xref: /openbmc/u-boot/drivers/mtd/nand/raw/nand_base.c (revision a353e6aa8ec8f0aa101cc7e9543fe7843ddc6d98)
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