	}
4274 
4275 	/* Calculate remaining oob bytes */
4276 	i = mtd->oobsize - (oob - chip->oob_poi);
4277 	if (i) {
4278 		ret = nand_write_data_op(chip, oob, i, false);
4279 		if (ret)
4280 			return ret;
4281 	}
4282 
4283 	return nand_prog_page_end_op(chip);
4284 }
4285 
4286 /**
4287  * nand_write_page - write one page
4288  * @mtd: MTD device structure
4289  * @chip: NAND chip descriptor
4290  * @offset: address offset within the page
4291  * @data_len: length of actual data to be written
4292  * @buf: the data to write
4293  * @oob_required: must write chip->oob_poi to OOB
4294  * @page: page number to write
4295  * @raw: use _raw version of write_page
4296  */
4297 static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
4298 		uint32_t offset, int data_len, const uint8_t *buf,
4299 		int oob_required, int page, int raw)
4300 {
4301 	int status, subpage;
4302 
4303 	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) &&
4304 		chip->ecc.write_subpage)
4305 		subpage = offset || (data_len < mtd->writesize);
4306 	else
4307 		subpage = 0;
4308 
4309 	if (unlikely(raw))
4310 		status = chip->ecc.write_page_raw(mtd, chip, buf,
4311 						  oob_required, page);
4312 	else if (subpage)
4313 		status = chip->ecc.write_subpage(mtd, chip, offset, data_len,
4314 						 buf, oob_required, page);
4315 	else
4316 		status = chip->ecc.write_page(mtd, chip, buf, oob_required,
4317 					      page);
4318 
4319 	if (status < 0)
4320 		return status;
4321 
4322 	return 0;
4323 }
4324 
4325 /**
4326  * nand_fill_oob - [INTERN] Transfer client buffer to oob
4327  * @mtd: MTD device structure
4328  * @oob: oob data buffer
4329  * @len: oob data write length
4330  * @ops: oob ops structure
4331  */
4332 static uint8_t *nand_fill_oob(struct mtd_info *mtd, uint8_t *oob, size_t len,
4333 			      struct mtd_oob_ops *ops)
4334 {
4335 	struct nand_chip *chip = mtd_to_nand(mtd);
4336 	int ret;
4337 
4338 	/*
4339 	 * Initialise to all 0xFF, to avoid the possibility of left over OOB
4340 	 * data from a previous OOB read.
4341 	 */
4342 	memset(chip->oob_poi, 0xff, mtd->oobsize);
4343 
4344 	switch (ops->mode) {
4345 
4346 	case MTD_OPS_PLACE_OOB:
4347 	case MTD_OPS_RAW:
4348 		memcpy(chip->oob_poi + ops->ooboffs, oob, len);
4349 		return oob + len;
4350 
4351 	case MTD_OPS_AUTO_OOB:
4352 		ret = mtd_ooblayout_set_databytes(mtd, oob, chip->oob_poi,
4353 						  ops->ooboffs, len);
4354 		BUG_ON(ret);
4355 		return oob + len;
4356 
4357 	default:
4358 		BUG();
4359 	}
4360 	return NULL;
4361 }
4362 
4363 #define NOTALIGNED(x)	((x & (chip->subpagesize - 1)) != 0)
4364 
4365 /**
4366  * nand_do_write_ops - [INTERN] NAND write with ECC
4367  * @mtd: MTD device structure
4368  * @to: offset to write to
4369  * @ops: oob operations description structure
4370  *
4371  * NAND write with ECC.
4372  */
4373 static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
4374 			     struct mtd_oob_ops *ops)
4375 {
4376 	int chipnr, realpage, page, column;
4377 	struct nand_chip *chip = mtd_to_nand(mtd);
4378 	uint32_t writelen = ops->len;
4379 
4380 	uint32_t oobwritelen = ops->ooblen;
4381 	uint32_t oobmaxlen = mtd_oobavail(mtd, ops);
4382 
4383 	uint8_t *oob = ops->oobbuf;
4384 	uint8_t *buf = ops->datbuf;
4385 	int ret;
4386 	int oob_required = oob ? 1 : 0;
4387 
4388 	ops->retlen = 0;
4389 	if (!writelen)
4390 		return 0;
4391 
4392 	/* Reject writes, which are not page aligned */
4393 	if (NOTALIGNED(to) || NOTALIGNED(ops->len)) {
4394 		pr_notice("%s: attempt to write non page aligned data\n",
4395 			   __func__);
4396 		return -EINVAL;
4397 	}
4398 
4399 	column = to & (mtd->writesize - 1);
4400 
4401 	chipnr = (int)(to >> chip->chip_shift);
4402 	chip->select_chip(mtd, chipnr);
4403 
4404 	/* Check, if it is write protected */
4405 	if (nand_check_wp(mtd)) {
4406 		ret = -EIO;
4407 		goto err_out;
4408 	}
4409 
4410 	realpage = (int)(to >> chip->page_shift);
4411 	page = realpage & chip->pagemask;
4412 
4413 	/* Invalidate the page cache, when we write to the cached page */
4414 	if (to <= ((loff_t)chip->pagebuf << chip->page_shift) &&
4415 	    ((loff_t)chip->pagebuf << chip->page_shift) < (to + ops->len))
4416 		chip->pagebuf = -1;
4417 
4418 	/* Don't allow multipage oob writes with offset */
4419 	if (oob && ops->ooboffs && (ops->ooboffs + ops->ooblen > oobmaxlen)) {
4420 		ret = -EINVAL;
4421 		goto err_out;
4422 	}
4423 
4424 	while (1) {
4425 		int bytes = mtd->writesize;
4426 		uint8_t *wbuf = buf;
4427 		int use_bufpoi;
4428 		int part_pagewr = (column || writelen < mtd->writesize);
4429 
4430 		if (part_pagewr)
4431 			use_bufpoi = 1;
4432 		else if (chip->options & NAND_USE_BOUNCE_BUFFER)
4433 			use_bufpoi = !virt_addr_valid(buf) ||
4434 				     !IS_ALIGNED((unsigned long)buf,
4435 						 chip->buf_align);
4436 		else
4437 			use_bufpoi = 0;
4438 
4439 		/* Partial page write?, or need to use bounce buffer */
4440 		if (use_bufpoi) {
4441 			pr_debug("%s: using write bounce buffer for buf@%p\n",
4442 					 __func__, buf);
4443 			if (part_pagewr)
4444 				bytes = min_t(int, bytes - column, writelen);
4445 			chip->pagebuf = -1;
4446 			memset(chip->data_buf, 0xff, mtd->writesize);
4447 			memcpy(&chip->data_buf[column], buf, bytes);
4448 			wbuf = chip->data_buf;
4449 		}
4450 
4451 		if (unlikely(oob)) {
4452 			size_t len = min(oobwritelen, oobmaxlen);
4453 			oob = nand_fill_oob(mtd, oob, len, ops);
4454 			oobwritelen -= len;
4455 		} else {
4456 			/* We still need to erase leftover OOB data */
4457 			memset(chip->oob_poi, 0xff, mtd->oobsize);
4458 		}
4459 
4460 		ret = nand_write_page(mtd, chip, column, bytes, wbuf,
4461 				      oob_required, page,
4462 				      (ops->mode == MTD_OPS_RAW));
4463 		if (ret)
4464 			break;
4465 
4466 		writelen -= bytes;
4467 		if (!writelen)
4468 			break;
4469 
4470 		column = 0;
4471 		buf += bytes;
4472 		realpage++;
4473 
4474 		page = realpage & chip->pagemask;
4475 		/* Check, if we cross a chip boundary */
4476 		if (!page) {
4477 			chipnr++;
4478 			chip->select_chip(mtd, -1);
4479 			chip->select_chip(mtd, chipnr);
4480 		}
4481 	}
4482 
4483 	ops->retlen = ops->len - writelen;
4484 	if (unlikely(oob))
4485 		ops->oobretlen = ops->ooblen;
4486 
4487 err_out:
4488 	chip->select_chip(mtd, -1);
4489 	return ret;
4490 }
4491 
4492 /**
4493  * panic_nand_write - [MTD Interface] NAND write with ECC
4494  * @mtd: MTD device structure
4495  * @to: offset to write to
4496  * @len: number of bytes to write
4497  * @retlen: pointer to variable to store the number of written bytes
4498  * @buf: the data to write
4499  *
4500  * NAND write with ECC. Used when performing writes in interrupt context, this
4501  * may for example be called by mtdoops when writing an oops while in panic.
4502  */
4503 static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
4504 			    size_t *retlen, const uint8_t *buf)
4505 {
4506 	struct nand_chip *chip = mtd_to_nand(mtd);
4507 	int chipnr = (int)(to >> chip->chip_shift);
4508 	struct mtd_oob_ops ops;
4509 	int ret;
4510 
4511 	/* Grab the device */
4512 	panic_nand_get_device(chip, mtd, FL_WRITING);
4513 
4514 	chip->select_chip(mtd, chipnr);
4515 
4516 	/* Wait for the device to get ready */
4517 	panic_nand_wait(mtd, chip, 400);
4518 
4519 	memset(&ops, 0, sizeof(ops));
4520 	ops.len = len;
4521 	ops.datbuf = (uint8_t *)buf;
4522 	ops.mode = MTD_OPS_PLACE_OOB;
4523 
4524 	ret = nand_do_write_ops(mtd, to, &ops);
4525 
4526 	*retlen = ops.retlen;
4527 	return ret;
4528 }
4529 
4530 /**
4531  * nand_do_write_oob - [MTD Interface] NAND write out-of-band
4532  * @mtd: MTD device structure
4533  * @to: offset to write to
4534  * @ops: oob operation description structure
4535  *
4536  * NAND write out-of-band.
4537  */
4538 static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
4539 			     struct mtd_oob_ops *ops)
4540 {
4541 	int chipnr, page, status, len;
4542 	struct nand_chip *chip = mtd_to_nand(mtd);
4543 
4544 	pr_debug("%s: to = 0x%08x, len = %i\n",
4545 			 __func__, (unsigned int)to, (int)ops->ooblen);
4546 
4547 	len = mtd_oobavail(mtd, ops);
4548 
4549 	/* Do not allow write past end of page */
4550 	if ((ops->ooboffs + ops->ooblen) > len) {
4551 		pr_debug("%s: attempt to write past end of page\n",
4552 				__func__);
4553 		return -EINVAL;
4554 	}
4555 
4556 	chipnr = (int)(to >> chip->chip_shift);
4557 
4558 	/*
4559 	 * Reset the chip. Some chips (like the Toshiba TC5832DC found in one
4560 	 * of my DiskOnChip 2000 test units) will clear the whole data page too
4561 	 * if we don't do this. I have no clue why, but I seem to have 'fixed'
4562 	 * it in the doc2000 driver in August 1999.  dwmw2.
4563 	 */
4564 	nand_reset(chip, chipnr);
4565 
4566 	chip->select_chip(mtd, chipnr);
4567 
4568 	/* Shift to get page */
4569 	page = (int)(to >> chip->page_shift);
4570 
4571 	/* Check, if it is write protected */
4572 	if (nand_check_wp(mtd)) {
4573 		chip->select_chip(mtd, -1);
4574 		return -EROFS;
4575 	}
4576 
4577 	/* Invalidate the page cache, if we write to the cached page */
4578 	if (page == chip->pagebuf)
4579 		chip->pagebuf = -1;
4580 
4581 	nand_fill_oob(mtd, ops->oobbuf, ops->ooblen, ops);
4582 
4583 	if (ops->mode == MTD_OPS_RAW)
4584 		status = chip->ecc.write_oob_raw(mtd, chip, page & chip->pagemask);
4585 	else
4586 		status = chip->ecc.write_oob(mtd, chip, page & chip->pagemask);
4587 
4588 	chip->select_chip(mtd, -1);
4589 
4590 	if (status)
4591 		return status;
4592 
4593 	ops->oobretlen = ops->ooblen;
4594 
4595 	return 0;
4596 }
4597 
4598 /**
4599  * nand_write_oob - [MTD Interface] NAND write data and/or out-of-band
4600  * @mtd: MTD device structure
4601  * @to: offset to write to
4602  * @ops: oob operation description structure
4603  */
4604 static int nand_write_oob(struct mtd_info *mtd, loff_t to,
4605 			  struct mtd_oob_ops *ops)
4606 {
4607 	int ret = -ENOTSUPP;
4608 
4609 	ops->retlen = 0;
4610 
4611 	nand_get_device(mtd, FL_WRITING);
4612 
4613 	switch (ops->mode) {
4614 	case MTD_OPS_PLACE_OOB:
4615 	case MTD_OPS_AUTO_OOB:
4616 	case MTD_OPS_RAW:
4617 		break;
4618 
4619 	default:
4620 		goto out;
4621 	}
4622 
4623 	if (!ops->datbuf)
4624 		ret = nand_do_write_oob(mtd, to, ops);
4625 	else
4626 		ret = nand_do_write_ops(mtd, to, ops);
4627 
4628 out:
4629 	nand_release_device(mtd);
4630 	return ret;
4631 }
4632 
4633 /**
4634  * single_erase - [GENERIC] NAND standard block erase command function
4635  * @mtd: MTD device structure
4636  * @page: the page address of the block which will be erased
4637  *
4638  * Standard erase command for NAND chips. Returns NAND status.
4639  */
4640 static int single_erase(struct mtd_info *mtd, int page)
4641 {
4642 	struct nand_chip *chip = mtd_to_nand(mtd);
4643 	unsigned int eraseblock;
4644 
4645 	/* Send commands to erase a block */
4646 	eraseblock = page >> (chip->phys_erase_shift - chip->page_shift);
4647 
4648 	return nand_erase_op(chip, eraseblock);
4649 }
4650 
4651 /**
4652  * nand_erase - [MTD Interface] erase block(s)
4653  * @mtd: MTD device structure
4654  * @instr: erase instruction
4655  *
4656  * Erase one ore more blocks.
4657  */
4658 static int nand_erase(struct mtd_info *mtd, struct erase_info *instr)
4659 {
4660 	return nand_erase_nand(mtd, instr, 0);
4661 }
4662 
4663 /**
4664  * nand_erase_nand - [INTERN] erase block(s)
4665  * @mtd: MTD device structure
4666  * @instr: erase instruction
4667  * @allowbbt: allow erasing the bbt area
4668  *
4669  * Erase one ore more blocks.
4670  */
4671 int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
4672 		    int allowbbt)
4673 {
4674 	int page, status, pages_per_block, ret, chipnr;
4675 	struct nand_chip *chip = mtd_to_nand(mtd);
4676 	loff_t len;
4677 
4678 	pr_debug("%s: start = 0x%012llx, len = %llu\n",
4679 			__func__, (unsigned long long)instr->addr,
4680 			(unsigned long long)instr->len);
4681 
4682 	if (check_offs_len(mtd, instr->addr, instr->len))
4683 		return -EINVAL;
4684 
4685 	/* Grab the lock and see if the device is available */
4686 	nand_get_device(mtd, FL_ERASING);
4687 
4688 	/* Shift to get first page */
4689 	page = (int)(instr->addr >> chip->page_shift);
4690 	chipnr = (int)(instr->addr >> chip->chip_shift);
4691 
4692 	/* Calculate pages in each block */
4693 	pages_per_block = 1 << (chip->phys_erase_shift - chip->page_shift);
4694 
4695 	/* Select the NAND device */
4696 	chip->select_chip(mtd, chipnr);
4697 
4698 	/* Check, if it is write protected */
4699 	if (nand_check_wp(mtd)) {
4700 		pr_debug("%s: device is write protected!\n",
4701 				__func__);
4702 		ret = -EIO;
4703 		goto erase_exit;
4704 	}
4705 
4706 	/* Loop through the pages */
4707 	len = instr->len;
4708 
4709 	while (len) {
4710 		/* Check if we have a bad block, we do not erase bad blocks! */
4711 		if (nand_block_checkbad(mtd, ((loff_t) page) <<
4712 					chip->page_shift, allowbbt)) {
4713 			pr_warn("%s: attempt to erase a bad block at page 0x%08x\n",
4714 				    __func__, page);
4715 			ret = -EIO;
4716 			goto erase_exit;
4717 		}
4718 
4719 		/*
4720 		 * Invalidate the page cache, if we erase the block which
4721 		 * contains the current cached page.
4722 		 */
4723 		if (page <= chip->pagebuf && chip->pagebuf <
4724 		    (page + pages_per_block))
4725 			chip->pagebuf = -1;
4726 
4727 		status = chip->erase(mtd, page & chip->pagemask);
4728 
4729 		/* See if block erase succeeded */
4730 		if (status) {
4731 			pr_debug("%s: failed erase, page 0x%08x\n",
4732 					__func__, page);
4733 			ret = -EIO;
4734 			instr->fail_addr =
4735 				((loff_t)page << chip->page_shift);
4736 			goto erase_exit;
4737 		}
4738 
4739 		/* Increment page address and decrement length */
4740 		len -= (1ULL << chip->phys_erase_shift);
4741 		page += pages_per_block;
4742 
4743 		/* Check, if we cross a chip boundary */
4744 		if (len && !(page & chip->pagemask)) {
4745 			chipnr++;
4746 			chip->select_chip(mtd, -1);
4747 			chip->select_chip(mtd, chipnr);
4748 		}
4749 	}
4750 
4751 	ret = 0;
4752 erase_exit:
4753 
4754 	/* Deselect and wake up anyone waiting on the device */
4755 	chip->select_chip(mtd, -1);
4756 	nand_release_device(mtd);
4757 
4758 	/* Return more or less happy */
4759 	return ret;
4760 }
4761 
4762 /**
4763  * nand_sync - [MTD Interface] sync
4764  * @mtd: MTD device structure
4765  *
4766  * Sync is actually a wait for chip ready function.
4767  */
4768 static void nand_sync(struct mtd_info *mtd)
4769 {
4770 	pr_debug("%s: called\n", __func__);
4771 
4772 	/* Grab the lock and see if the device is available */
4773 	nand_get_device(mtd, FL_SYNCING);
4774 	/* Release it and go back */
4775 	nand_release_device(mtd);
4776 }
4777 
4778 /**
4779  * nand_block_isbad - [MTD Interface] Check if block at offset is bad
4780  * @mtd: MTD device structure
4781  * @offs: offset relative to mtd start
4782  */
4783 static int nand_block_isbad(struct mtd_info *mtd, loff_t offs)
4784 {
4785 	struct nand_chip *chip = mtd_to_nand(mtd);
4786 	int chipnr = (int)(offs >> chip->chip_shift);
4787 	int ret;
4788 
4789 	/* Select the NAND device */
4790 	nand_get_device(mtd, FL_READING);
4791 	chip->select_chip(mtd, chipnr);
4792 
4793 	ret = nand_block_checkbad(mtd, offs, 0);
4794 
4795 	chip->select_chip(mtd, -1);
4796 	nand_release_device(mtd);
4797 
4798 	return ret;
4799 }
4800 
4801 /**
4802  * nand_block_markbad - [MTD Interface] Mark block at the given offset as bad
4803  * @mtd: MTD device structure
4804  * @ofs: offset relative to mtd start
4805  */
4806 static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
4807 {
4808 	int ret;
4809 
4810 	ret = nand_block_isbad(mtd, ofs);
4811 	if (ret) {
4812 		/* If it was bad already, return success and do nothing */
4813 		if (ret > 0)
4814 			return 0;
4815 		return ret;
4816 	}
4817 
4818 	return nand_block_markbad_lowlevel(mtd, ofs);
4819 }
4820 
4821 /**
4822  * nand_max_bad_blocks - [MTD Interface] Max number of bad blocks for an mtd
4823  * @mtd: MTD device structure
4824  * @ofs: offset relative to mtd start
4825  * @len: length of mtd
4826  */
4827 static int nand_max_bad_blocks(struct mtd_info *mtd, loff_t ofs, size_t len)
4828 {
4829 	struct nand_chip *chip = mtd_to_nand(mtd);
4830 	u32 part_start_block;
4831 	u32 part_end_block;
4832 	u32 part_start_die;
4833 	u32 part_end_die;
4834 
4835 	/*
4836 	 * max_bb_per_die and blocks_per_die used to determine
4837 	 * the maximum bad block count.
4838 	 */
4839 	if (!chip->max_bb_per_die || !chip->blocks_per_die)
4840 		return -ENOTSUPP;
4841 
4842 	/* Get the start and end of the partition in erase blocks. */
4843 	part_start_block = mtd_div_by_eb(ofs, mtd);
4844 	part_end_block = mtd_div_by_eb(len, mtd) + part_start_block - 1;
4845 
4846 	/* Get the start and end LUNs of the partition. */
4847 	part_start_die = part_start_block / chip->blocks_per_die;
4848 	part_end_die = part_end_block / chip->blocks_per_die;
4849 
4850 	/*
4851 	 * Look up the bad blocks per unit and multiply by the number of units
4852 	 * that the partition spans.
4853 	 */
4854 	return chip->max_bb_per_die * (part_end_die - part_start_die + 1);
4855 }
4856 
4857 /**
4858  * nand_default_set_features- [REPLACEABLE] set NAND chip features
4859  * @mtd: MTD device structure
4860  * @chip: nand chip info structure
4861  * @addr: feature address.
4862  * @subfeature_param: the subfeature parameters, a four bytes array.
4863  */
4864 static int nand_default_set_features(struct mtd_info *mtd,
4865 				     struct nand_chip *chip, int addr,
4866 				     uint8_t *subfeature_param)
4867 {
4868 	return nand_set_features_op(chip, addr, subfeature_param);
4869 }
4870 
4871 /**
4872  * nand_default_get_features- [REPLACEABLE] get NAND chip features
4873  * @mtd: MTD device structure
4874  * @chip: nand chip info structure
4875  * @addr: feature address.
4876  * @subfeature_param: the subfeature parameters, a four bytes array.
4877  */
4878 static int nand_default_get_features(struct mtd_info *mtd,
4879 				     struct nand_chip *chip, int addr,
4880 				     uint8_t *subfeature_param)
4881 {
4882 	return nand_get_features_op(chip, addr, subfeature_param);
4883 }
4884 
4885 /**
4886  * nand_get_set_features_notsupp - set/get features stub returning -ENOTSUPP
4887  * @mtd: MTD device structure
4888  * @chip: nand chip info structure
4889  * @addr: feature address.
4890  * @subfeature_param: the subfeature parameters, a four bytes array.
4891  *
4892  * Should be used by NAND controller drivers that do not support the SET/GET
4893  * FEATURES operations.
4894  */
4895 int nand_get_set_features_notsupp(struct mtd_info *mtd, struct nand_chip *chip,
4896 				  int addr, u8 *subfeature_param)
4897 {
4898 	return -ENOTSUPP;
4899 }
4900 EXPORT_SYMBOL(nand_get_set_features_notsupp);
4901 
4902 /**
4903  * nand_suspend - [MTD Interface] Suspend the NAND flash
4904  * @mtd: MTD device structure
4905  */
4906 static int nand_suspend(struct mtd_info *mtd)
4907 {
4908 	return nand_get_device(mtd, FL_PM_SUSPENDED);
4909 }
4910 
4911 /**
4912  * nand_resume - [MTD Interface] Resume the NAND flash
4913  * @mtd: MTD device structure
4914  */
4915 static void nand_resume(struct mtd_info *mtd)
4916 {
4917 	struct nand_chip *chip = mtd_to_nand(mtd);
4918 
4919 	if (chip->state == FL_PM_SUSPENDED)
4920 		nand_release_device(mtd);
4921 	else
4922 		pr_err("%s called for a chip which is not in suspended state\n",
4923 			__func__);
4924 }
4925 
4926 /**
4927  * nand_shutdown - [MTD Interface] Finish the current NAND operation and
4928  *                 prevent further operations
4929  * @mtd: MTD device structure
4930  */
4931 static void nand_shutdown(struct mtd_info *mtd)
4932 {
4933 	nand_get_device(mtd, FL_PM_SUSPENDED);
4934 }
4935 
4936 /* Set default functions */
4937 static void nand_set_defaults(struct nand_chip *chip)
4938 {
4939 	unsigned int busw = chip->options & NAND_BUSWIDTH_16;
4940 
4941 	/* check for proper chip_delay setup, set 20us if not */
4942 	if (!chip->chip_delay)
4943 		chip->chip_delay = 20;
4944 
4945 	/* check, if a user supplied command function given */
4946 	if (!chip->cmdfunc && !chip->exec_op)
4947 		chip->cmdfunc = nand_command;
4948 
4949 	/* check, if a user supplied wait function given */
4950 	if (chip->waitfunc == NULL)
4951 		chip->waitfunc = nand_wait;
4952 
4953 	if (!chip->select_chip)
4954 		chip->select_chip = nand_select_chip;
4955 
4956 	/* set for ONFI nand */
4957 	if (!chip->set_features)
4958 		chip->set_features = nand_default_set_features;
4959 	if (!chip->get_features)
4960 		chip->get_features = nand_default_get_features;
4961 
4962 	/* If called twice, pointers that depend on busw may need to be reset */
4963 	if (!chip->read_byte || chip->read_byte == nand_read_byte)
4964 		chip->read_byte = busw ? nand_read_byte16 : nand_read_byte;
4965 	if (!chip->read_word)
4966 		chip->read_word = nand_read_word;
4967 	if (!chip->block_bad)
4968 		chip->block_bad = nand_block_bad;
4969 	if (!chip->block_markbad)
4970 		chip->block_markbad = nand_default_block_markbad;
4971 	if (!chip->write_buf || chip->write_buf == nand_write_buf)
4972 		chip->write_buf = busw ? nand_write_buf16 : nand_write_buf;
4973 	if (!chip->write_byte || chip->write_byte == nand_write_byte)
4974 		chip->write_byte = busw ? nand_write_byte16 : nand_write_byte;
4975 	if (!chip->read_buf || chip->read_buf == nand_read_buf)
4976 		chip->read_buf = busw ? nand_read_buf16 : nand_read_buf;
4977 	if (!chip->scan_bbt)
4978 		chip->scan_bbt = nand_default_bbt;
4979 
4980 	if (!chip->controller) {
4981 		chip->controller = &chip->hwcontrol;
4982 		nand_hw_control_init(chip->controller);
4983 	}
4984 
4985 	if (!chip->buf_align)
4986 		chip->buf_align = 1;
4987 }
4988 
4989 /* Sanitize ONFI strings so we can safely print them */
4990 static void sanitize_string(uint8_t *s, size_t len)
4991 {
4992 	ssize_t i;
4993 
4994 	/* Null terminate */
4995 	s[len - 1] = 0;
4996 
4997 	/* Remove non printable chars */
4998 	for (i = 0; i < len - 1; i++) {
4999 		if (s[i] < ' ' || s[i] > 127)
5000 			s[i] = '?';
5001 	}
5002 
5003 	/* Remove trailing spaces */
5004 	strim(s);
5005 }
5006 
5007 static u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
5008 {
5009 	int i;
5010 	while (len--) {
5011 		crc ^= *p++ << 8;
5012 		for (i = 0; i < 8; i++)
5013 			crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
5014 	}
5015 
5016 	return crc;
5017 }
5018 
5019 /* Parse the Extended Parameter Page. */
5020 static int nand_flash_detect_ext_param_page(struct nand_chip *chip,
5021 					    struct nand_onfi_params *p)
5022 {
5023 	struct onfi_ext_param_page *ep;
5024 	struct onfi_ext_section *s;
5025 	struct onfi_ext_ecc_info *ecc;
5026 	uint8_t *cursor;
5027 	int ret;
5028 	int len;
5029 	int i;
5030 
5031 	len = le16_to_cpu(p->ext_param_page_length) * 16;
5032 	ep = kmalloc(len, GFP_KERNEL);
5033 	if (!ep)
5034 		return -ENOMEM;
5035 
5036 	/* Send our own NAND_CMD_PARAM. */
5037 	ret = nand_read_param_page_op(chip, 0, NULL, 0);
5038 	if (ret)
5039 		goto ext_out;
5040 
5041 	/* Use the Change Read Column command to skip the ONFI param pages. */
5042 	ret = nand_change_read_column_op(chip,
5043 					 sizeof(*p) * p->num_of_param_pages,
5044 					 ep, len, true);
5045 	if (ret)
5046 		goto ext_out;
5047 
5048 	ret = -EINVAL;
5049 	if ((onfi_crc16(ONFI_CRC_BASE, ((uint8_t *)ep) + 2, len - 2)
5050 		!= le16_to_cpu(ep->crc))) {
5051 		pr_debug("fail in the CRC.\n");
5052 		goto ext_out;
5053 	}
5054 
5055 	/*
5056 	 * Check the signature.
5057 	 * Do not strictly follow the ONFI spec, maybe changed in future.
5058 	 */
5059 	if (strncmp(ep->sig, "EPPS", 4)) {
5060 		pr_debug("The signature is invalid.\n");
5061 		goto ext_out;
5062 	}
5063 
5064 	/* find the ECC section. */
5065 	cursor = (uint8_t *)(ep + 1);
5066 	for (i = 0; i < ONFI_EXT_SECTION_MAX; i++) {
5067 		s = ep->sections + i;
5068 		if (s->type == ONFI_SECTION_TYPE_2)
5069 			break;
5070 		cursor += s->length * 16;
5071 	}
5072 	if (i == ONFI_EXT_SECTION_MAX) {
5073 		pr_debug("We can not find the ECC section.\n");
5074 		goto ext_out;
5075 	}
5076 
5077 	/* get the info we want. */
5078 	ecc = (struct onfi_ext_ecc_info *)cursor;
5079 
5080 	if (!ecc->codeword_size) {
5081 		pr_debug("Invalid codeword size\n");
5082 		goto ext_out;
5083 	}
5084 
5085 	chip->ecc_strength_ds = ecc->ecc_bits;
5086 	chip->ecc_step_ds = 1 << ecc->codeword_size;
5087 	ret = 0;
5088 
5089 ext_out:
5090 	kfree(ep);
5091 	return ret;
5092 }
5093 
5094 /*
5095  * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
5096  */
5097 static int nand_flash_detect_onfi(struct nand_chip *chip)
5098 {
5099 	struct mtd_info *mtd = nand_to_mtd(chip);
5100 	struct nand_onfi_params *p;
5101 	char id[4];
5102 	int i, ret, val;
5103 
5104 	/* Try ONFI for unknown chip or LP */
5105 	ret = nand_readid_op(chip, 0x20, id, sizeof(id));
5106 	if (ret || strncmp(id, "ONFI", 4))
5107 		return 0;
5108 
5109 	/* ONFI chip: allocate a buffer to hold its parameter page */
5110 	p = kzalloc(sizeof(*p), GFP_KERNEL);
5111 	if (!p)
5112 		return -ENOMEM;
5113 
5114 	ret = nand_read_param_page_op(chip, 0, NULL, 0);
5115 	if (ret) {
5116 		ret = 0;
5117 		goto free_onfi_param_page;
5118 	}
5119 
5120 	for (i = 0; i < 3; i++) {
5121 		ret = nand_read_data_op(chip, p, sizeof(*p), true);
5122 		if (ret) {
5123 			ret = 0;
5124 			goto free_onfi_param_page;
5125 		}
5126 
5127 		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
5128 				le16_to_cpu(p->crc)) {
5129 			break;
5130 		}
5131 	}
5132 
5133 	if (i == 3) {
5134 		pr_err("Could not find valid ONFI parameter page; aborting\n");
5135 		goto free_onfi_param_page;
5136 	}
5137 
5138 	/* Check version */
5139 	val = le16_to_cpu(p->revision);
5140 	if (val & (1 << 5))
5141 		chip->parameters.onfi.version = 23;
5142 	else if (val & (1 << 4))
5143 		chip->parameters.onfi.version = 22;
5144 	else if (val & (1 << 3))
5145 		chip->parameters.onfi.version = 21;
5146 	else if (val & (1 << 2))
5147 		chip->parameters.onfi.version = 20;
5148 	else if (val & (1 << 1))
5149 		chip->parameters.onfi.version = 10;
5150 
5151 	if (!chip->parameters.onfi.version) {
5152 		pr_info("unsupported ONFI version: %d\n", val);
5153 		goto free_onfi_param_page;
5154 	} else {
5155 		ret = 1;
5156 	}
5157 
5158 	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
5159 	sanitize_string(p->model, sizeof(p->model));
5160 	strncpy(chip->parameters.model, p->model,
5161 		sizeof(chip->parameters.model) - 1);
5162 
5163 	mtd->writesize = le32_to_cpu(p->byte_per_page);
5164 
5165 	/*
5166 	 * pages_per_block and blocks_per_lun may not be a power-of-2 size
5167 	 * (don't ask me who thought of this...). MTD assumes that these
5168 	 * dimensions will be power-of-2, so just truncate the remaining area.
5169 	 */
5170 	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
5171 	mtd->erasesize *= mtd->writesize;
5172 
5173 	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
5174 
5175 	/* See erasesize comment */
5176 	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
5177 	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
5178 	chip->bits_per_cell = p->bits_per_cell;
5179 
5180 	chip->max_bb_per_die = le16_to_cpu(p->bb_per_lun);
5181 	chip->blocks_per_die = le32_to_cpu(p->blocks_per_lun);
5182 
5183 	if (le16_to_cpu(p->features) & ONFI_FEATURE_16_BIT_BUS)
5184 		chip->options |= NAND_BUSWIDTH_16;
5185 
5186 	if (p->ecc_bits != 0xff) {
5187 		chip->ecc_strength_ds = p->ecc_bits;
5188 		chip->ecc_step_ds = 512;
5189 	} else if (chip->parameters.onfi.version >= 21 &&
5190 		(le16_to_cpu(p->features) & ONFI_FEATURE_EXT_PARAM_PAGE)) {
5191 
5192 		/*
5193 		 * The nand_flash_detect_ext_param_page() uses the
5194 		 * Change Read Column command which maybe not supported
5195 		 * by the chip->cmdfunc. So try to update the chip->cmdfunc
5196 		 * now. We do not replace user supplied command function.
5197 		 */
5198 		if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
5199 			chip->cmdfunc = nand_command_lp;
5200 
5201 		/* The Extended Parameter Page is supported since ONFI 2.1. */
5202 		if (nand_flash_detect_ext_param_page(chip, p))
5203 			pr_warn("Failed to detect ONFI extended param page\n");
5204 	} else {
5205 		pr_warn("Could not retrieve ONFI ECC requirements\n");
5206 	}
5207 
5208 	/* Save some parameters from the parameter page for future use */
5209 	if (le16_to_cpu(p->opt_cmd) & ONFI_OPT_CMD_SET_GET_FEATURES) {
5210 		chip->parameters.supports_set_get_features = true;
5211 		bitmap_set(chip->parameters.get_feature_list,
5212 			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
5213 		bitmap_set(chip->parameters.set_feature_list,
5214 			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
5215 	}
5216 	chip->parameters.onfi.tPROG = le16_to_cpu(p->t_prog);
5217 	chip->parameters.onfi.tBERS = le16_to_cpu(p->t_bers);
5218 	chip->parameters.onfi.tR = le16_to_cpu(p->t_r);
5219 	chip->parameters.onfi.tCCS = le16_to_cpu(p->t_ccs);
5220 	chip->parameters.onfi.async_timing_mode =
5221 		le16_to_cpu(p->async_timing_mode);
5222 	chip->parameters.onfi.vendor_revision =
5223 		le16_to_cpu(p->vendor_revision);
5224 	memcpy(chip->parameters.onfi.vendor, p->vendor,
5225 	       sizeof(p->vendor));
5226 
5227 free_onfi_param_page:
5228 	kfree(p);
5229 	return ret;
5230 }
5231 
5232 /*
5233  * Check if the NAND chip is JEDEC compliant, returns 1 if it is, 0 otherwise.
5234  */
5235 static int nand_flash_detect_jedec(struct nand_chip *chip)
5236 {
5237 	struct mtd_info *mtd = nand_to_mtd(chip);
5238 	struct nand_jedec_params *p;
5239 	struct jedec_ecc_info *ecc;
5240 	int jedec_version = 0;
5241 	char id[5];
5242 	int i, val, ret;
5243 
5244 	/* Try JEDEC for unknown chip or LP */
5245 	ret = nand_readid_op(chip, 0x40, id, sizeof(id));
5246 	if (ret || strncmp(id, "JEDEC", sizeof(id)))
5247 		return 0;
5248 
5249 	/* JEDEC chip: allocate a buffer to hold its parameter page */
5250 	p = kzalloc(sizeof(*p), GFP_KERNEL);
5251 	if (!p)
5252 		return -ENOMEM;
5253 
5254 	ret = nand_read_param_page_op(chip, 0x40, NULL, 0);
5255 	if (ret) {
5256 		ret = 0;
5257 		goto free_jedec_param_page;
5258 	}
5259 
5260 	for (i = 0; i < 3; i++) {
5261 		ret = nand_read_data_op(chip, p, sizeof(*p), true);
5262 		if (ret) {
5263 			ret = 0;
5264 			goto free_jedec_param_page;
5265 		}
5266 
5267 		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 510) ==
5268 				le16_to_cpu(p->crc))
5269 			break;
5270 	}
5271 
5272 	if (i == 3) {
5273 		pr_err("Could not find valid JEDEC parameter page; aborting\n");
5274 		goto free_jedec_param_page;
5275 	}
5276 
5277 	/* Check version */
5278 	val = le16_to_cpu(p->revision);
5279 	if (val & (1 << 2))
5280 		jedec_version = 10;
5281 	else if (val & (1 << 1))
5282 		jedec_version = 1; /* vendor specific version */
5283 
5284 	if (!jedec_version) {
5285 		pr_info("unsupported JEDEC version: %d\n", val);
5286 		goto free_jedec_param_page;
5287 	}
5288 
5289 	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
5290 	sanitize_string(p->model, sizeof(p->model));
5291 	strncpy(chip->parameters.model, p->model,
5292 		sizeof(chip->parameters.model) - 1);
5293 
5294 	mtd->writesize = le32_to_cpu(p->byte_per_page);
5295 
5296 	/* Please reference to the comment for nand_flash_detect_onfi. */
5297 	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
5298 	mtd->erasesize *= mtd->writesize;
5299 
5300 	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
5301 
5302 	/* Please reference to the comment for nand_flash_detect_onfi. */
5303 	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
5304 	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
5305 	chip->bits_per_cell = p->bits_per_cell;
5306 
5307 	if (le16_to_cpu(p->features) & JEDEC_FEATURE_16_BIT_BUS)
5308 		chip->options |= NAND_BUSWIDTH_16;
5309 
5310 	/* ECC info */
5311 	ecc = &p->ecc_info[0];
5312 
5313 	if (ecc->codeword_size >= 9) {
5314 		chip->ecc_strength_ds = ecc->ecc_bits;
5315 		chip->ecc_step_ds = 1 << ecc->codeword_size;
5316 	} else {
5317 		pr_warn("Invalid codeword size\n");
5318 	}
5319 
5320 free_jedec_param_page:
5321 	kfree(p);
5322 	return ret;
5323 }
5324 
5325 /*
5326  * nand_id_has_period - Check if an ID string has a given wraparound period
5327  * @id_data: the ID string
5328  * @arrlen: the length of the @id_data array
5329  * @period: the period of repitition
5330  *
5331  * Check if an ID string is repeated within a given sequence of bytes at
5332  * specific repetition interval period (e.g., {0x20,0x01,0x7F,0x20} has a
5333  * period of 3). This is a helper function for nand_id_len(). Returns non-zero
5334  * if the repetition has a period of @period; otherwise, returns zero.
5335  */
5336 static int nand_id_has_period(u8 *id_data, int arrlen, int period)
5337 {
5338 	int i, j;
5339 	for (i = 0; i < period; i++)
5340 		for (j = i + period; j < arrlen; j += period)
5341 			if (id_data[i] != id_data[j])
5342 				return 0;
5343 	return 1;
5344 }
5345 
5346 /*
5347  * nand_id_len - Get the length of an ID string returned by CMD_READID
5348  * @id_data: the ID string
5349  * @arrlen: the length of the @id_data array
5350 
5351  * Returns the length of the ID string, according to known wraparound/trailing
5352  * zero patterns. If no pattern exists, returns the length of the array.
5353  */
5354 static int nand_id_len(u8 *id_data, int arrlen)
5355 {
5356 	int last_nonzero, period;
5357 
5358 	/* Find last non-zero byte */
5359 	for (last_nonzero = arrlen - 1; last_nonzero >= 0; last_nonzero--)
5360 		if (id_data[last_nonzero])
5361 			break;
5362 
5363 	/* All zeros */
5364 	if (last_nonzero < 0)
5365 		return 0;
5366 
5367 	/* Calculate wraparound period */
5368 	for (period = 1; period < arrlen; period++)
5369 		if (nand_id_has_period(id_data, arrlen, period))
5370 			break;
5371 
5372 	/* There's a repeated pattern */
5373 	if (period < arrlen)
5374 		return period;
5375 
5376 	/* There are trailing zeros */
5377 	if (last_nonzero < arrlen - 1)
5378 		return last_nonzero + 1;
5379 
5380 	/* No pattern detected */
5381 	return arrlen;
5382 }
5383 
5384 /* Extract the bits of per cell from the 3rd byte of the extended ID */
5385 static int nand_get_bits_per_cell(u8 cellinfo)
5386 {
5387 	int bits;
5388 
5389 	bits = cellinfo & NAND_CI_CELLTYPE_MSK;
5390 	bits >>= NAND_CI_CELLTYPE_SHIFT;
5391 	return bits + 1;
5392 }
5393 
5394 /*
5395  * Many new NAND share similar device ID codes, which represent the size of the
5396  * chip. The rest of the parameters must be decoded according to generic or
5397  * manufacturer-specific "extended ID" decoding patterns.
5398  */
5399 void nand_decode_ext_id(struct nand_chip *chip)
5400 {
5401 	struct mtd_info *mtd = nand_to_mtd(chip);
5402 	int extid;
5403 	u8 *id_data = chip->id.data;
5404 	/* The 3rd id byte holds MLC / multichip data */
5405 	chip->bits_per_cell = nand_get_bits_per_cell(id_data[2]);
5406 	/* The 4th id byte is the important one */
5407 	extid = id_data[3];
5408 
5409 	/* Calc pagesize */
5410 	mtd->writesize = 1024 << (extid & 0x03);
5411 	extid >>= 2;
5412 	/* Calc oobsize */
5413 	mtd->oobsize = (8 << (extid & 0x01)) * (mtd->writesize >> 9);
5414 	extid >>= 2;
5415 	/* Calc blocksize. Blocksize is multiples of 64KiB */
5416 	mtd->erasesize = (64 * 1024) << (extid & 0x03);
5417 	extid >>= 2;
5418 	/* Get buswidth information */
5419 	if (extid & 0x1)
5420 		chip->options |= NAND_BUSWIDTH_16;
5421 }
5422 EXPORT_SYMBOL_GPL(nand_decode_ext_id);
5423 
5424 /*
5425  * Old devices have chip data hardcoded in the device ID table. nand_decode_id
5426  * decodes a matching ID table entry and assigns the MTD size parameters for
5427  * the chip.
5428  */
5429 static void nand_decode_id(struct nand_chip *chip, struct nand_flash_dev *type)
5430 {
5431 	struct mtd_info *mtd = nand_to_mtd(chip);
5432 
5433 	mtd->erasesize = type->erasesize;
5434 	mtd->writesize = type->pagesize;
5435 	mtd->oobsize = mtd->writesize / 32;
5436 
5437 	/* All legacy ID NAND are small-page, SLC */
5438 	chip->bits_per_cell = 1;
5439 }
5440 
5441 /*
5442  * Set the bad block marker/indicator (BBM/BBI) patterns according to some
5443  * heuristic patterns using various detected parameters (e.g., manufacturer,
5444  * page size, cell-type information).
5445  */
5446 static void nand_decode_bbm_options(struct nand_chip *chip)
5447 {
5448 	struct mtd_info *mtd = nand_to_mtd(chip);
5449 
5450 	/* Set the bad block position */
5451 	if (mtd->writesize > 512 || (chip->options & NAND_BUSWIDTH_16))
5452 		chip->badblockpos = NAND_LARGE_BADBLOCK_POS;
5453 	else
5454 		chip->badblockpos = NAND_SMALL_BADBLOCK_POS;
5455 }
5456 
5457 static inline bool is_full_id_nand(struct nand_flash_dev *type)
5458 {
5459 	return type->id_len;
5460 }
5461 
5462 static bool find_full_id_nand(struct nand_chip *chip,
5463 			      struct nand_flash_dev *type)
5464 {
5465 	struct mtd_info *mtd = nand_to_mtd(chip);
5466 	u8 *id_data = chip->id.data;
5467 
5468 	if (!strncmp(type->id, id_data, type->id_len)) {
5469 		mtd->writesize = type->pagesize;
5470 		mtd->erasesize = type->erasesize;
5471 		mtd->oobsize = type->oobsize;
5472 
5473 		chip->bits_per_cell = nand_get_bits_per_cell(id_data[2]);
5474 		chip->chipsize = (uint64_t)type->chipsize << 20;
5475 		chip->options |= type->options;
5476 		chip->ecc_strength_ds = NAND_ECC_STRENGTH(type);
5477 		chip->ecc_step_ds = NAND_ECC_STEP(type);
5478 		chip->onfi_timing_mode_default =
5479 					type->onfi_timing_mode_default;
5480 
5481 		strncpy(chip->parameters.model, type->name,
5482 			sizeof(chip->parameters.model) - 1);
5483 
5484 		return true;
5485 	}
5486 	return false;
5487 }
5488 
5489 /*
5490  * Manufacturer detection. Only used when the NAND is not ONFI or JEDEC
5491  * compliant and does not have a full-id or legacy-id entry in the nand_ids
5492  * table.
5493  */
5494 static void nand_manufacturer_detect(struct nand_chip *chip)
5495 {
5496 	/*
5497 	 * Try manufacturer detection if available and use
5498 	 * nand_decode_ext_id() otherwise.
5499 	 */
5500 	if (chip->manufacturer.desc && chip->manufacturer.desc->ops &&
5501 	    chip->manufacturer.desc->ops->detect) {
5502 		/* The 3rd id byte holds MLC / multichip data */
5503 		chip->bits_per_cell = nand_get_bits_per_cell(chip->id.data[2]);
5504 		chip->manufacturer.desc->ops->detect(chip);
5505 	} else {
5506 		nand_decode_ext_id(chip);
5507 	}
5508 }
5509 
5510 /*
5511  * Manufacturer initialization. This function is called for all NANDs including
5512  * ONFI and JEDEC compliant ones.
5513  * Manufacturer drivers should put all their specific initialization code in
5514  * their ->init() hook.
5515  */
5516 static int nand_manufacturer_init(struct nand_chip *chip)
5517 {
5518 	if (!chip->manufacturer.desc || !chip->manufacturer.desc->ops ||
5519 	    !chip->manufacturer.desc->ops->init)
5520 		return 0;
5521 
5522 	return chip->manufacturer.desc->ops->init(chip);
5523 }
5524 
5525 /*
5526  * Manufacturer cleanup. This function is called for all NANDs including
5527  * ONFI and JEDEC compliant ones.
5528  * Manufacturer drivers should put all their specific cleanup code in their
5529  * ->cleanup() hook.
5530  */
5531 static void nand_manufacturer_cleanup(struct nand_chip *chip)
5532 {
5533 	/* Release manufacturer private data */
5534 	if (chip->manufacturer.desc && chip->manufacturer.desc->ops &&
5535 	    chip->manufacturer.desc->ops->cleanup)
5536 		chip->manufacturer.desc->ops->cleanup(chip);
5537 }
5538 
5539 /*
5540  * Get the flash and manufacturer id and lookup if the type is supported.
5541  */
5542 static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type)
5543 {
5544 	const struct nand_manufacturer *manufacturer;
5545 	struct mtd_info *mtd = nand_to_mtd(chip);
5546 	int busw, ret;
5547 	u8 *id_data = chip->id.data;
5548 	u8 maf_id, dev_id;
5549 
5550 	/*
5551 	 * Reset the chip, required by some chips (e.g. Micron MT29FxGxxxxx)
5552 	 * after power-up.
5553 	 */
5554 	ret = nand_reset(chip, 0);
5555 	if (ret)
5556 		return ret;
5557 
5558 	/* Select the device */
5559 	chip->select_chip(mtd, 0);
5560 
5561 	/* Send the command for reading device ID */
5562 	ret = nand_readid_op(chip, 0, id_data, 2);
5563 	if (ret)
5564 		return ret;
5565 
5566 	/* Read manufacturer and device IDs */
5567 	maf_id = id_data[0];
5568 	dev_id = id_data[1];
5569 
5570 	/*
5571 	 * Try again to make sure, as some systems the bus-hold or other
5572 	 * interface concerns can cause random data which looks like a
5573 	 * possibly credible NAND flash to appear. If the two results do
5574 	 * not match, ignore the device completely.
5575 	 */
5576 
5577 	/* Read entire ID string */
5578 	ret = nand_readid_op(chip, 0, id_data, sizeof(chip->id.data));
5579 	if (ret)
5580 		return ret;
5581 
5582 	if (id_data[0] != maf_id || id_data[1] != dev_id) {
5583 		pr_info("second ID read did not match %02x,%02x against %02x,%02x\n",
5584 			maf_id, dev_id, id_data[0], id_data[1]);
5585 		return -ENODEV;
5586 	}
5587 
5588 	chip->id.len = nand_id_len(id_data, ARRAY_SIZE(chip->id.data));
5589 
5590 	/* Try to identify manufacturer */
5591 	manufacturer = nand_get_manufacturer(maf_id);
5592 	chip->manufacturer.desc = manufacturer;
5593 
5594 	if (!type)
5595 		type = nand_flash_ids;
5596 
5597 	/*
5598 	 * Save the NAND_BUSWIDTH_16 flag before letting auto-detection logic
5599 	 * override it.
5600 	 * This is required to make sure initial NAND bus width set by the
5601 	 * NAND controller driver is coherent with the real NAND bus width
5602 	 * (extracted by auto-detection code).
5603 	 */
5604 	busw = chip->options & NAND_BUSWIDTH_16;
5605 
5606 	/*
5607 	 * The flag is only set (never cleared), reset it to its default value
5608 	 * before starting auto-detection.
5609 	 */
5610 	chip->options &= ~NAND_BUSWIDTH_16;
5611 
5612 	for (; type->name != NULL; type++) {
5613 		if (is_full_id_nand(type)) {
5614 			if (find_full_id_nand(chip, type))
5615 				goto ident_done;
5616 		} else if (dev_id == type->dev_id) {
5617 			break;
5618 		}
5619 	}
5620 
5621 	chip->parameters.onfi.version = 0;
5622 	if (!type->name || !type->pagesize) {
5623 		/* Check if the chip is ONFI compliant */
5624 		ret = nand_flash_detect_onfi(chip);
5625 		if (ret < 0)
5626 			return ret;
5627 		else if (ret)
5628 			goto ident_done;
5629 
5630 		/* Check if the chip is JEDEC compliant */
5631 		ret = nand_flash_detect_jedec(chip);
5632 		if (ret < 0)
5633 			return ret;
5634 		else if (ret)
5635 			goto ident_done;
5636 	}
5637 
5638 	if (!type->name)
5639 		return -ENODEV;
5640 
5641 	strncpy(chip->parameters.model, type->name,
5642 		sizeof(chip->parameters.model) - 1);
5643 
5644 	chip->chipsize = (uint64_t)type->chipsize << 20;
5645 
5646 	if (!type->pagesize)
5647 		nand_manufacturer_detect(chip);
5648 	else
5649 		nand_decode_id(chip, type);
5650 
5651 	/* Get chip options */
5652 	chip->options |= type->options;
5653 
5654 ident_done:
5655 	if (!mtd->name)
5656 		mtd->name = chip->parameters.model;
5657 
5658 	if (chip->options & NAND_BUSWIDTH_AUTO) {
5659 		WARN_ON(busw & NAND_BUSWIDTH_16);
5660 		nand_set_defaults(chip);
5661 	} else if (busw != (chip->options & NAND_BUSWIDTH_16)) {
5662 		/*
5663 		 * Check, if buswidth is correct. Hardware drivers should set
5664 		 * chip correct!
5665 		 */
5666 		pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
5667 			maf_id, dev_id);
5668 		pr_info("%s %s\n", nand_manufacturer_name(manufacturer),
5669 			mtd->name);
5670 		pr_warn("bus width %d instead of %d bits\n", busw ? 16 : 8,
5671 			(chip->options & NAND_BUSWIDTH_16) ? 16 : 8);
5672 		return -EINVAL;
5673 	}
5674 
5675 	nand_decode_bbm_options(chip);
5676 
5677 	/* Calculate the address shift from the page size */
5678 	chip->page_shift = ffs(mtd->writesize) - 1;
5679 	/* Convert chipsize to number of pages per chip -1 */
5680 	chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
5681 
5682 	chip->bbt_erase_shift = chip->phys_erase_shift =
5683 		ffs(mtd->erasesize) - 1;
5684 	if (chip->chipsize & 0xffffffff)
5685 		chip->chip_shift = ffs((unsigned)chip->chipsize) - 1;
5686 	else {
5687 		chip->chip_shift = ffs((unsigned)(chip->chipsize >> 32));
5688 		chip->chip_shift += 32 - 1;
5689 	}
5690 
5691 	if (chip->chip_shift - chip->page_shift > 16)
5692 		chip->options |= NAND_ROW_ADDR_3;
5693 
5694 	chip->badblockbits = 8;
5695 	chip->erase = single_erase;
5696 
5697 	/* Do not replace user supplied command function! */
5698 	if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
5699 		chip->cmdfunc = nand_command_lp;
5700 
5701 	pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
5702 		maf_id, dev_id);
5703 	pr_info("%s %s\n", nand_manufacturer_name(manufacturer),
5704 		chip->parameters.model);
5705 	pr_info("%d MiB, %s, erase size: %d KiB, page size: %d, OOB size: %d\n",
5706 		(int)(chip->chipsize >> 20), nand_is_slc(chip) ? "SLC" : "MLC",
5707 		mtd->erasesize >> 10, mtd->writesize, mtd->oobsize);
5708 	return 0;
5709 }
5710 
5711 static const char * const nand_ecc_modes[] = {
5712 	[NAND_ECC_NONE]		= "none",
5713 	[NAND_ECC_SOFT]		= "soft",
5714 	[NAND_ECC_HW]		= "hw",
5715 	[NAND_ECC_HW_SYNDROME]	= "hw_syndrome",
5716 	[NAND_ECC_HW_OOB_FIRST]	= "hw_oob_first",
5717 	[NAND_ECC_ON_DIE]	= "on-die",
5718 };
5719 
5720 static int of_get_nand_ecc_mode(struct device_node *np)
5721 {
5722 	const char *pm;
5723 	int err, i;
5724 
5725 	err = of_property_read_string(np, "nand-ecc-mode", &pm);
5726 	if (err < 0)
5727 		return err;
5728 
5729 	for (i = 0; i < ARRAY_SIZE(nand_ecc_modes); i++)
5730 		if (!strcasecmp(pm, nand_ecc_modes[i]))
5731 			return i;
5732 
5733 	/*
5734 	 * For backward compatibility we support few obsoleted values that don't
5735 	 * have their mappings into nand_ecc_modes_t anymore (they were merged
5736 	 * with other enums).
5737 	 */
5738 	if (!strcasecmp(pm, "soft_bch"))
5739 		return NAND_ECC_SOFT;
5740 
5741 	return -ENODEV;
5742 }
5743 
5744 static const char * const nand_ecc_algos[] = {
5745 	[NAND_ECC_HAMMING]	= "hamming",
5746 	[NAND_ECC_BCH]		= "bch",
5747 };
5748 
5749 static int of_get_nand_ecc_algo(struct device_node *np)
5750 {
5751 	const char *pm;
5752 	int err, i;
5753 
5754 	err = of_property_read_string(np, "nand-ecc-algo", &pm);
5755 	if (!err) {
5756 		for (i = NAND_ECC_HAMMING; i < ARRAY_SIZE(nand_ecc_algos); i++)
5757 			if (!strcasecmp(pm, nand_ecc_algos[i]))
5758 				return i;
5759 		return -ENODEV;
5760 	}
5761 
5762 	/*
5763 	 * For backward compatibility we also read "nand-ecc-mode" checking
5764 	 * for some obsoleted values that were specifying ECC algorithm.
5765 	 */
5766 	err = of_property_read_string(np, "nand-ecc-mode", &pm);
5767 	if (err < 0)
5768 		return err;
5769 
5770 	if (!strcasecmp(pm, "soft"))
5771 		return NAND_ECC_HAMMING;
5772 	else if (!strcasecmp(pm, "soft_bch"))
5773 		return NAND_ECC_BCH;
5774 
5775 	return -ENODEV;
5776 }
5777 
5778 static int of_get_nand_ecc_step_size(struct device_node *np)
5779 {
5780 	int ret;
5781 	u32 val;
5782 
5783 	ret = of_property_read_u32(np, "nand-ecc-step-size", &val);
5784 	return ret ? ret : val;
5785 }
5786 
5787 static int of_get_nand_ecc_strength(struct device_node *np)
5788 {
5789 	int ret;
5790 	u32 val;
5791 
5792 	ret = of_property_read_u32(np, "nand-ecc-strength", &val);
5793 	return ret ? ret : val;
5794 }
5795 
5796 static int of_get_nand_bus_width(struct device_node *np)
5797 {
5798 	u32 val;
5799 
5800 	if (of_property_read_u32(np, "nand-bus-width", &val))
5801 		return 8;
5802 
5803 	switch (val) {
5804 	case 8:
5805 	case 16:
5806 		return val;
5807 	default:
5808 		return -EIO;
5809 	}
5810 }
5811 
5812 static bool of_get_nand_on_flash_bbt(struct device_node *np)
5813 {
5814 	return of_property_read_bool(np, "nand-on-flash-bbt");
5815 }
5816 
5817 static int nand_dt_init(struct nand_chip *chip)
5818 {
5819 	struct device_node *dn = nand_get_flash_node(chip);
5820 	int ecc_mode, ecc_algo, ecc_strength, ecc_step;
5821 
5822 	if (!dn)
5823 		return 0;
5824 
5825 	if (of_get_nand_bus_width(dn) == 16)
5826 		chip->options |= NAND_BUSWIDTH_16;
5827 
5828 	if (of_get_nand_on_flash_bbt(dn))
5829 		chip->bbt_options |= NAND_BBT_USE_FLASH;
5830 
5831 	ecc_mode = of_get_nand_ecc_mode(dn);
5832 	ecc_algo = of_get_nand_ecc_algo(dn);
5833 	ecc_strength = of_get_nand_ecc_strength(dn);
5834 	ecc_step = of_get_nand_ecc_step_size(dn);
5835 
5836 	if (ecc_mode >= 0)
5837 		chip->ecc.mode = ecc_mode;
5838 
5839 	if (ecc_algo >= 0)
5840 		chip->ecc.algo = ecc_algo;
5841 
5842 	if (ecc_strength >= 0)
5843 		chip->ecc.strength = ecc_strength;
5844 
5845 	if (ecc_step > 0)
5846 		chip->ecc.size = ecc_step;
5847 
5848 	if (of_property_read_bool(dn, "nand-ecc-maximize"))
5849 		chip->ecc.options |= NAND_ECC_MAXIMIZE;
5850 
5851 	return 0;
5852 }
5853 
5854 /**
5855  * nand_scan_ident - [NAND Interface] Scan for the NAND device
5856  * @mtd: MTD device structure
5857  * @maxchips: number of chips to scan for
5858  * @table: alternative NAND ID table
5859  *
5860  * This is the first phase of the normal nand_scan() function. It reads the
5861  * flash ID and sets up MTD fields accordingly.
5862  *
5863  */
5864 int nand_scan_ident(struct mtd_info *mtd, int maxchips,
5865 		    struct nand_flash_dev *table)
5866 {
5867 	int i, nand_maf_id, nand_dev_id;
5868 	struct nand_chip *chip = mtd_to_nand(mtd);
5869 	int ret;
5870 
5871 	/* Enforce the right timings for reset/detection */
5872 	onfi_fill_data_interface(chip, NAND_SDR_IFACE, 0);
5873 
5874 	ret = nand_dt_init(chip);
5875 	if (ret)
5876 		return ret;
5877 
5878 	if (!mtd->name && mtd->dev.parent)
5879 		mtd->name = dev_name(mtd->dev.parent);
5880 
5881 	/*
5882 	 * ->cmdfunc() is legacy and will only be used if ->exec_op() is not
5883 	 * populated.
5884 	 */
5885 	if (!chip->exec_op) {
5886 		/*
5887 		 * Default functions assigned for ->cmdfunc() and
5888 		 * ->select_chip() both expect ->cmd_ctrl() to be populated.
5889 		 */
5890 		if ((!chip->cmdfunc || !chip->select_chip) && !chip->cmd_ctrl) {
5891 			pr_err("->cmd_ctrl() should be provided\n");
5892 			return -EINVAL;
5893 		}
5894 	}
5895 
5896 	/* Set the default functions */
5897 	nand_set_defaults(chip);
5898 
5899 	/* Read the flash type */
5900 	ret = nand_detect(chip, table);
5901 	if (ret) {
5902 		if (!(chip->options & NAND_SCAN_SILENT_NODEV))
5903 			pr_warn("No NAND device found\n");
5904 		chip->select_chip(mtd, -1);
5905 		return ret;
5906 	}
5907 
5908 	nand_maf_id = chip->id.data[0];
5909 	nand_dev_id = chip->id.data[1];
5910 
5911 	chip->select_chip(mtd, -1);
5912 
5913 	/* Check for a chip array */
5914 	for (i = 1; i < maxchips; i++) {
5915 		u8 id[2];
5916 
5917 		/* See comment in nand_get_flash_type for reset */
5918 		nand_reset(chip, i);
5919 
5920 		chip->select_chip(mtd, i);
5921 		/* Send the command for reading device ID */
5922 		nand_readid_op(chip, 0, id, sizeof(id));
5923 		/* Read manufacturer and device IDs */
5924 		if (nand_maf_id != id[0] || nand_dev_id != id[1]) {
5925 			chip->select_chip(mtd, -1);
5926 			break;
5927 		}
5928 		chip->select_chip(mtd, -1);
5929 	}
5930 	if (i > 1)
5931 		pr_info("%d chips detected\n", i);
5932 
5933 	/* Store the number of chips and calc total size for mtd */
5934 	chip->numchips = i;
5935 	mtd->size = i * chip->chipsize;
5936 
5937 	return 0;
5938 }
5939 EXPORT_SYMBOL(nand_scan_ident);
5940 
5941 static int nand_set_ecc_soft_ops(struct mtd_info *mtd)
5942 {
5943 	struct nand_chip *chip = mtd_to_nand(mtd);
5944 	struct nand_ecc_ctrl *ecc = &chip->ecc;
5945 
5946 	if (WARN_ON(ecc->mode != NAND_ECC_SOFT))
5947 		return -EINVAL;
5948 
5949 	switch (ecc->algo) {
5950 	case NAND_ECC_HAMMING:
5951 		ecc->calculate = nand_calculate_ecc;
5952 		ecc->correct = nand_correct_data;
5953 		ecc->read_page = nand_read_page_swecc;
5954 		ecc->read_subpage = nand_read_subpage;
5955 		ecc->write_page = nand_write_page_swecc;
5956 		ecc->read_page_raw = nand_read_page_raw;
5957 		ecc->write_page_raw = nand_write_page_raw;
5958 		ecc->read_oob = nand_read_oob_std;
5959 		ecc->write_oob = nand_write_oob_std;
5960 		if (!ecc->size)
5961 			ecc->size = 256;
5962 		ecc->bytes = 3;
5963 		ecc->strength = 1;
5964 		return 0;
5965 	case NAND_ECC_BCH:
5966 		if (!mtd_nand_has_bch()) {
5967 			WARN(1, "CONFIG_MTD_NAND_ECC_BCH not enabled\n");
5968 			return -EINVAL;
5969 		}
5970 		ecc->calculate = nand_bch_calculate_ecc;
5971 		ecc->correct = nand_bch_correct_data;
5972 		ecc->read_page = nand_read_page_swecc;
5973 		ecc->read_subpage = nand_read_subpage;
5974 		ecc->write_page = nand_write_page_swecc;
5975 		ecc->read_page_raw = nand_read_page_raw;
5976 		ecc->write_page_raw = nand_write_page_raw;
5977 		ecc->read_oob = nand_read_oob_std;
5978 		ecc->write_oob = nand_write_oob_std;
5979 
5980 		/*
5981 		* Board driver should supply ecc.size and ecc.strength
5982 		* values to select how many bits are correctable.
5983 		* Otherwise, default to 4 bits for large page devices.
5984 		*/
5985 		if (!ecc->size && (mtd->oobsize >= 64)) {
5986 			ecc->size = 512;
5987 			ecc->strength = 4;
5988 		}
5989 
5990 		/*
5991 		 * if no ecc placement scheme was provided pickup the default
5992 		 * large page one.
5993 		 */
5994 		if (!mtd->ooblayout) {
5995 			/* handle large page devices only */
5996 			if (mtd->oobsize < 64) {
5997 				WARN(1, "OOB layout is required when using software BCH on small pages\n");
5998 				return -EINVAL;
5999 			}
6000 
6001 			mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);
6002 
6003 		}
6004 
6005 		/*
6006 		 * We can only maximize ECC config when the default layout is
6007 		 * used, otherwise we don't know how many bytes can really be
6008 		 * used.
6009 		 */
6010 		if (mtd->ooblayout == &nand_ooblayout_lp_ops &&
6011 		    ecc->options & NAND_ECC_MAXIMIZE) {
6012 			int steps, bytes;
6013 
6014 			/* Always prefer 1k blocks over 512bytes ones */
6015 			ecc->size = 1024;
6016 			steps = mtd->writesize / ecc->size;
6017 
6018 			/* Reserve 2 bytes for the BBM */
6019 			bytes = (mtd->oobsize - 2) / steps;
6020 			ecc->strength = bytes * 8 / fls(8 * ecc->size);
6021 		}
6022 
6023 		/* See nand_bch_init() for details. */
6024 		ecc->bytes = 0;
6025 		ecc->priv = nand_bch_init(mtd);
6026 		if (!ecc->priv) {
6027 			WARN(1, "BCH ECC initialization failed!\n");
6028 			return -EINVAL;
6029 		}
6030 		return 0;
6031 	default:
6032 		WARN(1, "Unsupported ECC algorithm!\n");
6033 		return -EINVAL;
6034 	}
6035 }
6036 
6037 /**
6038  * nand_check_ecc_caps - check the sanity of preset ECC settings
6039  * @chip: nand chip info structure
6040  * @caps: ECC caps info structure
6041  * @oobavail: OOB size that the ECC engine can use
6042  *
6043  * When ECC step size and strength are already set, check if they are supported
6044  * by the controller and the calculated ECC bytes fit within the chip's OOB.
6045  * On success, the calculated ECC bytes is set.
6046  */
6047 int nand_check_ecc_caps(struct nand_chip *chip,
6048 			const struct nand_ecc_caps *caps, int oobavail)
6049 {
6050 	struct mtd_info *mtd = nand_to_mtd(chip);
6051 	const struct nand_ecc_step_info *stepinfo;
6052 	int preset_step = chip->ecc.size;
6053 	int preset_strength = chip->ecc.strength;
6054 	int nsteps, ecc_bytes;
6055 	int i, j;
6056 
6057 	if (WARN_ON(oobavail < 0))
6058 		return -EINVAL;
6059 
6060 	if (!preset_step || !preset_strength)
6061 		return -ENODATA;
6062 
6063 	nsteps = mtd->writesize / preset_step;
6064 
6065 	for (i = 0; i < caps->nstepinfos; i++) {
6066 		stepinfo = &caps->stepinfos[i];
6067 
6068 		if (stepinfo->stepsize != preset_step)
6069 			continue;
6070 
6071 		for (j = 0; j < stepinfo->nstrengths; j++) {
6072 			if (stepinfo->strengths[j] != preset_strength)
6073 				continue;
6074 
6075 			ecc_bytes = caps->calc_ecc_bytes(preset_step,
6076 							 preset_strength);
6077 			if (WARN_ON_ONCE(ecc_bytes < 0))
6078 				return ecc_bytes;
6079 
6080 			if (ecc_bytes * nsteps > oobavail) {
6081 				pr_err("ECC (step, strength) = (%d, %d) does not fit in OOB",
6082 				       preset_step, preset_strength);
6083 				return -ENOSPC;
6084 			}
6085 
6086 			chip->ecc.bytes = ecc_bytes;
6087 
6088 			return 0;
6089 		}
6090 	}
6091 
6092 	pr_err("ECC (step, strength) = (%d, %d) not supported on this controller",
6093 	       preset_step, preset_strength);
6094 
6095 	return -ENOTSUPP;
6096 }
6097 EXPORT_SYMBOL_GPL(nand_check_ecc_caps);
6098 
6099 /**
6100  * nand_match_ecc_req - meet the chip's requirement with least ECC bytes
6101  * @chip: nand chip info structure
6102  * @caps: ECC engine caps info structure
6103  * @oobavail: OOB size that the ECC engine can use
6104  *
6105  * If a chip's ECC requirement is provided, try to meet it with the least
6106  * number of ECC bytes (i.e. with the largest number of OOB-free bytes).
6107  * On success, the chosen ECC settings are set.
6108  */
6109 int nand_match_ecc_req(struct nand_chip *chip,
6110 		       const struct nand_ecc_caps *caps, int oobavail)
6111 {
6112 	struct mtd_info *mtd = nand_to_mtd(chip);
6113 	const struct nand_ecc_step_info *stepinfo;
6114 	int req_step = chip->ecc_step_ds;
6115 	int req_strength = chip->ecc_strength_ds;
6116 	int req_corr, step_size, strength, nsteps, ecc_bytes, ecc_bytes_total;
6117 	int best_step, best_strength, best_ecc_bytes;
6118 	int best_ecc_bytes_total = INT_MAX;
6119 	int i, j;
6120 
6121 	if (WARN_ON(oobavail < 0))
6122 		return -EINVAL;
6123 
6124 	/* No information provided by the NAND chip */
6125 	if (!req_step || !req_strength)
6126 		return -ENOTSUPP;
6127 
6128 	/* number of correctable bits the chip requires in a page */
6129 	req_corr = mtd->writesize / req_step * req_strength;
6130 
6131 	for (i = 0; i < caps->nstepinfos; i++) {
6132 		stepinfo = &caps->stepinfos[i];
6133 		step_size = stepinfo->stepsize;
6134 
6135 		for (j = 0; j < stepinfo->nstrengths; j++) {
6136 			strength = stepinfo->strengths[j];
6137 
6138 			/*
6139 			 * If both step size and strength are smaller than the
6140 			 * chip's requirement, it is not easy to compare the
6141 			 * resulted reliability.
6142 			 */
6143 			if (step_size < req_step && strength < req_strength)
6144 				continue;
6145 
6146 			if (mtd->writesize % step_size)
6147 				continue;
6148 
6149 			nsteps = mtd->writesize / step_size;
6150 
6151 			ecc_bytes = caps->calc_ecc_bytes(step_size, strength);
6152 			if (WARN_ON_ONCE(ecc_bytes < 0))
6153 				continue;
6154 			ecc_bytes_total = ecc_bytes * nsteps;
6155 
6156 			if (ecc_bytes_total > oobavail ||
6157 			    strength * nsteps < req_corr)
6158 				continue;
6159 
6160 			/*
6161 			 * We assume the best is to meet the chip's requrement
6162 			 * with the least number of ECC bytes.
6163 			 */
6164 			if (ecc_bytes_total < best_ecc_bytes_total) {
6165 				best_ecc_bytes_total = ecc_bytes_total;
6166 				best_step = step_size;
6167 				best_strength = strength;
6168 				best_ecc_bytes = ecc_bytes;
6169 			}
6170 		}
6171 	}
6172 
6173 	if (best_ecc_bytes_total == INT_MAX)
6174 		return -ENOTSUPP;
6175 
6176 	chip->ecc.size = best_step;
6177 	chip->ecc.strength = best_strength;
6178 	chip->ecc.bytes = best_ecc_bytes;
6179 
6180 	return 0;
6181 }
6182 EXPORT_SYMBOL_GPL(nand_match_ecc_req);
6183 
6184 /**
6185  * nand_maximize_ecc - choose the max ECC strength available
6186  * @chip: nand chip info structure
6187  * @caps: ECC engine caps info structure
6188  * @oobavail: OOB size that the ECC engine can use
6189  *
6190  * Choose the max ECC strength that is supported on the controller, and can fit
6191  * within the chip's OOB.  On success, the chosen ECC settings are set.
6192  */
6193 int nand_maximize_ecc(struct nand_chip *chip,
6194 		      const struct nand_ecc_caps *caps, int oobavail)
6195 {
6196 	struct mtd_info *mtd = nand_to_mtd(chip);
6197 	const struct nand_ecc_step_info *stepinfo;
6198 	int step_size, strength, nsteps, ecc_bytes, corr;
6199 	int best_corr = 0;
6200 	int best_step = 0;
6201 	int best_strength, best_ecc_bytes;
6202 	int i, j;
6203 
6204 	if (WARN_ON(oobavail < 0))
6205 		return -EINVAL;
6206 
6207 	for (i = 0; i < caps->nstepinfos; i++) {
6208 		stepinfo = &caps->stepinfos[i];
6209 		step_size = stepinfo->stepsize;
6210 
6211 		/* If chip->ecc.size is already set, respect it */
6212 		if (chip->ecc.size && step_size != chip->ecc.size)
6213 			continue;
6214 
6215 		for (j = 0; j < stepinfo->nstrengths; j++) {
6216 			strength = stepinfo->strengths[j];
6217 
6218 			if (mtd->writesize % step_size)
6219 				continue;
6220 
6221 			nsteps = mtd->writesize / step_size;
6222 
6223 			ecc_bytes = caps->calc_ecc_bytes(step_size, strength);
6224 			if (WARN_ON_ONCE(ecc_bytes < 0))
6225 				continue;
6226 
6227 			if (ecc_bytes * nsteps > oobavail)
6228 				continue;
6229 
6230 			corr = strength * nsteps;
6231 
6232 			/*
6233 			 * If the number of correctable bits is the same,
6234 			 * bigger step_size has more reliability.
6235 			 */
6236 			if (corr > best_corr ||
6237 			    (corr == best_corr && step_size > best_step)) {
6238 				best_corr = corr;
6239 				best_step = step_size;
6240 				best_strength = strength;
6241 				best_ecc_bytes = ecc_bytes;
6242 			}
6243 		}
6244 	}
6245 
6246 	if (!best_corr)
6247 		return -ENOTSUPP;
6248 
6249 	chip->ecc.size = best_step;
6250 	chip->ecc.strength = best_strength;
6251 	chip->ecc.bytes = best_ecc_bytes;
6252 
6253 	return 0;
6254 }
6255 EXPORT_SYMBOL_GPL(nand_maximize_ecc);
6256 
6257 /*
6258  * Check if the chip configuration meet the datasheet requirements.
6259 
6260  * If our configuration corrects A bits per B bytes and the minimum
6261  * required correction level is X bits per Y bytes, then we must ensure
6262  * both of the following are true:
6263  *
6264  * (1) A / B >= X / Y
6265  * (2) A >= X
6266  *
6267  * Requirement (1) ensures we can correct for the required bitflip density.
6268  * Requirement (2) ensures we can correct even when all bitflips are clumped
6269  * in the same sector.
6270  */
6271 static bool nand_ecc_strength_good(struct mtd_info *mtd)
6272 {
6273 	struct nand_chip *chip = mtd_to_nand(mtd);
6274 	struct nand_ecc_ctrl *ecc = &chip->ecc;
6275 	int corr, ds_corr;
6276 
6277 	if (ecc->size == 0 || chip->ecc_step_ds == 0)
6278 		/* Not enough information */
6279 		return true;
6280 
6281 	/*
6282 	 * We get the number of corrected bits per page to compare
6283 	 * the correction density.
6284 	 */
6285 	corr = (mtd->writesize * ecc->strength) / ecc->size;
6286 	ds_corr = (mtd->writesize * chip->ecc_strength_ds) / chip->ecc_step_ds;
6287 
6288 	return corr >= ds_corr && ecc->strength >= chip->ecc_strength_ds;
6289 }
6290 
6291 /**
6292  * nand_scan_tail - [NAND Interface] Scan for the NAND device
6293  * @mtd: MTD device structure
6294  *
6295  * This is the second phase of the normal nand_scan() function. It fills out
6296  * all the uninitialized function pointers with the defaults and scans for a
6297  * bad block table if appropriate.
6298  */
6299 int nand_scan_tail(struct mtd_info *mtd)
6300 {
6301 	struct nand_chip *chip = mtd_to_nand(mtd);
6302 	struct nand_ecc_ctrl *ecc = &chip->ecc;
6303 	int ret, i;
6304 
6305 	/* New bad blocks should be marked in OOB, flash-based BBT, or both */
6306 	if (WARN_ON((chip->bbt_options & NAND_BBT_NO_OOB_BBM) &&
6307 		   !(chip->bbt_options & NAND_BBT_USE_FLASH))) {
6308 		return -EINVAL;
6309 	}
6310 
6311 	chip->data_buf = kmalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL);
6312 	if (!chip->data_buf)
6313 		return -ENOMEM;
6314 
6315 	/*
6316 	 * FIXME: some NAND manufacturer drivers expect the first die to be
6317 	 * selected when manufacturer->init() is called. They should be fixed
6318 	 * to explictly select the relevant die when interacting with the NAND
6319 	 * chip.
6320 	 */
6321 	chip->select_chip(mtd, 0);
6322 	ret = nand_manufacturer_init(chip);
6323 	chip->select_chip(mtd, -1);
6324 	if (ret)
6325 		goto err_free_buf;
6326 
6327 	/* Set the internal oob buffer location, just after the page data */
6328 	chip->oob_poi = chip->data_buf + mtd->writesize;
6329 
6330 	/*
6331 	 * If no default placement scheme is given, select an appropriate one.
6332 	 */
6333 	if (!mtd->ooblayout &&
6334 	    !(ecc->mode == NAND_ECC_SOFT && ecc->algo == NAND_ECC_BCH)) {
6335 		switch (mtd->oobsize) {
6336 		case 8:
6337 		case 16:
6338 			mtd_set_ooblayout(mtd, &nand_ooblayout_sp_ops);
6339 			break;
6340 		case 64:
6341 		case 128:
6342 			mtd_set_ooblayout(mtd, &nand_ooblayout_lp_hamming_ops);
6343 			break;
6344 		default:
6345 			/*
6346 			 * Expose the whole OOB area to users if ECC_NONE
6347 			 * is passed. We could do that for all kind of
6348 			 * ->oobsize, but we must keep the old large/small
6349 			 * page with ECC layout when ->oobsize <= 128 for
6350 			 * compatibility reasons.
6351 			 */
6352 			if (ecc->mode == NAND_ECC_NONE) {
6353 				mtd_set_ooblayout(mtd,
6354 						&nand_ooblayout_lp_ops);
6355 				break;
6356 			}
6357 
6358 			WARN(1, "No oob scheme defined for oobsize %d\n",
6359 				mtd->oobsize);
6360 			ret = -EINVAL;
6361 			goto err_nand_manuf_cleanup;
6362 		}
6363 	}
6364 
6365 	/*
6366 	 * Check ECC mode, default to software if 3byte/512byte hardware ECC is
6367 	 * selected and we have 256 byte pagesize fallback to software ECC
6368 	 */
6369 
6370 	switch (ecc->mode) {
6371 	case NAND_ECC_HW_OOB_FIRST:
6372 		/* Similar to NAND_ECC_HW, but a separate read_page handle */
6373 		if (!ecc->calculate || !ecc->correct || !ecc->hwctl) {
6374 			WARN(1, "No ECC functions supplied; hardware ECC not possible\n");
6375 			ret = -EINVAL;
6376 			goto err_nand_manuf_cleanup;
6377 		}
6378 		if (!ecc->read_page)
6379 			ecc->read_page = nand_read_page_hwecc_oob_first;
6380 
6381 	case NAND_ECC_HW:
6382 		/* Use standard hwecc read page function? */
6383 		if (!ecc->read_page)
6384 			ecc->read_page = nand_read_page_hwecc;
6385 		if (!ecc->write_page)
6386 			ecc->write_page = nand_write_page_hwecc;
6387 		if (!ecc->read_page_raw)
6388 			ecc->read_page_raw = nand_read_page_raw;
6389 		if (!ecc->write_page_raw)
6390 			ecc->write_page_raw = nand_write_page_raw;
6391 		if (!ecc->read_oob)
6392 			ecc->read_oob = nand_read_oob_std;
6393 		if (!ecc->write_oob)
6394 			ecc->write_oob = nand_write_oob_std;
6395 		if (!ecc->read_subpage)
6396 			ecc->read_subpage = nand_read_subpage;
6397 		if (!ecc->write_subpage && ecc->hwctl && ecc->calculate)
6398 			ecc->write_subpage = nand_write_subpage_hwecc;
6399 
6400 	case NAND_ECC_HW_SYNDROME:
6401 		if ((!ecc->calculate || !ecc->correct || !ecc->hwctl) &&
6402 		    (!ecc->read_page ||
6403 		     ecc->read_page == nand_read_page_hwecc ||
6404 		     !ecc->write_page ||
6405 		     ecc->write_page == nand_write_page_hwecc)) {
6406 			WARN(1, "No ECC functions supplied; hardware ECC not possible\n");
6407 			ret = -EINVAL;
6408 			goto err_nand_manuf_cleanup;
6409 		}
6410 		/* Use standard syndrome read/write page function? */
6411 		if (!ecc->read_page)
6412 			ecc->read_page = nand_read_page_syndrome;
6413 		if (!ecc->write_page)
6414 			ecc->write_page = nand_write_page_syndrome;
6415 		if (!ecc->read_page_raw)
6416 			ecc->read_page_raw = nand_read_page_raw_syndrome;
6417 		if (!ecc->write_page_raw)
6418 			ecc->write_page_raw = nand_write_page_raw_syndrome;
6419 		if (!ecc->read_oob)
6420 			ecc->read_oob = nand_read_oob_syndrome;
6421 		if (!ecc->write_oob)
6422 			ecc->write_oob = nand_write_oob_syndrome;
6423 
6424 		if (mtd->writesize >= ecc->size) {
6425 			if (!ecc->strength) {
6426 				WARN(1, "Driver must set ecc.strength when using hardware ECC\n");
6427 				ret = -EINVAL;
6428 				goto err_nand_manuf_cleanup;
6429 			}
6430 			break;
6431 		}
6432 		pr_warn("%d byte HW ECC not possible on %d byte page size, fallback to SW ECC\n",
6433 			ecc->size, mtd->writesize);
6434 		ecc->mode = NAND_ECC_SOFT;
6435 		ecc->algo = NAND_ECC_HAMMING;
6436 
6437 	case NAND_ECC_SOFT:
6438 		ret = nand_set_ecc_soft_ops(mtd);
6439 		if (ret) {
6440 			ret = -EINVAL;
6441 			goto err_nand_manuf_cleanup;
6442 		}
6443 		break;
6444 
6445 	case NAND_ECC_ON_DIE:
6446 		if (!ecc->read_page || !ecc->write_page) {
6447 			WARN(1, "No ECC functions supplied; on-die ECC not possible\n");
6448 			ret = -EINVAL;
6449 			goto err_nand_manuf_cleanup;
6450 		}
6451 		if (!ecc->read_oob)
6452 			ecc->read_oob = nand_read_oob_std;
6453 		if (!ecc->write_oob)
6454 			ecc->write_oob = nand_write_oob_std;
6455 		break;
6456 
6457 	case NAND_ECC_NONE:
6458 		pr_warn("NAND_ECC_NONE selected by board driver. This is not recommended!\n");
6459 		ecc->read_page = nand_read_page_raw;
6460 		ecc->write_page = nand_write_page_raw;
6461 		ecc->read_oob = nand_read_oob_std;
6462 		ecc->read_page_raw = nand_read_page_raw;
6463 		ecc->write_page_raw = nand_write_page_raw;
6464 		ecc->write_oob = nand_write_oob_std;
6465 		ecc->size = mtd->writesize;
6466 		ecc->bytes = 0;
6467 		ecc->strength = 0;
6468 		break;
6469 
6470 	default:
6471 		WARN(1, "Invalid NAND_ECC_MODE %d\n", ecc->mode);
6472 		ret = -EINVAL;
6473 		goto err_nand_manuf_cleanup;
6474 	}
6475 
6476 	if (ecc->correct || ecc->calculate) {
6477 		ecc->calc_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
6478 		ecc->code_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
6479 		if (!ecc->calc_buf || !ecc->code_buf) {
6480 			ret = -ENOMEM;
6481 			goto err_nand_manuf_cleanup;
6482 		}
6483 	}
6484 
6485 	/* For many systems, the standard OOB write also works for raw */
6486 	if (!ecc->read_oob_raw)
6487 		ecc->read_oob_raw = ecc->read_oob;
6488 	if (!ecc->write_oob_raw)
6489 		ecc->write_oob_raw = ecc->write_oob;
6490 
6491 	/* propagate ecc info to mtd_info */
6492 	mtd->ecc_strength = ecc->strength;
6493 	mtd->ecc_step_size = ecc->size;
6494 
6495 	/*
6496 	 * Set the number of read / write steps for one page depending on ECC
6497 	 * mode.
6498 	 */
6499 	ecc->steps = mtd->writesize / ecc->size;
6500 	if (ecc->steps * ecc->size != mtd->writesize) {
6501 		WARN(1, "Invalid ECC parameters\n");
6502 		ret = -EINVAL;
6503 		goto err_nand_manuf_cleanup;
6504 	}
6505 	ecc->total = ecc->steps * ecc->bytes;
6506 	if (ecc->total > mtd->oobsize) {
6507 		WARN(1, "Total number of ECC bytes exceeded oobsize\n");
6508 		ret = -EINVAL;
6509 		goto err_nand_manuf_cleanup;
6510 	}
6511 
6512 	/*
6513 	 * The number of bytes available for a client to place data into
6514 	 * the out of band area.
6515 	 */
6516 	ret = mtd_ooblayout_count_freebytes(mtd);
6517 	if (ret < 0)
6518 		ret = 0;
6519 
6520 	mtd->oobavail = ret;
6521 
6522 	/* ECC sanity check: warn if it's too weak */
6523 	if (!nand_ecc_strength_good(mtd))
6524 		pr_warn("WARNING: %s: the ECC used on your system is too weak compared to the one required by the NAND chip\n",
6525 			mtd->name);
6526 
6527 	/* Allow subpage writes up to ecc.steps. Not possible for MLC flash */
6528 	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) && nand_is_slc(chip)) {
6529 		switch (ecc->steps) {
6530 		case 2:
6531 			mtd->subpage_sft = 1;
6532 			break;
6533 		case 4:
6534 		case 8:
6535 		case 16:
6536 			mtd->subpage_sft = 2;
6537 			break;
6538 		}
6539 	}
6540 	chip->subpagesize = mtd->writesize >> mtd->subpage_sft;
6541 
6542 	/* Initialize state */
6543 	chip->state = FL_READY;
6544 
6545 	/* Invalidate the pagebuffer reference */
6546 	chip->pagebuf = -1;
6547 
6548 	/* Large page NAND with SOFT_ECC should support subpage reads */
6549 	switch (ecc->mode) {
6550 	case NAND_ECC_SOFT:
6551 		if (chip->page_shift > 9)
6552 			chip->options |= NAND_SUBPAGE_READ;
6553 		break;
6554 
6555 	default:
6556 		break;
6557 	}
6558 
6559 	/* Fill in remaining MTD driver data */
6560 	mtd->type = nand_is_slc(chip) ? MTD_NANDFLASH : MTD_MLCNANDFLASH;
6561 	mtd->flags = (chip->options & NAND_ROM) ? MTD_CAP_ROM :
6562 						MTD_CAP_NANDFLASH;
6563 	mtd->_erase = nand_erase;
6564 	mtd->_point = NULL;
6565 	mtd->_unpoint = NULL;
6566 	mtd->_panic_write = panic_nand_write;
6567 	mtd->_read_oob = nand_read_oob;
6568 	mtd->_write_oob = nand_write_oob;
6569 	mtd->_sync = nand_sync;
6570 	mtd->_lock = NULL;
6571 	mtd->_unlock = NULL;
6572 	mtd->_suspend = nand_suspend;
6573 	mtd->_resume = nand_resume;
6574 	mtd->_reboot = nand_shutdown;
6575 	mtd->_block_isreserved = nand_block_isreserved;
6576 	mtd->_block_isbad = nand_block_isbad;
6577 	mtd->_block_markbad = nand_block_markbad;
6578 	mtd->_max_bad_blocks = nand_max_bad_blocks;
6579 	mtd->writebufsize = mtd->writesize;
6580 
6581 	/*
6582 	 * Initialize bitflip_threshold to its default prior scan_bbt() call.
6583 	 * scan_bbt() might invoke mtd_read(), thus bitflip_threshold must be
6584 	 * properly set.
6585 	 */
6586 	if (!mtd->bitflip_threshold)
6587 		mtd->bitflip_threshold = DIV_ROUND_UP(mtd->ecc_strength * 3, 4);
6588 
6589 	/* Initialize the ->data_interface field. */
6590 	ret = nand_init_data_interface(chip);
6591 	if (ret)
6592 		goto err_nand_manuf_cleanup;
6593 
6594 	/* Enter fastest possible mode on all dies. */
6595 	for (i = 0; i < chip->numchips; i++) {
6596 		ret = nand_setup_data_interface(chip, i);
6597 		if (ret)
6598 			goto err_nand_manuf_cleanup;
6599 	}
6600 
6601 	/* Check, if we should skip the bad block table scan */
6602 	if (chip->options & NAND_SKIP_BBTSCAN)
6603 		return 0;
6604 
6605 	/* Build bad block table */
6606 	ret = chip->scan_bbt(mtd);
6607 	if (ret)
6608 		goto err_nand_manuf_cleanup;
6609 
6610 	return 0;
6611 
6612 
6613 err_nand_manuf_cleanup:
6614 	nand_manufacturer_cleanup(chip);
6615 
6616 err_free_buf:
6617 	kfree(chip->data_buf);
6618 	kfree(ecc->code_buf);
6619 	kfree(ecc->calc_buf);
6620 
6621 	return ret;
6622 }
6623 EXPORT_SYMBOL(nand_scan_tail);
6624 
6625 /*
6626  * is_module_text_address() isn't exported, and it's mostly a pointless
6627  * test if this is a module _anyway_ -- they'd have to try _really_ hard
6628  * to call us from in-kernel code if the core NAND support is modular.
6629  */
6630 #ifdef MODULE
6631 #define caller_is_module() (1)
6632 #else
6633 #define caller_is_module() \
6634 	is_module_text_address((unsigned long)__builtin_return_address(0))
6635 #endif
6636 
6637 /**
6638  * nand_scan - [NAND Interface] Scan for the NAND device
6639  * @mtd: MTD device structure
6640  * @maxchips: number of chips to scan for
6641  *
6642  * This fills out all the uninitialized function pointers with the defaults.
6643  * The flash ID is read and the mtd/chip structures are filled with the
6644  * appropriate values.
6645  */
6646 int nand_scan(struct mtd_info *mtd, int maxchips)
6647 {
6648 	int ret;
6649 
6650 	ret = nand_scan_ident(mtd, maxchips, NULL);
6651 	if (!ret)
6652 		ret = nand_scan_tail(mtd);
6653 	return ret;
6654 }
6655 EXPORT_SYMBOL(nand_scan);
6656 
6657 /**
6658  * nand_cleanup - [NAND Interface] Free resources held by the NAND device
6659  * @chip: NAND chip object
6660  */
6661 void nand_cleanup(struct nand_chip *chip)
6662 {
6663 	if (chip->ecc.mode == NAND_ECC_SOFT &&
6664 	    chip->ecc.algo == NAND_ECC_BCH)
6665 		nand_bch_free((struct nand_bch_control *)chip->ecc.priv);
6666 
6667 	/* Free bad block table memory */
6668 	kfree(chip->bbt);
6669 	kfree(chip->data_buf);
6670 	kfree(chip->ecc.code_buf);
6671 	kfree(chip->ecc.calc_buf);
6672 
6673 	/* Free bad block descriptor memory */
6674 	if (chip->badblock_pattern && chip->badblock_pattern->options
6675 			& NAND_BBT_DYNAMICSTRUCT)
6676 		kfree(chip->badblock_pattern);
6677 
6678 	/* Free manufacturer priv data. */
6679 	nand_manufacturer_cleanup(chip);
6680 }
6681 EXPORT_SYMBOL_GPL(nand_cleanup);
6682 
6683 /**
6684  * nand_release - [NAND Interface] Unregister the MTD device and free resources
6685  *		  held by the NAND device
6686  * @mtd: MTD device structure
6687  */
6688 void nand_release(struct mtd_info *mtd)
6689 {
6690 	mtd_device_unregister(mtd);
6691 	nand_cleanup(mtd_to_nand(mtd));
6692 }
6693 EXPORT_SYMBOL_GPL(nand_release);
6694 
6695 MODULE_LICENSE("GPL");
6696 MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>");
6697 MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
6698 MODULE_DESCRIPTION("Generic NAND flash driver code");
6699