xref: /openbmc/u-boot/drivers/mtd/nand/raw/nand_base.c (revision 1d6edcbf)
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 #include <common.h>
32 #if CONFIG_IS_ENABLED(OF_CONTROL)
33 #include <fdtdec.h>
34 #endif
35 #include <malloc.h>
36 #include <watchdog.h>
37 #include <linux/err.h>
38 #include <linux/compat.h>
39 #include <linux/mtd/mtd.h>
40 #include <linux/mtd/rawnand.h>
41 #include <linux/mtd/nand_ecc.h>
42 #include <linux/mtd/nand_bch.h>
43 #ifdef CONFIG_MTD_PARTITIONS
44 #include <linux/mtd/partitions.h>
45 #endif
46 #include <asm/io.h>
47 #include <linux/errno.h>
48 
49 /* Define default oob placement schemes for large and small page devices */
50 static struct nand_ecclayout nand_oob_8 = {
51 	.eccbytes = 3,
52 	.eccpos = {0, 1, 2},
53 	.oobfree = {
54 		{.offset = 3,
55 		 .length = 2},
56 		{.offset = 6,
57 		 .length = 2} }
58 };
59 
60 static struct nand_ecclayout nand_oob_16 = {
61 	.eccbytes = 6,
62 	.eccpos = {0, 1, 2, 3, 6, 7},
63 	.oobfree = {
64 		{.offset = 8,
65 		 . length = 8} }
66 };
67 
68 static struct nand_ecclayout nand_oob_64 = {
69 	.eccbytes = 24,
70 	.eccpos = {
71 		   40, 41, 42, 43, 44, 45, 46, 47,
72 		   48, 49, 50, 51, 52, 53, 54, 55,
73 		   56, 57, 58, 59, 60, 61, 62, 63},
74 	.oobfree = {
75 		{.offset = 2,
76 		 .length = 38} }
77 };
78 
79 static struct nand_ecclayout nand_oob_128 = {
80 	.eccbytes = 48,
81 	.eccpos = {
82 		   80, 81, 82, 83, 84, 85, 86, 87,
83 		   88, 89, 90, 91, 92, 93, 94, 95,
84 		   96, 97, 98, 99, 100, 101, 102, 103,
85 		   104, 105, 106, 107, 108, 109, 110, 111,
86 		   112, 113, 114, 115, 116, 117, 118, 119,
87 		   120, 121, 122, 123, 124, 125, 126, 127},
88 	.oobfree = {
89 		{.offset = 2,
90 		 .length = 78} }
91 };
92 
93 static int nand_get_device(struct mtd_info *mtd, int new_state);
94 
95 static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
96 			     struct mtd_oob_ops *ops);
97 
98 /*
99  * For devices which display every fart in the system on a separate LED. Is
100  * compiled away when LED support is disabled.
101  */
102 DEFINE_LED_TRIGGER(nand_led_trigger);
103 
104 static int check_offs_len(struct mtd_info *mtd,
105 					loff_t ofs, uint64_t len)
106 {
107 	struct nand_chip *chip = mtd_to_nand(mtd);
108 	int ret = 0;
109 
110 	/* Start address must align on block boundary */
111 	if (ofs & ((1ULL << chip->phys_erase_shift) - 1)) {
112 		pr_debug("%s: unaligned address\n", __func__);
113 		ret = -EINVAL;
114 	}
115 
116 	/* Length must align on block boundary */
117 	if (len & ((1ULL << chip->phys_erase_shift) - 1)) {
118 		pr_debug("%s: length not block aligned\n", __func__);
119 		ret = -EINVAL;
120 	}
121 
122 	return ret;
123 }
124 
125 /**
126  * nand_release_device - [GENERIC] release chip
127  * @mtd: MTD device structure
128  *
129  * Release chip lock and wake up anyone waiting on the device.
130  */
131 static void nand_release_device(struct mtd_info *mtd)
132 {
133 	struct nand_chip *chip = mtd_to_nand(mtd);
134 
135 	/* De-select the NAND device */
136 	chip->select_chip(mtd, -1);
137 }
138 
139 /**
140  * nand_read_byte - [DEFAULT] read one byte from the chip
141  * @mtd: MTD device structure
142  *
143  * Default read function for 8bit buswidth
144  */
145 uint8_t nand_read_byte(struct mtd_info *mtd)
146 {
147 	struct nand_chip *chip = mtd_to_nand(mtd);
148 	return readb(chip->IO_ADDR_R);
149 }
150 
151 /**
152  * nand_read_byte16 - [DEFAULT] read one byte endianness aware from the chip
153  * @mtd: MTD device structure
154  *
155  * Default read function for 16bit buswidth with endianness conversion.
156  *
157  */
158 static uint8_t nand_read_byte16(struct mtd_info *mtd)
159 {
160 	struct nand_chip *chip = mtd_to_nand(mtd);
161 	return (uint8_t) cpu_to_le16(readw(chip->IO_ADDR_R));
162 }
163 
164 /**
165  * nand_read_word - [DEFAULT] read one word from the chip
166  * @mtd: MTD device structure
167  *
168  * Default read function for 16bit buswidth without endianness conversion.
169  */
170 static u16 nand_read_word(struct mtd_info *mtd)
171 {
172 	struct nand_chip *chip = mtd_to_nand(mtd);
173 	return readw(chip->IO_ADDR_R);
174 }
175 
176 /**
177  * nand_select_chip - [DEFAULT] control CE line
178  * @mtd: MTD device structure
179  * @chipnr: chipnumber to select, -1 for deselect
180  *
181  * Default select function for 1 chip devices.
182  */
183 static void nand_select_chip(struct mtd_info *mtd, int chipnr)
184 {
185 	struct nand_chip *chip = mtd_to_nand(mtd);
186 
187 	switch (chipnr) {
188 	case -1:
189 		chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0 | NAND_CTRL_CHANGE);
190 		break;
191 	case 0:
192 		break;
193 
194 	default:
195 		BUG();
196 	}
197 }
198 
199 /**
200  * nand_write_byte - [DEFAULT] write single byte to chip
201  * @mtd: MTD device structure
202  * @byte: value to write
203  *
204  * Default function to write a byte to I/O[7:0]
205  */
206 static void nand_write_byte(struct mtd_info *mtd, uint8_t byte)
207 {
208 	struct nand_chip *chip = mtd_to_nand(mtd);
209 
210 	chip->write_buf(mtd, &byte, 1);
211 }
212 
213 /**
214  * nand_write_byte16 - [DEFAULT] write single byte to a chip with width 16
215  * @mtd: MTD device structure
216  * @byte: value to write
217  *
218  * Default function to write a byte to I/O[7:0] on a 16-bit wide chip.
219  */
220 static void nand_write_byte16(struct mtd_info *mtd, uint8_t byte)
221 {
222 	struct nand_chip *chip = mtd_to_nand(mtd);
223 	uint16_t word = byte;
224 
225 	/*
226 	 * It's not entirely clear what should happen to I/O[15:8] when writing
227 	 * a byte. The ONFi spec (Revision 3.1; 2012-09-19, Section 2.16) reads:
228 	 *
229 	 *    When the host supports a 16-bit bus width, only data is
230 	 *    transferred at the 16-bit width. All address and command line
231 	 *    transfers shall use only the lower 8-bits of the data bus. During
232 	 *    command transfers, the host may place any value on the upper
233 	 *    8-bits of the data bus. During address transfers, the host shall
234 	 *    set the upper 8-bits of the data bus to 00h.
235 	 *
236 	 * One user of the write_byte callback is nand_onfi_set_features. The
237 	 * four parameters are specified to be written to I/O[7:0], but this is
238 	 * neither an address nor a command transfer. Let's assume a 0 on the
239 	 * upper I/O lines is OK.
240 	 */
241 	chip->write_buf(mtd, (uint8_t *)&word, 2);
242 }
243 
244 static void iowrite8_rep(void *addr, const uint8_t *buf, int len)
245 {
246 	int i;
247 
248 	for (i = 0; i < len; i++)
249 		writeb(buf[i], addr);
250 }
251 static void ioread8_rep(void *addr, uint8_t *buf, int len)
252 {
253 	int i;
254 
255 	for (i = 0; i < len; i++)
256 		buf[i] = readb(addr);
257 }
258 
259 static void ioread16_rep(void *addr, void *buf, int len)
260 {
261 	int i;
262  	u16 *p = (u16 *) buf;
263 
264 	for (i = 0; i < len; i++)
265 		p[i] = readw(addr);
266 }
267 
268 static void iowrite16_rep(void *addr, void *buf, int len)
269 {
270 	int i;
271         u16 *p = (u16 *) buf;
272 
273         for (i = 0; i < len; i++)
274                 writew(p[i], addr);
275 }
276 
277 /**
278  * nand_write_buf - [DEFAULT] write buffer to chip
279  * @mtd: MTD device structure
280  * @buf: data buffer
281  * @len: number of bytes to write
282  *
283  * Default write function for 8bit buswidth.
284  */
285 void nand_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
286 {
287 	struct nand_chip *chip = mtd_to_nand(mtd);
288 
289 	iowrite8_rep(chip->IO_ADDR_W, buf, len);
290 }
291 
292 /**
293  * nand_read_buf - [DEFAULT] read chip data into buffer
294  * @mtd: MTD device structure
295  * @buf: buffer to store date
296  * @len: number of bytes to read
297  *
298  * Default read function for 8bit buswidth.
299  */
300 void nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
301 {
302 	struct nand_chip *chip = mtd_to_nand(mtd);
303 
304 	ioread8_rep(chip->IO_ADDR_R, buf, len);
305 }
306 
307 /**
308  * nand_write_buf16 - [DEFAULT] write buffer to chip
309  * @mtd: MTD device structure
310  * @buf: data buffer
311  * @len: number of bytes to write
312  *
313  * Default write function for 16bit buswidth.
314  */
315 void nand_write_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
316 {
317 	struct nand_chip *chip = mtd_to_nand(mtd);
318 	u16 *p = (u16 *) buf;
319 
320 	iowrite16_rep(chip->IO_ADDR_W, p, len >> 1);
321 }
322 
323 /**
324  * nand_read_buf16 - [DEFAULT] read chip data into buffer
325  * @mtd: MTD device structure
326  * @buf: buffer to store date
327  * @len: number of bytes to read
328  *
329  * Default read function for 16bit buswidth.
330  */
331 void nand_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
332 {
333 	struct nand_chip *chip = mtd_to_nand(mtd);
334 	u16 *p = (u16 *) buf;
335 
336 	ioread16_rep(chip->IO_ADDR_R, p, len >> 1);
337 }
338 
339 /**
340  * nand_block_bad - [DEFAULT] Read bad block marker from the chip
341  * @mtd: MTD device structure
342  * @ofs: offset from device start
343  *
344  * Check, if the block is bad.
345  */
346 static int nand_block_bad(struct mtd_info *mtd, loff_t ofs)
347 {
348 	int page, res = 0, i = 0;
349 	struct nand_chip *chip = mtd_to_nand(mtd);
350 	u16 bad;
351 
352 	if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
353 		ofs += mtd->erasesize - mtd->writesize;
354 
355 	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
356 
357 	do {
358 		if (chip->options & NAND_BUSWIDTH_16) {
359 			chip->cmdfunc(mtd, NAND_CMD_READOOB,
360 					chip->badblockpos & 0xFE, page);
361 			bad = cpu_to_le16(chip->read_word(mtd));
362 			if (chip->badblockpos & 0x1)
363 				bad >>= 8;
364 			else
365 				bad &= 0xFF;
366 		} else {
367 			chip->cmdfunc(mtd, NAND_CMD_READOOB, chip->badblockpos,
368 					page);
369 			bad = chip->read_byte(mtd);
370 		}
371 
372 		if (likely(chip->badblockbits == 8))
373 			res = bad != 0xFF;
374 		else
375 			res = hweight8(bad) < chip->badblockbits;
376 		ofs += mtd->writesize;
377 		page = (int)(ofs >> chip->page_shift) & chip->pagemask;
378 		i++;
379 	} while (!res && i < 2 && (chip->bbt_options & NAND_BBT_SCAN2NDPAGE));
380 
381 	return res;
382 }
383 
384 /**
385  * nand_default_block_markbad - [DEFAULT] mark a block bad via bad block marker
386  * @mtd: MTD device structure
387  * @ofs: offset from device start
388  *
389  * This is the default implementation, which can be overridden by a hardware
390  * specific driver. It provides the details for writing a bad block marker to a
391  * block.
392  */
393 static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
394 {
395 	struct nand_chip *chip = mtd_to_nand(mtd);
396 	struct mtd_oob_ops ops;
397 	uint8_t buf[2] = { 0, 0 };
398 	int ret = 0, res, i = 0;
399 
400 	memset(&ops, 0, sizeof(ops));
401 	ops.oobbuf = buf;
402 	ops.ooboffs = chip->badblockpos;
403 	if (chip->options & NAND_BUSWIDTH_16) {
404 		ops.ooboffs &= ~0x01;
405 		ops.len = ops.ooblen = 2;
406 	} else {
407 		ops.len = ops.ooblen = 1;
408 	}
409 	ops.mode = MTD_OPS_PLACE_OOB;
410 
411 	/* Write to first/last page(s) if necessary */
412 	if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
413 		ofs += mtd->erasesize - mtd->writesize;
414 	do {
415 		res = nand_do_write_oob(mtd, ofs, &ops);
416 		if (!ret)
417 			ret = res;
418 
419 		i++;
420 		ofs += mtd->writesize;
421 	} while ((chip->bbt_options & NAND_BBT_SCAN2NDPAGE) && i < 2);
422 
423 	return ret;
424 }
425 
426 /**
427  * nand_block_markbad_lowlevel - mark a block bad
428  * @mtd: MTD device structure
429  * @ofs: offset from device start
430  *
431  * This function performs the generic NAND bad block marking steps (i.e., bad
432  * block table(s) and/or marker(s)). We only allow the hardware driver to
433  * specify how to write bad block markers to OOB (chip->block_markbad).
434  *
435  * We try operations in the following order:
436  *  (1) erase the affected block, to allow OOB marker to be written cleanly
437  *  (2) write bad block marker to OOB area of affected block (unless flag
438  *      NAND_BBT_NO_OOB_BBM is present)
439  *  (3) update the BBT
440  * Note that we retain the first error encountered in (2) or (3), finish the
441  * procedures, and dump the error in the end.
442 */
443 static int nand_block_markbad_lowlevel(struct mtd_info *mtd, loff_t ofs)
444 {
445 	struct nand_chip *chip = mtd_to_nand(mtd);
446 	int res, ret = 0;
447 
448 	if (!(chip->bbt_options & NAND_BBT_NO_OOB_BBM)) {
449 		struct erase_info einfo;
450 
451 		/* Attempt erase before marking OOB */
452 		memset(&einfo, 0, sizeof(einfo));
453 		einfo.mtd = mtd;
454 		einfo.addr = ofs;
455 		einfo.len = 1ULL << chip->phys_erase_shift;
456 		nand_erase_nand(mtd, &einfo, 0);
457 
458 		/* Write bad block marker to OOB */
459 		nand_get_device(mtd, FL_WRITING);
460 		ret = chip->block_markbad(mtd, ofs);
461 		nand_release_device(mtd);
462 	}
463 
464 	/* Mark block bad in BBT */
465 	if (chip->bbt) {
466 		res = nand_markbad_bbt(mtd, ofs);
467 		if (!ret)
468 			ret = res;
469 	}
470 
471 	if (!ret)
472 		mtd->ecc_stats.badblocks++;
473 
474 	return ret;
475 }
476 
477 /**
478  * nand_check_wp - [GENERIC] check if the chip is write protected
479  * @mtd: MTD device structure
480  *
481  * Check, if the device is write protected. The function expects, that the
482  * device is already selected.
483  */
484 static int nand_check_wp(struct mtd_info *mtd)
485 {
486 	struct nand_chip *chip = mtd_to_nand(mtd);
487 
488 	/* Broken xD cards report WP despite being writable */
489 	if (chip->options & NAND_BROKEN_XD)
490 		return 0;
491 
492 	/* Check the WP bit */
493 	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
494 	return (chip->read_byte(mtd) & NAND_STATUS_WP) ? 0 : 1;
495 }
496 
497 /**
498  * nand_block_isreserved - [GENERIC] Check if a block is marked reserved.
499  * @mtd: MTD device structure
500  * @ofs: offset from device start
501  *
502  * Check if the block is marked as reserved.
503  */
504 static int nand_block_isreserved(struct mtd_info *mtd, loff_t ofs)
505 {
506 	struct nand_chip *chip = mtd_to_nand(mtd);
507 
508 	if (!chip->bbt)
509 		return 0;
510 	/* Return info from the table */
511 	return nand_isreserved_bbt(mtd, ofs);
512 }
513 
514 /**
515  * nand_block_checkbad - [GENERIC] Check if a block is marked bad
516  * @mtd: MTD device structure
517  * @ofs: offset from device start
518  * @allowbbt: 1, if its allowed to access the bbt area
519  *
520  * Check, if the block is bad. Either by reading the bad block table or
521  * calling of the scan function.
522  */
523 static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int allowbbt)
524 {
525 	struct nand_chip *chip = mtd_to_nand(mtd);
526 
527 	if (!(chip->options & NAND_SKIP_BBTSCAN) &&
528 	    !(chip->options & NAND_BBT_SCANNED)) {
529 		chip->options |= NAND_BBT_SCANNED;
530 		chip->scan_bbt(mtd);
531 	}
532 
533 	if (!chip->bbt)
534 		return chip->block_bad(mtd, ofs);
535 
536 	/* Return info from the table */
537 	return nand_isbad_bbt(mtd, ofs, allowbbt);
538 }
539 
540 /**
541  * nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
542  * @mtd: MTD device structure
543  *
544  * Wait for the ready pin after a command, and warn if a timeout occurs.
545  */
546 void nand_wait_ready(struct mtd_info *mtd)
547 {
548 	struct nand_chip *chip = mtd_to_nand(mtd);
549 	u32 timeo = (CONFIG_SYS_HZ * 400) / 1000;
550 	u32 time_start;
551 
552 	time_start = get_timer(0);
553 	/* Wait until command is processed or timeout occurs */
554 	while (get_timer(time_start) < timeo) {
555 		if (chip->dev_ready)
556 			if (chip->dev_ready(mtd))
557 				break;
558 	}
559 
560 	if (!chip->dev_ready(mtd))
561 		pr_warn("timeout while waiting for chip to become ready\n");
562 }
563 EXPORT_SYMBOL_GPL(nand_wait_ready);
564 
565 /**
566  * nand_wait_status_ready - [GENERIC] Wait for the ready status after commands.
567  * @mtd: MTD device structure
568  * @timeo: Timeout in ms
569  *
570  * Wait for status ready (i.e. command done) or timeout.
571  */
572 static void nand_wait_status_ready(struct mtd_info *mtd, unsigned long timeo)
573 {
574 	register struct nand_chip *chip = mtd_to_nand(mtd);
575 	u32 time_start;
576 
577 	timeo = (CONFIG_SYS_HZ * timeo) / 1000;
578 	time_start = get_timer(0);
579 	while (get_timer(time_start) < timeo) {
580 		if ((chip->read_byte(mtd) & NAND_STATUS_READY))
581 			break;
582 		WATCHDOG_RESET();
583 	}
584 };
585 
586 /**
587  * nand_command - [DEFAULT] Send command to NAND device
588  * @mtd: MTD device structure
589  * @command: the command to be sent
590  * @column: the column address for this command, -1 if none
591  * @page_addr: the page address for this command, -1 if none
592  *
593  * Send command to NAND device. This function is used for small page devices
594  * (512 Bytes per page).
595  */
596 static void nand_command(struct mtd_info *mtd, unsigned int command,
597 			 int column, int page_addr)
598 {
599 	register struct nand_chip *chip = mtd_to_nand(mtd);
600 	int ctrl = NAND_CTRL_CLE | NAND_CTRL_CHANGE;
601 
602 	/* Write out the command to the device */
603 	if (command == NAND_CMD_SEQIN) {
604 		int readcmd;
605 
606 		if (column >= mtd->writesize) {
607 			/* OOB area */
608 			column -= mtd->writesize;
609 			readcmd = NAND_CMD_READOOB;
610 		} else if (column < 256) {
611 			/* First 256 bytes --> READ0 */
612 			readcmd = NAND_CMD_READ0;
613 		} else {
614 			column -= 256;
615 			readcmd = NAND_CMD_READ1;
616 		}
617 		chip->cmd_ctrl(mtd, readcmd, ctrl);
618 		ctrl &= ~NAND_CTRL_CHANGE;
619 	}
620 	chip->cmd_ctrl(mtd, command, ctrl);
621 
622 	/* Address cycle, when necessary */
623 	ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE;
624 	/* Serially input address */
625 	if (column != -1) {
626 		/* Adjust columns for 16 bit buswidth */
627 		if (chip->options & NAND_BUSWIDTH_16 &&
628 				!nand_opcode_8bits(command))
629 			column >>= 1;
630 		chip->cmd_ctrl(mtd, column, ctrl);
631 		ctrl &= ~NAND_CTRL_CHANGE;
632 	}
633 	if (page_addr != -1) {
634 		chip->cmd_ctrl(mtd, page_addr, ctrl);
635 		ctrl &= ~NAND_CTRL_CHANGE;
636 		chip->cmd_ctrl(mtd, page_addr >> 8, ctrl);
637 		if (chip->options & NAND_ROW_ADDR_3)
638 			chip->cmd_ctrl(mtd, page_addr >> 16, ctrl);
639 	}
640 	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
641 
642 	/*
643 	 * Program and erase have their own busy handlers status and sequential
644 	 * in needs no delay
645 	 */
646 	switch (command) {
647 
648 	case NAND_CMD_PAGEPROG:
649 	case NAND_CMD_ERASE1:
650 	case NAND_CMD_ERASE2:
651 	case NAND_CMD_SEQIN:
652 	case NAND_CMD_STATUS:
653 	case NAND_CMD_READID:
654 	case NAND_CMD_SET_FEATURES:
655 		return;
656 
657 	case NAND_CMD_RESET:
658 		if (chip->dev_ready)
659 			break;
660 		udelay(chip->chip_delay);
661 		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
662 			       NAND_CTRL_CLE | NAND_CTRL_CHANGE);
663 		chip->cmd_ctrl(mtd,
664 			       NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
665 		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
666 		nand_wait_status_ready(mtd, 250);
667 		return;
668 
669 		/* This applies to read commands */
670 	default:
671 		/*
672 		 * If we don't have access to the busy pin, we apply the given
673 		 * command delay
674 		 */
675 		if (!chip->dev_ready) {
676 			udelay(chip->chip_delay);
677 			return;
678 		}
679 	}
680 	/*
681 	 * Apply this short delay always to ensure that we do wait tWB in
682 	 * any case on any machine.
683 	 */
684 	ndelay(100);
685 
686 	nand_wait_ready(mtd);
687 }
688 
689 /**
690  * nand_command_lp - [DEFAULT] Send command to NAND large page device
691  * @mtd: MTD device structure
692  * @command: the command to be sent
693  * @column: the column address for this command, -1 if none
694  * @page_addr: the page address for this command, -1 if none
695  *
696  * Send command to NAND device. This is the version for the new large page
697  * devices. We don't have the separate regions as we have in the small page
698  * devices. We must emulate NAND_CMD_READOOB to keep the code compatible.
699  */
700 static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
701 			    int column, int page_addr)
702 {
703 	register struct nand_chip *chip = mtd_to_nand(mtd);
704 
705 	/* Emulate NAND_CMD_READOOB */
706 	if (command == NAND_CMD_READOOB) {
707 		column += mtd->writesize;
708 		command = NAND_CMD_READ0;
709 	}
710 
711 	/* Command latch cycle */
712 	chip->cmd_ctrl(mtd, command, NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
713 
714 	if (column != -1 || page_addr != -1) {
715 		int ctrl = NAND_CTRL_CHANGE | NAND_NCE | NAND_ALE;
716 
717 		/* Serially input address */
718 		if (column != -1) {
719 			/* Adjust columns for 16 bit buswidth */
720 			if (chip->options & NAND_BUSWIDTH_16 &&
721 					!nand_opcode_8bits(command))
722 				column >>= 1;
723 			chip->cmd_ctrl(mtd, column, ctrl);
724 			ctrl &= ~NAND_CTRL_CHANGE;
725 			chip->cmd_ctrl(mtd, column >> 8, ctrl);
726 		}
727 		if (page_addr != -1) {
728 			chip->cmd_ctrl(mtd, page_addr, ctrl);
729 			chip->cmd_ctrl(mtd, page_addr >> 8,
730 				       NAND_NCE | NAND_ALE);
731 			if (chip->options & NAND_ROW_ADDR_3)
732 				chip->cmd_ctrl(mtd, page_addr >> 16,
733 					       NAND_NCE | NAND_ALE);
734 		}
735 	}
736 	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
737 
738 	/*
739 	 * Program and erase have their own busy handlers status, sequential
740 	 * in and status need no delay.
741 	 */
742 	switch (command) {
743 
744 	case NAND_CMD_CACHEDPROG:
745 	case NAND_CMD_PAGEPROG:
746 	case NAND_CMD_ERASE1:
747 	case NAND_CMD_ERASE2:
748 	case NAND_CMD_SEQIN:
749 	case NAND_CMD_RNDIN:
750 	case NAND_CMD_STATUS:
751 	case NAND_CMD_READID:
752 	case NAND_CMD_SET_FEATURES:
753 		return;
754 
755 	case NAND_CMD_RESET:
756 		if (chip->dev_ready)
757 			break;
758 		udelay(chip->chip_delay);
759 		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
760 			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
761 		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
762 			       NAND_NCE | NAND_CTRL_CHANGE);
763 		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
764 		nand_wait_status_ready(mtd, 250);
765 		return;
766 
767 	case NAND_CMD_RNDOUT:
768 		/* No ready / busy check necessary */
769 		chip->cmd_ctrl(mtd, NAND_CMD_RNDOUTSTART,
770 			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
771 		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
772 			       NAND_NCE | NAND_CTRL_CHANGE);
773 		return;
774 
775 	case NAND_CMD_READ0:
776 		chip->cmd_ctrl(mtd, NAND_CMD_READSTART,
777 			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
778 		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
779 			       NAND_NCE | NAND_CTRL_CHANGE);
780 
781 		/* This applies to read commands */
782 	default:
783 		/*
784 		 * If we don't have access to the busy pin, we apply the given
785 		 * command delay.
786 		 */
787 		if (!chip->dev_ready) {
788 			udelay(chip->chip_delay);
789 			return;
790 		}
791 	}
792 
793 	/*
794 	 * Apply this short delay always to ensure that we do wait tWB in
795 	 * any case on any machine.
796 	 */
797 	ndelay(100);
798 
799 	nand_wait_ready(mtd);
800 }
801 
802 /**
803  * panic_nand_get_device - [GENERIC] Get chip for selected access
804  * @chip: the nand chip descriptor
805  * @mtd: MTD device structure
806  * @new_state: the state which is requested
807  *
808  * Used when in panic, no locks are taken.
809  */
810 static void panic_nand_get_device(struct nand_chip *chip,
811 		      struct mtd_info *mtd, int new_state)
812 {
813 	/* Hardware controller shared among independent devices */
814 	chip->controller->active = chip;
815 	chip->state = new_state;
816 }
817 
818 /**
819  * nand_get_device - [GENERIC] Get chip for selected access
820  * @mtd: MTD device structure
821  * @new_state: the state which is requested
822  *
823  * Get the device and lock it for exclusive access
824  */
825 static int
826 nand_get_device(struct mtd_info *mtd, int new_state)
827 {
828 	struct nand_chip *chip = mtd_to_nand(mtd);
829 	chip->state = new_state;
830 	return 0;
831 }
832 
833 /**
834  * panic_nand_wait - [GENERIC] wait until the command is done
835  * @mtd: MTD device structure
836  * @chip: NAND chip structure
837  * @timeo: timeout
838  *
839  * Wait for command done. This is a helper function for nand_wait used when
840  * we are in interrupt context. May happen when in panic and trying to write
841  * an oops through mtdoops.
842  */
843 static void panic_nand_wait(struct mtd_info *mtd, struct nand_chip *chip,
844 			    unsigned long timeo)
845 {
846 	int i;
847 	for (i = 0; i < timeo; i++) {
848 		if (chip->dev_ready) {
849 			if (chip->dev_ready(mtd))
850 				break;
851 		} else {
852 			if (chip->read_byte(mtd) & NAND_STATUS_READY)
853 				break;
854 		}
855 		mdelay(1);
856 	}
857 }
858 
859 /**
860  * nand_wait - [DEFAULT] wait until the command is done
861  * @mtd: MTD device structure
862  * @chip: NAND chip structure
863  *
864  * Wait for command done. This applies to erase and program only.
865  */
866 static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
867 {
868 	int status;
869 	unsigned long timeo = 400;
870 
871 	led_trigger_event(nand_led_trigger, LED_FULL);
872 
873 	/*
874 	 * Apply this short delay always to ensure that we do wait tWB in any
875 	 * case on any machine.
876 	 */
877 	ndelay(100);
878 
879 	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
880 
881  	u32 timer = (CONFIG_SYS_HZ * timeo) / 1000;
882  	u32 time_start;
883 
884  	time_start = get_timer(0);
885  	while (get_timer(time_start) < timer) {
886 		if (chip->dev_ready) {
887 			if (chip->dev_ready(mtd))
888 				break;
889 		} else {
890 			if (chip->read_byte(mtd) & NAND_STATUS_READY)
891 				break;
892 		}
893 	}
894 	led_trigger_event(nand_led_trigger, LED_OFF);
895 
896 	status = (int)chip->read_byte(mtd);
897 	/* This can happen if in case of timeout or buggy dev_ready */
898 	WARN_ON(!(status & NAND_STATUS_READY));
899 	return status;
900 }
901 
902 /**
903  * nand_reset_data_interface - Reset data interface and timings
904  * @chip: The NAND chip
905  * @chipnr: Internal die id
906  *
907  * Reset the Data interface and timings to ONFI mode 0.
908  *
909  * Returns 0 for success or negative error code otherwise.
910  */
911 static int nand_reset_data_interface(struct nand_chip *chip, int chipnr)
912 {
913 	struct mtd_info *mtd = nand_to_mtd(chip);
914 	const struct nand_data_interface *conf;
915 	int ret;
916 
917 	if (!chip->setup_data_interface)
918 		return 0;
919 
920 	/*
921 	 * The ONFI specification says:
922 	 * "
923 	 * To transition from NV-DDR or NV-DDR2 to the SDR data
924 	 * interface, the host shall use the Reset (FFh) command
925 	 * using SDR timing mode 0. A device in any timing mode is
926 	 * required to recognize Reset (FFh) command issued in SDR
927 	 * timing mode 0.
928 	 * "
929 	 *
930 	 * Configure the data interface in SDR mode and set the
931 	 * timings to timing mode 0.
932 	 */
933 
934 	conf = nand_get_default_data_interface();
935 	ret = chip->setup_data_interface(mtd, chipnr, conf);
936 	if (ret)
937 		pr_err("Failed to configure data interface to SDR timing mode 0\n");
938 
939 	return ret;
940 }
941 
942 /**
943  * nand_setup_data_interface - Setup the best data interface and timings
944  * @chip: The NAND chip
945  * @chipnr: Internal die id
946  *
947  * Find and configure the best data interface and NAND timings supported by
948  * the chip and the driver.
949  * First tries to retrieve supported timing modes from ONFI information,
950  * and if the NAND chip does not support ONFI, relies on the
951  * ->onfi_timing_mode_default specified in the nand_ids table.
952  *
953  * Returns 0 for success or negative error code otherwise.
954  */
955 static int nand_setup_data_interface(struct nand_chip *chip, int chipnr)
956 {
957 	struct mtd_info *mtd = nand_to_mtd(chip);
958 	int ret;
959 
960 	if (!chip->setup_data_interface || !chip->data_interface)
961 		return 0;
962 
963 	/*
964 	 * Ensure the timing mode has been changed on the chip side
965 	 * before changing timings on the controller side.
966 	 */
967 	if (chip->onfi_version) {
968 		u8 tmode_param[ONFI_SUBFEATURE_PARAM_LEN] = {
969 			chip->onfi_timing_mode_default,
970 		};
971 
972 		ret = chip->onfi_set_features(mtd, chip,
973 				ONFI_FEATURE_ADDR_TIMING_MODE,
974 				tmode_param);
975 		if (ret)
976 			goto err;
977 	}
978 
979 	ret = chip->setup_data_interface(mtd, chipnr, chip->data_interface);
980 err:
981 	return ret;
982 }
983 
984 /**
985  * nand_init_data_interface - find the best data interface and timings
986  * @chip: The NAND chip
987  *
988  * Find the best data interface and NAND timings supported by the chip
989  * and the driver.
990  * First tries to retrieve supported timing modes from ONFI information,
991  * and if the NAND chip does not support ONFI, relies on the
992  * ->onfi_timing_mode_default specified in the nand_ids table. After this
993  * function nand_chip->data_interface is initialized with the best timing mode
994  * available.
995  *
996  * Returns 0 for success or negative error code otherwise.
997  */
998 static int nand_init_data_interface(struct nand_chip *chip)
999 {
1000 	struct mtd_info *mtd = nand_to_mtd(chip);
1001 	int modes, mode, ret;
1002 
1003 	if (!chip->setup_data_interface)
1004 		return 0;
1005 
1006 	/*
1007 	 * First try to identify the best timings from ONFI parameters and
1008 	 * if the NAND does not support ONFI, fallback to the default ONFI
1009 	 * timing mode.
1010 	 */
1011 	modes = onfi_get_async_timing_mode(chip);
1012 	if (modes == ONFI_TIMING_MODE_UNKNOWN) {
1013 		if (!chip->onfi_timing_mode_default)
1014 			return 0;
1015 
1016 		modes = GENMASK(chip->onfi_timing_mode_default, 0);
1017 	}
1018 
1019 	chip->data_interface = kzalloc(sizeof(*chip->data_interface),
1020 				       GFP_KERNEL);
1021 	if (!chip->data_interface)
1022 		return -ENOMEM;
1023 
1024 	for (mode = fls(modes) - 1; mode >= 0; mode--) {
1025 		ret = onfi_init_data_interface(chip, chip->data_interface,
1026 					       NAND_SDR_IFACE, mode);
1027 		if (ret)
1028 			continue;
1029 
1030 		/* Pass -1 to only */
1031 		ret = chip->setup_data_interface(mtd,
1032 						 NAND_DATA_IFACE_CHECK_ONLY,
1033 						 chip->data_interface);
1034 		if (!ret) {
1035 			chip->onfi_timing_mode_default = mode;
1036 			break;
1037 		}
1038 	}
1039 
1040 	return 0;
1041 }
1042 
1043 static void __maybe_unused nand_release_data_interface(struct nand_chip *chip)
1044 {
1045 	kfree(chip->data_interface);
1046 }
1047 
1048 /**
1049  * nand_reset - Reset and initialize a NAND device
1050  * @chip: The NAND chip
1051  * @chipnr: Internal die id
1052  *
1053  * Returns 0 for success or negative error code otherwise
1054  */
1055 int nand_reset(struct nand_chip *chip, int chipnr)
1056 {
1057 	struct mtd_info *mtd = nand_to_mtd(chip);
1058 	int ret;
1059 
1060 	ret = nand_reset_data_interface(chip, chipnr);
1061 	if (ret)
1062 		return ret;
1063 
1064 	/*
1065 	 * The CS line has to be released before we can apply the new NAND
1066 	 * interface settings, hence this weird ->select_chip() dance.
1067 	 */
1068 	chip->select_chip(mtd, chipnr);
1069 	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
1070 	chip->select_chip(mtd, -1);
1071 
1072 	chip->select_chip(mtd, chipnr);
1073 	ret = nand_setup_data_interface(chip, chipnr);
1074 	chip->select_chip(mtd, -1);
1075 	if (ret)
1076 		return ret;
1077 
1078 	return 0;
1079 }
1080 
1081 /**
1082  * nand_check_erased_buf - check if a buffer contains (almost) only 0xff data
1083  * @buf: buffer to test
1084  * @len: buffer length
1085  * @bitflips_threshold: maximum number of bitflips
1086  *
1087  * Check if a buffer contains only 0xff, which means the underlying region
1088  * has been erased and is ready to be programmed.
1089  * The bitflips_threshold specify the maximum number of bitflips before
1090  * considering the region is not erased.
1091  * Note: The logic of this function has been extracted from the memweight
1092  * implementation, except that nand_check_erased_buf function exit before
1093  * testing the whole buffer if the number of bitflips exceed the
1094  * bitflips_threshold value.
1095  *
1096  * Returns a positive number of bitflips less than or equal to
1097  * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the
1098  * threshold.
1099  */
1100 static int nand_check_erased_buf(void *buf, int len, int bitflips_threshold)
1101 {
1102 	const unsigned char *bitmap = buf;
1103 	int bitflips = 0;
1104 	int weight;
1105 
1106 	for (; len && ((uintptr_t)bitmap) % sizeof(long);
1107 	     len--, bitmap++) {
1108 		weight = hweight8(*bitmap);
1109 		bitflips += BITS_PER_BYTE - weight;
1110 		if (unlikely(bitflips > bitflips_threshold))
1111 			return -EBADMSG;
1112 	}
1113 
1114 	for (; len >= 4; len -= 4, bitmap += 4) {
1115 		weight = hweight32(*((u32 *)bitmap));
1116 		bitflips += 32 - weight;
1117 		if (unlikely(bitflips > bitflips_threshold))
1118 			return -EBADMSG;
1119 	}
1120 
1121 	for (; len > 0; len--, bitmap++) {
1122 		weight = hweight8(*bitmap);
1123 		bitflips += BITS_PER_BYTE - weight;
1124 		if (unlikely(bitflips > bitflips_threshold))
1125 			return -EBADMSG;
1126 	}
1127 
1128 	return bitflips;
1129 }
1130 
1131 /**
1132  * nand_check_erased_ecc_chunk - check if an ECC chunk contains (almost) only
1133  *				 0xff data
1134  * @data: data buffer to test
1135  * @datalen: data length
1136  * @ecc: ECC buffer
1137  * @ecclen: ECC length
1138  * @extraoob: extra OOB buffer
1139  * @extraooblen: extra OOB length
1140  * @bitflips_threshold: maximum number of bitflips
1141  *
1142  * Check if a data buffer and its associated ECC and OOB data contains only
1143  * 0xff pattern, which means the underlying region has been erased and is
1144  * ready to be programmed.
1145  * The bitflips_threshold specify the maximum number of bitflips before
1146  * considering the region as not erased.
1147  *
1148  * Note:
1149  * 1/ ECC algorithms are working on pre-defined block sizes which are usually
1150  *    different from the NAND page size. When fixing bitflips, ECC engines will
1151  *    report the number of errors per chunk, and the NAND core infrastructure
1152  *    expect you to return the maximum number of bitflips for the whole page.
1153  *    This is why you should always use this function on a single chunk and
1154  *    not on the whole page. After checking each chunk you should update your
1155  *    max_bitflips value accordingly.
1156  * 2/ When checking for bitflips in erased pages you should not only check
1157  *    the payload data but also their associated ECC data, because a user might
1158  *    have programmed almost all bits to 1 but a few. In this case, we
1159  *    shouldn't consider the chunk as erased, and checking ECC bytes prevent
1160  *    this case.
1161  * 3/ The extraoob argument is optional, and should be used if some of your OOB
1162  *    data are protected by the ECC engine.
1163  *    It could also be used if you support subpages and want to attach some
1164  *    extra OOB data to an ECC chunk.
1165  *
1166  * Returns a positive number of bitflips less than or equal to
1167  * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the
1168  * threshold. In case of success, the passed buffers are filled with 0xff.
1169  */
1170 int nand_check_erased_ecc_chunk(void *data, int datalen,
1171 				void *ecc, int ecclen,
1172 				void *extraoob, int extraooblen,
1173 				int bitflips_threshold)
1174 {
1175 	int data_bitflips = 0, ecc_bitflips = 0, extraoob_bitflips = 0;
1176 
1177 	data_bitflips = nand_check_erased_buf(data, datalen,
1178 					      bitflips_threshold);
1179 	if (data_bitflips < 0)
1180 		return data_bitflips;
1181 
1182 	bitflips_threshold -= data_bitflips;
1183 
1184 	ecc_bitflips = nand_check_erased_buf(ecc, ecclen, bitflips_threshold);
1185 	if (ecc_bitflips < 0)
1186 		return ecc_bitflips;
1187 
1188 	bitflips_threshold -= ecc_bitflips;
1189 
1190 	extraoob_bitflips = nand_check_erased_buf(extraoob, extraooblen,
1191 						  bitflips_threshold);
1192 	if (extraoob_bitflips < 0)
1193 		return extraoob_bitflips;
1194 
1195 	if (data_bitflips)
1196 		memset(data, 0xff, datalen);
1197 
1198 	if (ecc_bitflips)
1199 		memset(ecc, 0xff, ecclen);
1200 
1201 	if (extraoob_bitflips)
1202 		memset(extraoob, 0xff, extraooblen);
1203 
1204 	return data_bitflips + ecc_bitflips + extraoob_bitflips;
1205 }
1206 EXPORT_SYMBOL(nand_check_erased_ecc_chunk);
1207 
1208 /**
1209  * nand_read_page_raw - [INTERN] read raw page data without ecc
1210  * @mtd: mtd info structure
1211  * @chip: nand chip info structure
1212  * @buf: buffer to store read data
1213  * @oob_required: caller requires OOB data read to chip->oob_poi
1214  * @page: page number to read
1215  *
1216  * Not for syndrome calculating ECC controllers, which use a special oob layout.
1217  */
1218 static int nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
1219 			      uint8_t *buf, int oob_required, int page)
1220 {
1221 	chip->read_buf(mtd, buf, mtd->writesize);
1222 	if (oob_required)
1223 		chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1224 	return 0;
1225 }
1226 
1227 /**
1228  * nand_read_page_raw_syndrome - [INTERN] read raw page data without ecc
1229  * @mtd: mtd info structure
1230  * @chip: nand chip info structure
1231  * @buf: buffer to store read data
1232  * @oob_required: caller requires OOB data read to chip->oob_poi
1233  * @page: page number to read
1234  *
1235  * We need a special oob layout and handling even when OOB isn't used.
1236  */
1237 static int nand_read_page_raw_syndrome(struct mtd_info *mtd,
1238 				       struct nand_chip *chip, uint8_t *buf,
1239 				       int oob_required, int page)
1240 {
1241 	int eccsize = chip->ecc.size;
1242 	int eccbytes = chip->ecc.bytes;
1243 	uint8_t *oob = chip->oob_poi;
1244 	int steps, size;
1245 
1246 	for (steps = chip->ecc.steps; steps > 0; steps--) {
1247 		chip->read_buf(mtd, buf, eccsize);
1248 		buf += eccsize;
1249 
1250 		if (chip->ecc.prepad) {
1251 			chip->read_buf(mtd, oob, chip->ecc.prepad);
1252 			oob += chip->ecc.prepad;
1253 		}
1254 
1255 		chip->read_buf(mtd, oob, eccbytes);
1256 		oob += eccbytes;
1257 
1258 		if (chip->ecc.postpad) {
1259 			chip->read_buf(mtd, oob, chip->ecc.postpad);
1260 			oob += chip->ecc.postpad;
1261 		}
1262 	}
1263 
1264 	size = mtd->oobsize - (oob - chip->oob_poi);
1265 	if (size)
1266 		chip->read_buf(mtd, oob, size);
1267 
1268 	return 0;
1269 }
1270 
1271 /**
1272  * nand_read_page_swecc - [REPLACEABLE] software ECC based page read function
1273  * @mtd: mtd info structure
1274  * @chip: nand chip info structure
1275  * @buf: buffer to store read data
1276  * @oob_required: caller requires OOB data read to chip->oob_poi
1277  * @page: page number to read
1278  */
1279 static int nand_read_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
1280 				uint8_t *buf, int oob_required, int page)
1281 {
1282 	int i, eccsize = chip->ecc.size;
1283 	int eccbytes = chip->ecc.bytes;
1284 	int eccsteps = chip->ecc.steps;
1285 	uint8_t *p = buf;
1286 	uint8_t *ecc_calc = chip->buffers->ecccalc;
1287 	uint8_t *ecc_code = chip->buffers->ecccode;
1288 	uint32_t *eccpos = chip->ecc.layout->eccpos;
1289 	unsigned int max_bitflips = 0;
1290 
1291 	chip->ecc.read_page_raw(mtd, chip, buf, 1, page);
1292 
1293 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
1294 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1295 
1296 	for (i = 0; i < chip->ecc.total; i++)
1297 		ecc_code[i] = chip->oob_poi[eccpos[i]];
1298 
1299 	eccsteps = chip->ecc.steps;
1300 	p = buf;
1301 
1302 	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1303 		int stat;
1304 
1305 		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
1306 		if (stat < 0) {
1307 			mtd->ecc_stats.failed++;
1308 		} else {
1309 			mtd->ecc_stats.corrected += stat;
1310 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1311 		}
1312 	}
1313 	return max_bitflips;
1314 }
1315 
1316 /**
1317  * nand_read_subpage - [REPLACEABLE] ECC based sub-page read function
1318  * @mtd: mtd info structure
1319  * @chip: nand chip info structure
1320  * @data_offs: offset of requested data within the page
1321  * @readlen: data length
1322  * @bufpoi: buffer to store read data
1323  * @page: page number to read
1324  */
1325 static int nand_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
1326 			uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi,
1327 			int page)
1328 {
1329 	int start_step, end_step, num_steps;
1330 	uint32_t *eccpos = chip->ecc.layout->eccpos;
1331 	uint8_t *p;
1332 	int data_col_addr, i, gaps = 0;
1333 	int datafrag_len, eccfrag_len, aligned_len, aligned_pos;
1334 	int busw = (chip->options & NAND_BUSWIDTH_16) ? 2 : 1;
1335 	int index;
1336 	unsigned int max_bitflips = 0;
1337 
1338 	/* Column address within the page aligned to ECC size (256bytes) */
1339 	start_step = data_offs / chip->ecc.size;
1340 	end_step = (data_offs + readlen - 1) / chip->ecc.size;
1341 	num_steps = end_step - start_step + 1;
1342 	index = start_step * chip->ecc.bytes;
1343 
1344 	/* Data size aligned to ECC ecc.size */
1345 	datafrag_len = num_steps * chip->ecc.size;
1346 	eccfrag_len = num_steps * chip->ecc.bytes;
1347 
1348 	data_col_addr = start_step * chip->ecc.size;
1349 	/* If we read not a page aligned data */
1350 	if (data_col_addr != 0)
1351 		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, data_col_addr, -1);
1352 
1353 	p = bufpoi + data_col_addr;
1354 	chip->read_buf(mtd, p, datafrag_len);
1355 
1356 	/* Calculate ECC */
1357 	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size)
1358 		chip->ecc.calculate(mtd, p, &chip->buffers->ecccalc[i]);
1359 
1360 	/*
1361 	 * The performance is faster if we position offsets according to
1362 	 * ecc.pos. Let's make sure that there are no gaps in ECC positions.
1363 	 */
1364 	for (i = 0; i < eccfrag_len - 1; i++) {
1365 		if (eccpos[i + index] + 1 != eccpos[i + index + 1]) {
1366 			gaps = 1;
1367 			break;
1368 		}
1369 	}
1370 	if (gaps) {
1371 		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);
1372 		chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1373 	} else {
1374 		/*
1375 		 * Send the command to read the particular ECC bytes take care
1376 		 * about buswidth alignment in read_buf.
1377 		 */
1378 		aligned_pos = eccpos[index] & ~(busw - 1);
1379 		aligned_len = eccfrag_len;
1380 		if (eccpos[index] & (busw - 1))
1381 			aligned_len++;
1382 		if (eccpos[index + (num_steps * chip->ecc.bytes)] & (busw - 1))
1383 			aligned_len++;
1384 
1385 		chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
1386 					mtd->writesize + aligned_pos, -1);
1387 		chip->read_buf(mtd, &chip->oob_poi[aligned_pos], aligned_len);
1388 	}
1389 
1390 	for (i = 0; i < eccfrag_len; i++)
1391 		chip->buffers->ecccode[i] = chip->oob_poi[eccpos[i + index]];
1392 
1393 	p = bufpoi + data_col_addr;
1394 	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size) {
1395 		int stat;
1396 
1397 		stat = chip->ecc.correct(mtd, p,
1398 			&chip->buffers->ecccode[i], &chip->buffers->ecccalc[i]);
1399 		if (stat == -EBADMSG &&
1400 		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
1401 			/* check for empty pages with bitflips */
1402 			stat = nand_check_erased_ecc_chunk(p, chip->ecc.size,
1403 						&chip->buffers->ecccode[i],
1404 						chip->ecc.bytes,
1405 						NULL, 0,
1406 						chip->ecc.strength);
1407 		}
1408 
1409 		if (stat < 0) {
1410 			mtd->ecc_stats.failed++;
1411 		} else {
1412 			mtd->ecc_stats.corrected += stat;
1413 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1414 		}
1415 	}
1416 	return max_bitflips;
1417 }
1418 
1419 /**
1420  * nand_read_page_hwecc - [REPLACEABLE] hardware ECC based page read function
1421  * @mtd: mtd info structure
1422  * @chip: nand chip info structure
1423  * @buf: buffer to store read data
1424  * @oob_required: caller requires OOB data read to chip->oob_poi
1425  * @page: page number to read
1426  *
1427  * Not for syndrome calculating ECC controllers which need a special oob layout.
1428  */
1429 static int nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
1430 				uint8_t *buf, int oob_required, int page)
1431 {
1432 	int i, eccsize = chip->ecc.size;
1433 	int eccbytes = chip->ecc.bytes;
1434 	int eccsteps = chip->ecc.steps;
1435 	uint8_t *p = buf;
1436 	uint8_t *ecc_calc = chip->buffers->ecccalc;
1437 	uint8_t *ecc_code = chip->buffers->ecccode;
1438 	uint32_t *eccpos = chip->ecc.layout->eccpos;
1439 	unsigned int max_bitflips = 0;
1440 
1441 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1442 		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1443 		chip->read_buf(mtd, p, eccsize);
1444 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1445 	}
1446 	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1447 
1448 	for (i = 0; i < chip->ecc.total; i++)
1449 		ecc_code[i] = chip->oob_poi[eccpos[i]];
1450 
1451 	eccsteps = chip->ecc.steps;
1452 	p = buf;
1453 
1454 	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1455 		int stat;
1456 
1457 		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
1458 		if (stat == -EBADMSG &&
1459 		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
1460 			/* check for empty pages with bitflips */
1461 			stat = nand_check_erased_ecc_chunk(p, eccsize,
1462 						&ecc_code[i], eccbytes,
1463 						NULL, 0,
1464 						chip->ecc.strength);
1465 		}
1466 
1467 		if (stat < 0) {
1468 			mtd->ecc_stats.failed++;
1469 		} else {
1470 			mtd->ecc_stats.corrected += stat;
1471 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1472 		}
1473 	}
1474 	return max_bitflips;
1475 }
1476 
1477 /**
1478  * nand_read_page_hwecc_oob_first - [REPLACEABLE] hw ecc, read oob first
1479  * @mtd: mtd info structure
1480  * @chip: nand chip info structure
1481  * @buf: buffer to store read data
1482  * @oob_required: caller requires OOB data read to chip->oob_poi
1483  * @page: page number to read
1484  *
1485  * Hardware ECC for large page chips, require OOB to be read first. For this
1486  * ECC mode, the write_page method is re-used from ECC_HW. These methods
1487  * read/write ECC from the OOB area, unlike the ECC_HW_SYNDROME support with
1488  * multiple ECC steps, follows the "infix ECC" scheme and reads/writes ECC from
1489  * the data area, by overwriting the NAND manufacturer bad block markings.
1490  */
1491 static int nand_read_page_hwecc_oob_first(struct mtd_info *mtd,
1492 	struct nand_chip *chip, uint8_t *buf, int oob_required, int page)
1493 {
1494 	int i, eccsize = chip->ecc.size;
1495 	int eccbytes = chip->ecc.bytes;
1496 	int eccsteps = chip->ecc.steps;
1497 	uint8_t *p = buf;
1498 	uint8_t *ecc_code = chip->buffers->ecccode;
1499 	uint32_t *eccpos = chip->ecc.layout->eccpos;
1500 	uint8_t *ecc_calc = chip->buffers->ecccalc;
1501 	unsigned int max_bitflips = 0;
1502 
1503 	/* Read the OOB area first */
1504 	chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
1505 	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1506 	chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
1507 
1508 	for (i = 0; i < chip->ecc.total; i++)
1509 		ecc_code[i] = chip->oob_poi[eccpos[i]];
1510 
1511 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1512 		int stat;
1513 
1514 		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1515 		chip->read_buf(mtd, p, eccsize);
1516 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1517 
1518 		stat = chip->ecc.correct(mtd, p, &ecc_code[i], NULL);
1519 		if (stat == -EBADMSG &&
1520 		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
1521 			/* check for empty pages with bitflips */
1522 			stat = nand_check_erased_ecc_chunk(p, eccsize,
1523 						&ecc_code[i], eccbytes,
1524 						NULL, 0,
1525 						chip->ecc.strength);
1526 		}
1527 
1528 		if (stat < 0) {
1529 			mtd->ecc_stats.failed++;
1530 		} else {
1531 			mtd->ecc_stats.corrected += stat;
1532 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1533 		}
1534 	}
1535 	return max_bitflips;
1536 }
1537 
1538 /**
1539  * nand_read_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page read
1540  * @mtd: mtd info structure
1541  * @chip: nand chip info structure
1542  * @buf: buffer to store read data
1543  * @oob_required: caller requires OOB data read to chip->oob_poi
1544  * @page: page number to read
1545  *
1546  * The hw generator calculates the error syndrome automatically. Therefore we
1547  * need a special oob layout and handling.
1548  */
1549 static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
1550 				   uint8_t *buf, int oob_required, int page)
1551 {
1552 	int i, eccsize = chip->ecc.size;
1553 	int eccbytes = chip->ecc.bytes;
1554 	int eccsteps = chip->ecc.steps;
1555 	int eccpadbytes = eccbytes + chip->ecc.prepad + chip->ecc.postpad;
1556 	uint8_t *p = buf;
1557 	uint8_t *oob = chip->oob_poi;
1558 	unsigned int max_bitflips = 0;
1559 
1560 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1561 		int stat;
1562 
1563 		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1564 		chip->read_buf(mtd, p, eccsize);
1565 
1566 		if (chip->ecc.prepad) {
1567 			chip->read_buf(mtd, oob, chip->ecc.prepad);
1568 			oob += chip->ecc.prepad;
1569 		}
1570 
1571 		chip->ecc.hwctl(mtd, NAND_ECC_READSYN);
1572 		chip->read_buf(mtd, oob, eccbytes);
1573 		stat = chip->ecc.correct(mtd, p, oob, NULL);
1574 
1575 		oob += eccbytes;
1576 
1577 		if (chip->ecc.postpad) {
1578 			chip->read_buf(mtd, oob, chip->ecc.postpad);
1579 			oob += chip->ecc.postpad;
1580 		}
1581 
1582 		if (stat == -EBADMSG &&
1583 		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
1584 			/* check for empty pages with bitflips */
1585 			stat = nand_check_erased_ecc_chunk(p, chip->ecc.size,
1586 							   oob - eccpadbytes,
1587 							   eccpadbytes,
1588 							   NULL, 0,
1589 							   chip->ecc.strength);
1590 		}
1591 
1592 		if (stat < 0) {
1593 			mtd->ecc_stats.failed++;
1594 		} else {
1595 			mtd->ecc_stats.corrected += stat;
1596 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1597 		}
1598 	}
1599 
1600 	/* Calculate remaining oob bytes */
1601 	i = mtd->oobsize - (oob - chip->oob_poi);
1602 	if (i)
1603 		chip->read_buf(mtd, oob, i);
1604 
1605 	return max_bitflips;
1606 }
1607 
1608 /**
1609  * nand_transfer_oob - [INTERN] Transfer oob to client buffer
1610  * @chip: nand chip structure
1611  * @oob: oob destination address
1612  * @ops: oob ops structure
1613  * @len: size of oob to transfer
1614  */
1615 static uint8_t *nand_transfer_oob(struct nand_chip *chip, uint8_t *oob,
1616 				  struct mtd_oob_ops *ops, size_t len)
1617 {
1618 	switch (ops->mode) {
1619 
1620 	case MTD_OPS_PLACE_OOB:
1621 	case MTD_OPS_RAW:
1622 		memcpy(oob, chip->oob_poi + ops->ooboffs, len);
1623 		return oob + len;
1624 
1625 	case MTD_OPS_AUTO_OOB: {
1626 		struct nand_oobfree *free = chip->ecc.layout->oobfree;
1627 		uint32_t boffs = 0, roffs = ops->ooboffs;
1628 		size_t bytes = 0;
1629 
1630 		for (; free->length && len; free++, len -= bytes) {
1631 			/* Read request not from offset 0? */
1632 			if (unlikely(roffs)) {
1633 				if (roffs >= free->length) {
1634 					roffs -= free->length;
1635 					continue;
1636 				}
1637 				boffs = free->offset + roffs;
1638 				bytes = min_t(size_t, len,
1639 					      (free->length - roffs));
1640 				roffs = 0;
1641 			} else {
1642 				bytes = min_t(size_t, len, free->length);
1643 				boffs = free->offset;
1644 			}
1645 			memcpy(oob, chip->oob_poi + boffs, bytes);
1646 			oob += bytes;
1647 		}
1648 		return oob;
1649 	}
1650 	default:
1651 		BUG();
1652 	}
1653 	return NULL;
1654 }
1655 
1656 /**
1657  * nand_setup_read_retry - [INTERN] Set the READ RETRY mode
1658  * @mtd: MTD device structure
1659  * @retry_mode: the retry mode to use
1660  *
1661  * Some vendors supply a special command to shift the Vt threshold, to be used
1662  * when there are too many bitflips in a page (i.e., ECC error). After setting
1663  * a new threshold, the host should retry reading the page.
1664  */
1665 static int nand_setup_read_retry(struct mtd_info *mtd, int retry_mode)
1666 {
1667 	struct nand_chip *chip = mtd_to_nand(mtd);
1668 
1669 	pr_debug("setting READ RETRY mode %d\n", retry_mode);
1670 
1671 	if (retry_mode >= chip->read_retries)
1672 		return -EINVAL;
1673 
1674 	if (!chip->setup_read_retry)
1675 		return -EOPNOTSUPP;
1676 
1677 	return chip->setup_read_retry(mtd, retry_mode);
1678 }
1679 
1680 /**
1681  * nand_do_read_ops - [INTERN] Read data with ECC
1682  * @mtd: MTD device structure
1683  * @from: offset to read from
1684  * @ops: oob ops structure
1685  *
1686  * Internal function. Called with chip held.
1687  */
1688 static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
1689 			    struct mtd_oob_ops *ops)
1690 {
1691 	int chipnr, page, realpage, col, bytes, aligned, oob_required;
1692 	struct nand_chip *chip = mtd_to_nand(mtd);
1693 	int ret = 0;
1694 	uint32_t readlen = ops->len;
1695 	uint32_t oobreadlen = ops->ooblen;
1696 	uint32_t max_oobsize = mtd_oobavail(mtd, ops);
1697 
1698 	uint8_t *bufpoi, *oob, *buf;
1699 	int use_bufpoi;
1700 	unsigned int max_bitflips = 0;
1701 	int retry_mode = 0;
1702 	bool ecc_fail = false;
1703 
1704 	chipnr = (int)(from >> chip->chip_shift);
1705 	chip->select_chip(mtd, chipnr);
1706 
1707 	realpage = (int)(from >> chip->page_shift);
1708 	page = realpage & chip->pagemask;
1709 
1710 	col = (int)(from & (mtd->writesize - 1));
1711 
1712 	buf = ops->datbuf;
1713 	oob = ops->oobbuf;
1714 	oob_required = oob ? 1 : 0;
1715 
1716 	while (1) {
1717 		unsigned int ecc_failures = mtd->ecc_stats.failed;
1718 
1719 		WATCHDOG_RESET();
1720 		bytes = min(mtd->writesize - col, readlen);
1721 		aligned = (bytes == mtd->writesize);
1722 
1723 		if (!aligned)
1724 			use_bufpoi = 1;
1725 		else if (chip->options & NAND_USE_BOUNCE_BUFFER)
1726 			use_bufpoi = !IS_ALIGNED((unsigned long)buf,
1727 						 chip->buf_align);
1728 		else
1729 			use_bufpoi = 0;
1730 
1731 		/* Is the current page in the buffer? */
1732 		if (realpage != chip->pagebuf || oob) {
1733 			bufpoi = use_bufpoi ? chip->buffers->databuf : buf;
1734 
1735 			if (use_bufpoi && aligned)
1736 				pr_debug("%s: using read bounce buffer for buf@%p\n",
1737 						 __func__, buf);
1738 
1739 read_retry:
1740 			if (nand_standard_page_accessors(&chip->ecc))
1741 				chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
1742 
1743 			/*
1744 			 * Now read the page into the buffer.  Absent an error,
1745 			 * the read methods return max bitflips per ecc step.
1746 			 */
1747 			if (unlikely(ops->mode == MTD_OPS_RAW))
1748 				ret = chip->ecc.read_page_raw(mtd, chip, bufpoi,
1749 							      oob_required,
1750 							      page);
1751 			else if (!aligned && NAND_HAS_SUBPAGE_READ(chip) &&
1752 				 !oob)
1753 				ret = chip->ecc.read_subpage(mtd, chip,
1754 							col, bytes, bufpoi,
1755 							page);
1756 			else
1757 				ret = chip->ecc.read_page(mtd, chip, bufpoi,
1758 							  oob_required, page);
1759 			if (ret < 0) {
1760 				if (use_bufpoi)
1761 					/* Invalidate page cache */
1762 					chip->pagebuf = -1;
1763 				break;
1764 			}
1765 
1766 			max_bitflips = max_t(unsigned int, max_bitflips, ret);
1767 
1768 			/* Transfer not aligned data */
1769 			if (use_bufpoi) {
1770 				if (!NAND_HAS_SUBPAGE_READ(chip) && !oob &&
1771 				    !(mtd->ecc_stats.failed - ecc_failures) &&
1772 				    (ops->mode != MTD_OPS_RAW)) {
1773 					chip->pagebuf = realpage;
1774 					chip->pagebuf_bitflips = ret;
1775 				} else {
1776 					/* Invalidate page cache */
1777 					chip->pagebuf = -1;
1778 				}
1779 				memcpy(buf, chip->buffers->databuf + col, bytes);
1780 			}
1781 
1782 			if (unlikely(oob)) {
1783 				int toread = min(oobreadlen, max_oobsize);
1784 
1785 				if (toread) {
1786 					oob = nand_transfer_oob(chip,
1787 						oob, ops, toread);
1788 					oobreadlen -= toread;
1789 				}
1790 			}
1791 
1792 			if (chip->options & NAND_NEED_READRDY) {
1793 				/* Apply delay or wait for ready/busy pin */
1794 				if (!chip->dev_ready)
1795 					udelay(chip->chip_delay);
1796 				else
1797 					nand_wait_ready(mtd);
1798 			}
1799 
1800 			if (mtd->ecc_stats.failed - ecc_failures) {
1801 				if (retry_mode + 1 < chip->read_retries) {
1802 					retry_mode++;
1803 					ret = nand_setup_read_retry(mtd,
1804 							retry_mode);
1805 					if (ret < 0)
1806 						break;
1807 
1808 					/* Reset failures; retry */
1809 					mtd->ecc_stats.failed = ecc_failures;
1810 					goto read_retry;
1811 				} else {
1812 					/* No more retry modes; real failure */
1813 					ecc_fail = true;
1814 				}
1815 			}
1816 
1817 			buf += bytes;
1818 		} else {
1819 			memcpy(buf, chip->buffers->databuf + col, bytes);
1820 			buf += bytes;
1821 			max_bitflips = max_t(unsigned int, max_bitflips,
1822 					     chip->pagebuf_bitflips);
1823 		}
1824 
1825 		readlen -= bytes;
1826 
1827 		/* Reset to retry mode 0 */
1828 		if (retry_mode) {
1829 			ret = nand_setup_read_retry(mtd, 0);
1830 			if (ret < 0)
1831 				break;
1832 			retry_mode = 0;
1833 		}
1834 
1835 		if (!readlen)
1836 			break;
1837 
1838 		/* For subsequent reads align to page boundary */
1839 		col = 0;
1840 		/* Increment page address */
1841 		realpage++;
1842 
1843 		page = realpage & chip->pagemask;
1844 		/* Check, if we cross a chip boundary */
1845 		if (!page) {
1846 			chipnr++;
1847 			chip->select_chip(mtd, -1);
1848 			chip->select_chip(mtd, chipnr);
1849 		}
1850 	}
1851 	chip->select_chip(mtd, -1);
1852 
1853 	ops->retlen = ops->len - (size_t) readlen;
1854 	if (oob)
1855 		ops->oobretlen = ops->ooblen - oobreadlen;
1856 
1857 	if (ret < 0)
1858 		return ret;
1859 
1860 	if (ecc_fail)
1861 		return -EBADMSG;
1862 
1863 	return max_bitflips;
1864 }
1865 
1866 /**
1867  * nand_read_oob_std - [REPLACEABLE] the most common OOB data read function
1868  * @mtd: mtd info structure
1869  * @chip: nand chip info structure
1870  * @page: page number to read
1871  */
1872 static int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
1873 			     int page)
1874 {
1875 	chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
1876 	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1877 	return 0;
1878 }
1879 
1880 /**
1881  * nand_read_oob_syndrome - [REPLACEABLE] OOB data read function for HW ECC
1882  *			    with syndromes
1883  * @mtd: mtd info structure
1884  * @chip: nand chip info structure
1885  * @page: page number to read
1886  */
1887 static int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
1888 				  int page)
1889 {
1890 	int length = mtd->oobsize;
1891 	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
1892 	int eccsize = chip->ecc.size;
1893 	uint8_t *bufpoi = chip->oob_poi;
1894 	int i, toread, sndrnd = 0, pos;
1895 
1896 	chip->cmdfunc(mtd, NAND_CMD_READ0, chip->ecc.size, page);
1897 	for (i = 0; i < chip->ecc.steps; i++) {
1898 		if (sndrnd) {
1899 			pos = eccsize + i * (eccsize + chunk);
1900 			if (mtd->writesize > 512)
1901 				chip->cmdfunc(mtd, NAND_CMD_RNDOUT, pos, -1);
1902 			else
1903 				chip->cmdfunc(mtd, NAND_CMD_READ0, pos, page);
1904 		} else
1905 			sndrnd = 1;
1906 		toread = min_t(int, length, chunk);
1907 		chip->read_buf(mtd, bufpoi, toread);
1908 		bufpoi += toread;
1909 		length -= toread;
1910 	}
1911 	if (length > 0)
1912 		chip->read_buf(mtd, bufpoi, length);
1913 
1914 	return 0;
1915 }
1916 
1917 /**
1918  * nand_write_oob_std - [REPLACEABLE] the most common OOB data write function
1919  * @mtd: mtd info structure
1920  * @chip: nand chip info structure
1921  * @page: page number to write
1922  */
1923 static int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
1924 			      int page)
1925 {
1926 	int status = 0;
1927 	const uint8_t *buf = chip->oob_poi;
1928 	int length = mtd->oobsize;
1929 
1930 	chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, page);
1931 	chip->write_buf(mtd, buf, length);
1932 	/* Send command to program the OOB data */
1933 	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1934 
1935 	status = chip->waitfunc(mtd, chip);
1936 
1937 	return status & NAND_STATUS_FAIL ? -EIO : 0;
1938 }
1939 
1940 /**
1941  * nand_write_oob_syndrome - [REPLACEABLE] OOB data write function for HW ECC
1942  *			     with syndrome - only for large page flash
1943  * @mtd: mtd info structure
1944  * @chip: nand chip info structure
1945  * @page: page number to write
1946  */
1947 static int nand_write_oob_syndrome(struct mtd_info *mtd,
1948 				   struct nand_chip *chip, int page)
1949 {
1950 	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
1951 	int eccsize = chip->ecc.size, length = mtd->oobsize;
1952 	int i, len, pos, status = 0, sndcmd = 0, steps = chip->ecc.steps;
1953 	const uint8_t *bufpoi = chip->oob_poi;
1954 
1955 	/*
1956 	 * data-ecc-data-ecc ... ecc-oob
1957 	 * or
1958 	 * data-pad-ecc-pad-data-pad .... ecc-pad-oob
1959 	 */
1960 	if (!chip->ecc.prepad && !chip->ecc.postpad) {
1961 		pos = steps * (eccsize + chunk);
1962 		steps = 0;
1963 	} else
1964 		pos = eccsize;
1965 
1966 	chip->cmdfunc(mtd, NAND_CMD_SEQIN, pos, page);
1967 	for (i = 0; i < steps; i++) {
1968 		if (sndcmd) {
1969 			if (mtd->writesize <= 512) {
1970 				uint32_t fill = 0xFFFFFFFF;
1971 
1972 				len = eccsize;
1973 				while (len > 0) {
1974 					int num = min_t(int, len, 4);
1975 					chip->write_buf(mtd, (uint8_t *)&fill,
1976 							num);
1977 					len -= num;
1978 				}
1979 			} else {
1980 				pos = eccsize + i * (eccsize + chunk);
1981 				chip->cmdfunc(mtd, NAND_CMD_RNDIN, pos, -1);
1982 			}
1983 		} else
1984 			sndcmd = 1;
1985 		len = min_t(int, length, chunk);
1986 		chip->write_buf(mtd, bufpoi, len);
1987 		bufpoi += len;
1988 		length -= len;
1989 	}
1990 	if (length > 0)
1991 		chip->write_buf(mtd, bufpoi, length);
1992 
1993 	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1994 	status = chip->waitfunc(mtd, chip);
1995 
1996 	return status & NAND_STATUS_FAIL ? -EIO : 0;
1997 }
1998 
1999 /**
2000  * nand_do_read_oob - [INTERN] NAND read out-of-band
2001  * @mtd: MTD device structure
2002  * @from: offset to read from
2003  * @ops: oob operations description structure
2004  *
2005  * NAND read out-of-band data from the spare area.
2006  */
2007 static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
2008 			    struct mtd_oob_ops *ops)
2009 {
2010 	int page, realpage, chipnr;
2011 	struct nand_chip *chip = mtd_to_nand(mtd);
2012 	struct mtd_ecc_stats stats;
2013 	int readlen = ops->ooblen;
2014 	int len;
2015 	uint8_t *buf = ops->oobbuf;
2016 	int ret = 0;
2017 
2018 	pr_debug("%s: from = 0x%08Lx, len = %i\n",
2019 			__func__, (unsigned long long)from, readlen);
2020 
2021 	stats = mtd->ecc_stats;
2022 
2023 	len = mtd_oobavail(mtd, ops);
2024 
2025 	if (unlikely(ops->ooboffs >= len)) {
2026 		pr_debug("%s: attempt to start read outside oob\n",
2027 				__func__);
2028 		return -EINVAL;
2029 	}
2030 
2031 	/* Do not allow reads past end of device */
2032 	if (unlikely(from >= mtd->size ||
2033 		     ops->ooboffs + readlen > ((mtd->size >> chip->page_shift) -
2034 					(from >> chip->page_shift)) * len)) {
2035 		pr_debug("%s: attempt to read beyond end of device\n",
2036 				__func__);
2037 		return -EINVAL;
2038 	}
2039 
2040 	chipnr = (int)(from >> chip->chip_shift);
2041 	chip->select_chip(mtd, chipnr);
2042 
2043 	/* Shift to get page */
2044 	realpage = (int)(from >> chip->page_shift);
2045 	page = realpage & chip->pagemask;
2046 
2047 	while (1) {
2048 		WATCHDOG_RESET();
2049 
2050 		if (ops->mode == MTD_OPS_RAW)
2051 			ret = chip->ecc.read_oob_raw(mtd, chip, page);
2052 		else
2053 			ret = chip->ecc.read_oob(mtd, chip, page);
2054 
2055 		if (ret < 0)
2056 			break;
2057 
2058 		len = min(len, readlen);
2059 		buf = nand_transfer_oob(chip, buf, ops, len);
2060 
2061 		if (chip->options & NAND_NEED_READRDY) {
2062 			/* Apply delay or wait for ready/busy pin */
2063 			if (!chip->dev_ready)
2064 				udelay(chip->chip_delay);
2065 			else
2066 				nand_wait_ready(mtd);
2067 		}
2068 
2069 		readlen -= len;
2070 		if (!readlen)
2071 			break;
2072 
2073 		/* Increment page address */
2074 		realpage++;
2075 
2076 		page = realpage & chip->pagemask;
2077 		/* Check, if we cross a chip boundary */
2078 		if (!page) {
2079 			chipnr++;
2080 			chip->select_chip(mtd, -1);
2081 			chip->select_chip(mtd, chipnr);
2082 		}
2083 	}
2084 	chip->select_chip(mtd, -1);
2085 
2086 	ops->oobretlen = ops->ooblen - readlen;
2087 
2088 	if (ret < 0)
2089 		return ret;
2090 
2091 	if (mtd->ecc_stats.failed - stats.failed)
2092 		return -EBADMSG;
2093 
2094 	return  mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
2095 }
2096 
2097 /**
2098  * nand_read_oob - [MTD Interface] NAND read data and/or out-of-band
2099  * @mtd: MTD device structure
2100  * @from: offset to read from
2101  * @ops: oob operation description structure
2102  *
2103  * NAND read data and/or out-of-band data.
2104  */
2105 static int nand_read_oob(struct mtd_info *mtd, loff_t from,
2106 			 struct mtd_oob_ops *ops)
2107 {
2108 	int ret = -ENOTSUPP;
2109 
2110 	ops->retlen = 0;
2111 
2112 	/* Do not allow reads past end of device */
2113 	if (ops->datbuf && (from + ops->len) > mtd->size) {
2114 		pr_debug("%s: attempt to read beyond end of device\n",
2115 				__func__);
2116 		return -EINVAL;
2117 	}
2118 
2119 	nand_get_device(mtd, FL_READING);
2120 
2121 	switch (ops->mode) {
2122 	case MTD_OPS_PLACE_OOB:
2123 	case MTD_OPS_AUTO_OOB:
2124 	case MTD_OPS_RAW:
2125 		break;
2126 
2127 	default:
2128 		goto out;
2129 	}
2130 
2131 	if (!ops->datbuf)
2132 		ret = nand_do_read_oob(mtd, from, ops);
2133 	else
2134 		ret = nand_do_read_ops(mtd, from, ops);
2135 
2136 out:
2137 	nand_release_device(mtd);
2138 	return ret;
2139 }
2140 
2141 
2142 /**
2143  * nand_write_page_raw - [INTERN] raw page write function
2144  * @mtd: mtd info structure
2145  * @chip: nand chip info structure
2146  * @buf: data buffer
2147  * @oob_required: must write chip->oob_poi to OOB
2148  * @page: page number to write
2149  *
2150  * Not for syndrome calculating ECC controllers, which use a special oob layout.
2151  */
2152 static int nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
2153 			       const uint8_t *buf, int oob_required, int page)
2154 {
2155 	chip->write_buf(mtd, buf, mtd->writesize);
2156 	if (oob_required)
2157 		chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
2158 
2159 	return 0;
2160 }
2161 
2162 /**
2163  * nand_write_page_raw_syndrome - [INTERN] raw page write function
2164  * @mtd: mtd info structure
2165  * @chip: nand chip info structure
2166  * @buf: data buffer
2167  * @oob_required: must write chip->oob_poi to OOB
2168  * @page: page number to write
2169  *
2170  * We need a special oob layout and handling even when ECC isn't checked.
2171  */
2172 static int nand_write_page_raw_syndrome(struct mtd_info *mtd,
2173 					struct nand_chip *chip,
2174 					const uint8_t *buf, int oob_required,
2175 					int page)
2176 {
2177 	int eccsize = chip->ecc.size;
2178 	int eccbytes = chip->ecc.bytes;
2179 	uint8_t *oob = chip->oob_poi;
2180 	int steps, size;
2181 
2182 	for (steps = chip->ecc.steps; steps > 0; steps--) {
2183 		chip->write_buf(mtd, buf, eccsize);
2184 		buf += eccsize;
2185 
2186 		if (chip->ecc.prepad) {
2187 			chip->write_buf(mtd, oob, chip->ecc.prepad);
2188 			oob += chip->ecc.prepad;
2189 		}
2190 
2191 		chip->write_buf(mtd, oob, eccbytes);
2192 		oob += eccbytes;
2193 
2194 		if (chip->ecc.postpad) {
2195 			chip->write_buf(mtd, oob, chip->ecc.postpad);
2196 			oob += chip->ecc.postpad;
2197 		}
2198 	}
2199 
2200 	size = mtd->oobsize - (oob - chip->oob_poi);
2201 	if (size)
2202 		chip->write_buf(mtd, oob, size);
2203 
2204 	return 0;
2205 }
2206 /**
2207  * nand_write_page_swecc - [REPLACEABLE] software ECC based page write function
2208  * @mtd: mtd info structure
2209  * @chip: nand chip info structure
2210  * @buf: data buffer
2211  * @oob_required: must write chip->oob_poi to OOB
2212  * @page: page number to write
2213  */
2214 static int nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
2215 				 const uint8_t *buf, int oob_required,
2216 				 int page)
2217 {
2218 	int i, eccsize = chip->ecc.size;
2219 	int eccbytes = chip->ecc.bytes;
2220 	int eccsteps = chip->ecc.steps;
2221 	uint8_t *ecc_calc = chip->buffers->ecccalc;
2222 	const uint8_t *p = buf;
2223 	uint32_t *eccpos = chip->ecc.layout->eccpos;
2224 
2225 	/* Software ECC calculation */
2226 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
2227 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
2228 
2229 	for (i = 0; i < chip->ecc.total; i++)
2230 		chip->oob_poi[eccpos[i]] = ecc_calc[i];
2231 
2232 	return chip->ecc.write_page_raw(mtd, chip, buf, 1, page);
2233 }
2234 
2235 /**
2236  * nand_write_page_hwecc - [REPLACEABLE] hardware ECC based page write function
2237  * @mtd: mtd info structure
2238  * @chip: nand chip info structure
2239  * @buf: data buffer
2240  * @oob_required: must write chip->oob_poi to OOB
2241  * @page: page number to write
2242  */
2243 static int nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
2244 				  const uint8_t *buf, int oob_required,
2245 				  int page)
2246 {
2247 	int i, eccsize = chip->ecc.size;
2248 	int eccbytes = chip->ecc.bytes;
2249 	int eccsteps = chip->ecc.steps;
2250 	uint8_t *ecc_calc = chip->buffers->ecccalc;
2251 	const uint8_t *p = buf;
2252 	uint32_t *eccpos = chip->ecc.layout->eccpos;
2253 
2254 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
2255 		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
2256 		chip->write_buf(mtd, p, eccsize);
2257 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
2258 	}
2259 
2260 	for (i = 0; i < chip->ecc.total; i++)
2261 		chip->oob_poi[eccpos[i]] = ecc_calc[i];
2262 
2263 	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
2264 
2265 	return 0;
2266 }
2267 
2268 
2269 /**
2270  * nand_write_subpage_hwecc - [REPLACEABLE] hardware ECC based subpage write
2271  * @mtd:	mtd info structure
2272  * @chip:	nand chip info structure
2273  * @offset:	column address of subpage within the page
2274  * @data_len:	data length
2275  * @buf:	data buffer
2276  * @oob_required: must write chip->oob_poi to OOB
2277  * @page: page number to write
2278  */
2279 static int nand_write_subpage_hwecc(struct mtd_info *mtd,
2280 				struct nand_chip *chip, uint32_t offset,
2281 				uint32_t data_len, const uint8_t *buf,
2282 				int oob_required, int page)
2283 {
2284 	uint8_t *oob_buf  = chip->oob_poi;
2285 	uint8_t *ecc_calc = chip->buffers->ecccalc;
2286 	int ecc_size      = chip->ecc.size;
2287 	int ecc_bytes     = chip->ecc.bytes;
2288 	int ecc_steps     = chip->ecc.steps;
2289 	uint32_t *eccpos  = chip->ecc.layout->eccpos;
2290 	uint32_t start_step = offset / ecc_size;
2291 	uint32_t end_step   = (offset + data_len - 1) / ecc_size;
2292 	int oob_bytes       = mtd->oobsize / ecc_steps;
2293 	int step, i;
2294 
2295 	for (step = 0; step < ecc_steps; step++) {
2296 		/* configure controller for WRITE access */
2297 		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
2298 
2299 		/* write data (untouched subpages already masked by 0xFF) */
2300 		chip->write_buf(mtd, buf, ecc_size);
2301 
2302 		/* mask ECC of un-touched subpages by padding 0xFF */
2303 		if ((step < start_step) || (step > end_step))
2304 			memset(ecc_calc, 0xff, ecc_bytes);
2305 		else
2306 			chip->ecc.calculate(mtd, buf, ecc_calc);
2307 
2308 		/* mask OOB of un-touched subpages by padding 0xFF */
2309 		/* if oob_required, preserve OOB metadata of written subpage */
2310 		if (!oob_required || (step < start_step) || (step > end_step))
2311 			memset(oob_buf, 0xff, oob_bytes);
2312 
2313 		buf += ecc_size;
2314 		ecc_calc += ecc_bytes;
2315 		oob_buf  += oob_bytes;
2316 	}
2317 
2318 	/* copy calculated ECC for whole page to chip->buffer->oob */
2319 	/* this include masked-value(0xFF) for unwritten subpages */
2320 	ecc_calc = chip->buffers->ecccalc;
2321 	for (i = 0; i < chip->ecc.total; i++)
2322 		chip->oob_poi[eccpos[i]] = ecc_calc[i];
2323 
2324 	/* write OOB buffer to NAND device */
2325 	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
2326 
2327 	return 0;
2328 }
2329 
2330 
2331 /**
2332  * nand_write_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page write
2333  * @mtd: mtd info structure
2334  * @chip: nand chip info structure
2335  * @buf: data buffer
2336  * @oob_required: must write chip->oob_poi to OOB
2337  * @page: page number to write
2338  *
2339  * The hw generator calculates the error syndrome automatically. Therefore we
2340  * need a special oob layout and handling.
2341  */
2342 static int nand_write_page_syndrome(struct mtd_info *mtd,
2343 				    struct nand_chip *chip,
2344 				    const uint8_t *buf, int oob_required,
2345 				    int page)
2346 {
2347 	int i, eccsize = chip->ecc.size;
2348 	int eccbytes = chip->ecc.bytes;
2349 	int eccsteps = chip->ecc.steps;
2350 	const uint8_t *p = buf;
2351 	uint8_t *oob = chip->oob_poi;
2352 
2353 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
2354 
2355 		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
2356 		chip->write_buf(mtd, p, eccsize);
2357 
2358 		if (chip->ecc.prepad) {
2359 			chip->write_buf(mtd, oob, chip->ecc.prepad);
2360 			oob += chip->ecc.prepad;
2361 		}
2362 
2363 		chip->ecc.calculate(mtd, p, oob);
2364 		chip->write_buf(mtd, oob, eccbytes);
2365 		oob += eccbytes;
2366 
2367 		if (chip->ecc.postpad) {
2368 			chip->write_buf(mtd, oob, chip->ecc.postpad);
2369 			oob += chip->ecc.postpad;
2370 		}
2371 	}
2372 
2373 	/* Calculate remaining oob bytes */
2374 	i = mtd->oobsize - (oob - chip->oob_poi);
2375 	if (i)
2376 		chip->write_buf(mtd, oob, i);
2377 
2378 	return 0;
2379 }
2380 
2381 /**
2382  * nand_write_page - [REPLACEABLE] write one page
2383  * @mtd: MTD device structure
2384  * @chip: NAND chip descriptor
2385  * @offset: address offset within the page
2386  * @data_len: length of actual data to be written
2387  * @buf: the data to write
2388  * @oob_required: must write chip->oob_poi to OOB
2389  * @page: page number to write
2390  * @raw: use _raw version of write_page
2391  */
2392 static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
2393 		uint32_t offset, int data_len, const uint8_t *buf,
2394 		int oob_required, int page, int raw)
2395 {
2396 	int status, subpage;
2397 
2398 	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) &&
2399 		chip->ecc.write_subpage)
2400 		subpage = offset || (data_len < mtd->writesize);
2401 	else
2402 		subpage = 0;
2403 
2404 	if (nand_standard_page_accessors(&chip->ecc))
2405 		chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
2406 
2407 	if (unlikely(raw))
2408 		status = chip->ecc.write_page_raw(mtd, chip, buf,
2409 						  oob_required, page);
2410 	else if (subpage)
2411 		status = chip->ecc.write_subpage(mtd, chip, offset, data_len,
2412 						 buf, oob_required, page);
2413 	else
2414 		status = chip->ecc.write_page(mtd, chip, buf, oob_required,
2415 					      page);
2416 
2417 	if (status < 0)
2418 		return status;
2419 
2420 	if (nand_standard_page_accessors(&chip->ecc)) {
2421 		chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
2422 
2423 		status = chip->waitfunc(mtd, chip);
2424 		if (status & NAND_STATUS_FAIL)
2425 			return -EIO;
2426 	}
2427 
2428 	return 0;
2429 }
2430 
2431 /**
2432  * nand_fill_oob - [INTERN] Transfer client buffer to oob
2433  * @mtd: MTD device structure
2434  * @oob: oob data buffer
2435  * @len: oob data write length
2436  * @ops: oob ops structure
2437  */
2438 static uint8_t *nand_fill_oob(struct mtd_info *mtd, uint8_t *oob, size_t len,
2439 			      struct mtd_oob_ops *ops)
2440 {
2441 	struct nand_chip *chip = mtd_to_nand(mtd);
2442 
2443 	/*
2444 	 * Initialise to all 0xFF, to avoid the possibility of left over OOB
2445 	 * data from a previous OOB read.
2446 	 */
2447 	memset(chip->oob_poi, 0xff, mtd->oobsize);
2448 
2449 	switch (ops->mode) {
2450 
2451 	case MTD_OPS_PLACE_OOB:
2452 	case MTD_OPS_RAW:
2453 		memcpy(chip->oob_poi + ops->ooboffs, oob, len);
2454 		return oob + len;
2455 
2456 	case MTD_OPS_AUTO_OOB: {
2457 		struct nand_oobfree *free = chip->ecc.layout->oobfree;
2458 		uint32_t boffs = 0, woffs = ops->ooboffs;
2459 		size_t bytes = 0;
2460 
2461 		for (; free->length && len; free++, len -= bytes) {
2462 			/* Write request not from offset 0? */
2463 			if (unlikely(woffs)) {
2464 				if (woffs >= free->length) {
2465 					woffs -= free->length;
2466 					continue;
2467 				}
2468 				boffs = free->offset + woffs;
2469 				bytes = min_t(size_t, len,
2470 					      (free->length - woffs));
2471 				woffs = 0;
2472 			} else {
2473 				bytes = min_t(size_t, len, free->length);
2474 				boffs = free->offset;
2475 			}
2476 			memcpy(chip->oob_poi + boffs, oob, bytes);
2477 			oob += bytes;
2478 		}
2479 		return oob;
2480 	}
2481 	default:
2482 		BUG();
2483 	}
2484 	return NULL;
2485 }
2486 
2487 #define NOTALIGNED(x)	((x & (chip->subpagesize - 1)) != 0)
2488 
2489 /**
2490  * nand_do_write_ops - [INTERN] NAND write with ECC
2491  * @mtd: MTD device structure
2492  * @to: offset to write to
2493  * @ops: oob operations description structure
2494  *
2495  * NAND write with ECC.
2496  */
2497 static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
2498 			     struct mtd_oob_ops *ops)
2499 {
2500 	int chipnr, realpage, page, column;
2501 	struct nand_chip *chip = mtd_to_nand(mtd);
2502 	uint32_t writelen = ops->len;
2503 
2504 	uint32_t oobwritelen = ops->ooblen;
2505 	uint32_t oobmaxlen = mtd_oobavail(mtd, ops);
2506 
2507 	uint8_t *oob = ops->oobbuf;
2508 	uint8_t *buf = ops->datbuf;
2509 	int ret;
2510 	int oob_required = oob ? 1 : 0;
2511 
2512 	ops->retlen = 0;
2513 	if (!writelen)
2514 		return 0;
2515 
2516 	/* Reject writes, which are not page aligned */
2517 	if (NOTALIGNED(to)) {
2518 		pr_notice("%s: attempt to write non page aligned data\n",
2519 			   __func__);
2520 		return -EINVAL;
2521 	}
2522 
2523 	column = to & (mtd->writesize - 1);
2524 
2525 	chipnr = (int)(to >> chip->chip_shift);
2526 	chip->select_chip(mtd, chipnr);
2527 
2528 	/* Check, if it is write protected */
2529 	if (nand_check_wp(mtd)) {
2530 		ret = -EIO;
2531 		goto err_out;
2532 	}
2533 
2534 	realpage = (int)(to >> chip->page_shift);
2535 	page = realpage & chip->pagemask;
2536 
2537 	/* Invalidate the page cache, when we write to the cached page */
2538 	if (to <= ((loff_t)chip->pagebuf << chip->page_shift) &&
2539 	    ((loff_t)chip->pagebuf << chip->page_shift) < (to + ops->len))
2540 		chip->pagebuf = -1;
2541 
2542 	/* Don't allow multipage oob writes with offset */
2543 	if (oob && ops->ooboffs && (ops->ooboffs + ops->ooblen > oobmaxlen)) {
2544 		ret = -EINVAL;
2545 		goto err_out;
2546 	}
2547 
2548 	while (1) {
2549 		int bytes = mtd->writesize;
2550 		uint8_t *wbuf = buf;
2551 		int use_bufpoi;
2552 		int part_pagewr = (column || writelen < mtd->writesize);
2553 
2554 		if (part_pagewr)
2555 			use_bufpoi = 1;
2556 		else if (chip->options & NAND_USE_BOUNCE_BUFFER)
2557 			use_bufpoi = !IS_ALIGNED((unsigned long)buf,
2558 						 chip->buf_align);
2559 		else
2560 			use_bufpoi = 0;
2561 
2562 		WATCHDOG_RESET();
2563 		/* Partial page write?, or need to use bounce buffer */
2564 		if (use_bufpoi) {
2565 			pr_debug("%s: using write bounce buffer for buf@%p\n",
2566 					 __func__, buf);
2567 			if (part_pagewr)
2568 				bytes = min_t(int, bytes - column, writelen);
2569 			chip->pagebuf = -1;
2570 			memset(chip->buffers->databuf, 0xff, mtd->writesize);
2571 			memcpy(&chip->buffers->databuf[column], buf, bytes);
2572 			wbuf = chip->buffers->databuf;
2573 		}
2574 
2575 		if (unlikely(oob)) {
2576 			size_t len = min(oobwritelen, oobmaxlen);
2577 			oob = nand_fill_oob(mtd, oob, len, ops);
2578 			oobwritelen -= len;
2579 		} else {
2580 			/* We still need to erase leftover OOB data */
2581 			memset(chip->oob_poi, 0xff, mtd->oobsize);
2582 		}
2583 		ret = chip->write_page(mtd, chip, column, bytes, wbuf,
2584 					oob_required, page,
2585 					(ops->mode == MTD_OPS_RAW));
2586 		if (ret)
2587 			break;
2588 
2589 		writelen -= bytes;
2590 		if (!writelen)
2591 			break;
2592 
2593 		column = 0;
2594 		buf += bytes;
2595 		realpage++;
2596 
2597 		page = realpage & chip->pagemask;
2598 		/* Check, if we cross a chip boundary */
2599 		if (!page) {
2600 			chipnr++;
2601 			chip->select_chip(mtd, -1);
2602 			chip->select_chip(mtd, chipnr);
2603 		}
2604 	}
2605 
2606 	ops->retlen = ops->len - writelen;
2607 	if (unlikely(oob))
2608 		ops->oobretlen = ops->ooblen;
2609 
2610 err_out:
2611 	chip->select_chip(mtd, -1);
2612 	return ret;
2613 }
2614 
2615 /**
2616  * panic_nand_write - [MTD Interface] NAND write with ECC
2617  * @mtd: MTD device structure
2618  * @to: offset to write to
2619  * @len: number of bytes to write
2620  * @retlen: pointer to variable to store the number of written bytes
2621  * @buf: the data to write
2622  *
2623  * NAND write with ECC. Used when performing writes in interrupt context, this
2624  * may for example be called by mtdoops when writing an oops while in panic.
2625  */
2626 static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
2627 			    size_t *retlen, const uint8_t *buf)
2628 {
2629 	struct nand_chip *chip = mtd_to_nand(mtd);
2630 	struct mtd_oob_ops ops;
2631 	int ret;
2632 
2633 	/* Wait for the device to get ready */
2634 	panic_nand_wait(mtd, chip, 400);
2635 
2636 	/* Grab the device */
2637 	panic_nand_get_device(chip, mtd, FL_WRITING);
2638 
2639 	memset(&ops, 0, sizeof(ops));
2640 	ops.len = len;
2641 	ops.datbuf = (uint8_t *)buf;
2642 	ops.mode = MTD_OPS_PLACE_OOB;
2643 
2644 	ret = nand_do_write_ops(mtd, to, &ops);
2645 
2646 	*retlen = ops.retlen;
2647 	return ret;
2648 }
2649 
2650 /**
2651  * nand_do_write_oob - [MTD Interface] NAND write out-of-band
2652  * @mtd: MTD device structure
2653  * @to: offset to write to
2654  * @ops: oob operation description structure
2655  *
2656  * NAND write out-of-band.
2657  */
2658 static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
2659 			     struct mtd_oob_ops *ops)
2660 {
2661 	int chipnr, page, status, len;
2662 	struct nand_chip *chip = mtd_to_nand(mtd);
2663 
2664 	pr_debug("%s: to = 0x%08x, len = %i\n",
2665 			 __func__, (unsigned int)to, (int)ops->ooblen);
2666 
2667 	len = mtd_oobavail(mtd, ops);
2668 
2669 	/* Do not allow write past end of page */
2670 	if ((ops->ooboffs + ops->ooblen) > len) {
2671 		pr_debug("%s: attempt to write past end of page\n",
2672 				__func__);
2673 		return -EINVAL;
2674 	}
2675 
2676 	if (unlikely(ops->ooboffs >= len)) {
2677 		pr_debug("%s: attempt to start write outside oob\n",
2678 				__func__);
2679 		return -EINVAL;
2680 	}
2681 
2682 	/* Do not allow write past end of device */
2683 	if (unlikely(to >= mtd->size ||
2684 		     ops->ooboffs + ops->ooblen >
2685 			((mtd->size >> chip->page_shift) -
2686 			 (to >> chip->page_shift)) * len)) {
2687 		pr_debug("%s: attempt to write beyond end of device\n",
2688 				__func__);
2689 		return -EINVAL;
2690 	}
2691 
2692 	chipnr = (int)(to >> chip->chip_shift);
2693 
2694 	/*
2695 	 * Reset the chip. Some chips (like the Toshiba TC5832DC found in one
2696 	 * of my DiskOnChip 2000 test units) will clear the whole data page too
2697 	 * if we don't do this. I have no clue why, but I seem to have 'fixed'
2698 	 * it in the doc2000 driver in August 1999.  dwmw2.
2699 	 */
2700 	nand_reset(chip, chipnr);
2701 
2702 	chip->select_chip(mtd, chipnr);
2703 
2704 	/* Shift to get page */
2705 	page = (int)(to >> chip->page_shift);
2706 
2707 	/* Check, if it is write protected */
2708 	if (nand_check_wp(mtd)) {
2709 		chip->select_chip(mtd, -1);
2710 		return -EROFS;
2711 	}
2712 
2713 	/* Invalidate the page cache, if we write to the cached page */
2714 	if (page == chip->pagebuf)
2715 		chip->pagebuf = -1;
2716 
2717 	nand_fill_oob(mtd, ops->oobbuf, ops->ooblen, ops);
2718 
2719 	if (ops->mode == MTD_OPS_RAW)
2720 		status = chip->ecc.write_oob_raw(mtd, chip, page & chip->pagemask);
2721 	else
2722 		status = chip->ecc.write_oob(mtd, chip, page & chip->pagemask);
2723 
2724 	chip->select_chip(mtd, -1);
2725 
2726 	if (status)
2727 		return status;
2728 
2729 	ops->oobretlen = ops->ooblen;
2730 
2731 	return 0;
2732 }
2733 
2734 /**
2735  * nand_write_oob - [MTD Interface] NAND write data and/or out-of-band
2736  * @mtd: MTD device structure
2737  * @to: offset to write to
2738  * @ops: oob operation description structure
2739  */
2740 static int nand_write_oob(struct mtd_info *mtd, loff_t to,
2741 			  struct mtd_oob_ops *ops)
2742 {
2743 	int ret = -ENOTSUPP;
2744 
2745 	ops->retlen = 0;
2746 
2747 	/* Do not allow writes past end of device */
2748 	if (ops->datbuf && (to + ops->len) > mtd->size) {
2749 		pr_debug("%s: attempt to write beyond end of device\n",
2750 				__func__);
2751 		return -EINVAL;
2752 	}
2753 
2754 	nand_get_device(mtd, FL_WRITING);
2755 
2756 	switch (ops->mode) {
2757 	case MTD_OPS_PLACE_OOB:
2758 	case MTD_OPS_AUTO_OOB:
2759 	case MTD_OPS_RAW:
2760 		break;
2761 
2762 	default:
2763 		goto out;
2764 	}
2765 
2766 	if (!ops->datbuf)
2767 		ret = nand_do_write_oob(mtd, to, ops);
2768 	else
2769 		ret = nand_do_write_ops(mtd, to, ops);
2770 
2771 out:
2772 	nand_release_device(mtd);
2773 	return ret;
2774 }
2775 
2776 /**
2777  * single_erase - [GENERIC] NAND standard block erase command function
2778  * @mtd: MTD device structure
2779  * @page: the page address of the block which will be erased
2780  *
2781  * Standard erase command for NAND chips. Returns NAND status.
2782  */
2783 static int single_erase(struct mtd_info *mtd, int page)
2784 {
2785 	struct nand_chip *chip = mtd_to_nand(mtd);
2786 	/* Send commands to erase a block */
2787 	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
2788 	chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
2789 
2790 	return chip->waitfunc(mtd, chip);
2791 }
2792 
2793 /**
2794  * nand_erase - [MTD Interface] erase block(s)
2795  * @mtd: MTD device structure
2796  * @instr: erase instruction
2797  *
2798  * Erase one ore more blocks.
2799  */
2800 static int nand_erase(struct mtd_info *mtd, struct erase_info *instr)
2801 {
2802 	return nand_erase_nand(mtd, instr, 0);
2803 }
2804 
2805 /**
2806  * nand_erase_nand - [INTERN] erase block(s)
2807  * @mtd: MTD device structure
2808  * @instr: erase instruction
2809  * @allowbbt: allow erasing the bbt area
2810  *
2811  * Erase one ore more blocks.
2812  */
2813 int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
2814 		    int allowbbt)
2815 {
2816 	int page, status, pages_per_block, ret, chipnr;
2817 	struct nand_chip *chip = mtd_to_nand(mtd);
2818 	loff_t len;
2819 
2820 	pr_debug("%s: start = 0x%012llx, len = %llu\n",
2821 			__func__, (unsigned long long)instr->addr,
2822 			(unsigned long long)instr->len);
2823 
2824 	if (check_offs_len(mtd, instr->addr, instr->len))
2825 		return -EINVAL;
2826 
2827 	/* Grab the lock and see if the device is available */
2828 	nand_get_device(mtd, FL_ERASING);
2829 
2830 	/* Shift to get first page */
2831 	page = (int)(instr->addr >> chip->page_shift);
2832 	chipnr = (int)(instr->addr >> chip->chip_shift);
2833 
2834 	/* Calculate pages in each block */
2835 	pages_per_block = 1 << (chip->phys_erase_shift - chip->page_shift);
2836 
2837 	/* Select the NAND device */
2838 	chip->select_chip(mtd, chipnr);
2839 
2840 	/* Check, if it is write protected */
2841 	if (nand_check_wp(mtd)) {
2842 		pr_debug("%s: device is write protected!\n",
2843 				__func__);
2844 		instr->state = MTD_ERASE_FAILED;
2845 		goto erase_exit;
2846 	}
2847 
2848 	/* Loop through the pages */
2849 	len = instr->len;
2850 
2851 	instr->state = MTD_ERASING;
2852 
2853 	while (len) {
2854 		WATCHDOG_RESET();
2855 
2856 		/* Check if we have a bad block, we do not erase bad blocks! */
2857 		if (!instr->scrub && nand_block_checkbad(mtd, ((loff_t) page) <<
2858 					chip->page_shift, allowbbt)) {
2859 			pr_warn("%s: attempt to erase a bad block at page 0x%08x\n",
2860 				    __func__, page);
2861 			instr->state = MTD_ERASE_FAILED;
2862 			goto erase_exit;
2863 		}
2864 
2865 		/*
2866 		 * Invalidate the page cache, if we erase the block which
2867 		 * contains the current cached page.
2868 		 */
2869 		if (page <= chip->pagebuf && chip->pagebuf <
2870 		    (page + pages_per_block))
2871 			chip->pagebuf = -1;
2872 
2873 		status = chip->erase(mtd, page & chip->pagemask);
2874 
2875 		/* See if block erase succeeded */
2876 		if (status & NAND_STATUS_FAIL) {
2877 			pr_debug("%s: failed erase, page 0x%08x\n",
2878 					__func__, page);
2879 			instr->state = MTD_ERASE_FAILED;
2880 			instr->fail_addr =
2881 				((loff_t)page << chip->page_shift);
2882 			goto erase_exit;
2883 		}
2884 
2885 		/* Increment page address and decrement length */
2886 		len -= (1ULL << chip->phys_erase_shift);
2887 		page += pages_per_block;
2888 
2889 		/* Check, if we cross a chip boundary */
2890 		if (len && !(page & chip->pagemask)) {
2891 			chipnr++;
2892 			chip->select_chip(mtd, -1);
2893 			chip->select_chip(mtd, chipnr);
2894 		}
2895 	}
2896 	instr->state = MTD_ERASE_DONE;
2897 
2898 erase_exit:
2899 
2900 	ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
2901 
2902 	/* Deselect and wake up anyone waiting on the device */
2903 	chip->select_chip(mtd, -1);
2904 	nand_release_device(mtd);
2905 
2906 	/* Do call back function */
2907 	if (!ret)
2908 		mtd_erase_callback(instr);
2909 
2910 	/* Return more or less happy */
2911 	return ret;
2912 }
2913 
2914 /**
2915  * nand_sync - [MTD Interface] sync
2916  * @mtd: MTD device structure
2917  *
2918  * Sync is actually a wait for chip ready function.
2919  */
2920 static void nand_sync(struct mtd_info *mtd)
2921 {
2922 	pr_debug("%s: called\n", __func__);
2923 
2924 	/* Grab the lock and see if the device is available */
2925 	nand_get_device(mtd, FL_SYNCING);
2926 	/* Release it and go back */
2927 	nand_release_device(mtd);
2928 }
2929 
2930 /**
2931  * nand_block_isbad - [MTD Interface] Check if block at offset is bad
2932  * @mtd: MTD device structure
2933  * @offs: offset relative to mtd start
2934  */
2935 static int nand_block_isbad(struct mtd_info *mtd, loff_t offs)
2936 {
2937 	struct nand_chip *chip = mtd_to_nand(mtd);
2938 	int chipnr = (int)(offs >> chip->chip_shift);
2939 	int ret;
2940 
2941 	/* Select the NAND device */
2942 	nand_get_device(mtd, FL_READING);
2943 	chip->select_chip(mtd, chipnr);
2944 
2945 	ret = nand_block_checkbad(mtd, offs, 0);
2946 
2947 	chip->select_chip(mtd, -1);
2948 	nand_release_device(mtd);
2949 
2950 	return ret;
2951 }
2952 
2953 /**
2954  * nand_block_markbad - [MTD Interface] Mark block at the given offset as bad
2955  * @mtd: MTD device structure
2956  * @ofs: offset relative to mtd start
2957  */
2958 static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
2959 {
2960 	int ret;
2961 
2962 	ret = nand_block_isbad(mtd, ofs);
2963 	if (ret) {
2964 		/* If it was bad already, return success and do nothing */
2965 		if (ret > 0)
2966 			return 0;
2967 		return ret;
2968 	}
2969 
2970 	return nand_block_markbad_lowlevel(mtd, ofs);
2971 }
2972 
2973 /**
2974  * nand_onfi_set_features- [REPLACEABLE] set features for ONFI nand
2975  * @mtd: MTD device structure
2976  * @chip: nand chip info structure
2977  * @addr: feature address.
2978  * @subfeature_param: the subfeature parameters, a four bytes array.
2979  */
2980 static int nand_onfi_set_features(struct mtd_info *mtd, struct nand_chip *chip,
2981 			int addr, uint8_t *subfeature_param)
2982 {
2983 	int status;
2984 	int i;
2985 
2986 #ifdef CONFIG_SYS_NAND_ONFI_DETECTION
2987 	if (!chip->onfi_version ||
2988 	    !(le16_to_cpu(chip->onfi_params.opt_cmd)
2989 	      & ONFI_OPT_CMD_SET_GET_FEATURES))
2990 		return -ENOTSUPP;
2991 #endif
2992 
2993 	chip->cmdfunc(mtd, NAND_CMD_SET_FEATURES, addr, -1);
2994 	for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
2995 		chip->write_byte(mtd, subfeature_param[i]);
2996 
2997 	status = chip->waitfunc(mtd, chip);
2998 	if (status & NAND_STATUS_FAIL)
2999 		return -EIO;
3000 	return 0;
3001 }
3002 
3003 /**
3004  * nand_onfi_get_features- [REPLACEABLE] get features for ONFI nand
3005  * @mtd: MTD device structure
3006  * @chip: nand chip info structure
3007  * @addr: feature address.
3008  * @subfeature_param: the subfeature parameters, a four bytes array.
3009  */
3010 static int nand_onfi_get_features(struct mtd_info *mtd, struct nand_chip *chip,
3011 			int addr, uint8_t *subfeature_param)
3012 {
3013 	int i;
3014 
3015 #ifdef CONFIG_SYS_NAND_ONFI_DETECTION
3016 	if (!chip->onfi_version ||
3017 	    !(le16_to_cpu(chip->onfi_params.opt_cmd)
3018 	      & ONFI_OPT_CMD_SET_GET_FEATURES))
3019 		return -ENOTSUPP;
3020 #endif
3021 
3022 	chip->cmdfunc(mtd, NAND_CMD_GET_FEATURES, addr, -1);
3023 	for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
3024 		*subfeature_param++ = chip->read_byte(mtd);
3025 	return 0;
3026 }
3027 
3028 /* Set default functions */
3029 static void nand_set_defaults(struct nand_chip *chip, int busw)
3030 {
3031 	/* check for proper chip_delay setup, set 20us if not */
3032 	if (!chip->chip_delay)
3033 		chip->chip_delay = 20;
3034 
3035 	/* check, if a user supplied command function given */
3036 	if (chip->cmdfunc == NULL)
3037 		chip->cmdfunc = nand_command;
3038 
3039 	/* check, if a user supplied wait function given */
3040 	if (chip->waitfunc == NULL)
3041 		chip->waitfunc = nand_wait;
3042 
3043 	if (!chip->select_chip)
3044 		chip->select_chip = nand_select_chip;
3045 
3046 	/* set for ONFI nand */
3047 	if (!chip->onfi_set_features)
3048 		chip->onfi_set_features = nand_onfi_set_features;
3049 	if (!chip->onfi_get_features)
3050 		chip->onfi_get_features = nand_onfi_get_features;
3051 
3052 	/* If called twice, pointers that depend on busw may need to be reset */
3053 	if (!chip->read_byte || chip->read_byte == nand_read_byte)
3054 		chip->read_byte = busw ? nand_read_byte16 : nand_read_byte;
3055 	if (!chip->read_word)
3056 		chip->read_word = nand_read_word;
3057 	if (!chip->block_bad)
3058 		chip->block_bad = nand_block_bad;
3059 	if (!chip->block_markbad)
3060 		chip->block_markbad = nand_default_block_markbad;
3061 	if (!chip->write_buf || chip->write_buf == nand_write_buf)
3062 		chip->write_buf = busw ? nand_write_buf16 : nand_write_buf;
3063 	if (!chip->write_byte || chip->write_byte == nand_write_byte)
3064 		chip->write_byte = busw ? nand_write_byte16 : nand_write_byte;
3065 	if (!chip->read_buf || chip->read_buf == nand_read_buf)
3066 		chip->read_buf = busw ? nand_read_buf16 : nand_read_buf;
3067 	if (!chip->scan_bbt)
3068 		chip->scan_bbt = nand_default_bbt;
3069 
3070 	if (!chip->controller) {
3071 		chip->controller = &chip->hwcontrol;
3072 		spin_lock_init(&chip->controller->lock);
3073 		init_waitqueue_head(&chip->controller->wq);
3074 	}
3075 
3076 	if (!chip->buf_align)
3077 		chip->buf_align = 1;
3078 }
3079 
3080 /* Sanitize ONFI strings so we can safely print them */
3081 static void sanitize_string(char *s, size_t len)
3082 {
3083 	ssize_t i;
3084 
3085 	/* Null terminate */
3086 	s[len - 1] = 0;
3087 
3088 	/* Remove non printable chars */
3089 	for (i = 0; i < len - 1; i++) {
3090 		if (s[i] < ' ' || s[i] > 127)
3091 			s[i] = '?';
3092 	}
3093 
3094 	/* Remove trailing spaces */
3095 	strim(s);
3096 }
3097 
3098 static u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
3099 {
3100 	int i;
3101 	while (len--) {
3102 		crc ^= *p++ << 8;
3103 		for (i = 0; i < 8; i++)
3104 			crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
3105 	}
3106 
3107 	return crc;
3108 }
3109 
3110 #ifdef CONFIG_SYS_NAND_ONFI_DETECTION
3111 /* Parse the Extended Parameter Page. */
3112 static int nand_flash_detect_ext_param_page(struct mtd_info *mtd,
3113 		struct nand_chip *chip, struct nand_onfi_params *p)
3114 {
3115 	struct onfi_ext_param_page *ep;
3116 	struct onfi_ext_section *s;
3117 	struct onfi_ext_ecc_info *ecc;
3118 	uint8_t *cursor;
3119 	int ret = -EINVAL;
3120 	int len;
3121 	int i;
3122 
3123 	len = le16_to_cpu(p->ext_param_page_length) * 16;
3124 	ep = kmalloc(len, GFP_KERNEL);
3125 	if (!ep)
3126 		return -ENOMEM;
3127 
3128 	/* Send our own NAND_CMD_PARAM. */
3129 	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
3130 
3131 	/* Use the Change Read Column command to skip the ONFI param pages. */
3132 	chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
3133 			sizeof(*p) * p->num_of_param_pages , -1);
3134 
3135 	/* Read out the Extended Parameter Page. */
3136 	chip->read_buf(mtd, (uint8_t *)ep, len);
3137 	if ((onfi_crc16(ONFI_CRC_BASE, ((uint8_t *)ep) + 2, len - 2)
3138 		!= le16_to_cpu(ep->crc))) {
3139 		pr_debug("fail in the CRC.\n");
3140 		goto ext_out;
3141 	}
3142 
3143 	/*
3144 	 * Check the signature.
3145 	 * Do not strictly follow the ONFI spec, maybe changed in future.
3146 	 */
3147 	if (strncmp((char *)ep->sig, "EPPS", 4)) {
3148 		pr_debug("The signature is invalid.\n");
3149 		goto ext_out;
3150 	}
3151 
3152 	/* find the ECC section. */
3153 	cursor = (uint8_t *)(ep + 1);
3154 	for (i = 0; i < ONFI_EXT_SECTION_MAX; i++) {
3155 		s = ep->sections + i;
3156 		if (s->type == ONFI_SECTION_TYPE_2)
3157 			break;
3158 		cursor += s->length * 16;
3159 	}
3160 	if (i == ONFI_EXT_SECTION_MAX) {
3161 		pr_debug("We can not find the ECC section.\n");
3162 		goto ext_out;
3163 	}
3164 
3165 	/* get the info we want. */
3166 	ecc = (struct onfi_ext_ecc_info *)cursor;
3167 
3168 	if (!ecc->codeword_size) {
3169 		pr_debug("Invalid codeword size\n");
3170 		goto ext_out;
3171 	}
3172 
3173 	chip->ecc_strength_ds = ecc->ecc_bits;
3174 	chip->ecc_step_ds = 1 << ecc->codeword_size;
3175 	ret = 0;
3176 
3177 ext_out:
3178 	kfree(ep);
3179 	return ret;
3180 }
3181 
3182 static int nand_setup_read_retry_micron(struct mtd_info *mtd, int retry_mode)
3183 {
3184 	struct nand_chip *chip = mtd_to_nand(mtd);
3185 	uint8_t feature[ONFI_SUBFEATURE_PARAM_LEN] = {retry_mode};
3186 
3187 	return chip->onfi_set_features(mtd, chip, ONFI_FEATURE_ADDR_READ_RETRY,
3188 			feature);
3189 }
3190 
3191 /*
3192  * Configure chip properties from Micron vendor-specific ONFI table
3193  */
3194 static void nand_onfi_detect_micron(struct nand_chip *chip,
3195 		struct nand_onfi_params *p)
3196 {
3197 	struct nand_onfi_vendor_micron *micron = (void *)p->vendor;
3198 
3199 	if (le16_to_cpu(p->vendor_revision) < 1)
3200 		return;
3201 
3202 	chip->read_retries = micron->read_retry_options;
3203 	chip->setup_read_retry = nand_setup_read_retry_micron;
3204 }
3205 
3206 /*
3207  * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
3208  */
3209 static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
3210 					int *busw)
3211 {
3212 	struct nand_onfi_params *p = &chip->onfi_params;
3213 	int i, j;
3214 	int val;
3215 
3216 	/* Try ONFI for unknown chip or LP */
3217 	chip->cmdfunc(mtd, NAND_CMD_READID, 0x20, -1);
3218 	if (chip->read_byte(mtd) != 'O' || chip->read_byte(mtd) != 'N' ||
3219 		chip->read_byte(mtd) != 'F' || chip->read_byte(mtd) != 'I')
3220 		return 0;
3221 
3222 	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
3223 	for (i = 0; i < 3; i++) {
3224 		for (j = 0; j < sizeof(*p); j++)
3225 			((uint8_t *)p)[j] = chip->read_byte(mtd);
3226 		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
3227 				le16_to_cpu(p->crc)) {
3228 			break;
3229 		}
3230 	}
3231 
3232 	if (i == 3) {
3233 		pr_err("Could not find valid ONFI parameter page; aborting\n");
3234 		return 0;
3235 	}
3236 
3237 	/* Check version */
3238 	val = le16_to_cpu(p->revision);
3239 	if (val & (1 << 5))
3240 		chip->onfi_version = 23;
3241 	else if (val & (1 << 4))
3242 		chip->onfi_version = 22;
3243 	else if (val & (1 << 3))
3244 		chip->onfi_version = 21;
3245 	else if (val & (1 << 2))
3246 		chip->onfi_version = 20;
3247 	else if (val & (1 << 1))
3248 		chip->onfi_version = 10;
3249 
3250 	if (!chip->onfi_version) {
3251 		pr_info("unsupported ONFI version: %d\n", val);
3252 		return 0;
3253 	}
3254 
3255 	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
3256 	sanitize_string(p->model, sizeof(p->model));
3257 	if (!mtd->name)
3258 		mtd->name = p->model;
3259 
3260 	mtd->writesize = le32_to_cpu(p->byte_per_page);
3261 
3262 	/*
3263 	 * pages_per_block and blocks_per_lun may not be a power-of-2 size
3264 	 * (don't ask me who thought of this...). MTD assumes that these
3265 	 * dimensions will be power-of-2, so just truncate the remaining area.
3266 	 */
3267 	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
3268 	mtd->erasesize *= mtd->writesize;
3269 
3270 	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
3271 
3272 	/* See erasesize comment */
3273 	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
3274 	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
3275 	chip->bits_per_cell = p->bits_per_cell;
3276 
3277 	if (onfi_feature(chip) & ONFI_FEATURE_16_BIT_BUS)
3278 		*busw = NAND_BUSWIDTH_16;
3279 	else
3280 		*busw = 0;
3281 
3282 	if (p->ecc_bits != 0xff) {
3283 		chip->ecc_strength_ds = p->ecc_bits;
3284 		chip->ecc_step_ds = 512;
3285 	} else if (chip->onfi_version >= 21 &&
3286 		(onfi_feature(chip) & ONFI_FEATURE_EXT_PARAM_PAGE)) {
3287 
3288 		/*
3289 		 * The nand_flash_detect_ext_param_page() uses the
3290 		 * Change Read Column command which maybe not supported
3291 		 * by the chip->cmdfunc. So try to update the chip->cmdfunc
3292 		 * now. We do not replace user supplied command function.
3293 		 */
3294 		if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
3295 			chip->cmdfunc = nand_command_lp;
3296 
3297 		/* The Extended Parameter Page is supported since ONFI 2.1. */
3298 		if (nand_flash_detect_ext_param_page(mtd, chip, p))
3299 			pr_warn("Failed to detect ONFI extended param page\n");
3300 	} else {
3301 		pr_warn("Could not retrieve ONFI ECC requirements\n");
3302 	}
3303 
3304 	if (p->jedec_id == NAND_MFR_MICRON)
3305 		nand_onfi_detect_micron(chip, p);
3306 
3307 	return 1;
3308 }
3309 #else
3310 static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
3311 					int *busw)
3312 {
3313 	return 0;
3314 }
3315 #endif
3316 
3317 /*
3318  * Check if the NAND chip is JEDEC compliant, returns 1 if it is, 0 otherwise.
3319  */
3320 static int nand_flash_detect_jedec(struct mtd_info *mtd, struct nand_chip *chip,
3321 					int *busw)
3322 {
3323 	struct nand_jedec_params *p = &chip->jedec_params;
3324 	struct jedec_ecc_info *ecc;
3325 	int val;
3326 	int i, j;
3327 
3328 	/* Try JEDEC for unknown chip or LP */
3329 	chip->cmdfunc(mtd, NAND_CMD_READID, 0x40, -1);
3330 	if (chip->read_byte(mtd) != 'J' || chip->read_byte(mtd) != 'E' ||
3331 		chip->read_byte(mtd) != 'D' || chip->read_byte(mtd) != 'E' ||
3332 		chip->read_byte(mtd) != 'C')
3333 		return 0;
3334 
3335 	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0x40, -1);
3336 	for (i = 0; i < 3; i++) {
3337 		for (j = 0; j < sizeof(*p); j++)
3338 			((uint8_t *)p)[j] = chip->read_byte(mtd);
3339 
3340 		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 510) ==
3341 				le16_to_cpu(p->crc))
3342 			break;
3343 	}
3344 
3345 	if (i == 3) {
3346 		pr_err("Could not find valid JEDEC parameter page; aborting\n");
3347 		return 0;
3348 	}
3349 
3350 	/* Check version */
3351 	val = le16_to_cpu(p->revision);
3352 	if (val & (1 << 2))
3353 		chip->jedec_version = 10;
3354 	else if (val & (1 << 1))
3355 		chip->jedec_version = 1; /* vendor specific version */
3356 
3357 	if (!chip->jedec_version) {
3358 		pr_info("unsupported JEDEC version: %d\n", val);
3359 		return 0;
3360 	}
3361 
3362 	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
3363 	sanitize_string(p->model, sizeof(p->model));
3364 	if (!mtd->name)
3365 		mtd->name = p->model;
3366 
3367 	mtd->writesize = le32_to_cpu(p->byte_per_page);
3368 
3369 	/* Please reference to the comment for nand_flash_detect_onfi. */
3370 	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
3371 	mtd->erasesize *= mtd->writesize;
3372 
3373 	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
3374 
3375 	/* Please reference to the comment for nand_flash_detect_onfi. */
3376 	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
3377 	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
3378 	chip->bits_per_cell = p->bits_per_cell;
3379 
3380 	if (jedec_feature(chip) & JEDEC_FEATURE_16_BIT_BUS)
3381 		*busw = NAND_BUSWIDTH_16;
3382 	else
3383 		*busw = 0;
3384 
3385 	/* ECC info */
3386 	ecc = &p->ecc_info[0];
3387 
3388 	if (ecc->codeword_size >= 9) {
3389 		chip->ecc_strength_ds = ecc->ecc_bits;
3390 		chip->ecc_step_ds = 1 << ecc->codeword_size;
3391 	} else {
3392 		pr_warn("Invalid codeword size\n");
3393 	}
3394 
3395 	return 1;
3396 }
3397 
3398 /*
3399  * nand_id_has_period - Check if an ID string has a given wraparound period
3400  * @id_data: the ID string
3401  * @arrlen: the length of the @id_data array
3402  * @period: the period of repitition
3403  *
3404  * Check if an ID string is repeated within a given sequence of bytes at
3405  * specific repetition interval period (e.g., {0x20,0x01,0x7F,0x20} has a
3406  * period of 3). This is a helper function for nand_id_len(). Returns non-zero
3407  * if the repetition has a period of @period; otherwise, returns zero.
3408  */
3409 static int nand_id_has_period(u8 *id_data, int arrlen, int period)
3410 {
3411 	int i, j;
3412 	for (i = 0; i < period; i++)
3413 		for (j = i + period; j < arrlen; j += period)
3414 			if (id_data[i] != id_data[j])
3415 				return 0;
3416 	return 1;
3417 }
3418 
3419 /*
3420  * nand_id_len - Get the length of an ID string returned by CMD_READID
3421  * @id_data: the ID string
3422  * @arrlen: the length of the @id_data array
3423 
3424  * Returns the length of the ID string, according to known wraparound/trailing
3425  * zero patterns. If no pattern exists, returns the length of the array.
3426  */
3427 static int nand_id_len(u8 *id_data, int arrlen)
3428 {
3429 	int last_nonzero, period;
3430 
3431 	/* Find last non-zero byte */
3432 	for (last_nonzero = arrlen - 1; last_nonzero >= 0; last_nonzero--)
3433 		if (id_data[last_nonzero])
3434 			break;
3435 
3436 	/* All zeros */
3437 	if (last_nonzero < 0)
3438 		return 0;
3439 
3440 	/* Calculate wraparound period */
3441 	for (period = 1; period < arrlen; period++)
3442 		if (nand_id_has_period(id_data, arrlen, period))
3443 			break;
3444 
3445 	/* There's a repeated pattern */
3446 	if (period < arrlen)
3447 		return period;
3448 
3449 	/* There are trailing zeros */
3450 	if (last_nonzero < arrlen - 1)
3451 		return last_nonzero + 1;
3452 
3453 	/* No pattern detected */
3454 	return arrlen;
3455 }
3456 
3457 /* Extract the bits of per cell from the 3rd byte of the extended ID */
3458 static int nand_get_bits_per_cell(u8 cellinfo)
3459 {
3460 	int bits;
3461 
3462 	bits = cellinfo & NAND_CI_CELLTYPE_MSK;
3463 	bits >>= NAND_CI_CELLTYPE_SHIFT;
3464 	return bits + 1;
3465 }
3466 
3467 /*
3468  * Many new NAND share similar device ID codes, which represent the size of the
3469  * chip. The rest of the parameters must be decoded according to generic or
3470  * manufacturer-specific "extended ID" decoding patterns.
3471  */
3472 static void nand_decode_ext_id(struct mtd_info *mtd, struct nand_chip *chip,
3473 				u8 id_data[8], int *busw)
3474 {
3475 	int extid, id_len;
3476 	/* The 3rd id byte holds MLC / multichip data */
3477 	chip->bits_per_cell = nand_get_bits_per_cell(id_data[2]);
3478 	/* The 4th id byte is the important one */
3479 	extid = id_data[3];
3480 
3481 	id_len = nand_id_len(id_data, 8);
3482 
3483 	/*
3484 	 * Field definitions are in the following datasheets:
3485 	 * Old style (4,5 byte ID): Samsung K9GAG08U0M (p.32)
3486 	 * New Samsung (6 byte ID): Samsung K9GAG08U0F (p.44)
3487 	 * Hynix MLC   (6 byte ID): Hynix H27UBG8T2B (p.22)
3488 	 *
3489 	 * Check for ID length, non-zero 6th byte, cell type, and Hynix/Samsung
3490 	 * ID to decide what to do.
3491 	 */
3492 	if (id_len == 6 && id_data[0] == NAND_MFR_SAMSUNG &&
3493 			!nand_is_slc(chip) && id_data[5] != 0x00) {
3494 		/* Calc pagesize */
3495 		mtd->writesize = 2048 << (extid & 0x03);
3496 		extid >>= 2;
3497 		/* Calc oobsize */
3498 		switch (((extid >> 2) & 0x04) | (extid & 0x03)) {
3499 		case 1:
3500 			mtd->oobsize = 128;
3501 			break;
3502 		case 2:
3503 			mtd->oobsize = 218;
3504 			break;
3505 		case 3:
3506 			mtd->oobsize = 400;
3507 			break;
3508 		case 4:
3509 			mtd->oobsize = 436;
3510 			break;
3511 		case 5:
3512 			mtd->oobsize = 512;
3513 			break;
3514 		case 6:
3515 			mtd->oobsize = 640;
3516 			break;
3517 		case 7:
3518 		default: /* Other cases are "reserved" (unknown) */
3519 			mtd->oobsize = 1024;
3520 			break;
3521 		}
3522 		extid >>= 2;
3523 		/* Calc blocksize */
3524 		mtd->erasesize = (128 * 1024) <<
3525 			(((extid >> 1) & 0x04) | (extid & 0x03));
3526 		*busw = 0;
3527 	} else if (id_len == 6 && id_data[0] == NAND_MFR_HYNIX &&
3528 			!nand_is_slc(chip)) {
3529 		unsigned int tmp;
3530 
3531 		/* Calc pagesize */
3532 		mtd->writesize = 2048 << (extid & 0x03);
3533 		extid >>= 2;
3534 		/* Calc oobsize */
3535 		switch (((extid >> 2) & 0x04) | (extid & 0x03)) {
3536 		case 0:
3537 			mtd->oobsize = 128;
3538 			break;
3539 		case 1:
3540 			mtd->oobsize = 224;
3541 			break;
3542 		case 2:
3543 			mtd->oobsize = 448;
3544 			break;
3545 		case 3:
3546 			mtd->oobsize = 64;
3547 			break;
3548 		case 4:
3549 			mtd->oobsize = 32;
3550 			break;
3551 		case 5:
3552 			mtd->oobsize = 16;
3553 			break;
3554 		default:
3555 			mtd->oobsize = 640;
3556 			break;
3557 		}
3558 		extid >>= 2;
3559 		/* Calc blocksize */
3560 		tmp = ((extid >> 1) & 0x04) | (extid & 0x03);
3561 		if (tmp < 0x03)
3562 			mtd->erasesize = (128 * 1024) << tmp;
3563 		else if (tmp == 0x03)
3564 			mtd->erasesize = 768 * 1024;
3565 		else
3566 			mtd->erasesize = (64 * 1024) << tmp;
3567 		*busw = 0;
3568 	} else {
3569 		/* Calc pagesize */
3570 		mtd->writesize = 1024 << (extid & 0x03);
3571 		extid >>= 2;
3572 		/* Calc oobsize */
3573 		mtd->oobsize = (8 << (extid & 0x01)) *
3574 			(mtd->writesize >> 9);
3575 		extid >>= 2;
3576 		/* Calc blocksize. Blocksize is multiples of 64KiB */
3577 		mtd->erasesize = (64 * 1024) << (extid & 0x03);
3578 		extid >>= 2;
3579 		/* Get buswidth information */
3580 		*busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0;
3581 
3582 		/*
3583 		 * Toshiba 24nm raw SLC (i.e., not BENAND) have 32B OOB per
3584 		 * 512B page. For Toshiba SLC, we decode the 5th/6th byte as
3585 		 * follows:
3586 		 * - ID byte 6, bits[2:0]: 100b -> 43nm, 101b -> 32nm,
3587 		 *                         110b -> 24nm
3588 		 * - ID byte 5, bit[7]:    1 -> BENAND, 0 -> raw SLC
3589 		 */
3590 		if (id_len >= 6 && id_data[0] == NAND_MFR_TOSHIBA &&
3591 				nand_is_slc(chip) &&
3592 				(id_data[5] & 0x7) == 0x6 /* 24nm */ &&
3593 				!(id_data[4] & 0x80) /* !BENAND */) {
3594 			mtd->oobsize = 32 * mtd->writesize >> 9;
3595 		}
3596 
3597 	}
3598 }
3599 
3600 /*
3601  * Old devices have chip data hardcoded in the device ID table. nand_decode_id
3602  * decodes a matching ID table entry and assigns the MTD size parameters for
3603  * the chip.
3604  */
3605 static void nand_decode_id(struct mtd_info *mtd, struct nand_chip *chip,
3606 				struct nand_flash_dev *type, u8 id_data[8],
3607 				int *busw)
3608 {
3609 	int maf_id = id_data[0];
3610 
3611 	mtd->erasesize = type->erasesize;
3612 	mtd->writesize = type->pagesize;
3613 	mtd->oobsize = mtd->writesize / 32;
3614 	*busw = type->options & NAND_BUSWIDTH_16;
3615 
3616 	/* All legacy ID NAND are small-page, SLC */
3617 	chip->bits_per_cell = 1;
3618 
3619 	/*
3620 	 * Check for Spansion/AMD ID + repeating 5th, 6th byte since
3621 	 * some Spansion chips have erasesize that conflicts with size
3622 	 * listed in nand_ids table.
3623 	 * Data sheet (5 byte ID): Spansion S30ML-P ORNAND (p.39)
3624 	 */
3625 	if (maf_id == NAND_MFR_AMD && id_data[4] != 0x00 && id_data[5] == 0x00
3626 			&& id_data[6] == 0x00 && id_data[7] == 0x00
3627 			&& mtd->writesize == 512) {
3628 		mtd->erasesize = 128 * 1024;
3629 		mtd->erasesize <<= ((id_data[3] & 0x03) << 1);
3630 	}
3631 }
3632 
3633 /*
3634  * Set the bad block marker/indicator (BBM/BBI) patterns according to some
3635  * heuristic patterns using various detected parameters (e.g., manufacturer,
3636  * page size, cell-type information).
3637  */
3638 static void nand_decode_bbm_options(struct mtd_info *mtd,
3639 				    struct nand_chip *chip, u8 id_data[8])
3640 {
3641 	int maf_id = id_data[0];
3642 
3643 	/* Set the bad block position */
3644 	if (mtd->writesize > 512 || (chip->options & NAND_BUSWIDTH_16))
3645 		chip->badblockpos = NAND_LARGE_BADBLOCK_POS;
3646 	else
3647 		chip->badblockpos = NAND_SMALL_BADBLOCK_POS;
3648 
3649 	/*
3650 	 * Bad block marker is stored in the last page of each block on Samsung
3651 	 * and Hynix MLC devices; stored in first two pages of each block on
3652 	 * Micron devices with 2KiB pages and on SLC Samsung, Hynix, Toshiba,
3653 	 * AMD/Spansion, and Macronix.  All others scan only the first page.
3654 	 */
3655 	if (!nand_is_slc(chip) &&
3656 			(maf_id == NAND_MFR_SAMSUNG ||
3657 			 maf_id == NAND_MFR_HYNIX))
3658 		chip->bbt_options |= NAND_BBT_SCANLASTPAGE;
3659 	else if ((nand_is_slc(chip) &&
3660 				(maf_id == NAND_MFR_SAMSUNG ||
3661 				 maf_id == NAND_MFR_HYNIX ||
3662 				 maf_id == NAND_MFR_TOSHIBA ||
3663 				 maf_id == NAND_MFR_AMD ||
3664 				 maf_id == NAND_MFR_MACRONIX)) ||
3665 			(mtd->writesize == 2048 &&
3666 			 maf_id == NAND_MFR_MICRON))
3667 		chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
3668 }
3669 
3670 static inline bool is_full_id_nand(struct nand_flash_dev *type)
3671 {
3672 	return type->id_len;
3673 }
3674 
3675 static bool find_full_id_nand(struct mtd_info *mtd, struct nand_chip *chip,
3676 		   struct nand_flash_dev *type, u8 *id_data, int *busw)
3677 {
3678 	if (!strncmp((char *)type->id, (char *)id_data, type->id_len)) {
3679 		mtd->writesize = type->pagesize;
3680 		mtd->erasesize = type->erasesize;
3681 		mtd->oobsize = type->oobsize;
3682 
3683 		chip->bits_per_cell = nand_get_bits_per_cell(id_data[2]);
3684 		chip->chipsize = (uint64_t)type->chipsize << 20;
3685 		chip->options |= type->options;
3686 		chip->ecc_strength_ds = NAND_ECC_STRENGTH(type);
3687 		chip->ecc_step_ds = NAND_ECC_STEP(type);
3688 		chip->onfi_timing_mode_default =
3689 					type->onfi_timing_mode_default;
3690 
3691 		*busw = type->options & NAND_BUSWIDTH_16;
3692 
3693 		if (!mtd->name)
3694 			mtd->name = type->name;
3695 
3696 		return true;
3697 	}
3698 	return false;
3699 }
3700 
3701 /*
3702  * Get the flash and manufacturer id and lookup if the type is supported.
3703  */
3704 struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
3705 						  struct nand_chip *chip,
3706 						  int *maf_id, int *dev_id,
3707 						  struct nand_flash_dev *type)
3708 {
3709 	int busw;
3710 	int i, maf_idx;
3711 	u8 id_data[8];
3712 
3713 	/*
3714 	 * Reset the chip, required by some chips (e.g. Micron MT29FxGxxxxx)
3715 	 * after power-up.
3716 	 */
3717 	nand_reset(chip, 0);
3718 
3719 	/* Select the device */
3720 	chip->select_chip(mtd, 0);
3721 
3722 	/* Send the command for reading device ID */
3723 	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
3724 
3725 	/* Read manufacturer and device IDs */
3726 	*maf_id = chip->read_byte(mtd);
3727 	*dev_id = chip->read_byte(mtd);
3728 
3729 	/*
3730 	 * Try again to make sure, as some systems the bus-hold or other
3731 	 * interface concerns can cause random data which looks like a
3732 	 * possibly credible NAND flash to appear. If the two results do
3733 	 * not match, ignore the device completely.
3734 	 */
3735 
3736 	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
3737 
3738 	/* Read entire ID string */
3739 	for (i = 0; i < 8; i++)
3740 		id_data[i] = chip->read_byte(mtd);
3741 
3742 	if (id_data[0] != *maf_id || id_data[1] != *dev_id) {
3743 		pr_info("second ID read did not match %02x,%02x against %02x,%02x\n",
3744 			*maf_id, *dev_id, id_data[0], id_data[1]);
3745 		return ERR_PTR(-ENODEV);
3746 	}
3747 
3748 	if (!type)
3749 		type = nand_flash_ids;
3750 
3751 	for (; type->name != NULL; type++) {
3752 		if (is_full_id_nand(type)) {
3753 			if (find_full_id_nand(mtd, chip, type, id_data, &busw))
3754 				goto ident_done;
3755 		} else if (*dev_id == type->dev_id) {
3756 			break;
3757 		}
3758 	}
3759 
3760 	chip->onfi_version = 0;
3761 	if (!type->name || !type->pagesize) {
3762 		/* Check if the chip is ONFI compliant */
3763 		if (nand_flash_detect_onfi(mtd, chip, &busw))
3764 			goto ident_done;
3765 
3766 		/* Check if the chip is JEDEC compliant */
3767 		if (nand_flash_detect_jedec(mtd, chip, &busw))
3768 			goto ident_done;
3769 	}
3770 
3771 	if (!type->name)
3772 		return ERR_PTR(-ENODEV);
3773 
3774 	if (!mtd->name)
3775 		mtd->name = type->name;
3776 
3777 	chip->chipsize = (uint64_t)type->chipsize << 20;
3778 
3779 	if (!type->pagesize) {
3780 		/* Decode parameters from extended ID */
3781 		nand_decode_ext_id(mtd, chip, id_data, &busw);
3782 	} else {
3783 		nand_decode_id(mtd, chip, type, id_data, &busw);
3784 	}
3785 	/* Get chip options */
3786 	chip->options |= type->options;
3787 
3788 	/*
3789 	 * Check if chip is not a Samsung device. Do not clear the
3790 	 * options for chips which do not have an extended id.
3791 	 */
3792 	if (*maf_id != NAND_MFR_SAMSUNG && !type->pagesize)
3793 		chip->options &= ~NAND_SAMSUNG_LP_OPTIONS;
3794 ident_done:
3795 
3796 	/* Try to identify manufacturer */
3797 	for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_idx++) {
3798 		if (nand_manuf_ids[maf_idx].id == *maf_id)
3799 			break;
3800 	}
3801 
3802 	if (chip->options & NAND_BUSWIDTH_AUTO) {
3803 		WARN_ON(chip->options & NAND_BUSWIDTH_16);
3804 		chip->options |= busw;
3805 		nand_set_defaults(chip, busw);
3806 	} else if (busw != (chip->options & NAND_BUSWIDTH_16)) {
3807 		/*
3808 		 * Check, if buswidth is correct. Hardware drivers should set
3809 		 * chip correct!
3810 		 */
3811 		pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
3812 			*maf_id, *dev_id);
3813 		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name, mtd->name);
3814 		pr_warn("bus width %d instead %d bit\n",
3815 			   (chip->options & NAND_BUSWIDTH_16) ? 16 : 8,
3816 			   busw ? 16 : 8);
3817 		return ERR_PTR(-EINVAL);
3818 	}
3819 
3820 	nand_decode_bbm_options(mtd, chip, id_data);
3821 
3822 	/* Calculate the address shift from the page size */
3823 	chip->page_shift = ffs(mtd->writesize) - 1;
3824 	/* Convert chipsize to number of pages per chip -1 */
3825 	chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
3826 
3827 	chip->bbt_erase_shift = chip->phys_erase_shift =
3828 		ffs(mtd->erasesize) - 1;
3829 	if (chip->chipsize & 0xffffffff)
3830 		chip->chip_shift = ffs((unsigned)chip->chipsize) - 1;
3831 	else {
3832 		chip->chip_shift = ffs((unsigned)(chip->chipsize >> 32));
3833 		chip->chip_shift += 32 - 1;
3834 	}
3835 
3836 	if (chip->chip_shift - chip->page_shift > 16)
3837 		chip->options |= NAND_ROW_ADDR_3;
3838 
3839 	chip->badblockbits = 8;
3840 	chip->erase = single_erase;
3841 
3842 	/* Do not replace user supplied command function! */
3843 	if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
3844 		chip->cmdfunc = nand_command_lp;
3845 
3846 	pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
3847 		*maf_id, *dev_id);
3848 
3849 #ifdef CONFIG_SYS_NAND_ONFI_DETECTION
3850 	if (chip->onfi_version)
3851 		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3852 				chip->onfi_params.model);
3853 	else if (chip->jedec_version)
3854 		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3855 				chip->jedec_params.model);
3856 	else
3857 		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3858 				type->name);
3859 #else
3860 	if (chip->jedec_version)
3861 		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3862 				chip->jedec_params.model);
3863 	else
3864 		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3865 				type->name);
3866 
3867 	pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3868 		type->name);
3869 #endif
3870 
3871 	pr_info("%d MiB, %s, erase size: %d KiB, page size: %d, OOB size: %d\n",
3872 		(int)(chip->chipsize >> 20), nand_is_slc(chip) ? "SLC" : "MLC",
3873 		mtd->erasesize >> 10, mtd->writesize, mtd->oobsize);
3874 	return type;
3875 }
3876 EXPORT_SYMBOL(nand_get_flash_type);
3877 
3878 #if CONFIG_IS_ENABLED(OF_CONTROL)
3879 DECLARE_GLOBAL_DATA_PTR;
3880 
3881 static int nand_dt_init(struct mtd_info *mtd, struct nand_chip *chip, int node)
3882 {
3883 	int ret, ecc_mode = -1, ecc_strength, ecc_step;
3884 	const void *blob = gd->fdt_blob;
3885 	const char *str;
3886 
3887 	ret = fdtdec_get_int(blob, node, "nand-bus-width", -1);
3888 	if (ret == 16)
3889 		chip->options |= NAND_BUSWIDTH_16;
3890 
3891 	if (fdtdec_get_bool(blob, node, "nand-on-flash-bbt"))
3892 		chip->bbt_options |= NAND_BBT_USE_FLASH;
3893 
3894 	str = fdt_getprop(blob, node, "nand-ecc-mode", NULL);
3895 	if (str) {
3896 		if (!strcmp(str, "none"))
3897 			ecc_mode = NAND_ECC_NONE;
3898 		else if (!strcmp(str, "soft"))
3899 			ecc_mode = NAND_ECC_SOFT;
3900 		else if (!strcmp(str, "hw"))
3901 			ecc_mode = NAND_ECC_HW;
3902 		else if (!strcmp(str, "hw_syndrome"))
3903 			ecc_mode = NAND_ECC_HW_SYNDROME;
3904 		else if (!strcmp(str, "hw_oob_first"))
3905 			ecc_mode = NAND_ECC_HW_OOB_FIRST;
3906 		else if (!strcmp(str, "soft_bch"))
3907 			ecc_mode = NAND_ECC_SOFT_BCH;
3908 	}
3909 
3910 
3911 	ecc_strength = fdtdec_get_int(blob, node, "nand-ecc-strength", -1);
3912 	ecc_step = fdtdec_get_int(blob, node, "nand-ecc-step-size", -1);
3913 
3914 	if ((ecc_step >= 0 && !(ecc_strength >= 0)) ||
3915 	    (!(ecc_step >= 0) && ecc_strength >= 0)) {
3916 		pr_err("must set both strength and step size in DT\n");
3917 		return -EINVAL;
3918 	}
3919 
3920 	if (ecc_mode >= 0)
3921 		chip->ecc.mode = ecc_mode;
3922 
3923 	if (ecc_strength >= 0)
3924 		chip->ecc.strength = ecc_strength;
3925 
3926 	if (ecc_step > 0)
3927 		chip->ecc.size = ecc_step;
3928 
3929 	if (fdt_getprop(blob, node, "nand-ecc-maximize", NULL))
3930 		chip->ecc.options |= NAND_ECC_MAXIMIZE;
3931 
3932 	return 0;
3933 }
3934 #else
3935 static int nand_dt_init(struct mtd_info *mtd, struct nand_chip *chip, int node)
3936 {
3937 	return 0;
3938 }
3939 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
3940 
3941 /**
3942  * nand_scan_ident - [NAND Interface] Scan for the NAND device
3943  * @mtd: MTD device structure
3944  * @maxchips: number of chips to scan for
3945  * @table: alternative NAND ID table
3946  *
3947  * This is the first phase of the normal nand_scan() function. It reads the
3948  * flash ID and sets up MTD fields accordingly.
3949  *
3950  */
3951 int nand_scan_ident(struct mtd_info *mtd, int maxchips,
3952 		    struct nand_flash_dev *table)
3953 {
3954 	int i, nand_maf_id, nand_dev_id;
3955 	struct nand_chip *chip = mtd_to_nand(mtd);
3956 	struct nand_flash_dev *type;
3957 	int ret;
3958 
3959 	if (chip->flash_node) {
3960 		ret = nand_dt_init(mtd, chip, chip->flash_node);
3961 		if (ret)
3962 			return ret;
3963 	}
3964 
3965 	/* Set the default functions */
3966 	nand_set_defaults(chip, chip->options & NAND_BUSWIDTH_16);
3967 
3968 	/* Read the flash type */
3969 	type = nand_get_flash_type(mtd, chip, &nand_maf_id,
3970 				   &nand_dev_id, table);
3971 
3972 	if (IS_ERR(type)) {
3973 		if (!(chip->options & NAND_SCAN_SILENT_NODEV))
3974 			pr_warn("No NAND device found\n");
3975 		chip->select_chip(mtd, -1);
3976 		return PTR_ERR(type);
3977 	}
3978 
3979 	/* Initialize the ->data_interface field. */
3980 	ret = nand_init_data_interface(chip);
3981 	if (ret)
3982 		return ret;
3983 
3984 	/*
3985 	 * Setup the data interface correctly on the chip and controller side.
3986 	 * This explicit call to nand_setup_data_interface() is only required
3987 	 * for the first die, because nand_reset() has been called before
3988 	 * ->data_interface and ->default_onfi_timing_mode were set.
3989 	 * For the other dies, nand_reset() will automatically switch to the
3990 	 * best mode for us.
3991 	 */
3992 	ret = nand_setup_data_interface(chip, 0);
3993 	if (ret)
3994 		return ret;
3995 
3996 	chip->select_chip(mtd, -1);
3997 
3998 	/* Check for a chip array */
3999 	for (i = 1; i < maxchips; i++) {
4000 		/* See comment in nand_get_flash_type for reset */
4001 		nand_reset(chip, i);
4002 
4003 		chip->select_chip(mtd, i);
4004 		/* Send the command for reading device ID */
4005 		chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
4006 		/* Read manufacturer and device IDs */
4007 		if (nand_maf_id != chip->read_byte(mtd) ||
4008 		    nand_dev_id != chip->read_byte(mtd)) {
4009 			chip->select_chip(mtd, -1);
4010 			break;
4011 		}
4012 		chip->select_chip(mtd, -1);
4013 	}
4014 
4015 #ifdef DEBUG
4016 	if (i > 1)
4017 		pr_info("%d chips detected\n", i);
4018 #endif
4019 
4020 	/* Store the number of chips and calc total size for mtd */
4021 	chip->numchips = i;
4022 	mtd->size = i * chip->chipsize;
4023 
4024 	return 0;
4025 }
4026 EXPORT_SYMBOL(nand_scan_ident);
4027 
4028 /**
4029  * nand_check_ecc_caps - check the sanity of preset ECC settings
4030  * @chip: nand chip info structure
4031  * @caps: ECC caps info structure
4032  * @oobavail: OOB size that the ECC engine can use
4033  *
4034  * When ECC step size and strength are already set, check if they are supported
4035  * by the controller and the calculated ECC bytes fit within the chip's OOB.
4036  * On success, the calculated ECC bytes is set.
4037  */
4038 int nand_check_ecc_caps(struct nand_chip *chip,
4039 			const struct nand_ecc_caps *caps, int oobavail)
4040 {
4041 	struct mtd_info *mtd = nand_to_mtd(chip);
4042 	const struct nand_ecc_step_info *stepinfo;
4043 	int preset_step = chip->ecc.size;
4044 	int preset_strength = chip->ecc.strength;
4045 	int nsteps, ecc_bytes;
4046 	int i, j;
4047 
4048 	if (WARN_ON(oobavail < 0))
4049 		return -EINVAL;
4050 
4051 	if (!preset_step || !preset_strength)
4052 		return -ENODATA;
4053 
4054 	nsteps = mtd->writesize / preset_step;
4055 
4056 	for (i = 0; i < caps->nstepinfos; i++) {
4057 		stepinfo = &caps->stepinfos[i];
4058 
4059 		if (stepinfo->stepsize != preset_step)
4060 			continue;
4061 
4062 		for (j = 0; j < stepinfo->nstrengths; j++) {
4063 			if (stepinfo->strengths[j] != preset_strength)
4064 				continue;
4065 
4066 			ecc_bytes = caps->calc_ecc_bytes(preset_step,
4067 							 preset_strength);
4068 			if (WARN_ON_ONCE(ecc_bytes < 0))
4069 				return ecc_bytes;
4070 
4071 			if (ecc_bytes * nsteps > oobavail) {
4072 				pr_err("ECC (step, strength) = (%d, %d) does not fit in OOB",
4073 				       preset_step, preset_strength);
4074 				return -ENOSPC;
4075 			}
4076 
4077 			chip->ecc.bytes = ecc_bytes;
4078 
4079 			return 0;
4080 		}
4081 	}
4082 
4083 	pr_err("ECC (step, strength) = (%d, %d) not supported on this controller",
4084 	       preset_step, preset_strength);
4085 
4086 	return -ENOTSUPP;
4087 }
4088 EXPORT_SYMBOL_GPL(nand_check_ecc_caps);
4089 
4090 /**
4091  * nand_match_ecc_req - meet the chip's requirement with least ECC bytes
4092  * @chip: nand chip info structure
4093  * @caps: ECC engine caps info structure
4094  * @oobavail: OOB size that the ECC engine can use
4095  *
4096  * If a chip's ECC requirement is provided, try to meet it with the least
4097  * number of ECC bytes (i.e. with the largest number of OOB-free bytes).
4098  * On success, the chosen ECC settings are set.
4099  */
4100 int nand_match_ecc_req(struct nand_chip *chip,
4101 		       const struct nand_ecc_caps *caps, int oobavail)
4102 {
4103 	struct mtd_info *mtd = nand_to_mtd(chip);
4104 	const struct nand_ecc_step_info *stepinfo;
4105 	int req_step = chip->ecc_step_ds;
4106 	int req_strength = chip->ecc_strength_ds;
4107 	int req_corr, step_size, strength, nsteps, ecc_bytes, ecc_bytes_total;
4108 	int best_step, best_strength, best_ecc_bytes;
4109 	int best_ecc_bytes_total = INT_MAX;
4110 	int i, j;
4111 
4112 	if (WARN_ON(oobavail < 0))
4113 		return -EINVAL;
4114 
4115 	/* No information provided by the NAND chip */
4116 	if (!req_step || !req_strength)
4117 		return -ENOTSUPP;
4118 
4119 	/* number of correctable bits the chip requires in a page */
4120 	req_corr = mtd->writesize / req_step * req_strength;
4121 
4122 	for (i = 0; i < caps->nstepinfos; i++) {
4123 		stepinfo = &caps->stepinfos[i];
4124 		step_size = stepinfo->stepsize;
4125 
4126 		for (j = 0; j < stepinfo->nstrengths; j++) {
4127 			strength = stepinfo->strengths[j];
4128 
4129 			/*
4130 			 * If both step size and strength are smaller than the
4131 			 * chip's requirement, it is not easy to compare the
4132 			 * resulted reliability.
4133 			 */
4134 			if (step_size < req_step && strength < req_strength)
4135 				continue;
4136 
4137 			if (mtd->writesize % step_size)
4138 				continue;
4139 
4140 			nsteps = mtd->writesize / step_size;
4141 
4142 			ecc_bytes = caps->calc_ecc_bytes(step_size, strength);
4143 			if (WARN_ON_ONCE(ecc_bytes < 0))
4144 				continue;
4145 			ecc_bytes_total = ecc_bytes * nsteps;
4146 
4147 			if (ecc_bytes_total > oobavail ||
4148 			    strength * nsteps < req_corr)
4149 				continue;
4150 
4151 			/*
4152 			 * We assume the best is to meet the chip's requrement
4153 			 * with the least number of ECC bytes.
4154 			 */
4155 			if (ecc_bytes_total < best_ecc_bytes_total) {
4156 				best_ecc_bytes_total = ecc_bytes_total;
4157 				best_step = step_size;
4158 				best_strength = strength;
4159 				best_ecc_bytes = ecc_bytes;
4160 			}
4161 		}
4162 	}
4163 
4164 	if (best_ecc_bytes_total == INT_MAX)
4165 		return -ENOTSUPP;
4166 
4167 	chip->ecc.size = best_step;
4168 	chip->ecc.strength = best_strength;
4169 	chip->ecc.bytes = best_ecc_bytes;
4170 
4171 	return 0;
4172 }
4173 EXPORT_SYMBOL_GPL(nand_match_ecc_req);
4174 
4175 /**
4176  * nand_maximize_ecc - choose the max ECC strength available
4177  * @chip: nand chip info structure
4178  * @caps: ECC engine caps info structure
4179  * @oobavail: OOB size that the ECC engine can use
4180  *
4181  * Choose the max ECC strength that is supported on the controller, and can fit
4182  * within the chip's OOB.  On success, the chosen ECC settings are set.
4183  */
4184 int nand_maximize_ecc(struct nand_chip *chip,
4185 		      const struct nand_ecc_caps *caps, int oobavail)
4186 {
4187 	struct mtd_info *mtd = nand_to_mtd(chip);
4188 	const struct nand_ecc_step_info *stepinfo;
4189 	int step_size, strength, nsteps, ecc_bytes, corr;
4190 	int best_corr = 0;
4191 	int best_step = 0;
4192 	int best_strength, best_ecc_bytes;
4193 	int i, j;
4194 
4195 	if (WARN_ON(oobavail < 0))
4196 		return -EINVAL;
4197 
4198 	for (i = 0; i < caps->nstepinfos; i++) {
4199 		stepinfo = &caps->stepinfos[i];
4200 		step_size = stepinfo->stepsize;
4201 
4202 		/* If chip->ecc.size is already set, respect it */
4203 		if (chip->ecc.size && step_size != chip->ecc.size)
4204 			continue;
4205 
4206 		for (j = 0; j < stepinfo->nstrengths; j++) {
4207 			strength = stepinfo->strengths[j];
4208 
4209 			if (mtd->writesize % step_size)
4210 				continue;
4211 
4212 			nsteps = mtd->writesize / step_size;
4213 
4214 			ecc_bytes = caps->calc_ecc_bytes(step_size, strength);
4215 			if (WARN_ON_ONCE(ecc_bytes < 0))
4216 				continue;
4217 
4218 			if (ecc_bytes * nsteps > oobavail)
4219 				continue;
4220 
4221 			corr = strength * nsteps;
4222 
4223 			/*
4224 			 * If the number of correctable bits is the same,
4225 			 * bigger step_size has more reliability.
4226 			 */
4227 			if (corr > best_corr ||
4228 			    (corr == best_corr && step_size > best_step)) {
4229 				best_corr = corr;
4230 				best_step = step_size;
4231 				best_strength = strength;
4232 				best_ecc_bytes = ecc_bytes;
4233 			}
4234 		}
4235 	}
4236 
4237 	if (!best_corr)
4238 		return -ENOTSUPP;
4239 
4240 	chip->ecc.size = best_step;
4241 	chip->ecc.strength = best_strength;
4242 	chip->ecc.bytes = best_ecc_bytes;
4243 
4244 	return 0;
4245 }
4246 EXPORT_SYMBOL_GPL(nand_maximize_ecc);
4247 
4248 /*
4249  * Check if the chip configuration meet the datasheet requirements.
4250 
4251  * If our configuration corrects A bits per B bytes and the minimum
4252  * required correction level is X bits per Y bytes, then we must ensure
4253  * both of the following are true:
4254  *
4255  * (1) A / B >= X / Y
4256  * (2) A >= X
4257  *
4258  * Requirement (1) ensures we can correct for the required bitflip density.
4259  * Requirement (2) ensures we can correct even when all bitflips are clumped
4260  * in the same sector.
4261  */
4262 static bool nand_ecc_strength_good(struct mtd_info *mtd)
4263 {
4264 	struct nand_chip *chip = mtd_to_nand(mtd);
4265 	struct nand_ecc_ctrl *ecc = &chip->ecc;
4266 	int corr, ds_corr;
4267 
4268 	if (ecc->size == 0 || chip->ecc_step_ds == 0)
4269 		/* Not enough information */
4270 		return true;
4271 
4272 	/*
4273 	 * We get the number of corrected bits per page to compare
4274 	 * the correction density.
4275 	 */
4276 	corr = (mtd->writesize * ecc->strength) / ecc->size;
4277 	ds_corr = (mtd->writesize * chip->ecc_strength_ds) / chip->ecc_step_ds;
4278 
4279 	return corr >= ds_corr && ecc->strength >= chip->ecc_strength_ds;
4280 }
4281 
4282 static bool invalid_ecc_page_accessors(struct nand_chip *chip)
4283 {
4284 	struct nand_ecc_ctrl *ecc = &chip->ecc;
4285 
4286 	if (nand_standard_page_accessors(ecc))
4287 		return false;
4288 
4289 	/*
4290 	 * NAND_ECC_CUSTOM_PAGE_ACCESS flag is set, make sure the NAND
4291 	 * controller driver implements all the page accessors because
4292 	 * default helpers are not suitable when the core does not
4293 	 * send the READ0/PAGEPROG commands.
4294 	 */
4295 	return (!ecc->read_page || !ecc->write_page ||
4296 		!ecc->read_page_raw || !ecc->write_page_raw ||
4297 		(NAND_HAS_SUBPAGE_READ(chip) && !ecc->read_subpage) ||
4298 		(NAND_HAS_SUBPAGE_WRITE(chip) && !ecc->write_subpage &&
4299 		 ecc->hwctl && ecc->calculate));
4300 }
4301 
4302 /**
4303  * nand_scan_tail - [NAND Interface] Scan for the NAND device
4304  * @mtd: MTD device structure
4305  *
4306  * This is the second phase of the normal nand_scan() function. It fills out
4307  * all the uninitialized function pointers with the defaults and scans for a
4308  * bad block table if appropriate.
4309  */
4310 int nand_scan_tail(struct mtd_info *mtd)
4311 {
4312 	int i;
4313 	struct nand_chip *chip = mtd_to_nand(mtd);
4314 	struct nand_ecc_ctrl *ecc = &chip->ecc;
4315 	struct nand_buffers *nbuf;
4316 
4317 	/* New bad blocks should be marked in OOB, flash-based BBT, or both */
4318 	BUG_ON((chip->bbt_options & NAND_BBT_NO_OOB_BBM) &&
4319 			!(chip->bbt_options & NAND_BBT_USE_FLASH));
4320 
4321 	if (invalid_ecc_page_accessors(chip)) {
4322 		pr_err("Invalid ECC page accessors setup\n");
4323 		return -EINVAL;
4324 	}
4325 
4326 	if (!(chip->options & NAND_OWN_BUFFERS)) {
4327 		nbuf = kzalloc(sizeof(struct nand_buffers), GFP_KERNEL);
4328 		chip->buffers = nbuf;
4329 	} else {
4330 		if (!chip->buffers)
4331 			return -ENOMEM;
4332 	}
4333 
4334 	/* Set the internal oob buffer location, just after the page data */
4335 	chip->oob_poi = chip->buffers->databuf + mtd->writesize;
4336 
4337 	/*
4338 	 * If no default placement scheme is given, select an appropriate one.
4339 	 */
4340 	if (!ecc->layout && (ecc->mode != NAND_ECC_SOFT_BCH)) {
4341 		switch (mtd->oobsize) {
4342 		case 8:
4343 			ecc->layout = &nand_oob_8;
4344 			break;
4345 		case 16:
4346 			ecc->layout = &nand_oob_16;
4347 			break;
4348 		case 64:
4349 			ecc->layout = &nand_oob_64;
4350 			break;
4351 		case 128:
4352 			ecc->layout = &nand_oob_128;
4353 			break;
4354 		default:
4355 			pr_warn("No oob scheme defined for oobsize %d\n",
4356 				   mtd->oobsize);
4357 			BUG();
4358 		}
4359 	}
4360 
4361 	if (!chip->write_page)
4362 		chip->write_page = nand_write_page;
4363 
4364 	/*
4365 	 * Check ECC mode, default to software if 3byte/512byte hardware ECC is
4366 	 * selected and we have 256 byte pagesize fallback to software ECC
4367 	 */
4368 
4369 	switch (ecc->mode) {
4370 	case NAND_ECC_HW_OOB_FIRST:
4371 		/* Similar to NAND_ECC_HW, but a separate read_page handle */
4372 		if (!ecc->calculate || !ecc->correct || !ecc->hwctl) {
4373 			pr_warn("No ECC functions supplied; hardware ECC not possible\n");
4374 			BUG();
4375 		}
4376 		if (!ecc->read_page)
4377 			ecc->read_page = nand_read_page_hwecc_oob_first;
4378 
4379 	case NAND_ECC_HW:
4380 		/* Use standard hwecc read page function? */
4381 		if (!ecc->read_page)
4382 			ecc->read_page = nand_read_page_hwecc;
4383 		if (!ecc->write_page)
4384 			ecc->write_page = nand_write_page_hwecc;
4385 		if (!ecc->read_page_raw)
4386 			ecc->read_page_raw = nand_read_page_raw;
4387 		if (!ecc->write_page_raw)
4388 			ecc->write_page_raw = nand_write_page_raw;
4389 		if (!ecc->read_oob)
4390 			ecc->read_oob = nand_read_oob_std;
4391 		if (!ecc->write_oob)
4392 			ecc->write_oob = nand_write_oob_std;
4393 		if (!ecc->read_subpage)
4394 			ecc->read_subpage = nand_read_subpage;
4395 		if (!ecc->write_subpage && ecc->hwctl && ecc->calculate)
4396 			ecc->write_subpage = nand_write_subpage_hwecc;
4397 
4398 	case NAND_ECC_HW_SYNDROME:
4399 		if ((!ecc->calculate || !ecc->correct || !ecc->hwctl) &&
4400 		    (!ecc->read_page ||
4401 		     ecc->read_page == nand_read_page_hwecc ||
4402 		     !ecc->write_page ||
4403 		     ecc->write_page == nand_write_page_hwecc)) {
4404 			pr_warn("No ECC functions supplied; hardware ECC not possible\n");
4405 			BUG();
4406 		}
4407 		/* Use standard syndrome read/write page function? */
4408 		if (!ecc->read_page)
4409 			ecc->read_page = nand_read_page_syndrome;
4410 		if (!ecc->write_page)
4411 			ecc->write_page = nand_write_page_syndrome;
4412 		if (!ecc->read_page_raw)
4413 			ecc->read_page_raw = nand_read_page_raw_syndrome;
4414 		if (!ecc->write_page_raw)
4415 			ecc->write_page_raw = nand_write_page_raw_syndrome;
4416 		if (!ecc->read_oob)
4417 			ecc->read_oob = nand_read_oob_syndrome;
4418 		if (!ecc->write_oob)
4419 			ecc->write_oob = nand_write_oob_syndrome;
4420 
4421 		if (mtd->writesize >= ecc->size) {
4422 			if (!ecc->strength) {
4423 				pr_warn("Driver must set ecc.strength when using hardware ECC\n");
4424 				BUG();
4425 			}
4426 			break;
4427 		}
4428 		pr_warn("%d byte HW ECC not possible on %d byte page size, fallback to SW ECC\n",
4429 			ecc->size, mtd->writesize);
4430 		ecc->mode = NAND_ECC_SOFT;
4431 
4432 	case NAND_ECC_SOFT:
4433 		ecc->calculate = nand_calculate_ecc;
4434 		ecc->correct = nand_correct_data;
4435 		ecc->read_page = nand_read_page_swecc;
4436 		ecc->read_subpage = nand_read_subpage;
4437 		ecc->write_page = nand_write_page_swecc;
4438 		ecc->read_page_raw = nand_read_page_raw;
4439 		ecc->write_page_raw = nand_write_page_raw;
4440 		ecc->read_oob = nand_read_oob_std;
4441 		ecc->write_oob = nand_write_oob_std;
4442 		if (!ecc->size)
4443 			ecc->size = 256;
4444 		ecc->bytes = 3;
4445 		ecc->strength = 1;
4446 		break;
4447 
4448 	case NAND_ECC_SOFT_BCH:
4449 		if (!mtd_nand_has_bch()) {
4450 			pr_warn("CONFIG_MTD_NAND_ECC_BCH not enabled\n");
4451 			BUG();
4452 		}
4453 		ecc->calculate = nand_bch_calculate_ecc;
4454 		ecc->correct = nand_bch_correct_data;
4455 		ecc->read_page = nand_read_page_swecc;
4456 		ecc->read_subpage = nand_read_subpage;
4457 		ecc->write_page = nand_write_page_swecc;
4458 		ecc->read_page_raw = nand_read_page_raw;
4459 		ecc->write_page_raw = nand_write_page_raw;
4460 		ecc->read_oob = nand_read_oob_std;
4461 		ecc->write_oob = nand_write_oob_std;
4462 		/*
4463 		 * Board driver should supply ecc.size and ecc.strength values
4464 		 * to select how many bits are correctable. Otherwise, default
4465 		 * to 4 bits for large page devices.
4466 		 */
4467 		if (!ecc->size && (mtd->oobsize >= 64)) {
4468 			ecc->size = 512;
4469 			ecc->strength = 4;
4470 		}
4471 
4472 		/* See nand_bch_init() for details. */
4473 		ecc->bytes = 0;
4474 		ecc->priv = nand_bch_init(mtd);
4475 		if (!ecc->priv) {
4476 			pr_warn("BCH ECC initialization failed!\n");
4477 			BUG();
4478 		}
4479 		break;
4480 
4481 	case NAND_ECC_NONE:
4482 		pr_warn("NAND_ECC_NONE selected by board driver. This is not recommended!\n");
4483 		ecc->read_page = nand_read_page_raw;
4484 		ecc->write_page = nand_write_page_raw;
4485 		ecc->read_oob = nand_read_oob_std;
4486 		ecc->read_page_raw = nand_read_page_raw;
4487 		ecc->write_page_raw = nand_write_page_raw;
4488 		ecc->write_oob = nand_write_oob_std;
4489 		ecc->size = mtd->writesize;
4490 		ecc->bytes = 0;
4491 		ecc->strength = 0;
4492 		break;
4493 
4494 	default:
4495 		pr_warn("Invalid NAND_ECC_MODE %d\n", ecc->mode);
4496 		BUG();
4497 	}
4498 
4499 	/* For many systems, the standard OOB write also works for raw */
4500 	if (!ecc->read_oob_raw)
4501 		ecc->read_oob_raw = ecc->read_oob;
4502 	if (!ecc->write_oob_raw)
4503 		ecc->write_oob_raw = ecc->write_oob;
4504 
4505 	/*
4506 	 * The number of bytes available for a client to place data into
4507 	 * the out of band area.
4508 	 */
4509 	mtd->oobavail = 0;
4510 	if (ecc->layout) {
4511 		for (i = 0; ecc->layout->oobfree[i].length; i++)
4512 			mtd->oobavail += ecc->layout->oobfree[i].length;
4513 	}
4514 
4515 	/* ECC sanity check: warn if it's too weak */
4516 	if (!nand_ecc_strength_good(mtd))
4517 		pr_warn("WARNING: %s: the ECC used on your system is too weak compared to the one required by the NAND chip\n",
4518 			mtd->name);
4519 
4520 	/*
4521 	 * Set the number of read / write steps for one page depending on ECC
4522 	 * mode.
4523 	 */
4524 	ecc->steps = mtd->writesize / ecc->size;
4525 	if (ecc->steps * ecc->size != mtd->writesize) {
4526 		pr_warn("Invalid ECC parameters\n");
4527 		BUG();
4528 	}
4529 	ecc->total = ecc->steps * ecc->bytes;
4530 
4531 	/* Allow subpage writes up to ecc.steps. Not possible for MLC flash */
4532 	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) && nand_is_slc(chip)) {
4533 		switch (ecc->steps) {
4534 		case 2:
4535 			mtd->subpage_sft = 1;
4536 			break;
4537 		case 4:
4538 		case 8:
4539 		case 16:
4540 			mtd->subpage_sft = 2;
4541 			break;
4542 		}
4543 	}
4544 	chip->subpagesize = mtd->writesize >> mtd->subpage_sft;
4545 
4546 	/* Initialize state */
4547 	chip->state = FL_READY;
4548 
4549 	/* Invalidate the pagebuffer reference */
4550 	chip->pagebuf = -1;
4551 
4552 	/* Large page NAND with SOFT_ECC should support subpage reads */
4553 	switch (ecc->mode) {
4554 	case NAND_ECC_SOFT:
4555 	case NAND_ECC_SOFT_BCH:
4556 		if (chip->page_shift > 9)
4557 			chip->options |= NAND_SUBPAGE_READ;
4558 		break;
4559 
4560 	default:
4561 		break;
4562 	}
4563 
4564 	/* Fill in remaining MTD driver data */
4565 	mtd->type = nand_is_slc(chip) ? MTD_NANDFLASH : MTD_MLCNANDFLASH;
4566 	mtd->flags = (chip->options & NAND_ROM) ? MTD_CAP_ROM :
4567 						MTD_CAP_NANDFLASH;
4568 	mtd->_erase = nand_erase;
4569 	mtd->_panic_write = panic_nand_write;
4570 	mtd->_read_oob = nand_read_oob;
4571 	mtd->_write_oob = nand_write_oob;
4572 	mtd->_sync = nand_sync;
4573 	mtd->_lock = NULL;
4574 	mtd->_unlock = NULL;
4575 	mtd->_block_isreserved = nand_block_isreserved;
4576 	mtd->_block_isbad = nand_block_isbad;
4577 	mtd->_block_markbad = nand_block_markbad;
4578 	mtd->writebufsize = mtd->writesize;
4579 
4580 	/* propagate ecc info to mtd_info */
4581 	mtd->ecclayout = ecc->layout;
4582 	mtd->ecc_strength = ecc->strength;
4583 	mtd->ecc_step_size = ecc->size;
4584 	/*
4585 	 * Initialize bitflip_threshold to its default prior scan_bbt() call.
4586 	 * scan_bbt() might invoke mtd_read(), thus bitflip_threshold must be
4587 	 * properly set.
4588 	 */
4589 	if (!mtd->bitflip_threshold)
4590 		mtd->bitflip_threshold = DIV_ROUND_UP(mtd->ecc_strength * 3, 4);
4591 
4592 	return 0;
4593 }
4594 EXPORT_SYMBOL(nand_scan_tail);
4595 
4596 /**
4597  * nand_scan - [NAND Interface] Scan for the NAND device
4598  * @mtd: MTD device structure
4599  * @maxchips: number of chips to scan for
4600  *
4601  * This fills out all the uninitialized function pointers with the defaults.
4602  * The flash ID is read and the mtd/chip structures are filled with the
4603  * appropriate values.
4604  */
4605 int nand_scan(struct mtd_info *mtd, int maxchips)
4606 {
4607 	int ret;
4608 
4609 	ret = nand_scan_ident(mtd, maxchips, NULL);
4610 	if (!ret)
4611 		ret = nand_scan_tail(mtd);
4612 	return ret;
4613 }
4614 EXPORT_SYMBOL(nand_scan);
4615 
4616 MODULE_LICENSE("GPL");
4617 MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>");
4618 MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
4619 MODULE_DESCRIPTION("Generic NAND flash driver code");
4620