1/*
2 *  drivers/mtd/nand.c
3 *
4 *  Overview:
5 *   This is the generic MTD driver for NAND flash devices. It should be
6 *   capable of working with almost all NAND chips currently available.
7 *
8 *	Additional technical information is available on
9 *	http://www.linux-mtd.infradead.org/doc/nand.html
10 *
11 *  Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
12 *		  2002-2006 Thomas Gleixner (tglx@linutronix.de)
13 *
14 *  Credits:
15 *	David Woodhouse for adding multichip support
16 *
17 *	Aleph One Ltd. and Toby Churchill Ltd. for supporting the
18 *	rework for 2K page size chips
19 *
20 *  TODO:
21 *	Enable cached programming for 2k page size chips
22 *	Check, if mtd->ecctype should be set to MTD_ECC_HW
23 *	if we have HW ECC support.
24 *	BBT table is not serialized, has to be fixed
25 *
26 * This program is free software; you can redistribute it and/or modify
27 * it under the terms of the GNU General Public License version 2 as
28 * published by the Free Software Foundation.
29 *
30 */
31
32#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34#include <linux/module.h>
35#include <linux/delay.h>
36#include <linux/errno.h>
37#include <linux/err.h>
38#include <linux/sched.h>
39#include <linux/slab.h>
40#include <linux/mm.h>
41#include <linux/types.h>
42#include <linux/mtd/mtd.h>
43#include <linux/mtd/nand.h>
44#include <linux/mtd/nand_ecc.h>
45#include <linux/mtd/nand_bch.h>
46#include <linux/interrupt.h>
47#include <linux/bitops.h>
48#include <linux/leds.h>
49#include <linux/io.h>
50#include <linux/mtd/partitions.h>
51
52/* Define default oob placement schemes for large and small page devices */
53static struct nand_ecclayout nand_oob_8 = {
54	.eccbytes = 3,
55	.eccpos = {0, 1, 2},
56	.oobfree = {
57		{.offset = 3,
58		 .length = 2},
59		{.offset = 6,
60		 .length = 2} }
61};
62
63static struct nand_ecclayout nand_oob_16 = {
64	.eccbytes = 6,
65	.eccpos = {0, 1, 2, 3, 6, 7},
66	.oobfree = {
67		{.offset = 8,
68		 . length = 8} }
69};
70
71static struct nand_ecclayout nand_oob_64 = {
72	.eccbytes = 24,
73	.eccpos = {
74		   40, 41, 42, 43, 44, 45, 46, 47,
75		   48, 49, 50, 51, 52, 53, 54, 55,
76		   56, 57, 58, 59, 60, 61, 62, 63},
77	.oobfree = {
78		{.offset = 2,
79		 .length = 38} }
80};
81
82static struct nand_ecclayout nand_oob_128 = {
83	.eccbytes = 48,
84	.eccpos = {
85		   80, 81, 82, 83, 84, 85, 86, 87,
86		   88, 89, 90, 91, 92, 93, 94, 95,
87		   96, 97, 98, 99, 100, 101, 102, 103,
88		   104, 105, 106, 107, 108, 109, 110, 111,
89		   112, 113, 114, 115, 116, 117, 118, 119,
90		   120, 121, 122, 123, 124, 125, 126, 127},
91	.oobfree = {
92		{.offset = 2,
93		 .length = 78} }
94};
95
96static int nand_get_device(struct mtd_info *mtd, int new_state);
97
98static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
99			     struct mtd_oob_ops *ops);
100
101/*
102 * For devices which display every fart in the system on a separate LED. Is
103 * compiled away when LED support is disabled.
104 */
105DEFINE_LED_TRIGGER(nand_led_trigger);
106
107static int check_offs_len(struct mtd_info *mtd,
108					loff_t ofs, uint64_t len)
109{
110	struct nand_chip *chip = mtd->priv;
111	int ret = 0;
112
113	/* Start address must align on block boundary */
114	if (ofs & ((1ULL << chip->phys_erase_shift) - 1)) {
115		pr_debug("%s: unaligned address\n", __func__);
116		ret = -EINVAL;
117	}
118
119	/* Length must align on block boundary */
120	if (len & ((1ULL << chip->phys_erase_shift) - 1)) {
121		pr_debug("%s: length not block aligned\n", __func__);
122		ret = -EINVAL;
123	}
124
125	return ret;
126}
127
128/**
129 * nand_release_device - [GENERIC] release chip
130 * @mtd: MTD device structure
131 *
132 * Release chip lock and wake up anyone waiting on the device.
133 */
134static void nand_release_device(struct mtd_info *mtd)
135{
136	struct nand_chip *chip = mtd->priv;
137
138	/* Release the controller and the chip */
139	spin_lock(&chip->controller->lock);
140	chip->controller->active = NULL;
141	chip->state = FL_READY;
142	wake_up(&chip->controller->wq);
143	spin_unlock(&chip->controller->lock);
144}
145
146/**
147 * nand_read_byte - [DEFAULT] read one byte from the chip
148 * @mtd: MTD device structure
149 *
150 * Default read function for 8bit buswidth
151 */
152static uint8_t nand_read_byte(struct mtd_info *mtd)
153{
154	struct nand_chip *chip = mtd->priv;
155	return readb(chip->IO_ADDR_R);
156}
157
158/**
159 * nand_read_byte16 - [DEFAULT] read one byte endianness aware from the chip
160 * @mtd: MTD device structure
161 *
162 * Default read function for 16bit buswidth with endianness conversion.
163 *
164 */
165static uint8_t nand_read_byte16(struct mtd_info *mtd)
166{
167	struct nand_chip *chip = mtd->priv;
168	return (uint8_t) cpu_to_le16(readw(chip->IO_ADDR_R));
169}
170
171/**
172 * nand_read_word - [DEFAULT] read one word from the chip
173 * @mtd: MTD device structure
174 *
175 * Default read function for 16bit buswidth without endianness conversion.
176 */
177static u16 nand_read_word(struct mtd_info *mtd)
178{
179	struct nand_chip *chip = mtd->priv;
180	return readw(chip->IO_ADDR_R);
181}
182
183/**
184 * nand_select_chip - [DEFAULT] control CE line
185 * @mtd: MTD device structure
186 * @chipnr: chipnumber to select, -1 for deselect
187 *
188 * Default select function for 1 chip devices.
189 */
190static void nand_select_chip(struct mtd_info *mtd, int chipnr)
191{
192	struct nand_chip *chip = mtd->priv;
193
194	switch (chipnr) {
195	case -1:
196		chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0 | NAND_CTRL_CHANGE);
197		break;
198	case 0:
199		break;
200
201	default:
202		BUG();
203	}
204}
205
206/**
207 * nand_write_byte - [DEFAULT] write single byte to chip
208 * @mtd: MTD device structure
209 * @byte: value to write
210 *
211 * Default function to write a byte to I/O[7:0]
212 */
213static void nand_write_byte(struct mtd_info *mtd, uint8_t byte)
214{
215	struct nand_chip *chip = mtd->priv;
216
217	chip->write_buf(mtd, &byte, 1);
218}
219
220/**
221 * nand_write_byte16 - [DEFAULT] write single byte to a chip with width 16
222 * @mtd: MTD device structure
223 * @byte: value to write
224 *
225 * Default function to write a byte to I/O[7:0] on a 16-bit wide chip.
226 */
227static void nand_write_byte16(struct mtd_info *mtd, uint8_t byte)
228{
229	struct nand_chip *chip = mtd->priv;
230	uint16_t word = byte;
231
232	/*
233	 * It's not entirely clear what should happen to I/O[15:8] when writing
234	 * a byte. The ONFi spec (Revision 3.1; 2012-09-19, Section 2.16) reads:
235	 *
236	 *    When the host supports a 16-bit bus width, only data is
237	 *    transferred at the 16-bit width. All address and command line
238	 *    transfers shall use only the lower 8-bits of the data bus. During
239	 *    command transfers, the host may place any value on the upper
240	 *    8-bits of the data bus. During address transfers, the host shall
241	 *    set the upper 8-bits of the data bus to 00h.
242	 *
243	 * One user of the write_byte callback is nand_onfi_set_features. The
244	 * four parameters are specified to be written to I/O[7:0], but this is
245	 * neither an address nor a command transfer. Let's assume a 0 on the
246	 * upper I/O lines is OK.
247	 */
248	chip->write_buf(mtd, (uint8_t *)&word, 2);
249}
250
251/**
252 * nand_write_buf - [DEFAULT] write buffer to chip
253 * @mtd: MTD device structure
254 * @buf: data buffer
255 * @len: number of bytes to write
256 *
257 * Default write function for 8bit buswidth.
258 */
259static void nand_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
260{
261	struct nand_chip *chip = mtd->priv;
262
263	iowrite8_rep(chip->IO_ADDR_W, buf, len);
264}
265
266/**
267 * nand_read_buf - [DEFAULT] read chip data into buffer
268 * @mtd: MTD device structure
269 * @buf: buffer to store date
270 * @len: number of bytes to read
271 *
272 * Default read function for 8bit buswidth.
273 */
274static void nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
275{
276	struct nand_chip *chip = mtd->priv;
277
278	ioread8_rep(chip->IO_ADDR_R, buf, len);
279}
280
281/**
282 * nand_write_buf16 - [DEFAULT] write buffer to chip
283 * @mtd: MTD device structure
284 * @buf: data buffer
285 * @len: number of bytes to write
286 *
287 * Default write function for 16bit buswidth.
288 */
289static void nand_write_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
290{
291	struct nand_chip *chip = mtd->priv;
292	u16 *p = (u16 *) buf;
293
294	iowrite16_rep(chip->IO_ADDR_W, p, len >> 1);
295}
296
297/**
298 * nand_read_buf16 - [DEFAULT] read chip data into buffer
299 * @mtd: MTD device structure
300 * @buf: buffer to store date
301 * @len: number of bytes to read
302 *
303 * Default read function for 16bit buswidth.
304 */
305static void nand_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
306{
307	struct nand_chip *chip = mtd->priv;
308	u16 *p = (u16 *) buf;
309
310	ioread16_rep(chip->IO_ADDR_R, p, len >> 1);
311}
312
313/**
314 * nand_block_bad - [DEFAULT] Read bad block marker from the chip
315 * @mtd: MTD device structure
316 * @ofs: offset from device start
317 * @getchip: 0, if the chip is already selected
318 *
319 * Check, if the block is bad.
320 */
321static int nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
322{
323	int page, chipnr, res = 0, i = 0;
324	struct nand_chip *chip = mtd->priv;
325	u16 bad;
326
327	if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
328		ofs += mtd->erasesize - mtd->writesize;
329
330	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
331
332	if (getchip) {
333		chipnr = (int)(ofs >> chip->chip_shift);
334
335		nand_get_device(mtd, FL_READING);
336
337		/* Select the NAND device */
338		chip->select_chip(mtd, chipnr);
339	}
340
341	do {
342		if (chip->options & NAND_BUSWIDTH_16) {
343			chip->cmdfunc(mtd, NAND_CMD_READOOB,
344					chip->badblockpos & 0xFE, page);
345			bad = cpu_to_le16(chip->read_word(mtd));
346			if (chip->badblockpos & 0x1)
347				bad >>= 8;
348			else
349				bad &= 0xFF;
350		} else {
351			chip->cmdfunc(mtd, NAND_CMD_READOOB, chip->badblockpos,
352					page);
353			bad = chip->read_byte(mtd);
354		}
355
356		if (likely(chip->badblockbits == 8))
357			res = bad != 0xFF;
358		else
359			res = hweight8(bad) < chip->badblockbits;
360		ofs += mtd->writesize;
361		page = (int)(ofs >> chip->page_shift) & chip->pagemask;
362		i++;
363	} while (!res && i < 2 && (chip->bbt_options & NAND_BBT_SCAN2NDPAGE));
364
365	if (getchip) {
366		chip->select_chip(mtd, -1);
367		nand_release_device(mtd);
368	}
369
370	return res;
371}
372
373/**
374 * nand_default_block_markbad - [DEFAULT] mark a block bad via bad block marker
375 * @mtd: MTD device structure
376 * @ofs: offset from device start
377 *
378 * This is the default implementation, which can be overridden by a hardware
379 * specific driver. It provides the details for writing a bad block marker to a
380 * block.
381 */
382static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
383{
384	struct nand_chip *chip = mtd->priv;
385	struct mtd_oob_ops ops;
386	uint8_t buf[2] = { 0, 0 };
387	int ret = 0, res, i = 0;
388
389	memset(&ops, 0, sizeof(ops));
390	ops.oobbuf = buf;
391	ops.ooboffs = chip->badblockpos;
392	if (chip->options & NAND_BUSWIDTH_16) {
393		ops.ooboffs &= ~0x01;
394		ops.len = ops.ooblen = 2;
395	} else {
396		ops.len = ops.ooblen = 1;
397	}
398	ops.mode = MTD_OPS_PLACE_OOB;
399
400	/* Write to first/last page(s) if necessary */
401	if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
402		ofs += mtd->erasesize - mtd->writesize;
403	do {
404		res = nand_do_write_oob(mtd, ofs, &ops);
405		if (!ret)
406			ret = res;
407
408		i++;
409		ofs += mtd->writesize;
410	} while ((chip->bbt_options & NAND_BBT_SCAN2NDPAGE) && i < 2);
411
412	return ret;
413}
414
415/**
416 * nand_block_markbad_lowlevel - mark a block bad
417 * @mtd: MTD device structure
418 * @ofs: offset from device start
419 *
420 * This function performs the generic NAND bad block marking steps (i.e., bad
421 * block table(s) and/or marker(s)). We only allow the hardware driver to
422 * specify how to write bad block markers to OOB (chip->block_markbad).
423 *
424 * We try operations in the following order:
425 *  (1) erase the affected block, to allow OOB marker to be written cleanly
426 *  (2) write bad block marker to OOB area of affected block (unless flag
427 *      NAND_BBT_NO_OOB_BBM is present)
428 *  (3) update the BBT
429 * Note that we retain the first error encountered in (2) or (3), finish the
430 * procedures, and dump the error in the end.
431*/
432static int nand_block_markbad_lowlevel(struct mtd_info *mtd, loff_t ofs)
433{
434	struct nand_chip *chip = mtd->priv;
435	int res, ret = 0;
436
437	if (!(chip->bbt_options & NAND_BBT_NO_OOB_BBM)) {
438		struct erase_info einfo;
439
440		/* Attempt erase before marking OOB */
441		memset(&einfo, 0, sizeof(einfo));
442		einfo.mtd = mtd;
443		einfo.addr = ofs;
444		einfo.len = 1ULL << chip->phys_erase_shift;
445		nand_erase_nand(mtd, &einfo, 0);
446
447		/* Write bad block marker to OOB */
448		nand_get_device(mtd, FL_WRITING);
449		ret = chip->block_markbad(mtd, ofs);
450		nand_release_device(mtd);
451	}
452
453	/* Mark block bad in BBT */
454	if (chip->bbt) {
455		res = nand_markbad_bbt(mtd, ofs);
456		if (!ret)
457			ret = res;
458	}
459
460	if (!ret)
461		mtd->ecc_stats.badblocks++;
462
463	return ret;
464}
465
466/**
467 * nand_check_wp - [GENERIC] check if the chip is write protected
468 * @mtd: MTD device structure
469 *
470 * Check, if the device is write protected. The function expects, that the
471 * device is already selected.
472 */
473static int nand_check_wp(struct mtd_info *mtd)
474{
475	struct nand_chip *chip = mtd->priv;
476
477	/* Broken xD cards report WP despite being writable */
478	if (chip->options & NAND_BROKEN_XD)
479		return 0;
480
481	/* Check the WP bit */
482	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
483	return (chip->read_byte(mtd) & NAND_STATUS_WP) ? 0 : 1;
484}
485
486/**
487 * nand_block_isreserved - [GENERIC] Check if a block is marked reserved.
488 * @mtd: MTD device structure
489 * @ofs: offset from device start
490 *
491 * Check if the block is marked as reserved.
492 */
493static int nand_block_isreserved(struct mtd_info *mtd, loff_t ofs)
494{
495	struct nand_chip *chip = mtd->priv;
496
497	if (!chip->bbt)
498		return 0;
499	/* Return info from the table */
500	return nand_isreserved_bbt(mtd, ofs);
501}
502
503/**
504 * nand_block_checkbad - [GENERIC] Check if a block is marked bad
505 * @mtd: MTD device structure
506 * @ofs: offset from device start
507 * @getchip: 0, if the chip is already selected
508 * @allowbbt: 1, if its allowed to access the bbt area
509 *
510 * Check, if the block is bad. Either by reading the bad block table or
511 * calling of the scan function.
512 */
513static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip,
514			       int allowbbt)
515{
516	struct nand_chip *chip = mtd->priv;
517
518	if (!chip->bbt)
519		return chip->block_bad(mtd, ofs, getchip);
520
521	/* Return info from the table */
522	return nand_isbad_bbt(mtd, ofs, allowbbt);
523}
524
525/**
526 * panic_nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
527 * @mtd: MTD device structure
528 * @timeo: Timeout
529 *
530 * Helper function for nand_wait_ready used when needing to wait in interrupt
531 * context.
532 */
533static void panic_nand_wait_ready(struct mtd_info *mtd, unsigned long timeo)
534{
535	struct nand_chip *chip = mtd->priv;
536	int i;
537
538	/* Wait for the device to get ready */
539	for (i = 0; i < timeo; i++) {
540		if (chip->dev_ready(mtd))
541			break;
542		touch_softlockup_watchdog();
543		mdelay(1);
544	}
545}
546
547/* Wait for the ready pin, after a command. The timeout is caught later. */
548void nand_wait_ready(struct mtd_info *mtd)
549{
550	struct nand_chip *chip = mtd->priv;
551	unsigned long timeo = jiffies + msecs_to_jiffies(20);
552
553	/* 400ms timeout */
554	if (in_interrupt() || oops_in_progress)
555		return panic_nand_wait_ready(mtd, 400);
556
557	led_trigger_event(nand_led_trigger, LED_FULL);
558	/* Wait until command is processed or timeout occurs */
559	do {
560		if (chip->dev_ready(mtd))
561			break;
562		touch_softlockup_watchdog();
563	} while (time_before(jiffies, timeo));
564	led_trigger_event(nand_led_trigger, LED_OFF);
565}
566EXPORT_SYMBOL_GPL(nand_wait_ready);
567
568/**
569 * nand_wait_status_ready - [GENERIC] Wait for the ready status after commands.
570 * @mtd: MTD device structure
571 * @timeo: Timeout in ms
572 *
573 * Wait for status ready (i.e. command done) or timeout.
574 */
575static void nand_wait_status_ready(struct mtd_info *mtd, unsigned long timeo)
576{
577	register struct nand_chip *chip = mtd->priv;
578
579	timeo = jiffies + msecs_to_jiffies(timeo);
580	do {
581		if ((chip->read_byte(mtd) & NAND_STATUS_READY))
582			break;
583		touch_softlockup_watchdog();
584	} while (time_before(jiffies, timeo));
585};
586
587/**
588 * nand_command - [DEFAULT] Send command to NAND device
589 * @mtd: MTD device structure
590 * @command: the command to be sent
591 * @column: the column address for this command, -1 if none
592 * @page_addr: the page address for this command, -1 if none
593 *
594 * Send command to NAND device. This function is used for small page devices
595 * (512 Bytes per page).
596 */
597static void nand_command(struct mtd_info *mtd, unsigned int command,
598			 int column, int page_addr)
599{
600	register struct nand_chip *chip = mtd->priv;
601	int ctrl = NAND_CTRL_CLE | NAND_CTRL_CHANGE;
602
603	/* Write out the command to the device */
604	if (command == NAND_CMD_SEQIN) {
605		int readcmd;
606
607		if (column >= mtd->writesize) {
608			/* OOB area */
609			column -= mtd->writesize;
610			readcmd = NAND_CMD_READOOB;
611		} else if (column < 256) {
612			/* First 256 bytes --> READ0 */
613			readcmd = NAND_CMD_READ0;
614		} else {
615			column -= 256;
616			readcmd = NAND_CMD_READ1;
617		}
618		chip->cmd_ctrl(mtd, readcmd, ctrl);
619		ctrl &= ~NAND_CTRL_CHANGE;
620	}
621	chip->cmd_ctrl(mtd, command, ctrl);
622
623	/* Address cycle, when necessary */
624	ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE;
625	/* Serially input address */
626	if (column != -1) {
627		/* Adjust columns for 16 bit buswidth */
628		if (chip->options & NAND_BUSWIDTH_16 &&
629				!nand_opcode_8bits(command))
630			column >>= 1;
631		chip->cmd_ctrl(mtd, column, ctrl);
632		ctrl &= ~NAND_CTRL_CHANGE;
633	}
634	if (page_addr != -1) {
635		chip->cmd_ctrl(mtd, page_addr, ctrl);
636		ctrl &= ~NAND_CTRL_CHANGE;
637		chip->cmd_ctrl(mtd, page_addr >> 8, ctrl);
638		/* One more address cycle for devices > 32MiB */
639		if (chip->chipsize > (32 << 20))
640			chip->cmd_ctrl(mtd, page_addr >> 16, ctrl);
641	}
642	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
643
644	/*
645	 * Program and erase have their own busy handlers status and sequential
646	 * in needs no delay
647	 */
648	switch (command) {
649
650	case NAND_CMD_PAGEPROG:
651	case NAND_CMD_ERASE1:
652	case NAND_CMD_ERASE2:
653	case NAND_CMD_SEQIN:
654	case NAND_CMD_STATUS:
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 */
700static 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->priv;
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			/* One more address cycle for devices > 128MiB */
732			if (chip->chipsize > (128 << 20))
733				chip->cmd_ctrl(mtd, page_addr >> 16,
734					       NAND_NCE | NAND_ALE);
735		}
736	}
737	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
738
739	/*
740	 * Program and erase have their own busy handlers status, sequential
741	 * in and status need no delay.
742	 */
743	switch (command) {
744
745	case NAND_CMD_CACHEDPROG:
746	case NAND_CMD_PAGEPROG:
747	case NAND_CMD_ERASE1:
748	case NAND_CMD_ERASE2:
749	case NAND_CMD_SEQIN:
750	case NAND_CMD_RNDIN:
751	case NAND_CMD_STATUS:
752		return;
753
754	case NAND_CMD_RESET:
755		if (chip->dev_ready)
756			break;
757		udelay(chip->chip_delay);
758		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
759			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
760		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
761			       NAND_NCE | NAND_CTRL_CHANGE);
762		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
763		nand_wait_status_ready(mtd, 250);
764		return;
765
766	case NAND_CMD_RNDOUT:
767		/* No ready / busy check necessary */
768		chip->cmd_ctrl(mtd, NAND_CMD_RNDOUTSTART,
769			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
770		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
771			       NAND_NCE | NAND_CTRL_CHANGE);
772		return;
773
774	case NAND_CMD_READ0:
775		chip->cmd_ctrl(mtd, NAND_CMD_READSTART,
776			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
777		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
778			       NAND_NCE | NAND_CTRL_CHANGE);
779
780		/* This applies to read commands */
781	default:
782		/*
783		 * If we don't have access to the busy pin, we apply the given
784		 * command delay.
785		 */
786		if (!chip->dev_ready) {
787			udelay(chip->chip_delay);
788			return;
789		}
790	}
791
792	/*
793	 * Apply this short delay always to ensure that we do wait tWB in
794	 * any case on any machine.
795	 */
796	ndelay(100);
797
798	nand_wait_ready(mtd);
799}
800
801/**
802 * panic_nand_get_device - [GENERIC] Get chip for selected access
803 * @chip: the nand chip descriptor
804 * @mtd: MTD device structure
805 * @new_state: the state which is requested
806 *
807 * Used when in panic, no locks are taken.
808 */
809static void panic_nand_get_device(struct nand_chip *chip,
810		      struct mtd_info *mtd, int new_state)
811{
812	/* Hardware controller shared among independent devices */
813	chip->controller->active = chip;
814	chip->state = new_state;
815}
816
817/**
818 * nand_get_device - [GENERIC] Get chip for selected access
819 * @mtd: MTD device structure
820 * @new_state: the state which is requested
821 *
822 * Get the device and lock it for exclusive access
823 */
824static int
825nand_get_device(struct mtd_info *mtd, int new_state)
826{
827	struct nand_chip *chip = mtd->priv;
828	spinlock_t *lock = &chip->controller->lock;
829	wait_queue_head_t *wq = &chip->controller->wq;
830	DECLARE_WAITQUEUE(wait, current);
831retry:
832	spin_lock(lock);
833
834	/* Hardware controller shared among independent devices */
835	if (!chip->controller->active)
836		chip->controller->active = chip;
837
838	if (chip->controller->active == chip && chip->state == FL_READY) {
839		chip->state = new_state;
840		spin_unlock(lock);
841		return 0;
842	}
843	if (new_state == FL_PM_SUSPENDED) {
844		if (chip->controller->active->state == FL_PM_SUSPENDED) {
845			chip->state = FL_PM_SUSPENDED;
846			spin_unlock(lock);
847			return 0;
848		}
849	}
850	set_current_state(TASK_UNINTERRUPTIBLE);
851	add_wait_queue(wq, &wait);
852	spin_unlock(lock);
853	schedule();
854	remove_wait_queue(wq, &wait);
855	goto retry;
856}
857
858/**
859 * panic_nand_wait - [GENERIC] wait until the command is done
860 * @mtd: MTD device structure
861 * @chip: NAND chip structure
862 * @timeo: timeout
863 *
864 * Wait for command done. This is a helper function for nand_wait used when
865 * we are in interrupt context. May happen when in panic and trying to write
866 * an oops through mtdoops.
867 */
868static void panic_nand_wait(struct mtd_info *mtd, struct nand_chip *chip,
869			    unsigned long timeo)
870{
871	int i;
872	for (i = 0; i < timeo; i++) {
873		if (chip->dev_ready) {
874			if (chip->dev_ready(mtd))
875				break;
876		} else {
877			if (chip->read_byte(mtd) & NAND_STATUS_READY)
878				break;
879		}
880		mdelay(1);
881	}
882}
883
884/**
885 * nand_wait - [DEFAULT] wait until the command is done
886 * @mtd: MTD device structure
887 * @chip: NAND chip structure
888 *
889 * Wait for command done. This applies to erase and program only. Erase can
890 * take up to 400ms and program up to 20ms according to general NAND and
891 * SmartMedia specs.
892 */
893static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
894{
895
896	int status, state = chip->state;
897	unsigned long timeo = (state == FL_ERASING ? 400 : 20);
898
899	led_trigger_event(nand_led_trigger, LED_FULL);
900
901	/*
902	 * Apply this short delay always to ensure that we do wait tWB in any
903	 * case on any machine.
904	 */
905	ndelay(100);
906
907	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
908
909	if (in_interrupt() || oops_in_progress)
910		panic_nand_wait(mtd, chip, timeo);
911	else {
912		timeo = jiffies + msecs_to_jiffies(timeo);
913		while (time_before(jiffies, timeo)) {
914			if (chip->dev_ready) {
915				if (chip->dev_ready(mtd))
916					break;
917			} else {
918				if (chip->read_byte(mtd) & NAND_STATUS_READY)
919					break;
920			}
921			cond_resched();
922		}
923	}
924	led_trigger_event(nand_led_trigger, LED_OFF);
925
926	status = (int)chip->read_byte(mtd);
927	/* This can happen if in case of timeout or buggy dev_ready */
928	WARN_ON(!(status & NAND_STATUS_READY));
929	return status;
930}
931
932/**
933 * __nand_unlock - [REPLACEABLE] unlocks specified locked blocks
934 * @mtd: mtd info
935 * @ofs: offset to start unlock from
936 * @len: length to unlock
937 * @invert: when = 0, unlock the range of blocks within the lower and
938 *                    upper boundary address
939 *          when = 1, unlock the range of blocks outside the boundaries
940 *                    of the lower and upper boundary address
941 *
942 * Returs unlock status.
943 */
944static int __nand_unlock(struct mtd_info *mtd, loff_t ofs,
945					uint64_t len, int invert)
946{
947	int ret = 0;
948	int status, page;
949	struct nand_chip *chip = mtd->priv;
950
951	/* Submit address of first page to unlock */
952	page = ofs >> chip->page_shift;
953	chip->cmdfunc(mtd, NAND_CMD_UNLOCK1, -1, page & chip->pagemask);
954
955	/* Submit address of last page to unlock */
956	page = (ofs + len) >> chip->page_shift;
957	chip->cmdfunc(mtd, NAND_CMD_UNLOCK2, -1,
958				(page | invert) & chip->pagemask);
959
960	/* Call wait ready function */
961	status = chip->waitfunc(mtd, chip);
962	/* See if device thinks it succeeded */
963	if (status & NAND_STATUS_FAIL) {
964		pr_debug("%s: error status = 0x%08x\n",
965					__func__, status);
966		ret = -EIO;
967	}
968
969	return ret;
970}
971
972/**
973 * nand_unlock - [REPLACEABLE] unlocks specified locked blocks
974 * @mtd: mtd info
975 * @ofs: offset to start unlock from
976 * @len: length to unlock
977 *
978 * Returns unlock status.
979 */
980int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
981{
982	int ret = 0;
983	int chipnr;
984	struct nand_chip *chip = mtd->priv;
985
986	pr_debug("%s: start = 0x%012llx, len = %llu\n",
987			__func__, (unsigned long long)ofs, len);
988
989	if (check_offs_len(mtd, ofs, len))
990		return -EINVAL;
991
992	/* Align to last block address if size addresses end of the device */
993	if (ofs + len == mtd->size)
994		len -= mtd->erasesize;
995
996	nand_get_device(mtd, FL_UNLOCKING);
997
998	/* Shift to get chip number */
999	chipnr = ofs >> chip->chip_shift;
1000
1001	chip->select_chip(mtd, chipnr);
1002
1003	/*
1004	 * Reset the chip.
1005	 * If we want to check the WP through READ STATUS and check the bit 7
1006	 * we must reset the chip
1007	 * some operation can also clear the bit 7 of status register
1008	 * eg. erase/program a locked block
1009	 */
1010	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
1011
1012	/* Check, if it is write protected */
1013	if (nand_check_wp(mtd)) {
1014		pr_debug("%s: device is write protected!\n",
1015					__func__);
1016		ret = -EIO;
1017		goto out;
1018	}
1019
1020	ret = __nand_unlock(mtd, ofs, len, 0);
1021
1022out:
1023	chip->select_chip(mtd, -1);
1024	nand_release_device(mtd);
1025
1026	return ret;
1027}
1028EXPORT_SYMBOL(nand_unlock);
1029
1030/**
1031 * nand_lock - [REPLACEABLE] locks all blocks present in the device
1032 * @mtd: mtd info
1033 * @ofs: offset to start unlock from
1034 * @len: length to unlock
1035 *
1036 * This feature is not supported in many NAND parts. 'Micron' NAND parts do
1037 * have this feature, but it allows only to lock all blocks, not for specified
1038 * range for block. Implementing 'lock' feature by making use of 'unlock', for
1039 * now.
1040 *
1041 * Returns lock status.
1042 */
1043int nand_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1044{
1045	int ret = 0;
1046	int chipnr, status, page;
1047	struct nand_chip *chip = mtd->priv;
1048
1049	pr_debug("%s: start = 0x%012llx, len = %llu\n",
1050			__func__, (unsigned long long)ofs, len);
1051
1052	if (check_offs_len(mtd, ofs, len))
1053		return -EINVAL;
1054
1055	nand_get_device(mtd, FL_LOCKING);
1056
1057	/* Shift to get chip number */
1058	chipnr = ofs >> chip->chip_shift;
1059
1060	chip->select_chip(mtd, chipnr);
1061
1062	/*
1063	 * Reset the chip.
1064	 * If we want to check the WP through READ STATUS and check the bit 7
1065	 * we must reset the chip
1066	 * some operation can also clear the bit 7 of status register
1067	 * eg. erase/program a locked block
1068	 */
1069	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
1070
1071	/* Check, if it is write protected */
1072	if (nand_check_wp(mtd)) {
1073		pr_debug("%s: device is write protected!\n",
1074					__func__);
1075		status = MTD_ERASE_FAILED;
1076		ret = -EIO;
1077		goto out;
1078	}
1079
1080	/* Submit address of first page to lock */
1081	page = ofs >> chip->page_shift;
1082	chip->cmdfunc(mtd, NAND_CMD_LOCK, -1, page & chip->pagemask);
1083
1084	/* Call wait ready function */
1085	status = chip->waitfunc(mtd, chip);
1086	/* See if device thinks it succeeded */
1087	if (status & NAND_STATUS_FAIL) {
1088		pr_debug("%s: error status = 0x%08x\n",
1089					__func__, status);
1090		ret = -EIO;
1091		goto out;
1092	}
1093
1094	ret = __nand_unlock(mtd, ofs, len, 0x1);
1095
1096out:
1097	chip->select_chip(mtd, -1);
1098	nand_release_device(mtd);
1099
1100	return ret;
1101}
1102EXPORT_SYMBOL(nand_lock);
1103
1104/**
1105 * nand_read_page_raw - [INTERN] read raw page data without ecc
1106 * @mtd: mtd info structure
1107 * @chip: nand chip info structure
1108 * @buf: buffer to store read data
1109 * @oob_required: caller requires OOB data read to chip->oob_poi
1110 * @page: page number to read
1111 *
1112 * Not for syndrome calculating ECC controllers, which use a special oob layout.
1113 */
1114static int nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
1115			      uint8_t *buf, int oob_required, int page)
1116{
1117	chip->read_buf(mtd, buf, mtd->writesize);
1118	if (oob_required)
1119		chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1120	return 0;
1121}
1122
1123/**
1124 * nand_read_page_raw_syndrome - [INTERN] read raw page data without ecc
1125 * @mtd: mtd info structure
1126 * @chip: nand chip info structure
1127 * @buf: buffer to store read data
1128 * @oob_required: caller requires OOB data read to chip->oob_poi
1129 * @page: page number to read
1130 *
1131 * We need a special oob layout and handling even when OOB isn't used.
1132 */
1133static int nand_read_page_raw_syndrome(struct mtd_info *mtd,
1134				       struct nand_chip *chip, uint8_t *buf,
1135				       int oob_required, int page)
1136{
1137	int eccsize = chip->ecc.size;
1138	int eccbytes = chip->ecc.bytes;
1139	uint8_t *oob = chip->oob_poi;
1140	int steps, size;
1141
1142	for (steps = chip->ecc.steps; steps > 0; steps--) {
1143		chip->read_buf(mtd, buf, eccsize);
1144		buf += eccsize;
1145
1146		if (chip->ecc.prepad) {
1147			chip->read_buf(mtd, oob, chip->ecc.prepad);
1148			oob += chip->ecc.prepad;
1149		}
1150
1151		chip->read_buf(mtd, oob, eccbytes);
1152		oob += eccbytes;
1153
1154		if (chip->ecc.postpad) {
1155			chip->read_buf(mtd, oob, chip->ecc.postpad);
1156			oob += chip->ecc.postpad;
1157		}
1158	}
1159
1160	size = mtd->oobsize - (oob - chip->oob_poi);
1161	if (size)
1162		chip->read_buf(mtd, oob, size);
1163
1164	return 0;
1165}
1166
1167/**
1168 * nand_read_page_swecc - [REPLACEABLE] software ECC based page read function
1169 * @mtd: mtd info structure
1170 * @chip: nand chip info structure
1171 * @buf: buffer to store read data
1172 * @oob_required: caller requires OOB data read to chip->oob_poi
1173 * @page: page number to read
1174 */
1175static int nand_read_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
1176				uint8_t *buf, int oob_required, int page)
1177{
1178	int i, eccsize = chip->ecc.size;
1179	int eccbytes = chip->ecc.bytes;
1180	int eccsteps = chip->ecc.steps;
1181	uint8_t *p = buf;
1182	uint8_t *ecc_calc = chip->buffers->ecccalc;
1183	uint8_t *ecc_code = chip->buffers->ecccode;
1184	uint32_t *eccpos = chip->ecc.layout->eccpos;
1185	unsigned int max_bitflips = 0;
1186
1187	chip->ecc.read_page_raw(mtd, chip, buf, 1, page);
1188
1189	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
1190		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1191
1192	for (i = 0; i < chip->ecc.total; i++)
1193		ecc_code[i] = chip->oob_poi[eccpos[i]];
1194
1195	eccsteps = chip->ecc.steps;
1196	p = buf;
1197
1198	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1199		int stat;
1200
1201		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
1202		if (stat < 0) {
1203			mtd->ecc_stats.failed++;
1204		} else {
1205			mtd->ecc_stats.corrected += stat;
1206			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1207		}
1208	}
1209	return max_bitflips;
1210}
1211
1212/**
1213 * nand_read_subpage - [REPLACEABLE] ECC based sub-page read function
1214 * @mtd: mtd info structure
1215 * @chip: nand chip info structure
1216 * @data_offs: offset of requested data within the page
1217 * @readlen: data length
1218 * @bufpoi: buffer to store read data
1219 * @page: page number to read
1220 */
1221static int nand_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
1222			uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi,
1223			int page)
1224{
1225	int start_step, end_step, num_steps;
1226	uint32_t *eccpos = chip->ecc.layout->eccpos;
1227	uint8_t *p;
1228	int data_col_addr, i, gaps = 0;
1229	int datafrag_len, eccfrag_len, aligned_len, aligned_pos;
1230	int busw = (chip->options & NAND_BUSWIDTH_16) ? 2 : 1;
1231	int index;
1232	unsigned int max_bitflips = 0;
1233
1234	/* Column address within the page aligned to ECC size (256bytes) */
1235	start_step = data_offs / chip->ecc.size;
1236	end_step = (data_offs + readlen - 1) / chip->ecc.size;
1237	num_steps = end_step - start_step + 1;
1238	index = start_step * chip->ecc.bytes;
1239
1240	/* Data size aligned to ECC ecc.size */
1241	datafrag_len = num_steps * chip->ecc.size;
1242	eccfrag_len = num_steps * chip->ecc.bytes;
1243
1244	data_col_addr = start_step * chip->ecc.size;
1245	/* If we read not a page aligned data */
1246	if (data_col_addr != 0)
1247		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, data_col_addr, -1);
1248
1249	p = bufpoi + data_col_addr;
1250	chip->read_buf(mtd, p, datafrag_len);
1251
1252	/* Calculate ECC */
1253	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size)
1254		chip->ecc.calculate(mtd, p, &chip->buffers->ecccalc[i]);
1255
1256	/*
1257	 * The performance is faster if we position offsets according to
1258	 * ecc.pos. Let's make sure that there are no gaps in ECC positions.
1259	 */
1260	for (i = 0; i < eccfrag_len - 1; i++) {
1261		if (eccpos[i + index] + 1 != eccpos[i + index + 1]) {
1262			gaps = 1;
1263			break;
1264		}
1265	}
1266	if (gaps) {
1267		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);
1268		chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1269	} else {
1270		/*
1271		 * Send the command to read the particular ECC bytes take care
1272		 * about buswidth alignment in read_buf.
1273		 */
1274		aligned_pos = eccpos[index] & ~(busw - 1);
1275		aligned_len = eccfrag_len;
1276		if (eccpos[index] & (busw - 1))
1277			aligned_len++;
1278		if (eccpos[index + (num_steps * chip->ecc.bytes)] & (busw - 1))
1279			aligned_len++;
1280
1281		chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
1282					mtd->writesize + aligned_pos, -1);
1283		chip->read_buf(mtd, &chip->oob_poi[aligned_pos], aligned_len);
1284	}
1285
1286	for (i = 0; i < eccfrag_len; i++)
1287		chip->buffers->ecccode[i] = chip->oob_poi[eccpos[i + index]];
1288
1289	p = bufpoi + data_col_addr;
1290	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size) {
1291		int stat;
1292
1293		stat = chip->ecc.correct(mtd, p,
1294			&chip->buffers->ecccode[i], &chip->buffers->ecccalc[i]);
1295		if (stat < 0) {
1296			mtd->ecc_stats.failed++;
1297		} else {
1298			mtd->ecc_stats.corrected += stat;
1299			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1300		}
1301	}
1302	return max_bitflips;
1303}
1304
1305/**
1306 * nand_read_page_hwecc - [REPLACEABLE] hardware ECC based page read function
1307 * @mtd: mtd info structure
1308 * @chip: nand chip info structure
1309 * @buf: buffer to store read data
1310 * @oob_required: caller requires OOB data read to chip->oob_poi
1311 * @page: page number to read
1312 *
1313 * Not for syndrome calculating ECC controllers which need a special oob layout.
1314 */
1315static int nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
1316				uint8_t *buf, int oob_required, int page)
1317{
1318	int i, eccsize = chip->ecc.size;
1319	int eccbytes = chip->ecc.bytes;
1320	int eccsteps = chip->ecc.steps;
1321	uint8_t *p = buf;
1322	uint8_t *ecc_calc = chip->buffers->ecccalc;
1323	uint8_t *ecc_code = chip->buffers->ecccode;
1324	uint32_t *eccpos = chip->ecc.layout->eccpos;
1325	unsigned int max_bitflips = 0;
1326
1327	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1328		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1329		chip->read_buf(mtd, p, eccsize);
1330		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1331	}
1332	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1333
1334	for (i = 0; i < chip->ecc.total; i++)
1335		ecc_code[i] = chip->oob_poi[eccpos[i]];
1336
1337	eccsteps = chip->ecc.steps;
1338	p = buf;
1339
1340	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1341		int stat;
1342
1343		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
1344		if (stat < 0) {
1345			mtd->ecc_stats.failed++;
1346		} else {
1347			mtd->ecc_stats.corrected += stat;
1348			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1349		}
1350	}
1351	return max_bitflips;
1352}
1353
1354/**
1355 * nand_read_page_hwecc_oob_first - [REPLACEABLE] hw ecc, read oob first
1356 * @mtd: mtd info structure
1357 * @chip: nand chip info structure
1358 * @buf: buffer to store read data
1359 * @oob_required: caller requires OOB data read to chip->oob_poi
1360 * @page: page number to read
1361 *
1362 * Hardware ECC for large page chips, require OOB to be read first. For this
1363 * ECC mode, the write_page method is re-used from ECC_HW. These methods
1364 * read/write ECC from the OOB area, unlike the ECC_HW_SYNDROME support with
1365 * multiple ECC steps, follows the "infix ECC" scheme and reads/writes ECC from
1366 * the data area, by overwriting the NAND manufacturer bad block markings.
1367 */
1368static int nand_read_page_hwecc_oob_first(struct mtd_info *mtd,
1369	struct nand_chip *chip, uint8_t *buf, int oob_required, int page)
1370{
1371	int i, eccsize = chip->ecc.size;
1372	int eccbytes = chip->ecc.bytes;
1373	int eccsteps = chip->ecc.steps;
1374	uint8_t *p = buf;
1375	uint8_t *ecc_code = chip->buffers->ecccode;
1376	uint32_t *eccpos = chip->ecc.layout->eccpos;
1377	uint8_t *ecc_calc = chip->buffers->ecccalc;
1378	unsigned int max_bitflips = 0;
1379
1380	/* Read the OOB area first */
1381	chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
1382	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1383	chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
1384
1385	for (i = 0; i < chip->ecc.total; i++)
1386		ecc_code[i] = chip->oob_poi[eccpos[i]];
1387
1388	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1389		int stat;
1390
1391		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1392		chip->read_buf(mtd, p, eccsize);
1393		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1394
1395		stat = chip->ecc.correct(mtd, p, &ecc_code[i], NULL);
1396		if (stat < 0) {
1397			mtd->ecc_stats.failed++;
1398		} else {
1399			mtd->ecc_stats.corrected += stat;
1400			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1401		}
1402	}
1403	return max_bitflips;
1404}
1405
1406/**
1407 * nand_read_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page read
1408 * @mtd: mtd info structure
1409 * @chip: nand chip info structure
1410 * @buf: buffer to store read data
1411 * @oob_required: caller requires OOB data read to chip->oob_poi
1412 * @page: page number to read
1413 *
1414 * The hw generator calculates the error syndrome automatically. Therefore we
1415 * need a special oob layout and handling.
1416 */
1417static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
1418				   uint8_t *buf, int oob_required, int page)
1419{
1420	int i, eccsize = chip->ecc.size;
1421	int eccbytes = chip->ecc.bytes;
1422	int eccsteps = chip->ecc.steps;
1423	uint8_t *p = buf;
1424	uint8_t *oob = chip->oob_poi;
1425	unsigned int max_bitflips = 0;
1426
1427	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1428		int stat;
1429
1430		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1431		chip->read_buf(mtd, p, eccsize);
1432
1433		if (chip->ecc.prepad) {
1434			chip->read_buf(mtd, oob, chip->ecc.prepad);
1435			oob += chip->ecc.prepad;
1436		}
1437
1438		chip->ecc.hwctl(mtd, NAND_ECC_READSYN);
1439		chip->read_buf(mtd, oob, eccbytes);
1440		stat = chip->ecc.correct(mtd, p, oob, NULL);
1441
1442		if (stat < 0) {
1443			mtd->ecc_stats.failed++;
1444		} else {
1445			mtd->ecc_stats.corrected += stat;
1446			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1447		}
1448
1449		oob += eccbytes;
1450
1451		if (chip->ecc.postpad) {
1452			chip->read_buf(mtd, oob, chip->ecc.postpad);
1453			oob += chip->ecc.postpad;
1454		}
1455	}
1456
1457	/* Calculate remaining oob bytes */
1458	i = mtd->oobsize - (oob - chip->oob_poi);
1459	if (i)
1460		chip->read_buf(mtd, oob, i);
1461
1462	return max_bitflips;
1463}
1464
1465/**
1466 * nand_transfer_oob - [INTERN] Transfer oob to client buffer
1467 * @chip: nand chip structure
1468 * @oob: oob destination address
1469 * @ops: oob ops structure
1470 * @len: size of oob to transfer
1471 */
1472static uint8_t *nand_transfer_oob(struct nand_chip *chip, uint8_t *oob,
1473				  struct mtd_oob_ops *ops, size_t len)
1474{
1475	switch (ops->mode) {
1476
1477	case MTD_OPS_PLACE_OOB:
1478	case MTD_OPS_RAW:
1479		memcpy(oob, chip->oob_poi + ops->ooboffs, len);
1480		return oob + len;
1481
1482	case MTD_OPS_AUTO_OOB: {
1483		struct nand_oobfree *free = chip->ecc.layout->oobfree;
1484		uint32_t boffs = 0, roffs = ops->ooboffs;
1485		size_t bytes = 0;
1486
1487		for (; free->length && len; free++, len -= bytes) {
1488			/* Read request not from offset 0? */
1489			if (unlikely(roffs)) {
1490				if (roffs >= free->length) {
1491					roffs -= free->length;
1492					continue;
1493				}
1494				boffs = free->offset + roffs;
1495				bytes = min_t(size_t, len,
1496					      (free->length - roffs));
1497				roffs = 0;
1498			} else {
1499				bytes = min_t(size_t, len, free->length);
1500				boffs = free->offset;
1501			}
1502			memcpy(oob, chip->oob_poi + boffs, bytes);
1503			oob += bytes;
1504		}
1505		return oob;
1506	}
1507	default:
1508		BUG();
1509	}
1510	return NULL;
1511}
1512
1513/**
1514 * nand_setup_read_retry - [INTERN] Set the READ RETRY mode
1515 * @mtd: MTD device structure
1516 * @retry_mode: the retry mode to use
1517 *
1518 * Some vendors supply a special command to shift the Vt threshold, to be used
1519 * when there are too many bitflips in a page (i.e., ECC error). After setting
1520 * a new threshold, the host should retry reading the page.
1521 */
1522static int nand_setup_read_retry(struct mtd_info *mtd, int retry_mode)
1523{
1524	struct nand_chip *chip = mtd->priv;
1525
1526	pr_debug("setting READ RETRY mode %d\n", retry_mode);
1527
1528	if (retry_mode >= chip->read_retries)
1529		return -EINVAL;
1530
1531	if (!chip->setup_read_retry)
1532		return -EOPNOTSUPP;
1533
1534	return chip->setup_read_retry(mtd, retry_mode);
1535}
1536
1537/**
1538 * nand_do_read_ops - [INTERN] Read data with ECC
1539 * @mtd: MTD device structure
1540 * @from: offset to read from
1541 * @ops: oob ops structure
1542 *
1543 * Internal function. Called with chip held.
1544 */
1545static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
1546			    struct mtd_oob_ops *ops)
1547{
1548	int chipnr, page, realpage, col, bytes, aligned, oob_required;
1549	struct nand_chip *chip = mtd->priv;
1550	int ret = 0;
1551	uint32_t readlen = ops->len;
1552	uint32_t oobreadlen = ops->ooblen;
1553	uint32_t max_oobsize = ops->mode == MTD_OPS_AUTO_OOB ?
1554		mtd->oobavail : mtd->oobsize;
1555
1556	uint8_t *bufpoi, *oob, *buf;
1557	int use_bufpoi;
1558	unsigned int max_bitflips = 0;
1559	int retry_mode = 0;
1560	bool ecc_fail = false;
1561
1562	chipnr = (int)(from >> chip->chip_shift);
1563	chip->select_chip(mtd, chipnr);
1564
1565	realpage = (int)(from >> chip->page_shift);
1566	page = realpage & chip->pagemask;
1567
1568	col = (int)(from & (mtd->writesize - 1));
1569
1570	buf = ops->datbuf;
1571	oob = ops->oobbuf;
1572	oob_required = oob ? 1 : 0;
1573
1574	while (1) {
1575		unsigned int ecc_failures = mtd->ecc_stats.failed;
1576
1577		bytes = min(mtd->writesize - col, readlen);
1578		aligned = (bytes == mtd->writesize);
1579
1580		if (!aligned)
1581			use_bufpoi = 1;
1582		else if (chip->options & NAND_USE_BOUNCE_BUFFER)
1583			use_bufpoi = !virt_addr_valid(buf);
1584		else
1585			use_bufpoi = 0;
1586
1587		/* Is the current page in the buffer? */
1588		if (realpage != chip->pagebuf || oob) {
1589			bufpoi = use_bufpoi ? chip->buffers->databuf : buf;
1590
1591			if (use_bufpoi && aligned)
1592				pr_debug("%s: using read bounce buffer for buf@%p\n",
1593						 __func__, buf);
1594
1595read_retry:
1596			chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
1597
1598			/*
1599			 * Now read the page into the buffer.  Absent an error,
1600			 * the read methods return max bitflips per ecc step.
1601			 */
1602			if (unlikely(ops->mode == MTD_OPS_RAW))
1603				ret = chip->ecc.read_page_raw(mtd, chip, bufpoi,
1604							      oob_required,
1605							      page);
1606			else if (!aligned && NAND_HAS_SUBPAGE_READ(chip) &&
1607				 !oob)
1608				ret = chip->ecc.read_subpage(mtd, chip,
1609							col, bytes, bufpoi,
1610							page);
1611			else
1612				ret = chip->ecc.read_page(mtd, chip, bufpoi,
1613							  oob_required, page);
1614			if (ret < 0) {
1615				if (use_bufpoi)
1616					/* Invalidate page cache */
1617					chip->pagebuf = -1;
1618				break;
1619			}
1620
1621			max_bitflips = max_t(unsigned int, max_bitflips, ret);
1622
1623			/* Transfer not aligned data */
1624			if (use_bufpoi) {
1625				if (!NAND_HAS_SUBPAGE_READ(chip) && !oob &&
1626				    !(mtd->ecc_stats.failed - ecc_failures) &&
1627				    (ops->mode != MTD_OPS_RAW)) {
1628					chip->pagebuf = realpage;
1629					chip->pagebuf_bitflips = ret;
1630				} else {
1631					/* Invalidate page cache */
1632					chip->pagebuf = -1;
1633				}
1634				memcpy(buf, chip->buffers->databuf + col, bytes);
1635			}
1636
1637			if (unlikely(oob)) {
1638				int toread = min(oobreadlen, max_oobsize);
1639
1640				if (toread) {
1641					oob = nand_transfer_oob(chip,
1642						oob, ops, toread);
1643					oobreadlen -= toread;
1644				}
1645			}
1646
1647			if (chip->options & NAND_NEED_READRDY) {
1648				/* Apply delay or wait for ready/busy pin */
1649				if (!chip->dev_ready)
1650					udelay(chip->chip_delay);
1651				else
1652					nand_wait_ready(mtd);
1653			}
1654
1655			if (mtd->ecc_stats.failed - ecc_failures) {
1656				if (retry_mode + 1 < chip->read_retries) {
1657					retry_mode++;
1658					ret = nand_setup_read_retry(mtd,
1659							retry_mode);
1660					if (ret < 0)
1661						break;
1662
1663					/* Reset failures; retry */
1664					mtd->ecc_stats.failed = ecc_failures;
1665					goto read_retry;
1666				} else {
1667					/* No more retry modes; real failure */
1668					ecc_fail = true;
1669				}
1670			}
1671
1672			buf += bytes;
1673		} else {
1674			memcpy(buf, chip->buffers->databuf + col, bytes);
1675			buf += bytes;
1676			max_bitflips = max_t(unsigned int, max_bitflips,
1677					     chip->pagebuf_bitflips);
1678		}
1679
1680		readlen -= bytes;
1681
1682		/* Reset to retry mode 0 */
1683		if (retry_mode) {
1684			ret = nand_setup_read_retry(mtd, 0);
1685			if (ret < 0)
1686				break;
1687			retry_mode = 0;
1688		}
1689
1690		if (!readlen)
1691			break;
1692
1693		/* For subsequent reads align to page boundary */
1694		col = 0;
1695		/* Increment page address */
1696		realpage++;
1697
1698		page = realpage & chip->pagemask;
1699		/* Check, if we cross a chip boundary */
1700		if (!page) {
1701			chipnr++;
1702			chip->select_chip(mtd, -1);
1703			chip->select_chip(mtd, chipnr);
1704		}
1705	}
1706	chip->select_chip(mtd, -1);
1707
1708	ops->retlen = ops->len - (size_t) readlen;
1709	if (oob)
1710		ops->oobretlen = ops->ooblen - oobreadlen;
1711
1712	if (ret < 0)
1713		return ret;
1714
1715	if (ecc_fail)
1716		return -EBADMSG;
1717
1718	return max_bitflips;
1719}
1720
1721/**
1722 * nand_read - [MTD Interface] MTD compatibility function for nand_do_read_ecc
1723 * @mtd: MTD device structure
1724 * @from: offset to read from
1725 * @len: number of bytes to read
1726 * @retlen: pointer to variable to store the number of read bytes
1727 * @buf: the databuffer to put data
1728 *
1729 * Get hold of the chip and call nand_do_read.
1730 */
1731static int nand_read(struct mtd_info *mtd, loff_t from, size_t len,
1732		     size_t *retlen, uint8_t *buf)
1733{
1734	struct mtd_oob_ops ops;
1735	int ret;
1736
1737	nand_get_device(mtd, FL_READING);
1738	memset(&ops, 0, sizeof(ops));
1739	ops.len = len;
1740	ops.datbuf = buf;
1741	ops.mode = MTD_OPS_PLACE_OOB;
1742	ret = nand_do_read_ops(mtd, from, &ops);
1743	*retlen = ops.retlen;
1744	nand_release_device(mtd);
1745	return ret;
1746}
1747
1748/**
1749 * nand_read_oob_std - [REPLACEABLE] the most common OOB data read function
1750 * @mtd: mtd info structure
1751 * @chip: nand chip info structure
1752 * @page: page number to read
1753 */
1754static int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
1755			     int page)
1756{
1757	chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
1758	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1759	return 0;
1760}
1761
1762/**
1763 * nand_read_oob_syndrome - [REPLACEABLE] OOB data read function for HW ECC
1764 *			    with syndromes
1765 * @mtd: mtd info structure
1766 * @chip: nand chip info structure
1767 * @page: page number to read
1768 */
1769static int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
1770				  int page)
1771{
1772	int length = mtd->oobsize;
1773	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
1774	int eccsize = chip->ecc.size;
1775	uint8_t *bufpoi = chip->oob_poi;
1776	int i, toread, sndrnd = 0, pos;
1777
1778	chip->cmdfunc(mtd, NAND_CMD_READ0, chip->ecc.size, page);
1779	for (i = 0; i < chip->ecc.steps; i++) {
1780		if (sndrnd) {
1781			pos = eccsize + i * (eccsize + chunk);
1782			if (mtd->writesize > 512)
1783				chip->cmdfunc(mtd, NAND_CMD_RNDOUT, pos, -1);
1784			else
1785				chip->cmdfunc(mtd, NAND_CMD_READ0, pos, page);
1786		} else
1787			sndrnd = 1;
1788		toread = min_t(int, length, chunk);
1789		chip->read_buf(mtd, bufpoi, toread);
1790		bufpoi += toread;
1791		length -= toread;
1792	}
1793	if (length > 0)
1794		chip->read_buf(mtd, bufpoi, length);
1795
1796	return 0;
1797}
1798
1799/**
1800 * nand_write_oob_std - [REPLACEABLE] the most common OOB data write function
1801 * @mtd: mtd info structure
1802 * @chip: nand chip info structure
1803 * @page: page number to write
1804 */
1805static int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
1806			      int page)
1807{
1808	int status = 0;
1809	const uint8_t *buf = chip->oob_poi;
1810	int length = mtd->oobsize;
1811
1812	chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, page);
1813	chip->write_buf(mtd, buf, length);
1814	/* Send command to program the OOB data */
1815	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1816
1817	status = chip->waitfunc(mtd, chip);
1818
1819	return status & NAND_STATUS_FAIL ? -EIO : 0;
1820}
1821
1822/**
1823 * nand_write_oob_syndrome - [REPLACEABLE] OOB data write function for HW ECC
1824 *			     with syndrome - only for large page flash
1825 * @mtd: mtd info structure
1826 * @chip: nand chip info structure
1827 * @page: page number to write
1828 */
1829static int nand_write_oob_syndrome(struct mtd_info *mtd,
1830				   struct nand_chip *chip, int page)
1831{
1832	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
1833	int eccsize = chip->ecc.size, length = mtd->oobsize;
1834	int i, len, pos, status = 0, sndcmd = 0, steps = chip->ecc.steps;
1835	const uint8_t *bufpoi = chip->oob_poi;
1836
1837	/*
1838	 * data-ecc-data-ecc ... ecc-oob
1839	 * or
1840	 * data-pad-ecc-pad-data-pad .... ecc-pad-oob
1841	 */
1842	if (!chip->ecc.prepad && !chip->ecc.postpad) {
1843		pos = steps * (eccsize + chunk);
1844		steps = 0;
1845	} else
1846		pos = eccsize;
1847
1848	chip->cmdfunc(mtd, NAND_CMD_SEQIN, pos, page);
1849	for (i = 0; i < steps; i++) {
1850		if (sndcmd) {
1851			if (mtd->writesize <= 512) {
1852				uint32_t fill = 0xFFFFFFFF;
1853
1854				len = eccsize;
1855				while (len > 0) {
1856					int num = min_t(int, len, 4);
1857					chip->write_buf(mtd, (uint8_t *)&fill,
1858							num);
1859					len -= num;
1860				}
1861			} else {
1862				pos = eccsize + i * (eccsize + chunk);
1863				chip->cmdfunc(mtd, NAND_CMD_RNDIN, pos, -1);
1864			}
1865		} else
1866			sndcmd = 1;
1867		len = min_t(int, length, chunk);
1868		chip->write_buf(mtd, bufpoi, len);
1869		bufpoi += len;
1870		length -= len;
1871	}
1872	if (length > 0)
1873		chip->write_buf(mtd, bufpoi, length);
1874
1875	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1876	status = chip->waitfunc(mtd, chip);
1877
1878	return status & NAND_STATUS_FAIL ? -EIO : 0;
1879}
1880
1881/**
1882 * nand_do_read_oob - [INTERN] NAND read out-of-band
1883 * @mtd: MTD device structure
1884 * @from: offset to read from
1885 * @ops: oob operations description structure
1886 *
1887 * NAND read out-of-band data from the spare area.
1888 */
1889static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
1890			    struct mtd_oob_ops *ops)
1891{
1892	int page, realpage, chipnr;
1893	struct nand_chip *chip = mtd->priv;
1894	struct mtd_ecc_stats stats;
1895	int readlen = ops->ooblen;
1896	int len;
1897	uint8_t *buf = ops->oobbuf;
1898	int ret = 0;
1899
1900	pr_debug("%s: from = 0x%08Lx, len = %i\n",
1901			__func__, (unsigned long long)from, readlen);
1902
1903	stats = mtd->ecc_stats;
1904
1905	if (ops->mode == MTD_OPS_AUTO_OOB)
1906		len = chip->ecc.layout->oobavail;
1907	else
1908		len = mtd->oobsize;
1909
1910	if (unlikely(ops->ooboffs >= len)) {
1911		pr_debug("%s: attempt to start read outside oob\n",
1912				__func__);
1913		return -EINVAL;
1914	}
1915
1916	/* Do not allow reads past end of device */
1917	if (unlikely(from >= mtd->size ||
1918		     ops->ooboffs + readlen > ((mtd->size >> chip->page_shift) -
1919					(from >> chip->page_shift)) * len)) {
1920		pr_debug("%s: attempt to read beyond end of device\n",
1921				__func__);
1922		return -EINVAL;
1923	}
1924
1925	chipnr = (int)(from >> chip->chip_shift);
1926	chip->select_chip(mtd, chipnr);
1927
1928	/* Shift to get page */
1929	realpage = (int)(from >> chip->page_shift);
1930	page = realpage & chip->pagemask;
1931
1932	while (1) {
1933		if (ops->mode == MTD_OPS_RAW)
1934			ret = chip->ecc.read_oob_raw(mtd, chip, page);
1935		else
1936			ret = chip->ecc.read_oob(mtd, chip, page);
1937
1938		if (ret < 0)
1939			break;
1940
1941		len = min(len, readlen);
1942		buf = nand_transfer_oob(chip, buf, ops, len);
1943
1944		if (chip->options & NAND_NEED_READRDY) {
1945			/* Apply delay or wait for ready/busy pin */
1946			if (!chip->dev_ready)
1947				udelay(chip->chip_delay);
1948			else
1949				nand_wait_ready(mtd);
1950		}
1951
1952		readlen -= len;
1953		if (!readlen)
1954			break;
1955
1956		/* Increment page address */
1957		realpage++;
1958
1959		page = realpage & chip->pagemask;
1960		/* Check, if we cross a chip boundary */
1961		if (!page) {
1962			chipnr++;
1963			chip->select_chip(mtd, -1);
1964			chip->select_chip(mtd, chipnr);
1965		}
1966	}
1967	chip->select_chip(mtd, -1);
1968
1969	ops->oobretlen = ops->ooblen - readlen;
1970
1971	if (ret < 0)
1972		return ret;
1973
1974	if (mtd->ecc_stats.failed - stats.failed)
1975		return -EBADMSG;
1976
1977	return  mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
1978}
1979
1980/**
1981 * nand_read_oob - [MTD Interface] NAND read data and/or out-of-band
1982 * @mtd: MTD device structure
1983 * @from: offset to read from
1984 * @ops: oob operation description structure
1985 *
1986 * NAND read data and/or out-of-band data.
1987 */
1988static int nand_read_oob(struct mtd_info *mtd, loff_t from,
1989			 struct mtd_oob_ops *ops)
1990{
1991	int ret = -ENOTSUPP;
1992
1993	ops->retlen = 0;
1994
1995	/* Do not allow reads past end of device */
1996	if (ops->datbuf && (from + ops->len) > mtd->size) {
1997		pr_debug("%s: attempt to read beyond end of device\n",
1998				__func__);
1999		return -EINVAL;
2000	}
2001
2002	nand_get_device(mtd, FL_READING);
2003
2004	switch (ops->mode) {
2005	case MTD_OPS_PLACE_OOB:
2006	case MTD_OPS_AUTO_OOB:
2007	case MTD_OPS_RAW:
2008		break;
2009
2010	default:
2011		goto out;
2012	}
2013
2014	if (!ops->datbuf)
2015		ret = nand_do_read_oob(mtd, from, ops);
2016	else
2017		ret = nand_do_read_ops(mtd, from, ops);
2018
2019out:
2020	nand_release_device(mtd);
2021	return ret;
2022}
2023
2024
2025/**
2026 * nand_write_page_raw - [INTERN] raw page write function
2027 * @mtd: mtd info structure
2028 * @chip: nand chip info structure
2029 * @buf: data buffer
2030 * @oob_required: must write chip->oob_poi to OOB
2031 *
2032 * Not for syndrome calculating ECC controllers, which use a special oob layout.
2033 */
2034static int nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
2035				const uint8_t *buf, int oob_required)
2036{
2037	chip->write_buf(mtd, buf, mtd->writesize);
2038	if (oob_required)
2039		chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
2040
2041	return 0;
2042}
2043
2044/**
2045 * nand_write_page_raw_syndrome - [INTERN] raw page write function
2046 * @mtd: mtd info structure
2047 * @chip: nand chip info structure
2048 * @buf: data buffer
2049 * @oob_required: must write chip->oob_poi to OOB
2050 *
2051 * We need a special oob layout and handling even when ECC isn't checked.
2052 */
2053static int nand_write_page_raw_syndrome(struct mtd_info *mtd,
2054					struct nand_chip *chip,
2055					const uint8_t *buf, int oob_required)
2056{
2057	int eccsize = chip->ecc.size;
2058	int eccbytes = chip->ecc.bytes;
2059	uint8_t *oob = chip->oob_poi;
2060	int steps, size;
2061
2062	for (steps = chip->ecc.steps; steps > 0; steps--) {
2063		chip->write_buf(mtd, buf, eccsize);
2064		buf += eccsize;
2065
2066		if (chip->ecc.prepad) {
2067			chip->write_buf(mtd, oob, chip->ecc.prepad);
2068			oob += chip->ecc.prepad;
2069		}
2070
2071		chip->write_buf(mtd, oob, eccbytes);
2072		oob += eccbytes;
2073
2074		if (chip->ecc.postpad) {
2075			chip->write_buf(mtd, oob, chip->ecc.postpad);
2076			oob += chip->ecc.postpad;
2077		}
2078	}
2079
2080	size = mtd->oobsize - (oob - chip->oob_poi);
2081	if (size)
2082		chip->write_buf(mtd, oob, size);
2083
2084	return 0;
2085}
2086/**
2087 * nand_write_page_swecc - [REPLACEABLE] software ECC based page write function
2088 * @mtd: mtd info structure
2089 * @chip: nand chip info structure
2090 * @buf: data buffer
2091 * @oob_required: must write chip->oob_poi to OOB
2092 */
2093static int nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
2094				  const uint8_t *buf, int oob_required)
2095{
2096	int i, eccsize = chip->ecc.size;
2097	int eccbytes = chip->ecc.bytes;
2098	int eccsteps = chip->ecc.steps;
2099	uint8_t *ecc_calc = chip->buffers->ecccalc;
2100	const uint8_t *p = buf;
2101	uint32_t *eccpos = chip->ecc.layout->eccpos;
2102
2103	/* Software ECC calculation */
2104	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
2105		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
2106
2107	for (i = 0; i < chip->ecc.total; i++)
2108		chip->oob_poi[eccpos[i]] = ecc_calc[i];
2109
2110	return chip->ecc.write_page_raw(mtd, chip, buf, 1);
2111}
2112
2113/**
2114 * nand_write_page_hwecc - [REPLACEABLE] hardware ECC based page write function
2115 * @mtd: mtd info structure
2116 * @chip: nand chip info structure
2117 * @buf: data buffer
2118 * @oob_required: must write chip->oob_poi to OOB
2119 */
2120static int nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
2121				  const uint8_t *buf, int oob_required)
2122{
2123	int i, eccsize = chip->ecc.size;
2124	int eccbytes = chip->ecc.bytes;
2125	int eccsteps = chip->ecc.steps;
2126	uint8_t *ecc_calc = chip->buffers->ecccalc;
2127	const uint8_t *p = buf;
2128	uint32_t *eccpos = chip->ecc.layout->eccpos;
2129
2130	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
2131		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
2132		chip->write_buf(mtd, p, eccsize);
2133		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
2134	}
2135
2136	for (i = 0; i < chip->ecc.total; i++)
2137		chip->oob_poi[eccpos[i]] = ecc_calc[i];
2138
2139	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
2140
2141	return 0;
2142}
2143
2144
2145/**
2146 * nand_write_subpage_hwecc - [REPLACEABLE] hardware ECC based subpage write
2147 * @mtd:	mtd info structure
2148 * @chip:	nand chip info structure
2149 * @offset:	column address of subpage within the page
2150 * @data_len:	data length
2151 * @buf:	data buffer
2152 * @oob_required: must write chip->oob_poi to OOB
2153 */
2154static int nand_write_subpage_hwecc(struct mtd_info *mtd,
2155				struct nand_chip *chip, uint32_t offset,
2156				uint32_t data_len, const uint8_t *buf,
2157				int oob_required)
2158{
2159	uint8_t *oob_buf  = chip->oob_poi;
2160	uint8_t *ecc_calc = chip->buffers->ecccalc;
2161	int ecc_size      = chip->ecc.size;
2162	int ecc_bytes     = chip->ecc.bytes;
2163	int ecc_steps     = chip->ecc.steps;
2164	uint32_t *eccpos  = chip->ecc.layout->eccpos;
2165	uint32_t start_step = offset / ecc_size;
2166	uint32_t end_step   = (offset + data_len - 1) / ecc_size;
2167	int oob_bytes       = mtd->oobsize / ecc_steps;
2168	int step, i;
2169
2170	for (step = 0; step < ecc_steps; step++) {
2171		/* configure controller for WRITE access */
2172		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
2173
2174		/* write data (untouched subpages already masked by 0xFF) */
2175		chip->write_buf(mtd, buf, ecc_size);
2176
2177		/* mask ECC of un-touched subpages by padding 0xFF */
2178		if ((step < start_step) || (step > end_step))
2179			memset(ecc_calc, 0xff, ecc_bytes);
2180		else
2181			chip->ecc.calculate(mtd, buf, ecc_calc);
2182
2183		/* mask OOB of un-touched subpages by padding 0xFF */
2184		/* if oob_required, preserve OOB metadata of written subpage */
2185		if (!oob_required || (step < start_step) || (step > end_step))
2186			memset(oob_buf, 0xff, oob_bytes);
2187
2188		buf += ecc_size;
2189		ecc_calc += ecc_bytes;
2190		oob_buf  += oob_bytes;
2191	}
2192
2193	/* copy calculated ECC for whole page to chip->buffer->oob */
2194	/* this include masked-value(0xFF) for unwritten subpages */
2195	ecc_calc = chip->buffers->ecccalc;
2196	for (i = 0; i < chip->ecc.total; i++)
2197		chip->oob_poi[eccpos[i]] = ecc_calc[i];
2198
2199	/* write OOB buffer to NAND device */
2200	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
2201
2202	return 0;
2203}
2204
2205
2206/**
2207 * nand_write_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page write
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 *
2213 * The hw generator calculates the error syndrome automatically. Therefore we
2214 * need a special oob layout and handling.
2215 */
2216static int nand_write_page_syndrome(struct mtd_info *mtd,
2217				    struct nand_chip *chip,
2218				    const uint8_t *buf, int oob_required)
2219{
2220	int i, eccsize = chip->ecc.size;
2221	int eccbytes = chip->ecc.bytes;
2222	int eccsteps = chip->ecc.steps;
2223	const uint8_t *p = buf;
2224	uint8_t *oob = chip->oob_poi;
2225
2226	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
2227
2228		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
2229		chip->write_buf(mtd, p, eccsize);
2230
2231		if (chip->ecc.prepad) {
2232			chip->write_buf(mtd, oob, chip->ecc.prepad);
2233			oob += chip->ecc.prepad;
2234		}
2235
2236		chip->ecc.calculate(mtd, p, oob);
2237		chip->write_buf(mtd, oob, eccbytes);
2238		oob += eccbytes;
2239
2240		if (chip->ecc.postpad) {
2241			chip->write_buf(mtd, oob, chip->ecc.postpad);
2242			oob += chip->ecc.postpad;
2243		}
2244	}
2245
2246	/* Calculate remaining oob bytes */
2247	i = mtd->oobsize - (oob - chip->oob_poi);
2248	if (i)
2249		chip->write_buf(mtd, oob, i);
2250
2251	return 0;
2252}
2253
2254/**
2255 * nand_write_page - [REPLACEABLE] write one page
2256 * @mtd: MTD device structure
2257 * @chip: NAND chip descriptor
2258 * @offset: address offset within the page
2259 * @data_len: length of actual data to be written
2260 * @buf: the data to write
2261 * @oob_required: must write chip->oob_poi to OOB
2262 * @page: page number to write
2263 * @cached: cached programming
2264 * @raw: use _raw version of write_page
2265 */
2266static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
2267		uint32_t offset, int data_len, const uint8_t *buf,
2268		int oob_required, int page, int cached, int raw)
2269{
2270	int status, subpage;
2271
2272	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) &&
2273		chip->ecc.write_subpage)
2274		subpage = offset || (data_len < mtd->writesize);
2275	else
2276		subpage = 0;
2277
2278	chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
2279
2280	if (unlikely(raw))
2281		status = chip->ecc.write_page_raw(mtd, chip, buf,
2282							oob_required);
2283	else if (subpage)
2284		status = chip->ecc.write_subpage(mtd, chip, offset, data_len,
2285							 buf, oob_required);
2286	else
2287		status = chip->ecc.write_page(mtd, chip, buf, oob_required);
2288
2289	if (status < 0)
2290		return status;
2291
2292	/*
2293	 * Cached progamming disabled for now. Not sure if it's worth the
2294	 * trouble. The speed gain is not very impressive. (2.3->2.6Mib/s).
2295	 */
2296	cached = 0;
2297
2298	if (!cached || !NAND_HAS_CACHEPROG(chip)) {
2299
2300		chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
2301		status = chip->waitfunc(mtd, chip);
2302		/*
2303		 * See if operation failed and additional status checks are
2304		 * available.
2305		 */
2306		if ((status & NAND_STATUS_FAIL) && (chip->errstat))
2307			status = chip->errstat(mtd, chip, FL_WRITING, status,
2308					       page);
2309
2310		if (status & NAND_STATUS_FAIL)
2311			return -EIO;
2312	} else {
2313		chip->cmdfunc(mtd, NAND_CMD_CACHEDPROG, -1, -1);
2314		status = chip->waitfunc(mtd, chip);
2315	}
2316
2317	return 0;
2318}
2319
2320/**
2321 * nand_fill_oob - [INTERN] Transfer client buffer to oob
2322 * @mtd: MTD device structure
2323 * @oob: oob data buffer
2324 * @len: oob data write length
2325 * @ops: oob ops structure
2326 */
2327static uint8_t *nand_fill_oob(struct mtd_info *mtd, uint8_t *oob, size_t len,
2328			      struct mtd_oob_ops *ops)
2329{
2330	struct nand_chip *chip = mtd->priv;
2331
2332	/*
2333	 * Initialise to all 0xFF, to avoid the possibility of left over OOB
2334	 * data from a previous OOB read.
2335	 */
2336	memset(chip->oob_poi, 0xff, mtd->oobsize);
2337
2338	switch (ops->mode) {
2339
2340	case MTD_OPS_PLACE_OOB:
2341	case MTD_OPS_RAW:
2342		memcpy(chip->oob_poi + ops->ooboffs, oob, len);
2343		return oob + len;
2344
2345	case MTD_OPS_AUTO_OOB: {
2346		struct nand_oobfree *free = chip->ecc.layout->oobfree;
2347		uint32_t boffs = 0, woffs = ops->ooboffs;
2348		size_t bytes = 0;
2349
2350		for (; free->length && len; free++, len -= bytes) {
2351			/* Write request not from offset 0? */
2352			if (unlikely(woffs)) {
2353				if (woffs >= free->length) {
2354					woffs -= free->length;
2355					continue;
2356				}
2357				boffs = free->offset + woffs;
2358				bytes = min_t(size_t, len,
2359					      (free->length - woffs));
2360				woffs = 0;
2361			} else {
2362				bytes = min_t(size_t, len, free->length);
2363				boffs = free->offset;
2364			}
2365			memcpy(chip->oob_poi + boffs, oob, bytes);
2366			oob += bytes;
2367		}
2368		return oob;
2369	}
2370	default:
2371		BUG();
2372	}
2373	return NULL;
2374}
2375
2376#define NOTALIGNED(x)	((x & (chip->subpagesize - 1)) != 0)
2377
2378/**
2379 * nand_do_write_ops - [INTERN] NAND write with ECC
2380 * @mtd: MTD device structure
2381 * @to: offset to write to
2382 * @ops: oob operations description structure
2383 *
2384 * NAND write with ECC.
2385 */
2386static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
2387			     struct mtd_oob_ops *ops)
2388{
2389	int chipnr, realpage, page, blockmask, column;
2390	struct nand_chip *chip = mtd->priv;
2391	uint32_t writelen = ops->len;
2392
2393	uint32_t oobwritelen = ops->ooblen;
2394	uint32_t oobmaxlen = ops->mode == MTD_OPS_AUTO_OOB ?
2395				mtd->oobavail : mtd->oobsize;
2396
2397	uint8_t *oob = ops->oobbuf;
2398	uint8_t *buf = ops->datbuf;
2399	int ret;
2400	int oob_required = oob ? 1 : 0;
2401
2402	ops->retlen = 0;
2403	if (!writelen)
2404		return 0;
2405
2406	/* Reject writes, which are not page aligned */
2407	if (NOTALIGNED(to) || NOTALIGNED(ops->len)) {
2408		pr_notice("%s: attempt to write non page aligned data\n",
2409			   __func__);
2410		return -EINVAL;
2411	}
2412
2413	column = to & (mtd->writesize - 1);
2414
2415	chipnr = (int)(to >> chip->chip_shift);
2416	chip->select_chip(mtd, chipnr);
2417
2418	/* Check, if it is write protected */
2419	if (nand_check_wp(mtd)) {
2420		ret = -EIO;
2421		goto err_out;
2422	}
2423
2424	realpage = (int)(to >> chip->page_shift);
2425	page = realpage & chip->pagemask;
2426	blockmask = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
2427
2428	/* Invalidate the page cache, when we write to the cached page */
2429	if (to <= ((loff_t)chip->pagebuf << chip->page_shift) &&
2430	    ((loff_t)chip->pagebuf << chip->page_shift) < (to + ops->len))
2431		chip->pagebuf = -1;
2432
2433	/* Don't allow multipage oob writes with offset */
2434	if (oob && ops->ooboffs && (ops->ooboffs + ops->ooblen > oobmaxlen)) {
2435		ret = -EINVAL;
2436		goto err_out;
2437	}
2438
2439	while (1) {
2440		int bytes = mtd->writesize;
2441		int cached = writelen > bytes && page != blockmask;
2442		uint8_t *wbuf = buf;
2443		int use_bufpoi;
2444		int part_pagewr = (column || writelen < (mtd->writesize - 1));
2445
2446		if (part_pagewr)
2447			use_bufpoi = 1;
2448		else if (chip->options & NAND_USE_BOUNCE_BUFFER)
2449			use_bufpoi = !virt_addr_valid(buf);
2450		else
2451			use_bufpoi = 0;
2452
2453		/* Partial page write?, or need to use bounce buffer */
2454		if (use_bufpoi) {
2455			pr_debug("%s: using write bounce buffer for buf@%p\n",
2456					 __func__, buf);
2457			cached = 0;
2458			if (part_pagewr)
2459				bytes = min_t(int, bytes - column, writelen);
2460			chip->pagebuf = -1;
2461			memset(chip->buffers->databuf, 0xff, mtd->writesize);
2462			memcpy(&chip->buffers->databuf[column], buf, bytes);
2463			wbuf = chip->buffers->databuf;
2464		}
2465
2466		if (unlikely(oob)) {
2467			size_t len = min(oobwritelen, oobmaxlen);
2468			oob = nand_fill_oob(mtd, oob, len, ops);
2469			oobwritelen -= len;
2470		} else {
2471			/* We still need to erase leftover OOB data */
2472			memset(chip->oob_poi, 0xff, mtd->oobsize);
2473		}
2474		ret = chip->write_page(mtd, chip, column, bytes, wbuf,
2475					oob_required, page, cached,
2476					(ops->mode == MTD_OPS_RAW));
2477		if (ret)
2478			break;
2479
2480		writelen -= bytes;
2481		if (!writelen)
2482			break;
2483
2484		column = 0;
2485		buf += bytes;
2486		realpage++;
2487
2488		page = realpage & chip->pagemask;
2489		/* Check, if we cross a chip boundary */
2490		if (!page) {
2491			chipnr++;
2492			chip->select_chip(mtd, -1);
2493			chip->select_chip(mtd, chipnr);
2494		}
2495	}
2496
2497	ops->retlen = ops->len - writelen;
2498	if (unlikely(oob))
2499		ops->oobretlen = ops->ooblen;
2500
2501err_out:
2502	chip->select_chip(mtd, -1);
2503	return ret;
2504}
2505
2506/**
2507 * panic_nand_write - [MTD Interface] NAND write with ECC
2508 * @mtd: MTD device structure
2509 * @to: offset to write to
2510 * @len: number of bytes to write
2511 * @retlen: pointer to variable to store the number of written bytes
2512 * @buf: the data to write
2513 *
2514 * NAND write with ECC. Used when performing writes in interrupt context, this
2515 * may for example be called by mtdoops when writing an oops while in panic.
2516 */
2517static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
2518			    size_t *retlen, const uint8_t *buf)
2519{
2520	struct nand_chip *chip = mtd->priv;
2521	struct mtd_oob_ops ops;
2522	int ret;
2523
2524	/* Wait for the device to get ready */
2525	panic_nand_wait(mtd, chip, 400);
2526
2527	/* Grab the device */
2528	panic_nand_get_device(chip, mtd, FL_WRITING);
2529
2530	memset(&ops, 0, sizeof(ops));
2531	ops.len = len;
2532	ops.datbuf = (uint8_t *)buf;
2533	ops.mode = MTD_OPS_PLACE_OOB;
2534
2535	ret = nand_do_write_ops(mtd, to, &ops);
2536
2537	*retlen = ops.retlen;
2538	return ret;
2539}
2540
2541/**
2542 * nand_write - [MTD Interface] NAND write with ECC
2543 * @mtd: MTD device structure
2544 * @to: offset to write to
2545 * @len: number of bytes to write
2546 * @retlen: pointer to variable to store the number of written bytes
2547 * @buf: the data to write
2548 *
2549 * NAND write with ECC.
2550 */
2551static int nand_write(struct mtd_info *mtd, loff_t to, size_t len,
2552			  size_t *retlen, const uint8_t *buf)
2553{
2554	struct mtd_oob_ops ops;
2555	int ret;
2556
2557	nand_get_device(mtd, FL_WRITING);
2558	memset(&ops, 0, sizeof(ops));
2559	ops.len = len;
2560	ops.datbuf = (uint8_t *)buf;
2561	ops.mode = MTD_OPS_PLACE_OOB;
2562	ret = nand_do_write_ops(mtd, to, &ops);
2563	*retlen = ops.retlen;
2564	nand_release_device(mtd);
2565	return ret;
2566}
2567
2568/**
2569 * nand_do_write_oob - [MTD Interface] NAND write out-of-band
2570 * @mtd: MTD device structure
2571 * @to: offset to write to
2572 * @ops: oob operation description structure
2573 *
2574 * NAND write out-of-band.
2575 */
2576static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
2577			     struct mtd_oob_ops *ops)
2578{
2579	int chipnr, page, status, len;
2580	struct nand_chip *chip = mtd->priv;
2581
2582	pr_debug("%s: to = 0x%08x, len = %i\n",
2583			 __func__, (unsigned int)to, (int)ops->ooblen);
2584
2585	if (ops->mode == MTD_OPS_AUTO_OOB)
2586		len = chip->ecc.layout->oobavail;
2587	else
2588		len = mtd->oobsize;
2589
2590	/* Do not allow write past end of page */
2591	if ((ops->ooboffs + ops->ooblen) > len) {
2592		pr_debug("%s: attempt to write past end of page\n",
2593				__func__);
2594		return -EINVAL;
2595	}
2596
2597	if (unlikely(ops->ooboffs >= len)) {
2598		pr_debug("%s: attempt to start write outside oob\n",
2599				__func__);
2600		return -EINVAL;
2601	}
2602
2603	/* Do not allow write past end of device */
2604	if (unlikely(to >= mtd->size ||
2605		     ops->ooboffs + ops->ooblen >
2606			((mtd->size >> chip->page_shift) -
2607			 (to >> chip->page_shift)) * len)) {
2608		pr_debug("%s: attempt to write beyond end of device\n",
2609				__func__);
2610		return -EINVAL;
2611	}
2612
2613	chipnr = (int)(to >> chip->chip_shift);
2614	chip->select_chip(mtd, chipnr);
2615
2616	/* Shift to get page */
2617	page = (int)(to >> chip->page_shift);
2618
2619	/*
2620	 * Reset the chip. Some chips (like the Toshiba TC5832DC found in one
2621	 * of my DiskOnChip 2000 test units) will clear the whole data page too
2622	 * if we don't do this. I have no clue why, but I seem to have 'fixed'
2623	 * it in the doc2000 driver in August 1999.  dwmw2.
2624	 */
2625	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
2626
2627	/* Check, if it is write protected */
2628	if (nand_check_wp(mtd)) {
2629		chip->select_chip(mtd, -1);
2630		return -EROFS;
2631	}
2632
2633	/* Invalidate the page cache, if we write to the cached page */
2634	if (page == chip->pagebuf)
2635		chip->pagebuf = -1;
2636
2637	nand_fill_oob(mtd, ops->oobbuf, ops->ooblen, ops);
2638
2639	if (ops->mode == MTD_OPS_RAW)
2640		status = chip->ecc.write_oob_raw(mtd, chip, page & chip->pagemask);
2641	else
2642		status = chip->ecc.write_oob(mtd, chip, page & chip->pagemask);
2643
2644	chip->select_chip(mtd, -1);
2645
2646	if (status)
2647		return status;
2648
2649	ops->oobretlen = ops->ooblen;
2650
2651	return 0;
2652}
2653
2654/**
2655 * nand_write_oob - [MTD Interface] NAND write data and/or out-of-band
2656 * @mtd: MTD device structure
2657 * @to: offset to write to
2658 * @ops: oob operation description structure
2659 */
2660static int nand_write_oob(struct mtd_info *mtd, loff_t to,
2661			  struct mtd_oob_ops *ops)
2662{
2663	int ret = -ENOTSUPP;
2664
2665	ops->retlen = 0;
2666
2667	/* Do not allow writes past end of device */
2668	if (ops->datbuf && (to + ops->len) > mtd->size) {
2669		pr_debug("%s: attempt to write beyond end of device\n",
2670				__func__);
2671		return -EINVAL;
2672	}
2673
2674	nand_get_device(mtd, FL_WRITING);
2675
2676	switch (ops->mode) {
2677	case MTD_OPS_PLACE_OOB:
2678	case MTD_OPS_AUTO_OOB:
2679	case MTD_OPS_RAW:
2680		break;
2681
2682	default:
2683		goto out;
2684	}
2685
2686	if (!ops->datbuf)
2687		ret = nand_do_write_oob(mtd, to, ops);
2688	else
2689		ret = nand_do_write_ops(mtd, to, ops);
2690
2691out:
2692	nand_release_device(mtd);
2693	return ret;
2694}
2695
2696/**
2697 * single_erase - [GENERIC] NAND standard block erase command function
2698 * @mtd: MTD device structure
2699 * @page: the page address of the block which will be erased
2700 *
2701 * Standard erase command for NAND chips. Returns NAND status.
2702 */
2703static int single_erase(struct mtd_info *mtd, int page)
2704{
2705	struct nand_chip *chip = mtd->priv;
2706	/* Send commands to erase a block */
2707	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
2708	chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
2709
2710	return chip->waitfunc(mtd, chip);
2711}
2712
2713/**
2714 * nand_erase - [MTD Interface] erase block(s)
2715 * @mtd: MTD device structure
2716 * @instr: erase instruction
2717 *
2718 * Erase one ore more blocks.
2719 */
2720static int nand_erase(struct mtd_info *mtd, struct erase_info *instr)
2721{
2722	return nand_erase_nand(mtd, instr, 0);
2723}
2724
2725/**
2726 * nand_erase_nand - [INTERN] erase block(s)
2727 * @mtd: MTD device structure
2728 * @instr: erase instruction
2729 * @allowbbt: allow erasing the bbt area
2730 *
2731 * Erase one ore more blocks.
2732 */
2733int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
2734		    int allowbbt)
2735{
2736	int page, status, pages_per_block, ret, chipnr;
2737	struct nand_chip *chip = mtd->priv;
2738	loff_t len;
2739
2740	pr_debug("%s: start = 0x%012llx, len = %llu\n",
2741			__func__, (unsigned long long)instr->addr,
2742			(unsigned long long)instr->len);
2743
2744	if (check_offs_len(mtd, instr->addr, instr->len))
2745		return -EINVAL;
2746
2747	/* Grab the lock and see if the device is available */
2748	nand_get_device(mtd, FL_ERASING);
2749
2750	/* Shift to get first page */
2751	page = (int)(instr->addr >> chip->page_shift);
2752	chipnr = (int)(instr->addr >> chip->chip_shift);
2753
2754	/* Calculate pages in each block */
2755	pages_per_block = 1 << (chip->phys_erase_shift - chip->page_shift);
2756
2757	/* Select the NAND device */
2758	chip->select_chip(mtd, chipnr);
2759
2760	/* Check, if it is write protected */
2761	if (nand_check_wp(mtd)) {
2762		pr_debug("%s: device is write protected!\n",
2763				__func__);
2764		instr->state = MTD_ERASE_FAILED;
2765		goto erase_exit;
2766	}
2767
2768	/* Loop through the pages */
2769	len = instr->len;
2770
2771	instr->state = MTD_ERASING;
2772
2773	while (len) {
2774		/* Check if we have a bad block, we do not erase bad blocks! */
2775		if (nand_block_checkbad(mtd, ((loff_t) page) <<
2776					chip->page_shift, 0, allowbbt)) {
2777			pr_warn("%s: attempt to erase a bad block at page 0x%08x\n",
2778				    __func__, page);
2779			instr->state = MTD_ERASE_FAILED;
2780			goto erase_exit;
2781		}
2782
2783		/*
2784		 * Invalidate the page cache, if we erase the block which
2785		 * contains the current cached page.
2786		 */
2787		if (page <= chip->pagebuf && chip->pagebuf <
2788		    (page + pages_per_block))
2789			chip->pagebuf = -1;
2790
2791		status = chip->erase(mtd, page & chip->pagemask);
2792
2793		/*
2794		 * See if operation failed and additional status checks are
2795		 * available
2796		 */
2797		if ((status & NAND_STATUS_FAIL) && (chip->errstat))
2798			status = chip->errstat(mtd, chip, FL_ERASING,
2799					       status, page);
2800
2801		/* See if block erase succeeded */
2802		if (status & NAND_STATUS_FAIL) {
2803			pr_debug("%s: failed erase, page 0x%08x\n",
2804					__func__, page);
2805			instr->state = MTD_ERASE_FAILED;
2806			instr->fail_addr =
2807				((loff_t)page << chip->page_shift);
2808			goto erase_exit;
2809		}
2810
2811		/* Increment page address and decrement length */
2812		len -= (1ULL << chip->phys_erase_shift);
2813		page += pages_per_block;
2814
2815		/* Check, if we cross a chip boundary */
2816		if (len && !(page & chip->pagemask)) {
2817			chipnr++;
2818			chip->select_chip(mtd, -1);
2819			chip->select_chip(mtd, chipnr);
2820		}
2821	}
2822	instr->state = MTD_ERASE_DONE;
2823
2824erase_exit:
2825
2826	ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
2827
2828	/* Deselect and wake up anyone waiting on the device */
2829	chip->select_chip(mtd, -1);
2830	nand_release_device(mtd);
2831
2832	/* Do call back function */
2833	if (!ret)
2834		mtd_erase_callback(instr);
2835
2836	/* Return more or less happy */
2837	return ret;
2838}
2839
2840/**
2841 * nand_sync - [MTD Interface] sync
2842 * @mtd: MTD device structure
2843 *
2844 * Sync is actually a wait for chip ready function.
2845 */
2846static void nand_sync(struct mtd_info *mtd)
2847{
2848	pr_debug("%s: called\n", __func__);
2849
2850	/* Grab the lock and see if the device is available */
2851	nand_get_device(mtd, FL_SYNCING);
2852	/* Release it and go back */
2853	nand_release_device(mtd);
2854}
2855
2856/**
2857 * nand_block_isbad - [MTD Interface] Check if block at offset is bad
2858 * @mtd: MTD device structure
2859 * @offs: offset relative to mtd start
2860 */
2861static int nand_block_isbad(struct mtd_info *mtd, loff_t offs)
2862{
2863	return nand_block_checkbad(mtd, offs, 1, 0);
2864}
2865
2866/**
2867 * nand_block_markbad - [MTD Interface] Mark block at the given offset as bad
2868 * @mtd: MTD device structure
2869 * @ofs: offset relative to mtd start
2870 */
2871static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
2872{
2873	int ret;
2874
2875	ret = nand_block_isbad(mtd, ofs);
2876	if (ret) {
2877		/* If it was bad already, return success and do nothing */
2878		if (ret > 0)
2879			return 0;
2880		return ret;
2881	}
2882
2883	return nand_block_markbad_lowlevel(mtd, ofs);
2884}
2885
2886/**
2887 * nand_onfi_set_features- [REPLACEABLE] set features for ONFI nand
2888 * @mtd: MTD device structure
2889 * @chip: nand chip info structure
2890 * @addr: feature address.
2891 * @subfeature_param: the subfeature parameters, a four bytes array.
2892 */
2893static int nand_onfi_set_features(struct mtd_info *mtd, struct nand_chip *chip,
2894			int addr, uint8_t *subfeature_param)
2895{
2896	int status;
2897	int i;
2898
2899	if (!chip->onfi_version ||
2900	    !(le16_to_cpu(chip->onfi_params.opt_cmd)
2901	      & ONFI_OPT_CMD_SET_GET_FEATURES))
2902		return -EINVAL;
2903
2904	chip->cmdfunc(mtd, NAND_CMD_SET_FEATURES, addr, -1);
2905	for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
2906		chip->write_byte(mtd, subfeature_param[i]);
2907
2908	status = chip->waitfunc(mtd, chip);
2909	if (status & NAND_STATUS_FAIL)
2910		return -EIO;
2911	return 0;
2912}
2913
2914/**
2915 * nand_onfi_get_features- [REPLACEABLE] get features for ONFI nand
2916 * @mtd: MTD device structure
2917 * @chip: nand chip info structure
2918 * @addr: feature address.
2919 * @subfeature_param: the subfeature parameters, a four bytes array.
2920 */
2921static int nand_onfi_get_features(struct mtd_info *mtd, struct nand_chip *chip,
2922			int addr, uint8_t *subfeature_param)
2923{
2924	int i;
2925
2926	if (!chip->onfi_version ||
2927	    !(le16_to_cpu(chip->onfi_params.opt_cmd)
2928	      & ONFI_OPT_CMD_SET_GET_FEATURES))
2929		return -EINVAL;
2930
2931	/* clear the sub feature parameters */
2932	memset(subfeature_param, 0, ONFI_SUBFEATURE_PARAM_LEN);
2933
2934	chip->cmdfunc(mtd, NAND_CMD_GET_FEATURES, addr, -1);
2935	for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
2936		*subfeature_param++ = chip->read_byte(mtd);
2937	return 0;
2938}
2939
2940/**
2941 * nand_suspend - [MTD Interface] Suspend the NAND flash
2942 * @mtd: MTD device structure
2943 */
2944static int nand_suspend(struct mtd_info *mtd)
2945{
2946	return nand_get_device(mtd, FL_PM_SUSPENDED);
2947}
2948
2949/**
2950 * nand_resume - [MTD Interface] Resume the NAND flash
2951 * @mtd: MTD device structure
2952 */
2953static void nand_resume(struct mtd_info *mtd)
2954{
2955	struct nand_chip *chip = mtd->priv;
2956
2957	if (chip->state == FL_PM_SUSPENDED)
2958		nand_release_device(mtd);
2959	else
2960		pr_err("%s called for a chip which is not in suspended state\n",
2961			__func__);
2962}
2963
2964/**
2965 * nand_shutdown - [MTD Interface] Finish the current NAND operation and
2966 *                 prevent further operations
2967 * @mtd: MTD device structure
2968 */
2969static void nand_shutdown(struct mtd_info *mtd)
2970{
2971	nand_get_device(mtd, FL_SHUTDOWN);
2972}
2973
2974/* Set default functions */
2975static void nand_set_defaults(struct nand_chip *chip, int busw)
2976{
2977	/* check for proper chip_delay setup, set 20us if not */
2978	if (!chip->chip_delay)
2979		chip->chip_delay = 20;
2980
2981	/* check, if a user supplied command function given */
2982	if (chip->cmdfunc == NULL)
2983		chip->cmdfunc = nand_command;
2984
2985	/* check, if a user supplied wait function given */
2986	if (chip->waitfunc == NULL)
2987		chip->waitfunc = nand_wait;
2988
2989	if (!chip->select_chip)
2990		chip->select_chip = nand_select_chip;
2991
2992	/* set for ONFI nand */
2993	if (!chip->onfi_set_features)
2994		chip->onfi_set_features = nand_onfi_set_features;
2995	if (!chip->onfi_get_features)
2996		chip->onfi_get_features = nand_onfi_get_features;
2997
2998	/* If called twice, pointers that depend on busw may need to be reset */
2999	if (!chip->read_byte || chip->read_byte == nand_read_byte)
3000		chip->read_byte = busw ? nand_read_byte16 : nand_read_byte;
3001	if (!chip->read_word)
3002		chip->read_word = nand_read_word;
3003	if (!chip->block_bad)
3004		chip->block_bad = nand_block_bad;
3005	if (!chip->block_markbad)
3006		chip->block_markbad = nand_default_block_markbad;
3007	if (!chip->write_buf || chip->write_buf == nand_write_buf)
3008		chip->write_buf = busw ? nand_write_buf16 : nand_write_buf;
3009	if (!chip->write_byte || chip->write_byte == nand_write_byte)
3010		chip->write_byte = busw ? nand_write_byte16 : nand_write_byte;
3011	if (!chip->read_buf || chip->read_buf == nand_read_buf)
3012		chip->read_buf = busw ? nand_read_buf16 : nand_read_buf;
3013	if (!chip->scan_bbt)
3014		chip->scan_bbt = nand_default_bbt;
3015
3016	if (!chip->controller) {
3017		chip->controller = &chip->hwcontrol;
3018		spin_lock_init(&chip->controller->lock);
3019		init_waitqueue_head(&chip->controller->wq);
3020	}
3021
3022}
3023
3024/* Sanitize ONFI strings so we can safely print them */
3025static void sanitize_string(uint8_t *s, size_t len)
3026{
3027	ssize_t i;
3028
3029	/* Null terminate */
3030	s[len - 1] = 0;
3031
3032	/* Remove non printable chars */
3033	for (i = 0; i < len - 1; i++) {
3034		if (s[i] < ' ' || s[i] > 127)
3035			s[i] = '?';
3036	}
3037
3038	/* Remove trailing spaces */
3039	strim(s);
3040}
3041
3042static u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
3043{
3044	int i;
3045	while (len--) {
3046		crc ^= *p++ << 8;
3047		for (i = 0; i < 8; i++)
3048			crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
3049	}
3050
3051	return crc;
3052}
3053
3054/* Parse the Extended Parameter Page. */
3055static int nand_flash_detect_ext_param_page(struct mtd_info *mtd,
3056		struct nand_chip *chip, struct nand_onfi_params *p)
3057{
3058	struct onfi_ext_param_page *ep;
3059	struct onfi_ext_section *s;
3060	struct onfi_ext_ecc_info *ecc;
3061	uint8_t *cursor;
3062	int ret = -EINVAL;
3063	int len;
3064	int i;
3065
3066	len = le16_to_cpu(p->ext_param_page_length) * 16;
3067	ep = kmalloc(len, GFP_KERNEL);
3068	if (!ep)
3069		return -ENOMEM;
3070
3071	/* Send our own NAND_CMD_PARAM. */
3072	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
3073
3074	/* Use the Change Read Column command to skip the ONFI param pages. */
3075	chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
3076			sizeof(*p) * p->num_of_param_pages , -1);
3077
3078	/* Read out the Extended Parameter Page. */
3079	chip->read_buf(mtd, (uint8_t *)ep, len);
3080	if ((onfi_crc16(ONFI_CRC_BASE, ((uint8_t *)ep) + 2, len - 2)
3081		!= le16_to_cpu(ep->crc))) {
3082		pr_debug("fail in the CRC.\n");
3083		goto ext_out;
3084	}
3085
3086	/*
3087	 * Check the signature.
3088	 * Do not strictly follow the ONFI spec, maybe changed in future.
3089	 */
3090	if (strncmp(ep->sig, "EPPS", 4)) {
3091		pr_debug("The signature is invalid.\n");
3092		goto ext_out;
3093	}
3094
3095	/* find the ECC section. */
3096	cursor = (uint8_t *)(ep + 1);
3097	for (i = 0; i < ONFI_EXT_SECTION_MAX; i++) {
3098		s = ep->sections + i;
3099		if (s->type == ONFI_SECTION_TYPE_2)
3100			break;
3101		cursor += s->length * 16;
3102	}
3103	if (i == ONFI_EXT_SECTION_MAX) {
3104		pr_debug("We can not find the ECC section.\n");
3105		goto ext_out;
3106	}
3107
3108	/* get the info we want. */
3109	ecc = (struct onfi_ext_ecc_info *)cursor;
3110
3111	if (!ecc->codeword_size) {
3112		pr_debug("Invalid codeword size\n");
3113		goto ext_out;
3114	}
3115
3116	chip->ecc_strength_ds = ecc->ecc_bits;
3117	chip->ecc_step_ds = 1 << ecc->codeword_size;
3118	ret = 0;
3119
3120ext_out:
3121	kfree(ep);
3122	return ret;
3123}
3124
3125static int nand_setup_read_retry_micron(struct mtd_info *mtd, int retry_mode)
3126{
3127	struct nand_chip *chip = mtd->priv;
3128	uint8_t feature[ONFI_SUBFEATURE_PARAM_LEN] = {retry_mode};
3129
3130	return chip->onfi_set_features(mtd, chip, ONFI_FEATURE_ADDR_READ_RETRY,
3131			feature);
3132}
3133
3134/*
3135 * Configure chip properties from Micron vendor-specific ONFI table
3136 */
3137static void nand_onfi_detect_micron(struct nand_chip *chip,
3138		struct nand_onfi_params *p)
3139{
3140	struct nand_onfi_vendor_micron *micron = (void *)p->vendor;
3141
3142	if (le16_to_cpu(p->vendor_revision) < 1)
3143		return;
3144
3145	chip->read_retries = micron->read_retry_options;
3146	chip->setup_read_retry = nand_setup_read_retry_micron;
3147}
3148
3149/*
3150 * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
3151 */
3152static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
3153					int *busw)
3154{
3155	struct nand_onfi_params *p = &chip->onfi_params;
3156	int i, j;
3157	int val;
3158
3159	/* Try ONFI for unknown chip or LP */
3160	chip->cmdfunc(mtd, NAND_CMD_READID, 0x20, -1);
3161	if (chip->read_byte(mtd) != 'O' || chip->read_byte(mtd) != 'N' ||
3162		chip->read_byte(mtd) != 'F' || chip->read_byte(mtd) != 'I')
3163		return 0;
3164
3165	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
3166	for (i = 0; i < 3; i++) {
3167		for (j = 0; j < sizeof(*p); j++)
3168			((uint8_t *)p)[j] = chip->read_byte(mtd);
3169		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
3170				le16_to_cpu(p->crc)) {
3171			break;
3172		}
3173	}
3174
3175	if (i == 3) {
3176		pr_err("Could not find valid ONFI parameter page; aborting\n");
3177		return 0;
3178	}
3179
3180	/* Check version */
3181	val = le16_to_cpu(p->revision);
3182	if (val & (1 << 5))
3183		chip->onfi_version = 23;
3184	else if (val & (1 << 4))
3185		chip->onfi_version = 22;
3186	else if (val & (1 << 3))
3187		chip->onfi_version = 21;
3188	else if (val & (1 << 2))
3189		chip->onfi_version = 20;
3190	else if (val & (1 << 1))
3191		chip->onfi_version = 10;
3192
3193	if (!chip->onfi_version) {
3194		pr_info("unsupported ONFI version: %d\n", val);
3195		return 0;
3196	}
3197
3198	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
3199	sanitize_string(p->model, sizeof(p->model));
3200	if (!mtd->name)
3201		mtd->name = p->model;
3202
3203	mtd->writesize = le32_to_cpu(p->byte_per_page);
3204
3205	/*
3206	 * pages_per_block and blocks_per_lun may not be a power-of-2 size
3207	 * (don't ask me who thought of this...). MTD assumes that these
3208	 * dimensions will be power-of-2, so just truncate the remaining area.
3209	 */
3210	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
3211	mtd->erasesize *= mtd->writesize;
3212
3213	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
3214
3215	/* See erasesize comment */
3216	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
3217	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
3218	chip->bits_per_cell = p->bits_per_cell;
3219
3220	if (onfi_feature(chip) & ONFI_FEATURE_16_BIT_BUS)
3221		*busw = NAND_BUSWIDTH_16;
3222	else
3223		*busw = 0;
3224
3225	if (p->ecc_bits != 0xff) {
3226		chip->ecc_strength_ds = p->ecc_bits;
3227		chip->ecc_step_ds = 512;
3228	} else if (chip->onfi_version >= 21 &&
3229		(onfi_feature(chip) & ONFI_FEATURE_EXT_PARAM_PAGE)) {
3230
3231		/*
3232		 * The nand_flash_detect_ext_param_page() uses the
3233		 * Change Read Column command which maybe not supported
3234		 * by the chip->cmdfunc. So try to update the chip->cmdfunc
3235		 * now. We do not replace user supplied command function.
3236		 */
3237		if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
3238			chip->cmdfunc = nand_command_lp;
3239
3240		/* The Extended Parameter Page is supported since ONFI 2.1. */
3241		if (nand_flash_detect_ext_param_page(mtd, chip, p))
3242			pr_warn("Failed to detect ONFI extended param page\n");
3243	} else {
3244		pr_warn("Could not retrieve ONFI ECC requirements\n");
3245	}
3246
3247	if (p->jedec_id == NAND_MFR_MICRON)
3248		nand_onfi_detect_micron(chip, p);
3249
3250	return 1;
3251}
3252
3253/*
3254 * Check if the NAND chip is JEDEC compliant, returns 1 if it is, 0 otherwise.
3255 */
3256static int nand_flash_detect_jedec(struct mtd_info *mtd, struct nand_chip *chip,
3257					int *busw)
3258{
3259	struct nand_jedec_params *p = &chip->jedec_params;
3260	struct jedec_ecc_info *ecc;
3261	int val;
3262	int i, j;
3263
3264	/* Try JEDEC for unknown chip or LP */
3265	chip->cmdfunc(mtd, NAND_CMD_READID, 0x40, -1);
3266	if (chip->read_byte(mtd) != 'J' || chip->read_byte(mtd) != 'E' ||
3267		chip->read_byte(mtd) != 'D' || chip->read_byte(mtd) != 'E' ||
3268		chip->read_byte(mtd) != 'C')
3269		return 0;
3270
3271	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0x40, -1);
3272	for (i = 0; i < 3; i++) {
3273		for (j = 0; j < sizeof(*p); j++)
3274			((uint8_t *)p)[j] = chip->read_byte(mtd);
3275
3276		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 510) ==
3277				le16_to_cpu(p->crc))
3278			break;
3279	}
3280
3281	if (i == 3) {
3282		pr_err("Could not find valid JEDEC parameter page; aborting\n");
3283		return 0;
3284	}
3285
3286	/* Check version */
3287	val = le16_to_cpu(p->revision);
3288	if (val & (1 << 2))
3289		chip->jedec_version = 10;
3290	else if (val & (1 << 1))
3291		chip->jedec_version = 1; /* vendor specific version */
3292
3293	if (!chip->jedec_version) {
3294		pr_info("unsupported JEDEC version: %d\n", val);
3295		return 0;
3296	}
3297
3298	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
3299	sanitize_string(p->model, sizeof(p->model));
3300	if (!mtd->name)
3301		mtd->name = p->model;
3302
3303	mtd->writesize = le32_to_cpu(p->byte_per_page);
3304
3305	/* Please reference to the comment for nand_flash_detect_onfi. */
3306	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
3307	mtd->erasesize *= mtd->writesize;
3308
3309	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
3310
3311	/* Please reference to the comment for nand_flash_detect_onfi. */
3312	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
3313	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
3314	chip->bits_per_cell = p->bits_per_cell;
3315
3316	if (jedec_feature(chip) & JEDEC_FEATURE_16_BIT_BUS)
3317		*busw = NAND_BUSWIDTH_16;
3318	else
3319		*busw = 0;
3320
3321	/* ECC info */
3322	ecc = &p->ecc_info[0];
3323
3324	if (ecc->codeword_size >= 9) {
3325		chip->ecc_strength_ds = ecc->ecc_bits;
3326		chip->ecc_step_ds = 1 << ecc->codeword_size;
3327	} else {
3328		pr_warn("Invalid codeword size\n");
3329	}
3330
3331	return 1;
3332}
3333
3334/*
3335 * nand_id_has_period - Check if an ID string has a given wraparound period
3336 * @id_data: the ID string
3337 * @arrlen: the length of the @id_data array
3338 * @period: the period of repitition
3339 *
3340 * Check if an ID string is repeated within a given sequence of bytes at
3341 * specific repetition interval period (e.g., {0x20,0x01,0x7F,0x20} has a
3342 * period of 3). This is a helper function for nand_id_len(). Returns non-zero
3343 * if the repetition has a period of @period; otherwise, returns zero.
3344 */
3345static int nand_id_has_period(u8 *id_data, int arrlen, int period)
3346{
3347	int i, j;
3348	for (i = 0; i < period; i++)
3349		for (j = i + period; j < arrlen; j += period)
3350			if (id_data[i] != id_data[j])
3351				return 0;
3352	return 1;
3353}
3354
3355/*
3356 * nand_id_len - Get the length of an ID string returned by CMD_READID
3357 * @id_data: the ID string
3358 * @arrlen: the length of the @id_data array
3359
3360 * Returns the length of the ID string, according to known wraparound/trailing
3361 * zero patterns. If no pattern exists, returns the length of the array.
3362 */
3363static int nand_id_len(u8 *id_data, int arrlen)
3364{
3365	int last_nonzero, period;
3366
3367	/* Find last non-zero byte */
3368	for (last_nonzero = arrlen - 1; last_nonzero >= 0; last_nonzero--)
3369		if (id_data[last_nonzero])
3370			break;
3371
3372	/* All zeros */
3373	if (last_nonzero < 0)
3374		return 0;
3375
3376	/* Calculate wraparound period */
3377	for (period = 1; period < arrlen; period++)
3378		if (nand_id_has_period(id_data, arrlen, period))
3379			break;
3380
3381	/* There's a repeated pattern */
3382	if (period < arrlen)
3383		return period;
3384
3385	/* There are trailing zeros */
3386	if (last_nonzero < arrlen - 1)
3387		return last_nonzero + 1;
3388
3389	/* No pattern detected */
3390	return arrlen;
3391}
3392
3393/* Extract the bits of per cell from the 3rd byte of the extended ID */
3394static int nand_get_bits_per_cell(u8 cellinfo)
3395{
3396	int bits;
3397
3398	bits = cellinfo & NAND_CI_CELLTYPE_MSK;
3399	bits >>= NAND_CI_CELLTYPE_SHIFT;
3400	return bits + 1;
3401}
3402
3403/*
3404 * Many new NAND share similar device ID codes, which represent the size of the
3405 * chip. The rest of the parameters must be decoded according to generic or
3406 * manufacturer-specific "extended ID" decoding patterns.
3407 */
3408static void nand_decode_ext_id(struct mtd_info *mtd, struct nand_chip *chip,
3409				u8 id_data[8], int *busw)
3410{
3411	int extid, id_len;
3412	/* The 3rd id byte holds MLC / multichip data */
3413	chip->bits_per_cell = nand_get_bits_per_cell(id_data[2]);
3414	/* The 4th id byte is the important one */
3415	extid = id_data[3];
3416
3417	id_len = nand_id_len(id_data, 8);
3418
3419	/*
3420	 * Field definitions are in the following datasheets:
3421	 * Old style (4,5 byte ID): Samsung K9GAG08U0M (p.32)
3422	 * New Samsung (6 byte ID): Samsung K9GAG08U0F (p.44)
3423	 * Hynix MLC   (6 byte ID): Hynix H27UBG8T2B (p.22)
3424	 *
3425	 * Check for ID length, non-zero 6th byte, cell type, and Hynix/Samsung
3426	 * ID to decide what to do.
3427	 */
3428	if (id_len == 6 && id_data[0] == NAND_MFR_SAMSUNG &&
3429			!nand_is_slc(chip) && id_data[5] != 0x00) {
3430		/* Calc pagesize */
3431		mtd->writesize = 2048 << (extid & 0x03);
3432		extid >>= 2;
3433		/* Calc oobsize */
3434		switch (((extid >> 2) & 0x04) | (extid & 0x03)) {
3435		case 1:
3436			mtd->oobsize = 128;
3437			break;
3438		case 2:
3439			mtd->oobsize = 218;
3440			break;
3441		case 3:
3442			mtd->oobsize = 400;
3443			break;
3444		case 4:
3445			mtd->oobsize = 436;
3446			break;
3447		case 5:
3448			mtd->oobsize = 512;
3449			break;
3450		case 6:
3451			mtd->oobsize = 640;
3452			break;
3453		case 7:
3454		default: /* Other cases are "reserved" (unknown) */
3455			mtd->oobsize = 1024;
3456			break;
3457		}
3458		extid >>= 2;
3459		/* Calc blocksize */
3460		mtd->erasesize = (128 * 1024) <<
3461			(((extid >> 1) & 0x04) | (extid & 0x03));
3462		*busw = 0;
3463	} else if (id_len == 6 && id_data[0] == NAND_MFR_HYNIX &&
3464			!nand_is_slc(chip)) {
3465		unsigned int tmp;
3466
3467		/* Calc pagesize */
3468		mtd->writesize = 2048 << (extid & 0x03);
3469		extid >>= 2;
3470		/* Calc oobsize */
3471		switch (((extid >> 2) & 0x04) | (extid & 0x03)) {
3472		case 0:
3473			mtd->oobsize = 128;
3474			break;
3475		case 1:
3476			mtd->oobsize = 224;
3477			break;
3478		case 2:
3479			mtd->oobsize = 448;
3480			break;
3481		case 3:
3482			mtd->oobsize = 64;
3483			break;
3484		case 4:
3485			mtd->oobsize = 32;
3486			break;
3487		case 5:
3488			mtd->oobsize = 16;
3489			break;
3490		default:
3491			mtd->oobsize = 640;
3492			break;
3493		}
3494		extid >>= 2;
3495		/* Calc blocksize */
3496		tmp = ((extid >> 1) & 0x04) | (extid & 0x03);
3497		if (tmp < 0x03)
3498			mtd->erasesize = (128 * 1024) << tmp;
3499		else if (tmp == 0x03)
3500			mtd->erasesize = 768 * 1024;
3501		else
3502			mtd->erasesize = (64 * 1024) << tmp;
3503		*busw = 0;
3504	} else {
3505		/* Calc pagesize */
3506		mtd->writesize = 1024 << (extid & 0x03);
3507		extid >>= 2;
3508		/* Calc oobsize */
3509		mtd->oobsize = (8 << (extid & 0x01)) *
3510			(mtd->writesize >> 9);
3511		extid >>= 2;
3512		/* Calc blocksize. Blocksize is multiples of 64KiB */
3513		mtd->erasesize = (64 * 1024) << (extid & 0x03);
3514		extid >>= 2;
3515		/* Get buswidth information */
3516		*busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0;
3517
3518		/*
3519		 * Toshiba 24nm raw SLC (i.e., not BENAND) have 32B OOB per
3520		 * 512B page. For Toshiba SLC, we decode the 5th/6th byte as
3521		 * follows:
3522		 * - ID byte 6, bits[2:0]: 100b -> 43nm, 101b -> 32nm,
3523		 *                         110b -> 24nm
3524		 * - ID byte 5, bit[7]:    1 -> BENAND, 0 -> raw SLC
3525		 */
3526		if (id_len >= 6 && id_data[0] == NAND_MFR_TOSHIBA &&
3527				nand_is_slc(chip) &&
3528				(id_data[5] & 0x7) == 0x6 /* 24nm */ &&
3529				!(id_data[4] & 0x80) /* !BENAND */) {
3530			mtd->oobsize = 32 * mtd->writesize >> 9;
3531		}
3532
3533	}
3534}
3535
3536/*
3537 * Old devices have chip data hardcoded in the device ID table. nand_decode_id
3538 * decodes a matching ID table entry and assigns the MTD size parameters for
3539 * the chip.
3540 */
3541static void nand_decode_id(struct mtd_info *mtd, struct nand_chip *chip,
3542				struct nand_flash_dev *type, u8 id_data[8],
3543				int *busw)
3544{
3545	int maf_id = id_data[0];
3546
3547	mtd->erasesize = type->erasesize;
3548	mtd->writesize = type->pagesize;
3549	mtd->oobsize = mtd->writesize / 32;
3550	*busw = type->options & NAND_BUSWIDTH_16;
3551
3552	/* All legacy ID NAND are small-page, SLC */
3553	chip->bits_per_cell = 1;
3554
3555	/*
3556	 * Check for Spansion/AMD ID + repeating 5th, 6th byte since
3557	 * some Spansion chips have erasesize that conflicts with size
3558	 * listed in nand_ids table.
3559	 * Data sheet (5 byte ID): Spansion S30ML-P ORNAND (p.39)
3560	 */
3561	if (maf_id == NAND_MFR_AMD && id_data[4] != 0x00 && id_data[5] == 0x00
3562			&& id_data[6] == 0x00 && id_data[7] == 0x00
3563			&& mtd->writesize == 512) {
3564		mtd->erasesize = 128 * 1024;
3565		mtd->erasesize <<= ((id_data[3] & 0x03) << 1);
3566	}
3567}
3568
3569/*
3570 * Set the bad block marker/indicator (BBM/BBI) patterns according to some
3571 * heuristic patterns using various detected parameters (e.g., manufacturer,
3572 * page size, cell-type information).
3573 */
3574static void nand_decode_bbm_options(struct mtd_info *mtd,
3575				    struct nand_chip *chip, u8 id_data[8])
3576{
3577	int maf_id = id_data[0];
3578
3579	/* Set the bad block position */
3580	if (mtd->writesize > 512 || (chip->options & NAND_BUSWIDTH_16))
3581		chip->badblockpos = NAND_LARGE_BADBLOCK_POS;
3582	else
3583		chip->badblockpos = NAND_SMALL_BADBLOCK_POS;
3584
3585	/*
3586	 * Bad block marker is stored in the last page of each block on Samsung
3587	 * and Hynix MLC devices; stored in first two pages of each block on
3588	 * Micron devices with 2KiB pages and on SLC Samsung, Hynix, Toshiba,
3589	 * AMD/Spansion, and Macronix.  All others scan only the first page.
3590	 */
3591	if (!nand_is_slc(chip) &&
3592			(maf_id == NAND_MFR_SAMSUNG ||
3593			 maf_id == NAND_MFR_HYNIX))
3594		chip->bbt_options |= NAND_BBT_SCANLASTPAGE;
3595	else if ((nand_is_slc(chip) &&
3596				(maf_id == NAND_MFR_SAMSUNG ||
3597				 maf_id == NAND_MFR_HYNIX ||
3598				 maf_id == NAND_MFR_TOSHIBA ||
3599				 maf_id == NAND_MFR_AMD ||
3600				 maf_id == NAND_MFR_MACRONIX)) ||
3601			(mtd->writesize == 2048 &&
3602			 maf_id == NAND_MFR_MICRON))
3603		chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
3604}
3605
3606static inline bool is_full_id_nand(struct nand_flash_dev *type)
3607{
3608	return type->id_len;
3609}
3610
3611static bool find_full_id_nand(struct mtd_info *mtd, struct nand_chip *chip,
3612		   struct nand_flash_dev *type, u8 *id_data, int *busw)
3613{
3614	if (!strncmp(type->id, id_data, type->id_len)) {
3615		mtd->writesize = type->pagesize;
3616		mtd->erasesize = type->erasesize;
3617		mtd->oobsize = type->oobsize;
3618
3619		chip->bits_per_cell = nand_get_bits_per_cell(id_data[2]);
3620		chip->chipsize = (uint64_t)type->chipsize << 20;
3621		chip->options |= type->options;
3622		chip->ecc_strength_ds = NAND_ECC_STRENGTH(type);
3623		chip->ecc_step_ds = NAND_ECC_STEP(type);
3624		chip->onfi_timing_mode_default =
3625					type->onfi_timing_mode_default;
3626
3627		*busw = type->options & NAND_BUSWIDTH_16;
3628
3629		if (!mtd->name)
3630			mtd->name = type->name;
3631
3632		return true;
3633	}
3634	return false;
3635}
3636
3637/*
3638 * Get the flash and manufacturer id and lookup if the type is supported.
3639 */
3640static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
3641						  struct nand_chip *chip,
3642						  int *maf_id, int *dev_id,
3643						  struct nand_flash_dev *type)
3644{
3645	int busw;
3646	int i, maf_idx;
3647	u8 id_data[8];
3648
3649	/* Select the device */
3650	chip->select_chip(mtd, 0);
3651
3652	/*
3653	 * Reset the chip, required by some chips (e.g. Micron MT29FxGxxxxx)
3654	 * after power-up.
3655	 */
3656	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
3657
3658	/* Send the command for reading device ID */
3659	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
3660
3661	/* Read manufacturer and device IDs */
3662	*maf_id = chip->read_byte(mtd);
3663	*dev_id = chip->read_byte(mtd);
3664
3665	/*
3666	 * Try again to make sure, as some systems the bus-hold or other
3667	 * interface concerns can cause random data which looks like a
3668	 * possibly credible NAND flash to appear. If the two results do
3669	 * not match, ignore the device completely.
3670	 */
3671
3672	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
3673
3674	/* Read entire ID string */
3675	for (i = 0; i < 8; i++)
3676		id_data[i] = chip->read_byte(mtd);
3677
3678	if (id_data[0] != *maf_id || id_data[1] != *dev_id) {
3679		pr_info("second ID read did not match %02x,%02x against %02x,%02x\n",
3680			*maf_id, *dev_id, id_data[0], id_data[1]);
3681		return ERR_PTR(-ENODEV);
3682	}
3683
3684	if (!type)
3685		type = nand_flash_ids;
3686
3687	for (; type->name != NULL; type++) {
3688		if (is_full_id_nand(type)) {
3689			if (find_full_id_nand(mtd, chip, type, id_data, &busw))
3690				goto ident_done;
3691		} else if (*dev_id == type->dev_id) {
3692				break;
3693		}
3694	}
3695
3696	chip->onfi_version = 0;
3697	if (!type->name || !type->pagesize) {
3698		/* Check if the chip is ONFI compliant */
3699		if (nand_flash_detect_onfi(mtd, chip, &busw))
3700			goto ident_done;
3701
3702		/* Check if the chip is JEDEC compliant */
3703		if (nand_flash_detect_jedec(mtd, chip, &busw))
3704			goto ident_done;
3705	}
3706
3707	if (!type->name)
3708		return ERR_PTR(-ENODEV);
3709
3710	if (!mtd->name)
3711		mtd->name = type->name;
3712
3713	chip->chipsize = (uint64_t)type->chipsize << 20;
3714
3715	if (!type->pagesize && chip->init_size) {
3716		/* Set the pagesize, oobsize, erasesize by the driver */
3717		busw = chip->init_size(mtd, chip, id_data);
3718	} else if (!type->pagesize) {
3719		/* Decode parameters from extended ID */
3720		nand_decode_ext_id(mtd, chip, id_data, &busw);
3721	} else {
3722		nand_decode_id(mtd, chip, type, id_data, &busw);
3723	}
3724	/* Get chip options */
3725	chip->options |= type->options;
3726
3727	/*
3728	 * Check if chip is not a Samsung device. Do not clear the
3729	 * options for chips which do not have an extended id.
3730	 */
3731	if (*maf_id != NAND_MFR_SAMSUNG && !type->pagesize)
3732		chip->options &= ~NAND_SAMSUNG_LP_OPTIONS;
3733ident_done:
3734
3735	/* Try to identify manufacturer */
3736	for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_idx++) {
3737		if (nand_manuf_ids[maf_idx].id == *maf_id)
3738			break;
3739	}
3740
3741	if (chip->options & NAND_BUSWIDTH_AUTO) {
3742		WARN_ON(chip->options & NAND_BUSWIDTH_16);
3743		chip->options |= busw;
3744		nand_set_defaults(chip, busw);
3745	} else if (busw != (chip->options & NAND_BUSWIDTH_16)) {
3746		/*
3747		 * Check, if buswidth is correct. Hardware drivers should set
3748		 * chip correct!
3749		 */
3750		pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
3751			*maf_id, *dev_id);
3752		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name, mtd->name);
3753		pr_warn("bus width %d instead %d bit\n",
3754			   (chip->options & NAND_BUSWIDTH_16) ? 16 : 8,
3755			   busw ? 16 : 8);
3756		return ERR_PTR(-EINVAL);
3757	}
3758
3759	nand_decode_bbm_options(mtd, chip, id_data);
3760
3761	/* Calculate the address shift from the page size */
3762	chip->page_shift = ffs(mtd->writesize) - 1;
3763	/* Convert chipsize to number of pages per chip -1 */
3764	chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
3765
3766	chip->bbt_erase_shift = chip->phys_erase_shift =
3767		ffs(mtd->erasesize) - 1;
3768	if (chip->chipsize & 0xffffffff)
3769		chip->chip_shift = ffs((unsigned)chip->chipsize) - 1;
3770	else {
3771		chip->chip_shift = ffs((unsigned)(chip->chipsize >> 32));
3772		chip->chip_shift += 32 - 1;
3773	}
3774
3775	chip->badblockbits = 8;
3776	chip->erase = single_erase;
3777
3778	/* Do not replace user supplied command function! */
3779	if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
3780		chip->cmdfunc = nand_command_lp;
3781
3782	pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
3783		*maf_id, *dev_id);
3784
3785	if (chip->onfi_version)
3786		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3787				chip->onfi_params.model);
3788	else if (chip->jedec_version)
3789		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3790				chip->jedec_params.model);
3791	else
3792		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3793				type->name);
3794
3795	pr_info("%d MiB, %s, erase size: %d KiB, page size: %d, OOB size: %d\n",
3796		(int)(chip->chipsize >> 20), nand_is_slc(chip) ? "SLC" : "MLC",
3797		mtd->erasesize >> 10, mtd->writesize, mtd->oobsize);
3798	return type;
3799}
3800
3801/**
3802 * nand_scan_ident - [NAND Interface] Scan for the NAND device
3803 * @mtd: MTD device structure
3804 * @maxchips: number of chips to scan for
3805 * @table: alternative NAND ID table
3806 *
3807 * This is the first phase of the normal nand_scan() function. It reads the
3808 * flash ID and sets up MTD fields accordingly.
3809 *
3810 * The mtd->owner field must be set to the module of the caller.
3811 */
3812int nand_scan_ident(struct mtd_info *mtd, int maxchips,
3813		    struct nand_flash_dev *table)
3814{
3815	int i, nand_maf_id, nand_dev_id;
3816	struct nand_chip *chip = mtd->priv;
3817	struct nand_flash_dev *type;
3818
3819	/* Set the default functions */
3820	nand_set_defaults(chip, chip->options & NAND_BUSWIDTH_16);
3821
3822	/* Read the flash type */
3823	type = nand_get_flash_type(mtd, chip, &nand_maf_id,
3824				   &nand_dev_id, table);
3825
3826	if (IS_ERR(type)) {
3827		if (!(chip->options & NAND_SCAN_SILENT_NODEV))
3828			pr_warn("No NAND device found\n");
3829		chip->select_chip(mtd, -1);
3830		return PTR_ERR(type);
3831	}
3832
3833	chip->select_chip(mtd, -1);
3834
3835	/* Check for a chip array */
3836	for (i = 1; i < maxchips; i++) {
3837		chip->select_chip(mtd, i);
3838		/* See comment in nand_get_flash_type for reset */
3839		chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
3840		/* Send the command for reading device ID */
3841		chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
3842		/* Read manufacturer and device IDs */
3843		if (nand_maf_id != chip->read_byte(mtd) ||
3844		    nand_dev_id != chip->read_byte(mtd)) {
3845			chip->select_chip(mtd, -1);
3846			break;
3847		}
3848		chip->select_chip(mtd, -1);
3849	}
3850	if (i > 1)
3851		pr_info("%d chips detected\n", i);
3852
3853	/* Store the number of chips and calc total size for mtd */
3854	chip->numchips = i;
3855	mtd->size = i * chip->chipsize;
3856
3857	return 0;
3858}
3859EXPORT_SYMBOL(nand_scan_ident);
3860
3861/*
3862 * Check if the chip configuration meet the datasheet requirements.
3863
3864 * If our configuration corrects A bits per B bytes and the minimum
3865 * required correction level is X bits per Y bytes, then we must ensure
3866 * both of the following are true:
3867 *
3868 * (1) A / B >= X / Y
3869 * (2) A >= X
3870 *
3871 * Requirement (1) ensures we can correct for the required bitflip density.
3872 * Requirement (2) ensures we can correct even when all bitflips are clumped
3873 * in the same sector.
3874 */
3875static bool nand_ecc_strength_good(struct mtd_info *mtd)
3876{
3877	struct nand_chip *chip = mtd->priv;
3878	struct nand_ecc_ctrl *ecc = &chip->ecc;
3879	int corr, ds_corr;
3880
3881	if (ecc->size == 0 || chip->ecc_step_ds == 0)
3882		/* Not enough information */
3883		return true;
3884
3885	/*
3886	 * We get the number of corrected bits per page to compare
3887	 * the correction density.
3888	 */
3889	corr = (mtd->writesize * ecc->strength) / ecc->size;
3890	ds_corr = (mtd->writesize * chip->ecc_strength_ds) / chip->ecc_step_ds;
3891
3892	return corr >= ds_corr && ecc->strength >= chip->ecc_strength_ds;
3893}
3894
3895/**
3896 * nand_scan_tail - [NAND Interface] Scan for the NAND device
3897 * @mtd: MTD device structure
3898 *
3899 * This is the second phase of the normal nand_scan() function. It fills out
3900 * all the uninitialized function pointers with the defaults and scans for a
3901 * bad block table if appropriate.
3902 */
3903int nand_scan_tail(struct mtd_info *mtd)
3904{
3905	int i;
3906	struct nand_chip *chip = mtd->priv;
3907	struct nand_ecc_ctrl *ecc = &chip->ecc;
3908	struct nand_buffers *nbuf;
3909
3910	/* New bad blocks should be marked in OOB, flash-based BBT, or both */
3911	BUG_ON((chip->bbt_options & NAND_BBT_NO_OOB_BBM) &&
3912			!(chip->bbt_options & NAND_BBT_USE_FLASH));
3913
3914	if (!(chip->options & NAND_OWN_BUFFERS)) {
3915		nbuf = kzalloc(sizeof(*nbuf) + mtd->writesize
3916				+ mtd->oobsize * 3, GFP_KERNEL);
3917		if (!nbuf)
3918			return -ENOMEM;
3919		nbuf->ecccalc = (uint8_t *)(nbuf + 1);
3920		nbuf->ecccode = nbuf->ecccalc + mtd->oobsize;
3921		nbuf->databuf = nbuf->ecccode + mtd->oobsize;
3922
3923		chip->buffers = nbuf;
3924	} else {
3925		if (!chip->buffers)
3926			return -ENOMEM;
3927	}
3928
3929	/* Set the internal oob buffer location, just after the page data */
3930	chip->oob_poi = chip->buffers->databuf + mtd->writesize;
3931
3932	/*
3933	 * If no default placement scheme is given, select an appropriate one.
3934	 */
3935	if (!ecc->layout && (ecc->mode != NAND_ECC_SOFT_BCH)) {
3936		switch (mtd->oobsize) {
3937		case 8:
3938			ecc->layout = &nand_oob_8;
3939			break;
3940		case 16:
3941			ecc->layout = &nand_oob_16;
3942			break;
3943		case 64:
3944			ecc->layout = &nand_oob_64;
3945			break;
3946		case 128:
3947			ecc->layout = &nand_oob_128;
3948			break;
3949		default:
3950			pr_warn("No oob scheme defined for oobsize %d\n",
3951				   mtd->oobsize);
3952			BUG();
3953		}
3954	}
3955
3956	if (!chip->write_page)
3957		chip->write_page = nand_write_page;
3958
3959	/*
3960	 * Check ECC mode, default to software if 3byte/512byte hardware ECC is
3961	 * selected and we have 256 byte pagesize fallback to software ECC
3962	 */
3963
3964	switch (ecc->mode) {
3965	case NAND_ECC_HW_OOB_FIRST:
3966		/* Similar to NAND_ECC_HW, but a separate read_page handle */
3967		if (!ecc->calculate || !ecc->correct || !ecc->hwctl) {
3968			pr_warn("No ECC functions supplied; hardware ECC not possible\n");
3969			BUG();
3970		}
3971		if (!ecc->read_page)
3972			ecc->read_page = nand_read_page_hwecc_oob_first;
3973
3974	case NAND_ECC_HW:
3975		/* Use standard hwecc read page function? */
3976		if (!ecc->read_page)
3977			ecc->read_page = nand_read_page_hwecc;
3978		if (!ecc->write_page)
3979			ecc->write_page = nand_write_page_hwecc;
3980		if (!ecc->read_page_raw)
3981			ecc->read_page_raw = nand_read_page_raw;
3982		if (!ecc->write_page_raw)
3983			ecc->write_page_raw = nand_write_page_raw;
3984		if (!ecc->read_oob)
3985			ecc->read_oob = nand_read_oob_std;
3986		if (!ecc->write_oob)
3987			ecc->write_oob = nand_write_oob_std;
3988		if (!ecc->read_subpage)
3989			ecc->read_subpage = nand_read_subpage;
3990		if (!ecc->write_subpage)
3991			ecc->write_subpage = nand_write_subpage_hwecc;
3992
3993	case NAND_ECC_HW_SYNDROME:
3994		if ((!ecc->calculate || !ecc->correct || !ecc->hwctl) &&
3995		    (!ecc->read_page ||
3996		     ecc->read_page == nand_read_page_hwecc ||
3997		     !ecc->write_page ||
3998		     ecc->write_page == nand_write_page_hwecc)) {
3999			pr_warn("No ECC functions supplied; hardware ECC not possible\n");
4000			BUG();
4001		}
4002		/* Use standard syndrome read/write page function? */
4003		if (!ecc->read_page)
4004			ecc->read_page = nand_read_page_syndrome;
4005		if (!ecc->write_page)
4006			ecc->write_page = nand_write_page_syndrome;
4007		if (!ecc->read_page_raw)
4008			ecc->read_page_raw = nand_read_page_raw_syndrome;
4009		if (!ecc->write_page_raw)
4010			ecc->write_page_raw = nand_write_page_raw_syndrome;
4011		if (!ecc->read_oob)
4012			ecc->read_oob = nand_read_oob_syndrome;
4013		if (!ecc->write_oob)
4014			ecc->write_oob = nand_write_oob_syndrome;
4015
4016		if (mtd->writesize >= ecc->size) {
4017			if (!ecc->strength) {
4018				pr_warn("Driver must set ecc.strength when using hardware ECC\n");
4019				BUG();
4020			}
4021			break;
4022		}
4023		pr_warn("%d byte HW ECC not possible on %d byte page size, fallback to SW ECC\n",
4024			ecc->size, mtd->writesize);
4025		ecc->mode = NAND_ECC_SOFT;
4026
4027	case NAND_ECC_SOFT:
4028		ecc->calculate = nand_calculate_ecc;
4029		ecc->correct = nand_correct_data;
4030		ecc->read_page = nand_read_page_swecc;
4031		ecc->read_subpage = nand_read_subpage;
4032		ecc->write_page = nand_write_page_swecc;
4033		ecc->read_page_raw = nand_read_page_raw;
4034		ecc->write_page_raw = nand_write_page_raw;
4035		ecc->read_oob = nand_read_oob_std;
4036		ecc->write_oob = nand_write_oob_std;
4037		if (!ecc->size)
4038			ecc->size = 256;
4039		ecc->bytes = 3;
4040		ecc->strength = 1;
4041		break;
4042
4043	case NAND_ECC_SOFT_BCH:
4044		if (!mtd_nand_has_bch()) {
4045			pr_warn("CONFIG_MTD_NAND_ECC_BCH not enabled\n");
4046			BUG();
4047		}
4048		ecc->calculate = nand_bch_calculate_ecc;
4049		ecc->correct = nand_bch_correct_data;
4050		ecc->read_page = nand_read_page_swecc;
4051		ecc->read_subpage = nand_read_subpage;
4052		ecc->write_page = nand_write_page_swecc;
4053		ecc->read_page_raw = nand_read_page_raw;
4054		ecc->write_page_raw = nand_write_page_raw;
4055		ecc->read_oob = nand_read_oob_std;
4056		ecc->write_oob = nand_write_oob_std;
4057		/*
4058		 * Board driver should supply ecc.size and ecc.strength values
4059		 * to select how many bits are correctable. Otherwise, default
4060		 * to 4 bits for large page devices.
4061		 */
4062		if (!ecc->size && (mtd->oobsize >= 64)) {
4063			ecc->size = 512;
4064			ecc->strength = 4;
4065		}
4066
4067		/* See nand_bch_init() for details. */
4068		ecc->bytes = DIV_ROUND_UP(
4069				ecc->strength * fls(8 * ecc->size), 8);
4070		ecc->priv = nand_bch_init(mtd, ecc->size, ecc->bytes,
4071					       &ecc->layout);
4072		if (!ecc->priv) {
4073			pr_warn("BCH ECC initialization failed!\n");
4074			BUG();
4075		}
4076		break;
4077
4078	case NAND_ECC_NONE:
4079		pr_warn("NAND_ECC_NONE selected by board driver. This is not recommended!\n");
4080		ecc->read_page = nand_read_page_raw;
4081		ecc->write_page = nand_write_page_raw;
4082		ecc->read_oob = nand_read_oob_std;
4083		ecc->read_page_raw = nand_read_page_raw;
4084		ecc->write_page_raw = nand_write_page_raw;
4085		ecc->write_oob = nand_write_oob_std;
4086		ecc->size = mtd->writesize;
4087		ecc->bytes = 0;
4088		ecc->strength = 0;
4089		break;
4090
4091	default:
4092		pr_warn("Invalid NAND_ECC_MODE %d\n", ecc->mode);
4093		BUG();
4094	}
4095
4096	/* For many systems, the standard OOB write also works for raw */
4097	if (!ecc->read_oob_raw)
4098		ecc->read_oob_raw = ecc->read_oob;
4099	if (!ecc->write_oob_raw)
4100		ecc->write_oob_raw = ecc->write_oob;
4101
4102	/*
4103	 * The number of bytes available for a client to place data into
4104	 * the out of band area.
4105	 */
4106	ecc->layout->oobavail = 0;
4107	for (i = 0; ecc->layout->oobfree[i].length
4108			&& i < ARRAY_SIZE(ecc->layout->oobfree); i++)
4109		ecc->layout->oobavail += ecc->layout->oobfree[i].length;
4110	mtd->oobavail = ecc->layout->oobavail;
4111
4112	/* ECC sanity check: warn if it's too weak */
4113	if (!nand_ecc_strength_good(mtd))
4114		pr_warn("WARNING: %s: the ECC used on your system is too weak compared to the one required by the NAND chip\n",
4115			mtd->name);
4116
4117	/*
4118	 * Set the number of read / write steps for one page depending on ECC
4119	 * mode.
4120	 */
4121	ecc->steps = mtd->writesize / ecc->size;
4122	if (ecc->steps * ecc->size != mtd->writesize) {
4123		pr_warn("Invalid ECC parameters\n");
4124		BUG();
4125	}
4126	ecc->total = ecc->steps * ecc->bytes;
4127
4128	/* Allow subpage writes up to ecc.steps. Not possible for MLC flash */
4129	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) && nand_is_slc(chip)) {
4130		switch (ecc->steps) {
4131		case 2:
4132			mtd->subpage_sft = 1;
4133			break;
4134		case 4:
4135		case 8:
4136		case 16:
4137			mtd->subpage_sft = 2;
4138			break;
4139		}
4140	}
4141	chip->subpagesize = mtd->writesize >> mtd->subpage_sft;
4142
4143	/* Initialize state */
4144	chip->state = FL_READY;
4145
4146	/* Invalidate the pagebuffer reference */
4147	chip->pagebuf = -1;
4148
4149	/* Large page NAND with SOFT_ECC should support subpage reads */
4150	switch (ecc->mode) {
4151	case NAND_ECC_SOFT:
4152	case NAND_ECC_SOFT_BCH:
4153		if (chip->page_shift > 9)
4154			chip->options |= NAND_SUBPAGE_READ;
4155		break;
4156
4157	default:
4158		break;
4159	}
4160
4161	/* Fill in remaining MTD driver data */
4162	mtd->type = nand_is_slc(chip) ? MTD_NANDFLASH : MTD_MLCNANDFLASH;
4163	mtd->flags = (chip->options & NAND_ROM) ? MTD_CAP_ROM :
4164						MTD_CAP_NANDFLASH;
4165	mtd->_erase = nand_erase;
4166	mtd->_point = NULL;
4167	mtd->_unpoint = NULL;
4168	mtd->_read = nand_read;
4169	mtd->_write = nand_write;
4170	mtd->_panic_write = panic_nand_write;
4171	mtd->_read_oob = nand_read_oob;
4172	mtd->_write_oob = nand_write_oob;
4173	mtd->_sync = nand_sync;
4174	mtd->_lock = NULL;
4175	mtd->_unlock = NULL;
4176	mtd->_suspend = nand_suspend;
4177	mtd->_resume = nand_resume;
4178	mtd->_reboot = nand_shutdown;
4179	mtd->_block_isreserved = nand_block_isreserved;
4180	mtd->_block_isbad = nand_block_isbad;
4181	mtd->_block_markbad = nand_block_markbad;
4182	mtd->writebufsize = mtd->writesize;
4183
4184	/* propagate ecc info to mtd_info */
4185	mtd->ecclayout = ecc->layout;
4186	mtd->ecc_strength = ecc->strength;
4187	mtd->ecc_step_size = ecc->size;
4188	/*
4189	 * Initialize bitflip_threshold to its default prior scan_bbt() call.
4190	 * scan_bbt() might invoke mtd_read(), thus bitflip_threshold must be
4191	 * properly set.
4192	 */
4193	if (!mtd->bitflip_threshold)
4194		mtd->bitflip_threshold = DIV_ROUND_UP(mtd->ecc_strength * 3, 4);
4195
4196	/* Check, if we should skip the bad block table scan */
4197	if (chip->options & NAND_SKIP_BBTSCAN)
4198		return 0;
4199
4200	/* Build bad block table */
4201	return chip->scan_bbt(mtd);
4202}
4203EXPORT_SYMBOL(nand_scan_tail);
4204
4205/*
4206 * is_module_text_address() isn't exported, and it's mostly a pointless
4207 * test if this is a module _anyway_ -- they'd have to try _really_ hard
4208 * to call us from in-kernel code if the core NAND support is modular.
4209 */
4210#ifdef MODULE
4211#define caller_is_module() (1)
4212#else
4213#define caller_is_module() \
4214	is_module_text_address((unsigned long)__builtin_return_address(0))
4215#endif
4216
4217/**
4218 * nand_scan - [NAND Interface] Scan for the NAND device
4219 * @mtd: MTD device structure
4220 * @maxchips: number of chips to scan for
4221 *
4222 * This fills out all the uninitialized function pointers with the defaults.
4223 * The flash ID is read and the mtd/chip structures are filled with the
4224 * appropriate values. The mtd->owner field must be set to the module of the
4225 * caller.
4226 */
4227int nand_scan(struct mtd_info *mtd, int maxchips)
4228{
4229	int ret;
4230
4231	/* Many callers got this wrong, so check for it for a while... */
4232	if (!mtd->owner && caller_is_module()) {
4233		pr_crit("%s called with NULL mtd->owner!\n", __func__);
4234		BUG();
4235	}
4236
4237	ret = nand_scan_ident(mtd, maxchips, NULL);
4238	if (!ret)
4239		ret = nand_scan_tail(mtd);
4240	return ret;
4241}
4242EXPORT_SYMBOL(nand_scan);
4243
4244/**
4245 * nand_release - [NAND Interface] Free resources held by the NAND device
4246 * @mtd: MTD device structure
4247 */
4248void nand_release(struct mtd_info *mtd)
4249{
4250	struct nand_chip *chip = mtd->priv;
4251
4252	if (chip->ecc.mode == NAND_ECC_SOFT_BCH)
4253		nand_bch_free((struct nand_bch_control *)chip->ecc.priv);
4254
4255	mtd_device_unregister(mtd);
4256
4257	/* Free bad block table memory */
4258	kfree(chip->bbt);
4259	if (!(chip->options & NAND_OWN_BUFFERS))
4260		kfree(chip->buffers);
4261
4262	/* Free bad block descriptor memory */
4263	if (chip->badblock_pattern && chip->badblock_pattern->options
4264			& NAND_BBT_DYNAMICSTRUCT)
4265		kfree(chip->badblock_pattern);
4266}
4267EXPORT_SYMBOL_GPL(nand_release);
4268
4269static int __init nand_base_init(void)
4270{
4271	led_trigger_register_simple("nand-disk", &nand_led_trigger);
4272	return 0;
4273}
4274
4275static void __exit nand_base_exit(void)
4276{
4277	led_trigger_unregister_simple(nand_led_trigger);
4278}
4279
4280module_init(nand_base_init);
4281module_exit(nand_base_exit);
4282
4283MODULE_LICENSE("GPL");
4284MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>");
4285MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
4286MODULE_DESCRIPTION("Generic NAND flash driver code");
4287