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 *   Basic support for AG-AND chips is provided.
8 *
9 *	Additional technical information is available on
10 *	http://www.linux-mtd.infradead.org/doc/nand.html
11 *
12 *  Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
13 *		  2002-2006 Thomas Gleixner (tglx@linutronix.de)
14 *
15 *  Credits:
16 *	David Woodhouse for adding multichip support
17 *
18 *	Aleph One Ltd. and Toby Churchill Ltd. for supporting the
19 *	rework for 2K page size chips
20 *
21 *  TODO:
22 *	Enable cached programming for 2k page size chips
23 *	Check, if mtd->ecctype should be set to MTD_ECC_HW
24 *	if we have HW ECC support.
25 *	The AG-AND chips have nice features for speed improvement,
26 *	which are not supported yet. Read / program 4 pages in one go.
27 *	BBT table is not serialized, has to be fixed
28 *
29 * This program is free software; you can redistribute it and/or modify
30 * it under the terms of the GNU General Public License version 2 as
31 * published by the Free Software Foundation.
32 *
33 */
34
35#include <linux/module.h>
36#include <linux/delay.h>
37#include <linux/errno.h>
38#include <linux/err.h>
39#include <linux/sched.h>
40#include <linux/slab.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 nand_chip *chip, struct mtd_info *mtd,
97			   int new_state);
98
99static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
100			     struct mtd_oob_ops *ops);
101
102/*
103 * For devices which display every fart in the system on a separate LED. Is
104 * compiled away when LED support is disabled.
105 */
106DEFINE_LED_TRIGGER(nand_led_trigger);
107
108static int check_offs_len(struct mtd_info *mtd,
109					loff_t ofs, uint64_t len)
110{
111	struct nand_chip *chip = mtd->priv;
112	int ret = 0;
113
114	/* Start address must align on block boundary */
115	if (ofs & ((1 << chip->phys_erase_shift) - 1)) {
116		pr_debug("%s: unaligned address\n", __func__);
117		ret = -EINVAL;
118	}
119
120	/* Length must align on block boundary */
121	if (len & ((1 << chip->phys_erase_shift) - 1)) {
122		pr_debug("%s: length not block aligned\n", __func__);
123		ret = -EINVAL;
124	}
125
126	return ret;
127}
128
129/**
130 * nand_release_device - [GENERIC] release chip
131 * @mtd: MTD device structure
132 *
133 * Deselect, release chip lock and wake up anyone waiting on the device.
134 */
135static void nand_release_device(struct mtd_info *mtd)
136{
137	struct nand_chip *chip = mtd->priv;
138
139	/* De-select the NAND device */
140	chip->select_chip(mtd, -1);
141
142	/* Release the controller and the chip */
143	spin_lock(&chip->controller->lock);
144	chip->controller->active = NULL;
145	chip->state = FL_READY;
146	wake_up(&chip->controller->wq);
147	spin_unlock(&chip->controller->lock);
148}
149
150/**
151 * nand_read_byte - [DEFAULT] read one byte from the chip
152 * @mtd: MTD device structure
153 *
154 * Default read function for 8bit buswidth
155 */
156static uint8_t nand_read_byte(struct mtd_info *mtd)
157{
158	struct nand_chip *chip = mtd->priv;
159	return readb(chip->IO_ADDR_R);
160}
161
162/**
163 * nand_read_byte16 - [DEFAULT] read one byte endianess aware from the chip
164 * nand_read_byte16 - [DEFAULT] read one byte endianness aware from the chip
165 * @mtd: MTD device structure
166 *
167 * Default read function for 16bit buswidth with endianness conversion.
168 *
169 */
170static uint8_t nand_read_byte16(struct mtd_info *mtd)
171{
172	struct nand_chip *chip = mtd->priv;
173	return (uint8_t) cpu_to_le16(readw(chip->IO_ADDR_R));
174}
175
176/**
177 * nand_read_word - [DEFAULT] read one word from the chip
178 * @mtd: MTD device structure
179 *
180 * Default read function for 16bit buswidth without endianness conversion.
181 */
182static u16 nand_read_word(struct mtd_info *mtd)
183{
184	struct nand_chip *chip = mtd->priv;
185	return readw(chip->IO_ADDR_R);
186}
187
188/**
189 * nand_select_chip - [DEFAULT] control CE line
190 * @mtd: MTD device structure
191 * @chipnr: chipnumber to select, -1 for deselect
192 *
193 * Default select function for 1 chip devices.
194 */
195static void nand_select_chip(struct mtd_info *mtd, int chipnr)
196{
197	struct nand_chip *chip = mtd->priv;
198
199	switch (chipnr) {
200	case -1:
201		chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0 | NAND_CTRL_CHANGE);
202		break;
203	case 0:
204		break;
205
206	default:
207		BUG();
208	}
209}
210
211/**
212 * nand_write_buf - [DEFAULT] write buffer to chip
213 * @mtd: MTD device structure
214 * @buf: data buffer
215 * @len: number of bytes to write
216 *
217 * Default write function for 8bit buswidth.
218 */
219static void nand_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
220{
221	int i;
222	struct nand_chip *chip = mtd->priv;
223
224	for (i = 0; i < len; i++)
225		writeb(buf[i], chip->IO_ADDR_W);
226}
227
228/**
229 * nand_read_buf - [DEFAULT] read chip data into buffer
230 * @mtd: MTD device structure
231 * @buf: buffer to store date
232 * @len: number of bytes to read
233 *
234 * Default read function for 8bit buswidth.
235 */
236static void nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
237{
238	int i;
239	struct nand_chip *chip = mtd->priv;
240
241	for (i = 0; i < len; i++)
242		buf[i] = readb(chip->IO_ADDR_R);
243}
244
245/**
246 * nand_verify_buf - [DEFAULT] Verify chip data against buffer
247 * @mtd: MTD device structure
248 * @buf: buffer containing the data to compare
249 * @len: number of bytes to compare
250 *
251 * Default verify function for 8bit buswidth.
252 */
253static int nand_verify_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
254{
255	int i;
256	struct nand_chip *chip = mtd->priv;
257
258	for (i = 0; i < len; i++)
259		if (buf[i] != readb(chip->IO_ADDR_R))
260			return -EFAULT;
261	return 0;
262}
263
264/**
265 * nand_write_buf16 - [DEFAULT] write buffer to chip
266 * @mtd: MTD device structure
267 * @buf: data buffer
268 * @len: number of bytes to write
269 *
270 * Default write function for 16bit buswidth.
271 */
272static void nand_write_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
273{
274	int i;
275	struct nand_chip *chip = mtd->priv;
276	u16 *p = (u16 *) buf;
277	len >>= 1;
278
279	for (i = 0; i < len; i++)
280		writew(p[i], chip->IO_ADDR_W);
281
282}
283
284/**
285 * nand_read_buf16 - [DEFAULT] read chip data into buffer
286 * @mtd: MTD device structure
287 * @buf: buffer to store date
288 * @len: number of bytes to read
289 *
290 * Default read function for 16bit buswidth.
291 */
292static void nand_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
293{
294	int i;
295	struct nand_chip *chip = mtd->priv;
296	u16 *p = (u16 *) buf;
297	len >>= 1;
298
299	for (i = 0; i < len; i++)
300		p[i] = readw(chip->IO_ADDR_R);
301}
302
303/**
304 * nand_verify_buf16 - [DEFAULT] Verify chip data against buffer
305 * @mtd: MTD device structure
306 * @buf: buffer containing the data to compare
307 * @len: number of bytes to compare
308 *
309 * Default verify function for 16bit buswidth.
310 */
311static int nand_verify_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
312{
313	int i;
314	struct nand_chip *chip = mtd->priv;
315	u16 *p = (u16 *) buf;
316	len >>= 1;
317
318	for (i = 0; i < len; i++)
319		if (p[i] != readw(chip->IO_ADDR_R))
320			return -EFAULT;
321
322	return 0;
323}
324
325/**
326 * nand_block_bad - [DEFAULT] Read bad block marker from the chip
327 * @mtd: MTD device structure
328 * @ofs: offset from device start
329 * @getchip: 0, if the chip is already selected
330 *
331 * Check, if the block is bad.
332 */
333static int nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
334{
335	int page, chipnr, res = 0, i = 0;
336	struct nand_chip *chip = mtd->priv;
337	u16 bad;
338
339	if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
340		ofs += mtd->erasesize - mtd->writesize;
341
342	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
343
344	if (getchip) {
345		chipnr = (int)(ofs >> chip->chip_shift);
346
347		nand_get_device(chip, mtd, FL_READING);
348
349		/* Select the NAND device */
350		chip->select_chip(mtd, chipnr);
351	}
352
353	do {
354		if (chip->options & NAND_BUSWIDTH_16) {
355			chip->cmdfunc(mtd, NAND_CMD_READOOB,
356					chip->badblockpos & 0xFE, page);
357			bad = cpu_to_le16(chip->read_word(mtd));
358			if (chip->badblockpos & 0x1)
359				bad >>= 8;
360			else
361				bad &= 0xFF;
362		} else {
363			chip->cmdfunc(mtd, NAND_CMD_READOOB, chip->badblockpos,
364					page);
365			bad = chip->read_byte(mtd);
366		}
367
368		if (likely(chip->badblockbits == 8))
369			res = bad != 0xFF;
370		else
371			res = hweight8(bad) < chip->badblockbits;
372		ofs += mtd->writesize;
373		page = (int)(ofs >> chip->page_shift) & chip->pagemask;
374		i++;
375	} while (!res && i < 2 && (chip->bbt_options & NAND_BBT_SCAN2NDPAGE));
376
377	if (getchip)
378		nand_release_device(mtd);
379
380	return res;
381}
382
383/**
384 * nand_default_block_markbad - [DEFAULT] mark a block bad
385 * @mtd: MTD device structure
386 * @ofs: offset from device start
387 *
388 * This is the default implementation, which can be overridden by a hardware
389 * specific driver. We try operations in the following order, according to our
390 * bbt_options (NAND_BBT_NO_OOB_BBM and NAND_BBT_USE_FLASH):
391 *  (1) erase the affected block, to allow OOB marker to be written cleanly
392 *  (2) update in-memory BBT
393 *  (3) write bad block marker to OOB area of affected block
394 *  (4) update flash-based BBT
395 * Note that we retain the first error encountered in (3) or (4), finish the
396 * procedures, and dump the error in the end.
397*/
398static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
399{
400	struct nand_chip *chip = mtd->priv;
401	uint8_t buf[2] = { 0, 0 };
402	int block, res, ret = 0, i = 0;
403	int write_oob = !(chip->bbt_options & NAND_BBT_NO_OOB_BBM);
404
405	if (write_oob) {
406		struct erase_info einfo;
407
408		/* Attempt erase before marking OOB */
409		memset(&einfo, 0, sizeof(einfo));
410		einfo.mtd = mtd;
411		einfo.addr = ofs;
412		einfo.len = 1 << chip->phys_erase_shift;
413		nand_erase_nand(mtd, &einfo, 0);
414	}
415
416	/* Get block number */
417	block = (int)(ofs >> chip->bbt_erase_shift);
418	/* Mark block bad in memory-based BBT */
419	if (chip->bbt)
420		chip->bbt[block >> 2] |= 0x01 << ((block & 0x03) << 1);
421
422	/* Write bad block marker to OOB */
423	if (write_oob) {
424		struct mtd_oob_ops ops;
425		loff_t wr_ofs = ofs;
426
427		nand_get_device(chip, mtd, FL_WRITING);
428
429		ops.datbuf = NULL;
430		ops.oobbuf = buf;
431		ops.ooboffs = chip->badblockpos;
432		if (chip->options & NAND_BUSWIDTH_16) {
433			ops.ooboffs &= ~0x01;
434			ops.len = ops.ooblen = 2;
435		} else {
436			ops.len = ops.ooblen = 1;
437		}
438		ops.mode = MTD_OPS_PLACE_OOB;
439
440		/* Write to first/last page(s) if necessary */
441		if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
442			wr_ofs += mtd->erasesize - mtd->writesize;
443		do {
444			res = nand_do_write_oob(mtd, wr_ofs, &ops);
445			if (!ret)
446				ret = res;
447
448			i++;
449			wr_ofs += mtd->writesize;
450		} while ((chip->bbt_options & NAND_BBT_SCAN2NDPAGE) && i < 2);
451
452		nand_release_device(mtd);
453	}
454
455	/* Update flash-based bad block table */
456	if (chip->bbt_options & NAND_BBT_USE_FLASH) {
457		res = nand_update_bbt(mtd, ofs);
458		if (!ret)
459			ret = res;
460	}
461
462	if (!ret)
463		mtd->ecc_stats.badblocks++;
464
465	return ret;
466}
467
468/**
469 * nand_check_wp - [GENERIC] check if the chip is write protected
470 * @mtd: MTD device structure
471 *
472 * Check, if the device is write protected. The function expects, that the
473 * device is already selected.
474 */
475static int nand_check_wp(struct mtd_info *mtd)
476{
477	struct nand_chip *chip = mtd->priv;
478
479	/* Broken xD cards report WP despite being writable */
480	if (chip->options & NAND_BROKEN_XD)
481		return 0;
482
483	/* Check the WP bit */
484	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
485	return (chip->read_byte(mtd) & NAND_STATUS_WP) ? 0 : 1;
486}
487
488/**
489 * nand_block_checkbad - [GENERIC] Check if a block is marked bad
490 * @mtd: MTD device structure
491 * @ofs: offset from device start
492 * @getchip: 0, if the chip is already selected
493 * @allowbbt: 1, if its allowed to access the bbt area
494 *
495 * Check, if the block is bad. Either by reading the bad block table or
496 * calling of the scan function.
497 */
498static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip,
499			       int allowbbt)
500{
501	struct nand_chip *chip = mtd->priv;
502
503	if (!chip->bbt)
504		return chip->block_bad(mtd, ofs, getchip);
505
506	/* Return info from the table */
507	return nand_isbad_bbt(mtd, ofs, allowbbt);
508}
509
510/**
511 * panic_nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
512 * @mtd: MTD device structure
513 * @timeo: Timeout
514 *
515 * Helper function for nand_wait_ready used when needing to wait in interrupt
516 * context.
517 */
518static void panic_nand_wait_ready(struct mtd_info *mtd, unsigned long timeo)
519{
520	struct nand_chip *chip = mtd->priv;
521	int i;
522
523	/* Wait for the device to get ready */
524	for (i = 0; i < timeo; i++) {
525		if (chip->dev_ready(mtd))
526			break;
527		touch_softlockup_watchdog();
528		mdelay(1);
529	}
530}
531
532/* Wait for the ready pin, after a command. The timeout is caught later. */
533void nand_wait_ready(struct mtd_info *mtd)
534{
535	struct nand_chip *chip = mtd->priv;
536	unsigned long timeo = jiffies + 2;
537
538	/* 400ms timeout */
539	if (in_interrupt() || oops_in_progress)
540		return panic_nand_wait_ready(mtd, 400);
541
542	led_trigger_event(nand_led_trigger, LED_FULL);
543	/* Wait until command is processed or timeout occurs */
544	do {
545		if (chip->dev_ready(mtd))
546			break;
547		touch_softlockup_watchdog();
548	} while (time_before(jiffies, timeo));
549	led_trigger_event(nand_led_trigger, LED_OFF);
550}
551EXPORT_SYMBOL_GPL(nand_wait_ready);
552
553/**
554 * nand_command - [DEFAULT] Send command to NAND device
555 * @mtd: MTD device structure
556 * @command: the command to be sent
557 * @column: the column address for this command, -1 if none
558 * @page_addr: the page address for this command, -1 if none
559 *
560 * Send command to NAND device. This function is used for small page devices
561 * (256/512 Bytes per page).
562 */
563static void nand_command(struct mtd_info *mtd, unsigned int command,
564			 int column, int page_addr)
565{
566	register struct nand_chip *chip = mtd->priv;
567	int ctrl = NAND_CTRL_CLE | NAND_CTRL_CHANGE;
568
569	/* Write out the command to the device */
570	if (command == NAND_CMD_SEQIN) {
571		int readcmd;
572
573		if (column >= mtd->writesize) {
574			/* OOB area */
575			column -= mtd->writesize;
576			readcmd = NAND_CMD_READOOB;
577		} else if (column < 256) {
578			/* First 256 bytes --> READ0 */
579			readcmd = NAND_CMD_READ0;
580		} else {
581			column -= 256;
582			readcmd = NAND_CMD_READ1;
583		}
584		chip->cmd_ctrl(mtd, readcmd, ctrl);
585		ctrl &= ~NAND_CTRL_CHANGE;
586	}
587	chip->cmd_ctrl(mtd, command, ctrl);
588
589	/* Address cycle, when necessary */
590	ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE;
591	/* Serially input address */
592	if (column != -1) {
593		/* Adjust columns for 16 bit buswidth */
594		if (chip->options & NAND_BUSWIDTH_16)
595			column >>= 1;
596		chip->cmd_ctrl(mtd, column, ctrl);
597		ctrl &= ~NAND_CTRL_CHANGE;
598	}
599	if (page_addr != -1) {
600		chip->cmd_ctrl(mtd, page_addr, ctrl);
601		ctrl &= ~NAND_CTRL_CHANGE;
602		chip->cmd_ctrl(mtd, page_addr >> 8, ctrl);
603		/* One more address cycle for devices > 32MiB */
604		if (chip->chipsize > (32 << 20))
605			chip->cmd_ctrl(mtd, page_addr >> 16, ctrl);
606	}
607	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
608
609	/*
610	 * Program and erase have their own busy handlers status and sequential
611	 * in needs no delay
612	 */
613	switch (command) {
614
615	case NAND_CMD_PAGEPROG:
616	case NAND_CMD_ERASE1:
617	case NAND_CMD_ERASE2:
618	case NAND_CMD_SEQIN:
619	case NAND_CMD_STATUS:
620		return;
621
622	case NAND_CMD_RESET:
623		if (chip->dev_ready)
624			break;
625		udelay(chip->chip_delay);
626		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
627			       NAND_CTRL_CLE | NAND_CTRL_CHANGE);
628		chip->cmd_ctrl(mtd,
629			       NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
630		while (!(chip->read_byte(mtd) & NAND_STATUS_READY))
631				;
632		return;
633
634		/* This applies to read commands */
635	default:
636		/*
637		 * If we don't have access to the busy pin, we apply the given
638		 * command delay
639		 */
640		if (!chip->dev_ready) {
641			udelay(chip->chip_delay);
642			return;
643		}
644	}
645	/*
646	 * Apply this short delay always to ensure that we do wait tWB in
647	 * any case on any machine.
648	 */
649	ndelay(100);
650
651	nand_wait_ready(mtd);
652}
653
654/**
655 * nand_command_lp - [DEFAULT] Send command to NAND large page device
656 * @mtd: MTD device structure
657 * @command: the command to be sent
658 * @column: the column address for this command, -1 if none
659 * @page_addr: the page address for this command, -1 if none
660 *
661 * Send command to NAND device. This is the version for the new large page
662 * devices. We don't have the separate regions as we have in the small page
663 * devices. We must emulate NAND_CMD_READOOB to keep the code compatible.
664 */
665static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
666			    int column, int page_addr)
667{
668	register struct nand_chip *chip = mtd->priv;
669
670	/* Emulate NAND_CMD_READOOB */
671	if (command == NAND_CMD_READOOB) {
672		column += mtd->writesize;
673		command = NAND_CMD_READ0;
674	}
675
676	/* Command latch cycle */
677	chip->cmd_ctrl(mtd, command & 0xff,
678		       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
679
680	if (column != -1 || page_addr != -1) {
681		int ctrl = NAND_CTRL_CHANGE | NAND_NCE | NAND_ALE;
682
683		/* Serially input address */
684		if (column != -1) {
685			/* Adjust columns for 16 bit buswidth */
686			if (chip->options & NAND_BUSWIDTH_16)
687				column >>= 1;
688			chip->cmd_ctrl(mtd, column, ctrl);
689			ctrl &= ~NAND_CTRL_CHANGE;
690			chip->cmd_ctrl(mtd, column >> 8, ctrl);
691		}
692		if (page_addr != -1) {
693			chip->cmd_ctrl(mtd, page_addr, ctrl);
694			chip->cmd_ctrl(mtd, page_addr >> 8,
695				       NAND_NCE | NAND_ALE);
696			/* One more address cycle for devices > 128MiB */
697			if (chip->chipsize > (128 << 20))
698				chip->cmd_ctrl(mtd, page_addr >> 16,
699					       NAND_NCE | NAND_ALE);
700		}
701	}
702	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
703
704	/*
705	 * Program and erase have their own busy handlers status, sequential
706	 * in, and deplete1 need no delay.
707	 */
708	switch (command) {
709
710	case NAND_CMD_CACHEDPROG:
711	case NAND_CMD_PAGEPROG:
712	case NAND_CMD_ERASE1:
713	case NAND_CMD_ERASE2:
714	case NAND_CMD_SEQIN:
715	case NAND_CMD_RNDIN:
716	case NAND_CMD_STATUS:
717	case NAND_CMD_DEPLETE1:
718		return;
719
720	case NAND_CMD_STATUS_ERROR:
721	case NAND_CMD_STATUS_ERROR0:
722	case NAND_CMD_STATUS_ERROR1:
723	case NAND_CMD_STATUS_ERROR2:
724	case NAND_CMD_STATUS_ERROR3:
725		/* Read error status commands require only a short delay */
726		udelay(chip->chip_delay);
727		return;
728
729	case NAND_CMD_RESET:
730		if (chip->dev_ready)
731			break;
732		udelay(chip->chip_delay);
733		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
734			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
735		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
736			       NAND_NCE | NAND_CTRL_CHANGE);
737		while (!(chip->read_byte(mtd) & NAND_STATUS_READY))
738				;
739		return;
740
741	case NAND_CMD_RNDOUT:
742		/* No ready / busy check necessary */
743		chip->cmd_ctrl(mtd, NAND_CMD_RNDOUTSTART,
744			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
745		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
746			       NAND_NCE | NAND_CTRL_CHANGE);
747		return;
748
749	case NAND_CMD_READ0:
750		chip->cmd_ctrl(mtd, NAND_CMD_READSTART,
751			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
752		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
753			       NAND_NCE | NAND_CTRL_CHANGE);
754
755		/* This applies to read commands */
756	default:
757		/*
758		 * If we don't have access to the busy pin, we apply the given
759		 * command delay.
760		 */
761		if (!chip->dev_ready) {
762			udelay(chip->chip_delay);
763			return;
764		}
765	}
766
767	/*
768	 * Apply this short delay always to ensure that we do wait tWB in
769	 * any case on any machine.
770	 */
771	ndelay(100);
772
773	nand_wait_ready(mtd);
774}
775
776/**
777 * panic_nand_get_device - [GENERIC] Get chip for selected access
778 * @chip: the nand chip descriptor
779 * @mtd: MTD device structure
780 * @new_state: the state which is requested
781 *
782 * Used when in panic, no locks are taken.
783 */
784static void panic_nand_get_device(struct nand_chip *chip,
785		      struct mtd_info *mtd, int new_state)
786{
787	/* Hardware controller shared among independent devices */
788	chip->controller->active = chip;
789	chip->state = new_state;
790}
791
792/**
793 * nand_get_device - [GENERIC] Get chip for selected access
794 * @chip: the nand chip descriptor
795 * @mtd: MTD device structure
796 * @new_state: the state which is requested
797 *
798 * Get the device and lock it for exclusive access
799 */
800static int
801nand_get_device(struct nand_chip *chip, struct mtd_info *mtd, int new_state)
802{
803	spinlock_t *lock = &chip->controller->lock;
804	wait_queue_head_t *wq = &chip->controller->wq;
805	DECLARE_WAITQUEUE(wait, current);
806retry:
807	spin_lock(lock);
808
809	/* Hardware controller shared among independent devices */
810	if (!chip->controller->active)
811		chip->controller->active = chip;
812
813	if (chip->controller->active == chip && chip->state == FL_READY) {
814		chip->state = new_state;
815		spin_unlock(lock);
816		return 0;
817	}
818	if (new_state == FL_PM_SUSPENDED) {
819		if (chip->controller->active->state == FL_PM_SUSPENDED) {
820			chip->state = FL_PM_SUSPENDED;
821			spin_unlock(lock);
822			return 0;
823		}
824	}
825	set_current_state(TASK_UNINTERRUPTIBLE);
826	add_wait_queue(wq, &wait);
827	spin_unlock(lock);
828	schedule();
829	remove_wait_queue(wq, &wait);
830	goto retry;
831}
832
833/**
834 * panic_nand_wait - [GENERIC] wait until the command is done
835 * @mtd: MTD device structure
836 * @chip: NAND chip structure
837 * @timeo: timeout
838 *
839 * Wait for command done. This is a helper function for nand_wait used when
840 * we are in interrupt context. May happen when in panic and trying to write
841 * an oops through mtdoops.
842 */
843static void panic_nand_wait(struct mtd_info *mtd, struct nand_chip *chip,
844			    unsigned long timeo)
845{
846	int i;
847	for (i = 0; i < timeo; i++) {
848		if (chip->dev_ready) {
849			if (chip->dev_ready(mtd))
850				break;
851		} else {
852			if (chip->read_byte(mtd) & NAND_STATUS_READY)
853				break;
854		}
855		mdelay(1);
856	}
857}
858
859/**
860 * nand_wait - [DEFAULT] wait until the command is done
861 * @mtd: MTD device structure
862 * @chip: NAND chip structure
863 *
864 * Wait for command done. This applies to erase and program only. Erase can
865 * take up to 400ms and program up to 20ms according to general NAND and
866 * SmartMedia specs.
867 */
868static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
869{
870
871	unsigned long timeo = jiffies;
872	int status, state = chip->state;
873
874	if (state == FL_ERASING)
875		timeo += (HZ * 400) / 1000;
876	else
877		timeo += (HZ * 20) / 1000;
878
879	led_trigger_event(nand_led_trigger, LED_FULL);
880
881	/*
882	 * Apply this short delay always to ensure that we do wait tWB in any
883	 * case on any machine.
884	 */
885	ndelay(100);
886
887	if ((state == FL_ERASING) && (chip->options & NAND_IS_AND))
888		chip->cmdfunc(mtd, NAND_CMD_STATUS_MULTI, -1, -1);
889	else
890		chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
891
892	if (in_interrupt() || oops_in_progress)
893		panic_nand_wait(mtd, chip, timeo);
894	else {
895		while (time_before(jiffies, timeo)) {
896			if (chip->dev_ready) {
897				if (chip->dev_ready(mtd))
898					break;
899			} else {
900				if (chip->read_byte(mtd) & NAND_STATUS_READY)
901					break;
902			}
903			cond_resched();
904		}
905	}
906	led_trigger_event(nand_led_trigger, LED_OFF);
907
908	status = (int)chip->read_byte(mtd);
909	return status;
910}
911
912/**
913 * __nand_unlock - [REPLACEABLE] unlocks specified locked blocks
914 * @mtd: mtd info
915 * @ofs: offset to start unlock from
916 * @len: length to unlock
917 * @invert: when = 0, unlock the range of blocks within the lower and
918 *                    upper boundary address
919 *          when = 1, unlock the range of blocks outside the boundaries
920 *                    of the lower and upper boundary address
921 *
922 * Returs unlock status.
923 */
924static int __nand_unlock(struct mtd_info *mtd, loff_t ofs,
925					uint64_t len, int invert)
926{
927	int ret = 0;
928	int status, page;
929	struct nand_chip *chip = mtd->priv;
930
931	/* Submit address of first page to unlock */
932	page = ofs >> chip->page_shift;
933	chip->cmdfunc(mtd, NAND_CMD_UNLOCK1, -1, page & chip->pagemask);
934
935	/* Submit address of last page to unlock */
936	page = (ofs + len) >> chip->page_shift;
937	chip->cmdfunc(mtd, NAND_CMD_UNLOCK2, -1,
938				(page | invert) & chip->pagemask);
939
940	/* Call wait ready function */
941	status = chip->waitfunc(mtd, chip);
942	/* See if device thinks it succeeded */
943	if (status & 0x01) {
944		pr_debug("%s: error status = 0x%08x\n",
945					__func__, status);
946		ret = -EIO;
947	}
948
949	return ret;
950}
951
952/**
953 * nand_unlock - [REPLACEABLE] unlocks specified locked blocks
954 * @mtd: mtd info
955 * @ofs: offset to start unlock from
956 * @len: length to unlock
957 *
958 * Returns unlock status.
959 */
960int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
961{
962	int ret = 0;
963	int chipnr;
964	struct nand_chip *chip = mtd->priv;
965
966	pr_debug("%s: start = 0x%012llx, len = %llu\n",
967			__func__, (unsigned long long)ofs, len);
968
969	if (check_offs_len(mtd, ofs, len))
970		ret = -EINVAL;
971
972	/* Align to last block address if size addresses end of the device */
973	if (ofs + len == mtd->size)
974		len -= mtd->erasesize;
975
976	nand_get_device(chip, mtd, FL_UNLOCKING);
977
978	/* Shift to get chip number */
979	chipnr = ofs >> chip->chip_shift;
980
981	chip->select_chip(mtd, chipnr);
982
983	/* Check, if it is write protected */
984	if (nand_check_wp(mtd)) {
985		pr_debug("%s: device is write protected!\n",
986					__func__);
987		ret = -EIO;
988		goto out;
989	}
990
991	ret = __nand_unlock(mtd, ofs, len, 0);
992
993out:
994	nand_release_device(mtd);
995
996	return ret;
997}
998EXPORT_SYMBOL(nand_unlock);
999
1000/**
1001 * nand_lock - [REPLACEABLE] locks all blocks present in the device
1002 * @mtd: mtd info
1003 * @ofs: offset to start unlock from
1004 * @len: length to unlock
1005 *
1006 * This feature is not supported in many NAND parts. 'Micron' NAND parts do
1007 * have this feature, but it allows only to lock all blocks, not for specified
1008 * range for block. Implementing 'lock' feature by making use of 'unlock', for
1009 * now.
1010 *
1011 * Returns lock status.
1012 */
1013int nand_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1014{
1015	int ret = 0;
1016	int chipnr, status, page;
1017	struct nand_chip *chip = mtd->priv;
1018
1019	pr_debug("%s: start = 0x%012llx, len = %llu\n",
1020			__func__, (unsigned long long)ofs, len);
1021
1022	if (check_offs_len(mtd, ofs, len))
1023		ret = -EINVAL;
1024
1025	nand_get_device(chip, mtd, FL_LOCKING);
1026
1027	/* Shift to get chip number */
1028	chipnr = ofs >> chip->chip_shift;
1029
1030	chip->select_chip(mtd, chipnr);
1031
1032	/* Check, if it is write protected */
1033	if (nand_check_wp(mtd)) {
1034		pr_debug("%s: device is write protected!\n",
1035					__func__);
1036		status = MTD_ERASE_FAILED;
1037		ret = -EIO;
1038		goto out;
1039	}
1040
1041	/* Submit address of first page to lock */
1042	page = ofs >> chip->page_shift;
1043	chip->cmdfunc(mtd, NAND_CMD_LOCK, -1, page & chip->pagemask);
1044
1045	/* Call wait ready function */
1046	status = chip->waitfunc(mtd, chip);
1047	/* See if device thinks it succeeded */
1048	if (status & 0x01) {
1049		pr_debug("%s: error status = 0x%08x\n",
1050					__func__, status);
1051		ret = -EIO;
1052		goto out;
1053	}
1054
1055	ret = __nand_unlock(mtd, ofs, len, 0x1);
1056
1057out:
1058	nand_release_device(mtd);
1059
1060	return ret;
1061}
1062EXPORT_SYMBOL(nand_lock);
1063
1064/**
1065 * nand_read_page_raw - [INTERN] read raw page data without ecc
1066 * @mtd: mtd info structure
1067 * @chip: nand chip info structure
1068 * @buf: buffer to store read data
1069 * @page: page number to read
1070 *
1071 * Not for syndrome calculating ECC controllers, which use a special oob layout.
1072 */
1073static int nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
1074			      uint8_t *buf, int page)
1075{
1076	chip->read_buf(mtd, buf, mtd->writesize);
1077	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1078	return 0;
1079}
1080
1081/**
1082 * nand_read_page_raw_syndrome - [INTERN] read raw page data without ecc
1083 * @mtd: mtd info structure
1084 * @chip: nand chip info structure
1085 * @buf: buffer to store read data
1086 * @page: page number to read
1087 *
1088 * We need a special oob layout and handling even when OOB isn't used.
1089 */
1090static int nand_read_page_raw_syndrome(struct mtd_info *mtd,
1091					struct nand_chip *chip,
1092					uint8_t *buf, int page)
1093{
1094	int eccsize = chip->ecc.size;
1095	int eccbytes = chip->ecc.bytes;
1096	uint8_t *oob = chip->oob_poi;
1097	int steps, size;
1098
1099	for (steps = chip->ecc.steps; steps > 0; steps--) {
1100		chip->read_buf(mtd, buf, eccsize);
1101		buf += eccsize;
1102
1103		if (chip->ecc.prepad) {
1104			chip->read_buf(mtd, oob, chip->ecc.prepad);
1105			oob += chip->ecc.prepad;
1106		}
1107
1108		chip->read_buf(mtd, oob, eccbytes);
1109		oob += eccbytes;
1110
1111		if (chip->ecc.postpad) {
1112			chip->read_buf(mtd, oob, chip->ecc.postpad);
1113			oob += chip->ecc.postpad;
1114		}
1115	}
1116
1117	size = mtd->oobsize - (oob - chip->oob_poi);
1118	if (size)
1119		chip->read_buf(mtd, oob, size);
1120
1121	return 0;
1122}
1123
1124/**
1125 * nand_read_page_swecc - [REPLACEABLE] software ECC based page read function
1126 * @mtd: mtd info structure
1127 * @chip: nand chip info structure
1128 * @buf: buffer to store read data
1129 * @page: page number to read
1130 */
1131static int nand_read_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
1132				uint8_t *buf, int page)
1133{
1134	int i, eccsize = chip->ecc.size;
1135	int eccbytes = chip->ecc.bytes;
1136	int eccsteps = chip->ecc.steps;
1137	uint8_t *p = buf;
1138	uint8_t *ecc_calc = chip->buffers->ecccalc;
1139	uint8_t *ecc_code = chip->buffers->ecccode;
1140	uint32_t *eccpos = chip->ecc.layout->eccpos;
1141
1142	chip->ecc.read_page_raw(mtd, chip, buf, page);
1143
1144	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
1145		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1146
1147	for (i = 0; i < chip->ecc.total; i++)
1148		ecc_code[i] = chip->oob_poi[eccpos[i]];
1149
1150	eccsteps = chip->ecc.steps;
1151	p = buf;
1152
1153	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1154		int stat;
1155
1156		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
1157		if (stat < 0)
1158			mtd->ecc_stats.failed++;
1159		else
1160			mtd->ecc_stats.corrected += stat;
1161	}
1162	return 0;
1163}
1164
1165/**
1166 * nand_read_subpage - [REPLACEABLE] software ECC based sub-page read function
1167 * @mtd: mtd info structure
1168 * @chip: nand chip info structure
1169 * @data_offs: offset of requested data within the page
1170 * @readlen: data length
1171 * @bufpoi: buffer to store read data
1172 */
1173static int nand_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
1174			uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi)
1175{
1176	int start_step, end_step, num_steps;
1177	uint32_t *eccpos = chip->ecc.layout->eccpos;
1178	uint8_t *p;
1179	int data_col_addr, i, gaps = 0;
1180	int datafrag_len, eccfrag_len, aligned_len, aligned_pos;
1181	int busw = (chip->options & NAND_BUSWIDTH_16) ? 2 : 1;
1182	int index = 0;
1183
1184	/* Column address within the page aligned to ECC size (256bytes) */
1185	start_step = data_offs / chip->ecc.size;
1186	end_step = (data_offs + readlen - 1) / chip->ecc.size;
1187	num_steps = end_step - start_step + 1;
1188
1189	/* Data size aligned to ECC ecc.size */
1190	datafrag_len = num_steps * chip->ecc.size;
1191	eccfrag_len = num_steps * chip->ecc.bytes;
1192
1193	data_col_addr = start_step * chip->ecc.size;
1194	/* If we read not a page aligned data */
1195	if (data_col_addr != 0)
1196		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, data_col_addr, -1);
1197
1198	p = bufpoi + data_col_addr;
1199	chip->read_buf(mtd, p, datafrag_len);
1200
1201	/* Calculate ECC */
1202	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size)
1203		chip->ecc.calculate(mtd, p, &chip->buffers->ecccalc[i]);
1204
1205	/*
1206	 * The performance is faster if we position offsets according to
1207	 * ecc.pos. Let's make sure that there are no gaps in ECC positions.
1208	 */
1209	for (i = 0; i < eccfrag_len - 1; i++) {
1210		if (eccpos[i + start_step * chip->ecc.bytes] + 1 !=
1211			eccpos[i + start_step * chip->ecc.bytes + 1]) {
1212			gaps = 1;
1213			break;
1214		}
1215	}
1216	if (gaps) {
1217		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);
1218		chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1219	} else {
1220		/*
1221		 * Send the command to read the particular ECC bytes take care
1222		 * about buswidth alignment in read_buf.
1223		 */
1224		index = start_step * chip->ecc.bytes;
1225
1226		aligned_pos = eccpos[index] & ~(busw - 1);
1227		aligned_len = eccfrag_len;
1228		if (eccpos[index] & (busw - 1))
1229			aligned_len++;
1230		if (eccpos[index + (num_steps * chip->ecc.bytes)] & (busw - 1))
1231			aligned_len++;
1232
1233		chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
1234					mtd->writesize + aligned_pos, -1);
1235		chip->read_buf(mtd, &chip->oob_poi[aligned_pos], aligned_len);
1236	}
1237
1238	for (i = 0; i < eccfrag_len; i++)
1239		chip->buffers->ecccode[i] = chip->oob_poi[eccpos[i + index]];
1240
1241	p = bufpoi + data_col_addr;
1242	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size) {
1243		int stat;
1244
1245		stat = chip->ecc.correct(mtd, p,
1246			&chip->buffers->ecccode[i], &chip->buffers->ecccalc[i]);
1247		if (stat < 0)
1248			mtd->ecc_stats.failed++;
1249		else
1250			mtd->ecc_stats.corrected += stat;
1251	}
1252	return 0;
1253}
1254
1255/**
1256 * nand_read_page_hwecc - [REPLACEABLE] hardware ECC based page read function
1257 * @mtd: mtd info structure
1258 * @chip: nand chip info structure
1259 * @buf: buffer to store read data
1260 * @page: page number to read
1261 *
1262 * Not for syndrome calculating ECC controllers which need a special oob layout.
1263 */
1264static int nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
1265				uint8_t *buf, int page)
1266{
1267	int i, eccsize = chip->ecc.size;
1268	int eccbytes = chip->ecc.bytes;
1269	int eccsteps = chip->ecc.steps;
1270	uint8_t *p = buf;
1271	uint8_t *ecc_calc = chip->buffers->ecccalc;
1272	uint8_t *ecc_code = chip->buffers->ecccode;
1273	uint32_t *eccpos = chip->ecc.layout->eccpos;
1274
1275	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1276		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1277		chip->read_buf(mtd, p, eccsize);
1278		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1279	}
1280	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1281
1282	for (i = 0; i < chip->ecc.total; i++)
1283		ecc_code[i] = chip->oob_poi[eccpos[i]];
1284
1285	eccsteps = chip->ecc.steps;
1286	p = buf;
1287
1288	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1289		int stat;
1290
1291		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
1292		if (stat < 0)
1293			mtd->ecc_stats.failed++;
1294		else
1295			mtd->ecc_stats.corrected += stat;
1296	}
1297	return 0;
1298}
1299
1300/**
1301 * nand_read_page_hwecc_oob_first - [REPLACEABLE] hw ecc, read oob first
1302 * @mtd: mtd info structure
1303 * @chip: nand chip info structure
1304 * @buf: buffer to store read data
1305 * @page: page number to read
1306 *
1307 * Hardware ECC for large page chips, require OOB to be read first. For this
1308 * ECC mode, the write_page method is re-used from ECC_HW. These methods
1309 * read/write ECC from the OOB area, unlike the ECC_HW_SYNDROME support with
1310 * multiple ECC steps, follows the "infix ECC" scheme and reads/writes ECC from
1311 * the data area, by overwriting the NAND manufacturer bad block markings.
1312 */
1313static int nand_read_page_hwecc_oob_first(struct mtd_info *mtd,
1314	struct nand_chip *chip, uint8_t *buf, int page)
1315{
1316	int i, eccsize = chip->ecc.size;
1317	int eccbytes = chip->ecc.bytes;
1318	int eccsteps = chip->ecc.steps;
1319	uint8_t *p = buf;
1320	uint8_t *ecc_code = chip->buffers->ecccode;
1321	uint32_t *eccpos = chip->ecc.layout->eccpos;
1322	uint8_t *ecc_calc = chip->buffers->ecccalc;
1323
1324	/* Read the OOB area first */
1325	chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
1326	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1327	chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
1328
1329	for (i = 0; i < chip->ecc.total; i++)
1330		ecc_code[i] = chip->oob_poi[eccpos[i]];
1331
1332	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1333		int stat;
1334
1335		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1336		chip->read_buf(mtd, p, eccsize);
1337		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1338
1339		stat = chip->ecc.correct(mtd, p, &ecc_code[i], NULL);
1340		if (stat < 0)
1341			mtd->ecc_stats.failed++;
1342		else
1343			mtd->ecc_stats.corrected += stat;
1344	}
1345	return 0;
1346}
1347
1348/**
1349 * nand_read_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page read
1350 * @mtd: mtd info structure
1351 * @chip: nand chip info structure
1352 * @buf: buffer to store read data
1353 * @page: page number to read
1354 *
1355 * The hw generator calculates the error syndrome automatically. Therefore we
1356 * need a special oob layout and handling.
1357 */
1358static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
1359				   uint8_t *buf, int page)
1360{
1361	int i, eccsize = chip->ecc.size;
1362	int eccbytes = chip->ecc.bytes;
1363	int eccsteps = chip->ecc.steps;
1364	uint8_t *p = buf;
1365	uint8_t *oob = chip->oob_poi;
1366
1367	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1368		int stat;
1369
1370		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1371		chip->read_buf(mtd, p, eccsize);
1372
1373		if (chip->ecc.prepad) {
1374			chip->read_buf(mtd, oob, chip->ecc.prepad);
1375			oob += chip->ecc.prepad;
1376		}
1377
1378		chip->ecc.hwctl(mtd, NAND_ECC_READSYN);
1379		chip->read_buf(mtd, oob, eccbytes);
1380		stat = chip->ecc.correct(mtd, p, oob, NULL);
1381
1382		if (stat < 0)
1383			mtd->ecc_stats.failed++;
1384		else
1385			mtd->ecc_stats.corrected += stat;
1386
1387		oob += eccbytes;
1388
1389		if (chip->ecc.postpad) {
1390			chip->read_buf(mtd, oob, chip->ecc.postpad);
1391			oob += chip->ecc.postpad;
1392		}
1393	}
1394
1395	/* Calculate remaining oob bytes */
1396	i = mtd->oobsize - (oob - chip->oob_poi);
1397	if (i)
1398		chip->read_buf(mtd, oob, i);
1399
1400	return 0;
1401}
1402
1403/**
1404 * nand_transfer_oob - [INTERN] Transfer oob to client buffer
1405 * @chip: nand chip structure
1406 * @oob: oob destination address
1407 * @ops: oob ops structure
1408 * @len: size of oob to transfer
1409 */
1410static uint8_t *nand_transfer_oob(struct nand_chip *chip, uint8_t *oob,
1411				  struct mtd_oob_ops *ops, size_t len)
1412{
1413	switch (ops->mode) {
1414
1415	case MTD_OPS_PLACE_OOB:
1416	case MTD_OPS_RAW:
1417		memcpy(oob, chip->oob_poi + ops->ooboffs, len);
1418		return oob + len;
1419
1420	case MTD_OPS_AUTO_OOB: {
1421		struct nand_oobfree *free = chip->ecc.layout->oobfree;
1422		uint32_t boffs = 0, roffs = ops->ooboffs;
1423		size_t bytes = 0;
1424
1425		for (; free->length && len; free++, len -= bytes) {
1426			/* Read request not from offset 0? */
1427			if (unlikely(roffs)) {
1428				if (roffs >= free->length) {
1429					roffs -= free->length;
1430					continue;
1431				}
1432				boffs = free->offset + roffs;
1433				bytes = min_t(size_t, len,
1434					      (free->length - roffs));
1435				roffs = 0;
1436			} else {
1437				bytes = min_t(size_t, len, free->length);
1438				boffs = free->offset;
1439			}
1440			memcpy(oob, chip->oob_poi + boffs, bytes);
1441			oob += bytes;
1442		}
1443		return oob;
1444	}
1445	default:
1446		BUG();
1447	}
1448	return NULL;
1449}
1450
1451/**
1452 * nand_do_read_ops - [INTERN] Read data with ECC
1453 * @mtd: MTD device structure
1454 * @from: offset to read from
1455 * @ops: oob ops structure
1456 *
1457 * Internal function. Called with chip held.
1458 */
1459static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
1460			    struct mtd_oob_ops *ops)
1461{
1462	int chipnr, page, realpage, col, bytes, aligned;
1463	struct nand_chip *chip = mtd->priv;
1464	struct mtd_ecc_stats stats;
1465	int blkcheck = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
1466	int sndcmd = 1;
1467	int ret = 0;
1468	uint32_t readlen = ops->len;
1469	uint32_t oobreadlen = ops->ooblen;
1470	uint32_t max_oobsize = ops->mode == MTD_OPS_AUTO_OOB ?
1471		mtd->oobavail : mtd->oobsize;
1472
1473	uint8_t *bufpoi, *oob, *buf;
1474
1475	stats = mtd->ecc_stats;
1476
1477	chipnr = (int)(from >> chip->chip_shift);
1478	chip->select_chip(mtd, chipnr);
1479
1480	realpage = (int)(from >> chip->page_shift);
1481	page = realpage & chip->pagemask;
1482
1483	col = (int)(from & (mtd->writesize - 1));
1484
1485	buf = ops->datbuf;
1486	oob = ops->oobbuf;
1487
1488	while (1) {
1489		bytes = min(mtd->writesize - col, readlen);
1490		aligned = (bytes == mtd->writesize);
1491
1492		/* Is the current page in the buffer? */
1493		if (realpage != chip->pagebuf || oob) {
1494			bufpoi = aligned ? buf : chip->buffers->databuf;
1495
1496			if (likely(sndcmd)) {
1497				chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
1498				sndcmd = 0;
1499			}
1500
1501			/* Now read the page into the buffer */
1502			if (unlikely(ops->mode == MTD_OPS_RAW))
1503				ret = chip->ecc.read_page_raw(mtd, chip,
1504							      bufpoi, page);
1505			else if (!aligned && NAND_SUBPAGE_READ(chip) && !oob)
1506				ret = chip->ecc.read_subpage(mtd, chip,
1507							col, bytes, bufpoi);
1508			else
1509				ret = chip->ecc.read_page(mtd, chip, bufpoi,
1510							  page);
1511			if (ret < 0) {
1512				if (!aligned)
1513					/* Invalidate page cache */
1514					chip->pagebuf = -1;
1515				break;
1516			}
1517
1518			/* Transfer not aligned data */
1519			if (!aligned) {
1520				if (!NAND_SUBPAGE_READ(chip) && !oob &&
1521				    !(mtd->ecc_stats.failed - stats.failed) &&
1522				    (ops->mode != MTD_OPS_RAW))
1523					chip->pagebuf = realpage;
1524				else
1525					/* Invalidate page cache */
1526					chip->pagebuf = -1;
1527				memcpy(buf, chip->buffers->databuf + col, bytes);
1528			}
1529
1530			buf += bytes;
1531
1532			if (unlikely(oob)) {
1533
1534				int toread = min(oobreadlen, max_oobsize);
1535
1536				if (toread) {
1537					oob = nand_transfer_oob(chip,
1538						oob, ops, toread);
1539					oobreadlen -= toread;
1540				}
1541			}
1542
1543			if (!(chip->options & NAND_NO_READRDY)) {
1544				/*
1545				 * Apply delay or wait for ready/busy pin. Do
1546				 * this before the AUTOINCR check, so no
1547				 * problems arise if a chip which does auto
1548				 * increment is marked as NOAUTOINCR by the
1549				 * board driver.
1550				 */
1551				if (!chip->dev_ready)
1552					udelay(chip->chip_delay);
1553				else
1554					nand_wait_ready(mtd);
1555			}
1556		} else {
1557			memcpy(buf, chip->buffers->databuf + col, bytes);
1558			buf += bytes;
1559		}
1560
1561		readlen -= bytes;
1562
1563		if (!readlen)
1564			break;
1565
1566		/* For subsequent reads align to page boundary */
1567		col = 0;
1568		/* Increment page address */
1569		realpage++;
1570
1571		page = realpage & chip->pagemask;
1572		/* Check, if we cross a chip boundary */
1573		if (!page) {
1574			chipnr++;
1575			chip->select_chip(mtd, -1);
1576			chip->select_chip(mtd, chipnr);
1577		}
1578
1579		/*
1580		 * Check, if the chip supports auto page increment or if we
1581		 * have hit a block boundary.
1582		 */
1583		if (!NAND_CANAUTOINCR(chip) || !(page & blkcheck))
1584			sndcmd = 1;
1585	}
1586
1587	ops->retlen = ops->len - (size_t) readlen;
1588	if (oob)
1589		ops->oobretlen = ops->ooblen - oobreadlen;
1590
1591	if (ret)
1592		return ret;
1593
1594	if (mtd->ecc_stats.failed - stats.failed)
1595		return -EBADMSG;
1596
1597	return  mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
1598}
1599
1600/**
1601 * nand_read - [MTD Interface] MTD compatibility function for nand_do_read_ecc
1602 * @mtd: MTD device structure
1603 * @from: offset to read from
1604 * @len: number of bytes to read
1605 * @retlen: pointer to variable to store the number of read bytes
1606 * @buf: the databuffer to put data
1607 *
1608 * Get hold of the chip and call nand_do_read.
1609 */
1610static int nand_read(struct mtd_info *mtd, loff_t from, size_t len,
1611		     size_t *retlen, uint8_t *buf)
1612{
1613	struct nand_chip *chip = mtd->priv;
1614	struct mtd_oob_ops ops;
1615	int ret;
1616
1617	nand_get_device(chip, mtd, FL_READING);
1618	ops.len = len;
1619	ops.datbuf = buf;
1620	ops.oobbuf = NULL;
1621	ops.mode = 0;
1622	ret = nand_do_read_ops(mtd, from, &ops);
1623	*retlen = ops.retlen;
1624	nand_release_device(mtd);
1625	return ret;
1626}
1627
1628/**
1629 * nand_read_oob_std - [REPLACEABLE] the most common OOB data read function
1630 * @mtd: mtd info structure
1631 * @chip: nand chip info structure
1632 * @page: page number to read
1633 * @sndcmd: flag whether to issue read command or not
1634 */
1635static int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
1636			     int page, int sndcmd)
1637{
1638	if (sndcmd) {
1639		chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
1640		sndcmd = 0;
1641	}
1642	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1643	return sndcmd;
1644}
1645
1646/**
1647 * nand_read_oob_syndrome - [REPLACEABLE] OOB data read function for HW ECC
1648 *			    with syndromes
1649 * @mtd: mtd info structure
1650 * @chip: nand chip info structure
1651 * @page: page number to read
1652 * @sndcmd: flag whether to issue read command or not
1653 */
1654static int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
1655				  int page, int sndcmd)
1656{
1657	uint8_t *buf = chip->oob_poi;
1658	int length = mtd->oobsize;
1659	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
1660	int eccsize = chip->ecc.size;
1661	uint8_t *bufpoi = buf;
1662	int i, toread, sndrnd = 0, pos;
1663
1664	chip->cmdfunc(mtd, NAND_CMD_READ0, chip->ecc.size, page);
1665	for (i = 0; i < chip->ecc.steps; i++) {
1666		if (sndrnd) {
1667			pos = eccsize + i * (eccsize + chunk);
1668			if (mtd->writesize > 512)
1669				chip->cmdfunc(mtd, NAND_CMD_RNDOUT, pos, -1);
1670			else
1671				chip->cmdfunc(mtd, NAND_CMD_READ0, pos, page);
1672		} else
1673			sndrnd = 1;
1674		toread = min_t(int, length, chunk);
1675		chip->read_buf(mtd, bufpoi, toread);
1676		bufpoi += toread;
1677		length -= toread;
1678	}
1679	if (length > 0)
1680		chip->read_buf(mtd, bufpoi, length);
1681
1682	return 1;
1683}
1684
1685/**
1686 * nand_write_oob_std - [REPLACEABLE] the most common OOB data write function
1687 * @mtd: mtd info structure
1688 * @chip: nand chip info structure
1689 * @page: page number to write
1690 */
1691static int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
1692			      int page)
1693{
1694	int status = 0;
1695	const uint8_t *buf = chip->oob_poi;
1696	int length = mtd->oobsize;
1697
1698	chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, page);
1699	chip->write_buf(mtd, buf, length);
1700	/* Send command to program the OOB data */
1701	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1702
1703	status = chip->waitfunc(mtd, chip);
1704
1705	return status & NAND_STATUS_FAIL ? -EIO : 0;
1706}
1707
1708/**
1709 * nand_write_oob_syndrome - [REPLACEABLE] OOB data write function for HW ECC
1710 *			     with syndrome - only for large page flash
1711 * @mtd: mtd info structure
1712 * @chip: nand chip info structure
1713 * @page: page number to write
1714 */
1715static int nand_write_oob_syndrome(struct mtd_info *mtd,
1716				   struct nand_chip *chip, int page)
1717{
1718	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
1719	int eccsize = chip->ecc.size, length = mtd->oobsize;
1720	int i, len, pos, status = 0, sndcmd = 0, steps = chip->ecc.steps;
1721	const uint8_t *bufpoi = chip->oob_poi;
1722
1723	/*
1724	 * data-ecc-data-ecc ... ecc-oob
1725	 * or
1726	 * data-pad-ecc-pad-data-pad .... ecc-pad-oob
1727	 */
1728	if (!chip->ecc.prepad && !chip->ecc.postpad) {
1729		pos = steps * (eccsize + chunk);
1730		steps = 0;
1731	} else
1732		pos = eccsize;
1733
1734	chip->cmdfunc(mtd, NAND_CMD_SEQIN, pos, page);
1735	for (i = 0; i < steps; i++) {
1736		if (sndcmd) {
1737			if (mtd->writesize <= 512) {
1738				uint32_t fill = 0xFFFFFFFF;
1739
1740				len = eccsize;
1741				while (len > 0) {
1742					int num = min_t(int, len, 4);
1743					chip->write_buf(mtd, (uint8_t *)&fill,
1744							num);
1745					len -= num;
1746				}
1747			} else {
1748				pos = eccsize + i * (eccsize + chunk);
1749				chip->cmdfunc(mtd, NAND_CMD_RNDIN, pos, -1);
1750			}
1751		} else
1752			sndcmd = 1;
1753		len = min_t(int, length, chunk);
1754		chip->write_buf(mtd, bufpoi, len);
1755		bufpoi += len;
1756		length -= len;
1757	}
1758	if (length > 0)
1759		chip->write_buf(mtd, bufpoi, length);
1760
1761	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1762	status = chip->waitfunc(mtd, chip);
1763
1764	return status & NAND_STATUS_FAIL ? -EIO : 0;
1765}
1766
1767/**
1768 * nand_do_read_oob - [INTERN] NAND read out-of-band
1769 * @mtd: MTD device structure
1770 * @from: offset to read from
1771 * @ops: oob operations description structure
1772 *
1773 * NAND read out-of-band data from the spare area.
1774 */
1775static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
1776			    struct mtd_oob_ops *ops)
1777{
1778	int page, realpage, chipnr, sndcmd = 1;
1779	struct nand_chip *chip = mtd->priv;
1780	struct mtd_ecc_stats stats;
1781	int blkcheck = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
1782	int readlen = ops->ooblen;
1783	int len;
1784	uint8_t *buf = ops->oobbuf;
1785
1786	pr_debug("%s: from = 0x%08Lx, len = %i\n",
1787			__func__, (unsigned long long)from, readlen);
1788
1789	stats = mtd->ecc_stats;
1790
1791	if (ops->mode == MTD_OPS_AUTO_OOB)
1792		len = chip->ecc.layout->oobavail;
1793	else
1794		len = mtd->oobsize;
1795
1796	if (unlikely(ops->ooboffs >= len)) {
1797		pr_debug("%s: attempt to start read outside oob\n",
1798				__func__);
1799		return -EINVAL;
1800	}
1801
1802	/* Do not allow reads past end of device */
1803	if (unlikely(from >= mtd->size ||
1804		     ops->ooboffs + readlen > ((mtd->size >> chip->page_shift) -
1805					(from >> chip->page_shift)) * len)) {
1806		pr_debug("%s: attempt to read beyond end of device\n",
1807				__func__);
1808		return -EINVAL;
1809	}
1810
1811	chipnr = (int)(from >> chip->chip_shift);
1812	chip->select_chip(mtd, chipnr);
1813
1814	/* Shift to get page */
1815	realpage = (int)(from >> chip->page_shift);
1816	page = realpage & chip->pagemask;
1817
1818	while (1) {
1819		if (ops->mode == MTD_OPS_RAW)
1820			sndcmd = chip->ecc.read_oob_raw(mtd, chip, page, sndcmd);
1821		else
1822			sndcmd = chip->ecc.read_oob(mtd, chip, page, sndcmd);
1823
1824		len = min(len, readlen);
1825		buf = nand_transfer_oob(chip, buf, ops, len);
1826
1827		if (!(chip->options & NAND_NO_READRDY)) {
1828			/*
1829			 * Apply delay or wait for ready/busy pin. Do this
1830			 * before the AUTOINCR check, so no problems arise if a
1831			 * chip which does auto increment is marked as
1832			 * NOAUTOINCR by the board driver.
1833			 */
1834			if (!chip->dev_ready)
1835				udelay(chip->chip_delay);
1836			else
1837				nand_wait_ready(mtd);
1838		}
1839
1840		readlen -= len;
1841		if (!readlen)
1842			break;
1843
1844		/* Increment page address */
1845		realpage++;
1846
1847		page = realpage & chip->pagemask;
1848		/* Check, if we cross a chip boundary */
1849		if (!page) {
1850			chipnr++;
1851			chip->select_chip(mtd, -1);
1852			chip->select_chip(mtd, chipnr);
1853		}
1854
1855		/*
1856		 * Check, if the chip supports auto page increment or if we
1857		 * have hit a block boundary.
1858		 */
1859		if (!NAND_CANAUTOINCR(chip) || !(page & blkcheck))
1860			sndcmd = 1;
1861	}
1862
1863	ops->oobretlen = ops->ooblen;
1864
1865	if (mtd->ecc_stats.failed - stats.failed)
1866		return -EBADMSG;
1867
1868	return  mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
1869}
1870
1871/**
1872 * nand_read_oob - [MTD Interface] NAND read data and/or out-of-band
1873 * @mtd: MTD device structure
1874 * @from: offset to read from
1875 * @ops: oob operation description structure
1876 *
1877 * NAND read data and/or out-of-band data.
1878 */
1879static int nand_read_oob(struct mtd_info *mtd, loff_t from,
1880			 struct mtd_oob_ops *ops)
1881{
1882	struct nand_chip *chip = mtd->priv;
1883	int ret = -ENOTSUPP;
1884
1885	ops->retlen = 0;
1886
1887	/* Do not allow reads past end of device */
1888	if (ops->datbuf && (from + ops->len) > mtd->size) {
1889		pr_debug("%s: attempt to read beyond end of device\n",
1890				__func__);
1891		return -EINVAL;
1892	}
1893
1894	nand_get_device(chip, mtd, FL_READING);
1895
1896	switch (ops->mode) {
1897	case MTD_OPS_PLACE_OOB:
1898	case MTD_OPS_AUTO_OOB:
1899	case MTD_OPS_RAW:
1900		break;
1901
1902	default:
1903		goto out;
1904	}
1905
1906	if (!ops->datbuf)
1907		ret = nand_do_read_oob(mtd, from, ops);
1908	else
1909		ret = nand_do_read_ops(mtd, from, ops);
1910
1911out:
1912	nand_release_device(mtd);
1913	return ret;
1914}
1915
1916
1917/**
1918 * nand_write_page_raw - [INTERN] raw page write function
1919 * @mtd: mtd info structure
1920 * @chip: nand chip info structure
1921 * @buf: data buffer
1922 *
1923 * Not for syndrome calculating ECC controllers, which use a special oob layout.
1924 */
1925static void nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
1926				const uint8_t *buf)
1927{
1928	chip->write_buf(mtd, buf, mtd->writesize);
1929	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
1930}
1931
1932/**
1933 * nand_write_page_raw_syndrome - [INTERN] raw page write function
1934 * @mtd: mtd info structure
1935 * @chip: nand chip info structure
1936 * @buf: data buffer
1937 *
1938 * We need a special oob layout and handling even when ECC isn't checked.
1939 */
1940static void nand_write_page_raw_syndrome(struct mtd_info *mtd,
1941					struct nand_chip *chip,
1942					const uint8_t *buf)
1943{
1944	int eccsize = chip->ecc.size;
1945	int eccbytes = chip->ecc.bytes;
1946	uint8_t *oob = chip->oob_poi;
1947	int steps, size;
1948
1949	for (steps = chip->ecc.steps; steps > 0; steps--) {
1950		chip->write_buf(mtd, buf, eccsize);
1951		buf += eccsize;
1952
1953		if (chip->ecc.prepad) {
1954			chip->write_buf(mtd, oob, chip->ecc.prepad);
1955			oob += chip->ecc.prepad;
1956		}
1957
1958		chip->read_buf(mtd, oob, eccbytes);
1959		oob += eccbytes;
1960
1961		if (chip->ecc.postpad) {
1962			chip->write_buf(mtd, oob, chip->ecc.postpad);
1963			oob += chip->ecc.postpad;
1964		}
1965	}
1966
1967	size = mtd->oobsize - (oob - chip->oob_poi);
1968	if (size)
1969		chip->write_buf(mtd, oob, size);
1970}
1971/**
1972 * nand_write_page_swecc - [REPLACEABLE] software ECC based page write function
1973 * @mtd: mtd info structure
1974 * @chip: nand chip info structure
1975 * @buf: data buffer
1976 */
1977static void nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
1978				  const uint8_t *buf)
1979{
1980	int i, eccsize = chip->ecc.size;
1981	int eccbytes = chip->ecc.bytes;
1982	int eccsteps = chip->ecc.steps;
1983	uint8_t *ecc_calc = chip->buffers->ecccalc;
1984	const uint8_t *p = buf;
1985	uint32_t *eccpos = chip->ecc.layout->eccpos;
1986
1987	/* Software ECC calculation */
1988	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
1989		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1990
1991	for (i = 0; i < chip->ecc.total; i++)
1992		chip->oob_poi[eccpos[i]] = ecc_calc[i];
1993
1994	chip->ecc.write_page_raw(mtd, chip, buf);
1995}
1996
1997/**
1998 * nand_write_page_hwecc - [REPLACEABLE] hardware ECC based page write function
1999 * @mtd: mtd info structure
2000 * @chip: nand chip info structure
2001 * @buf: data buffer
2002 */
2003static void nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
2004				  const uint8_t *buf)
2005{
2006	int i, eccsize = chip->ecc.size;
2007	int eccbytes = chip->ecc.bytes;
2008	int eccsteps = chip->ecc.steps;
2009	uint8_t *ecc_calc = chip->buffers->ecccalc;
2010	const uint8_t *p = buf;
2011	uint32_t *eccpos = chip->ecc.layout->eccpos;
2012
2013	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
2014		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
2015		chip->write_buf(mtd, p, eccsize);
2016		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
2017	}
2018
2019	for (i = 0; i < chip->ecc.total; i++)
2020		chip->oob_poi[eccpos[i]] = ecc_calc[i];
2021
2022	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
2023}
2024
2025/**
2026 * nand_write_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page write
2027 * @mtd: mtd info structure
2028 * @chip: nand chip info structure
2029 * @buf: data buffer
2030 *
2031 * The hw generator calculates the error syndrome automatically. Therefore we
2032 * need a special oob layout and handling.
2033 */
2034static void nand_write_page_syndrome(struct mtd_info *mtd,
2035				    struct nand_chip *chip, const uint8_t *buf)
2036{
2037	int i, eccsize = chip->ecc.size;
2038	int eccbytes = chip->ecc.bytes;
2039	int eccsteps = chip->ecc.steps;
2040	const uint8_t *p = buf;
2041	uint8_t *oob = chip->oob_poi;
2042
2043	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
2044
2045		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
2046		chip->write_buf(mtd, p, eccsize);
2047
2048		if (chip->ecc.prepad) {
2049			chip->write_buf(mtd, oob, chip->ecc.prepad);
2050			oob += chip->ecc.prepad;
2051		}
2052
2053		chip->ecc.calculate(mtd, p, oob);
2054		chip->write_buf(mtd, oob, eccbytes);
2055		oob += eccbytes;
2056
2057		if (chip->ecc.postpad) {
2058			chip->write_buf(mtd, oob, chip->ecc.postpad);
2059			oob += chip->ecc.postpad;
2060		}
2061	}
2062
2063	/* Calculate remaining oob bytes */
2064	i = mtd->oobsize - (oob - chip->oob_poi);
2065	if (i)
2066		chip->write_buf(mtd, oob, i);
2067}
2068
2069/**
2070 * nand_write_page - [REPLACEABLE] write one page
2071 * @mtd: MTD device structure
2072 * @chip: NAND chip descriptor
2073 * @buf: the data to write
2074 * @page: page number to write
2075 * @cached: cached programming
2076 * @raw: use _raw version of write_page
2077 */
2078static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
2079			   const uint8_t *buf, int page, int cached, int raw)
2080{
2081	int status;
2082
2083	chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
2084
2085	if (unlikely(raw))
2086		chip->ecc.write_page_raw(mtd, chip, buf);
2087	else
2088		chip->ecc.write_page(mtd, chip, buf);
2089
2090	/*
2091	 * Cached progamming disabled for now. Not sure if it's worth the
2092	 * trouble. The speed gain is not very impressive. (2.3->2.6Mib/s).
2093	 */
2094	cached = 0;
2095
2096	if (!cached || !(chip->options & NAND_CACHEPRG)) {
2097
2098		chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
2099		status = chip->waitfunc(mtd, chip);
2100		/*
2101		 * See if operation failed and additional status checks are
2102		 * available.
2103		 */
2104		if ((status & NAND_STATUS_FAIL) && (chip->errstat))
2105			status = chip->errstat(mtd, chip, FL_WRITING, status,
2106					       page);
2107
2108		if (status & NAND_STATUS_FAIL)
2109			return -EIO;
2110	} else {
2111		chip->cmdfunc(mtd, NAND_CMD_CACHEDPROG, -1, -1);
2112		status = chip->waitfunc(mtd, chip);
2113	}
2114
2115#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
2116	/* Send command to read back the data */
2117	chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
2118
2119	if (chip->verify_buf(mtd, buf, mtd->writesize))
2120		return -EIO;
2121#endif
2122	return 0;
2123}
2124
2125/**
2126 * nand_fill_oob - [INTERN] Transfer client buffer to oob
2127 * @mtd: MTD device structure
2128 * @oob: oob data buffer
2129 * @len: oob data write length
2130 * @ops: oob ops structure
2131 */
2132static uint8_t *nand_fill_oob(struct mtd_info *mtd, uint8_t *oob, size_t len,
2133			      struct mtd_oob_ops *ops)
2134{
2135	struct nand_chip *chip = mtd->priv;
2136
2137	/*
2138	 * Initialise to all 0xFF, to avoid the possibility of left over OOB
2139	 * data from a previous OOB read.
2140	 */
2141	memset(chip->oob_poi, 0xff, mtd->oobsize);
2142
2143	switch (ops->mode) {
2144
2145	case MTD_OPS_PLACE_OOB:
2146	case MTD_OPS_RAW:
2147		memcpy(chip->oob_poi + ops->ooboffs, oob, len);
2148		return oob + len;
2149
2150	case MTD_OPS_AUTO_OOB: {
2151		struct nand_oobfree *free = chip->ecc.layout->oobfree;
2152		uint32_t boffs = 0, woffs = ops->ooboffs;
2153		size_t bytes = 0;
2154
2155		for (; free->length && len; free++, len -= bytes) {
2156			/* Write request not from offset 0? */
2157			if (unlikely(woffs)) {
2158				if (woffs >= free->length) {
2159					woffs -= free->length;
2160					continue;
2161				}
2162				boffs = free->offset + woffs;
2163				bytes = min_t(size_t, len,
2164					      (free->length - woffs));
2165				woffs = 0;
2166			} else {
2167				bytes = min_t(size_t, len, free->length);
2168				boffs = free->offset;
2169			}
2170			memcpy(chip->oob_poi + boffs, oob, bytes);
2171			oob += bytes;
2172		}
2173		return oob;
2174	}
2175	default:
2176		BUG();
2177	}
2178	return NULL;
2179}
2180
2181#define NOTALIGNED(x)	((x & (chip->subpagesize - 1)) != 0)
2182
2183/**
2184 * nand_do_write_ops - [INTERN] NAND write with ECC
2185 * @mtd: MTD device structure
2186 * @to: offset to write to
2187 * @ops: oob operations description structure
2188 *
2189 * NAND write with ECC.
2190 */
2191static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
2192			     struct mtd_oob_ops *ops)
2193{
2194	int chipnr, realpage, page, blockmask, column;
2195	struct nand_chip *chip = mtd->priv;
2196	uint32_t writelen = ops->len;
2197
2198	uint32_t oobwritelen = ops->ooblen;
2199	uint32_t oobmaxlen = ops->mode == MTD_OPS_AUTO_OOB ?
2200				mtd->oobavail : mtd->oobsize;
2201
2202	uint8_t *oob = ops->oobbuf;
2203	uint8_t *buf = ops->datbuf;
2204	int ret, subpage;
2205
2206	ops->retlen = 0;
2207	if (!writelen)
2208		return 0;
2209
2210	/* Reject writes, which are not page aligned */
2211	if (NOTALIGNED(to) || NOTALIGNED(ops->len)) {
2212		pr_notice("%s: attempt to write non page aligned data\n",
2213			   __func__);
2214		return -EINVAL;
2215	}
2216
2217	column = to & (mtd->writesize - 1);
2218	subpage = column || (writelen & (mtd->writesize - 1));
2219
2220	if (subpage && oob)
2221		return -EINVAL;
2222
2223	chipnr = (int)(to >> chip->chip_shift);
2224	chip->select_chip(mtd, chipnr);
2225
2226	/* Check, if it is write protected */
2227	if (nand_check_wp(mtd))
2228		return -EIO;
2229
2230	realpage = (int)(to >> chip->page_shift);
2231	page = realpage & chip->pagemask;
2232	blockmask = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
2233
2234	/* Invalidate the page cache, when we write to the cached page */
2235	if (to <= (chip->pagebuf << chip->page_shift) &&
2236	    (chip->pagebuf << chip->page_shift) < (to + ops->len))
2237		chip->pagebuf = -1;
2238
2239	/* Don't allow multipage oob writes with offset */
2240	if (oob && ops->ooboffs && (ops->ooboffs + ops->ooblen > oobmaxlen))
2241		return -EINVAL;
2242
2243	while (1) {
2244		int bytes = mtd->writesize;
2245		int cached = writelen > bytes && page != blockmask;
2246		uint8_t *wbuf = buf;
2247
2248		/* Partial page write? */
2249		if (unlikely(column || writelen < (mtd->writesize - 1))) {
2250			cached = 0;
2251			bytes = min_t(int, bytes - column, (int) writelen);
2252			chip->pagebuf = -1;
2253			memset(chip->buffers->databuf, 0xff, mtd->writesize);
2254			memcpy(&chip->buffers->databuf[column], buf, bytes);
2255			wbuf = chip->buffers->databuf;
2256		}
2257
2258		if (unlikely(oob)) {
2259			size_t len = min(oobwritelen, oobmaxlen);
2260			oob = nand_fill_oob(mtd, oob, len, ops);
2261			oobwritelen -= len;
2262		} else {
2263			/* We still need to erase leftover OOB data */
2264			memset(chip->oob_poi, 0xff, mtd->oobsize);
2265		}
2266
2267		ret = chip->write_page(mtd, chip, wbuf, page, cached,
2268				       (ops->mode == MTD_OPS_RAW));
2269		if (ret)
2270			break;
2271
2272		writelen -= bytes;
2273		if (!writelen)
2274			break;
2275
2276		column = 0;
2277		buf += bytes;
2278		realpage++;
2279
2280		page = realpage & chip->pagemask;
2281		/* Check, if we cross a chip boundary */
2282		if (!page) {
2283			chipnr++;
2284			chip->select_chip(mtd, -1);
2285			chip->select_chip(mtd, chipnr);
2286		}
2287	}
2288
2289	ops->retlen = ops->len - writelen;
2290	if (unlikely(oob))
2291		ops->oobretlen = ops->ooblen;
2292	return ret;
2293}
2294
2295/**
2296 * panic_nand_write - [MTD Interface] NAND write with ECC
2297 * @mtd: MTD device structure
2298 * @to: offset to write to
2299 * @len: number of bytes to write
2300 * @retlen: pointer to variable to store the number of written bytes
2301 * @buf: the data to write
2302 *
2303 * NAND write with ECC. Used when performing writes in interrupt context, this
2304 * may for example be called by mtdoops when writing an oops while in panic.
2305 */
2306static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
2307			    size_t *retlen, const uint8_t *buf)
2308{
2309	struct nand_chip *chip = mtd->priv;
2310	struct mtd_oob_ops ops;
2311	int ret;
2312
2313	/* Wait for the device to get ready */
2314	panic_nand_wait(mtd, chip, 400);
2315
2316	/* Grab the device */
2317	panic_nand_get_device(chip, mtd, FL_WRITING);
2318
2319	ops.len = len;
2320	ops.datbuf = (uint8_t *)buf;
2321	ops.oobbuf = NULL;
2322	ops.mode = 0;
2323
2324	ret = nand_do_write_ops(mtd, to, &ops);
2325
2326	*retlen = ops.retlen;
2327	return ret;
2328}
2329
2330/**
2331 * nand_write - [MTD Interface] NAND write with ECC
2332 * @mtd: MTD device structure
2333 * @to: offset to write to
2334 * @len: number of bytes to write
2335 * @retlen: pointer to variable to store the number of written bytes
2336 * @buf: the data to write
2337 *
2338 * NAND write with ECC.
2339 */
2340static int nand_write(struct mtd_info *mtd, loff_t to, size_t len,
2341			  size_t *retlen, const uint8_t *buf)
2342{
2343	struct nand_chip *chip = mtd->priv;
2344	struct mtd_oob_ops ops;
2345	int ret;
2346
2347	nand_get_device(chip, mtd, FL_WRITING);
2348	ops.len = len;
2349	ops.datbuf = (uint8_t *)buf;
2350	ops.oobbuf = NULL;
2351	ops.mode = 0;
2352	ret = nand_do_write_ops(mtd, to, &ops);
2353	*retlen = ops.retlen;
2354	nand_release_device(mtd);
2355	return ret;
2356}
2357
2358/**
2359 * nand_do_write_oob - [MTD Interface] NAND write out-of-band
2360 * @mtd: MTD device structure
2361 * @to: offset to write to
2362 * @ops: oob operation description structure
2363 *
2364 * NAND write out-of-band.
2365 */
2366static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
2367			     struct mtd_oob_ops *ops)
2368{
2369	int chipnr, page, status, len;
2370	struct nand_chip *chip = mtd->priv;
2371
2372	pr_debug("%s: to = 0x%08x, len = %i\n",
2373			 __func__, (unsigned int)to, (int)ops->ooblen);
2374
2375	if (ops->mode == MTD_OPS_AUTO_OOB)
2376		len = chip->ecc.layout->oobavail;
2377	else
2378		len = mtd->oobsize;
2379
2380	/* Do not allow write past end of page */
2381	if ((ops->ooboffs + ops->ooblen) > len) {
2382		pr_debug("%s: attempt to write past end of page\n",
2383				__func__);
2384		return -EINVAL;
2385	}
2386
2387	if (unlikely(ops->ooboffs >= len)) {
2388		pr_debug("%s: attempt to start write outside oob\n",
2389				__func__);
2390		return -EINVAL;
2391	}
2392
2393	/* Do not allow write past end of device */
2394	if (unlikely(to >= mtd->size ||
2395		     ops->ooboffs + ops->ooblen >
2396			((mtd->size >> chip->page_shift) -
2397			 (to >> chip->page_shift)) * len)) {
2398		pr_debug("%s: attempt to write beyond end of device\n",
2399				__func__);
2400		return -EINVAL;
2401	}
2402
2403	chipnr = (int)(to >> chip->chip_shift);
2404	chip->select_chip(mtd, chipnr);
2405
2406	/* Shift to get page */
2407	page = (int)(to >> chip->page_shift);
2408
2409	/*
2410	 * Reset the chip. Some chips (like the Toshiba TC5832DC found in one
2411	 * of my DiskOnChip 2000 test units) will clear the whole data page too
2412	 * if we don't do this. I have no clue why, but I seem to have 'fixed'
2413	 * it in the doc2000 driver in August 1999.  dwmw2.
2414	 */
2415	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
2416
2417	/* Check, if it is write protected */
2418	if (nand_check_wp(mtd))
2419		return -EROFS;
2420
2421	/* Invalidate the page cache, if we write to the cached page */
2422	if (page == chip->pagebuf)
2423		chip->pagebuf = -1;
2424
2425	nand_fill_oob(mtd, ops->oobbuf, ops->ooblen, ops);
2426
2427	if (ops->mode == MTD_OPS_RAW)
2428		status = chip->ecc.write_oob_raw(mtd, chip, page & chip->pagemask);
2429	else
2430		status = chip->ecc.write_oob(mtd, chip, page & chip->pagemask);
2431
2432	if (status)
2433		return status;
2434
2435	ops->oobretlen = ops->ooblen;
2436
2437	return 0;
2438}
2439
2440/**
2441 * nand_write_oob - [MTD Interface] NAND write data and/or out-of-band
2442 * @mtd: MTD device structure
2443 * @to: offset to write to
2444 * @ops: oob operation description structure
2445 */
2446static int nand_write_oob(struct mtd_info *mtd, loff_t to,
2447			  struct mtd_oob_ops *ops)
2448{
2449	struct nand_chip *chip = mtd->priv;
2450	int ret = -ENOTSUPP;
2451
2452	ops->retlen = 0;
2453
2454	/* Do not allow writes past end of device */
2455	if (ops->datbuf && (to + ops->len) > mtd->size) {
2456		pr_debug("%s: attempt to write beyond end of device\n",
2457				__func__);
2458		return -EINVAL;
2459	}
2460
2461	nand_get_device(chip, mtd, FL_WRITING);
2462
2463	switch (ops->mode) {
2464	case MTD_OPS_PLACE_OOB:
2465	case MTD_OPS_AUTO_OOB:
2466	case MTD_OPS_RAW:
2467		break;
2468
2469	default:
2470		goto out;
2471	}
2472
2473	if (!ops->datbuf)
2474		ret = nand_do_write_oob(mtd, to, ops);
2475	else
2476		ret = nand_do_write_ops(mtd, to, ops);
2477
2478out:
2479	nand_release_device(mtd);
2480	return ret;
2481}
2482
2483/**
2484 * single_erase_cmd - [GENERIC] NAND standard block erase command function
2485 * @mtd: MTD device structure
2486 * @page: the page address of the block which will be erased
2487 *
2488 * Standard erase command for NAND chips.
2489 */
2490static void single_erase_cmd(struct mtd_info *mtd, int page)
2491{
2492	struct nand_chip *chip = mtd->priv;
2493	/* Send commands to erase a block */
2494	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
2495	chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
2496}
2497
2498/**
2499 * multi_erase_cmd - [GENERIC] AND specific block erase command function
2500 * @mtd: MTD device structure
2501 * @page: the page address of the block which will be erased
2502 *
2503 * AND multi block erase command function. Erase 4 consecutive blocks.
2504 */
2505static void multi_erase_cmd(struct mtd_info *mtd, int page)
2506{
2507	struct nand_chip *chip = mtd->priv;
2508	/* Send commands to erase a block */
2509	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
2510	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
2511	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
2512	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
2513	chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
2514}
2515
2516/**
2517 * nand_erase - [MTD Interface] erase block(s)
2518 * @mtd: MTD device structure
2519 * @instr: erase instruction
2520 *
2521 * Erase one ore more blocks.
2522 */
2523static int nand_erase(struct mtd_info *mtd, struct erase_info *instr)
2524{
2525	return nand_erase_nand(mtd, instr, 0);
2526}
2527
2528#define BBT_PAGE_MASK	0xffffff3f
2529/**
2530 * nand_erase_nand - [INTERN] erase block(s)
2531 * @mtd: MTD device structure
2532 * @instr: erase instruction
2533 * @allowbbt: allow erasing the bbt area
2534 *
2535 * Erase one ore more blocks.
2536 */
2537int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
2538		    int allowbbt)
2539{
2540	int page, status, pages_per_block, ret, chipnr;
2541	struct nand_chip *chip = mtd->priv;
2542	loff_t rewrite_bbt[NAND_MAX_CHIPS] = {0};
2543	unsigned int bbt_masked_page = 0xffffffff;
2544	loff_t len;
2545
2546	pr_debug("%s: start = 0x%012llx, len = %llu\n",
2547			__func__, (unsigned long long)instr->addr,
2548			(unsigned long long)instr->len);
2549
2550	if (check_offs_len(mtd, instr->addr, instr->len))
2551		return -EINVAL;
2552
2553	/* Grab the lock and see if the device is available */
2554	nand_get_device(chip, mtd, FL_ERASING);
2555
2556	/* Shift to get first page */
2557	page = (int)(instr->addr >> chip->page_shift);
2558	chipnr = (int)(instr->addr >> chip->chip_shift);
2559
2560	/* Calculate pages in each block */
2561	pages_per_block = 1 << (chip->phys_erase_shift - chip->page_shift);
2562
2563	/* Select the NAND device */
2564	chip->select_chip(mtd, chipnr);
2565
2566	/* Check, if it is write protected */
2567	if (nand_check_wp(mtd)) {
2568		pr_debug("%s: device is write protected!\n",
2569				__func__);
2570		instr->state = MTD_ERASE_FAILED;
2571		goto erase_exit;
2572	}
2573
2574	/*
2575	 * If BBT requires refresh, set the BBT page mask to see if the BBT
2576	 * should be rewritten. Otherwise the mask is set to 0xffffffff which
2577	 * can not be matched. This is also done when the bbt is actually
2578	 * erased to avoid recursive updates.
2579	 */
2580	if (chip->options & BBT_AUTO_REFRESH && !allowbbt)
2581		bbt_masked_page = chip->bbt_td->pages[chipnr] & BBT_PAGE_MASK;
2582
2583	/* Loop through the pages */
2584	len = instr->len;
2585
2586	instr->state = MTD_ERASING;
2587
2588	while (len) {
2589		/* Check if we have a bad block, we do not erase bad blocks! */
2590		if (nand_block_checkbad(mtd, ((loff_t) page) <<
2591					chip->page_shift, 0, allowbbt)) {
2592			pr_warn("%s: attempt to erase a bad block at page 0x%08x\n",
2593				    __func__, page);
2594			instr->state = MTD_ERASE_FAILED;
2595			goto erase_exit;
2596		}
2597
2598		/*
2599		 * Invalidate the page cache, if we erase the block which
2600		 * contains the current cached page.
2601		 */
2602		if (page <= chip->pagebuf && chip->pagebuf <
2603		    (page + pages_per_block))
2604			chip->pagebuf = -1;
2605
2606		chip->erase_cmd(mtd, page & chip->pagemask);
2607
2608		status = chip->waitfunc(mtd, chip);
2609
2610		/*
2611		 * See if operation failed and additional status checks are
2612		 * available
2613		 */
2614		if ((status & NAND_STATUS_FAIL) && (chip->errstat))
2615			status = chip->errstat(mtd, chip, FL_ERASING,
2616					       status, page);
2617
2618		/* See if block erase succeeded */
2619		if (status & NAND_STATUS_FAIL) {
2620			pr_debug("%s: failed erase, page 0x%08x\n",
2621					__func__, page);
2622			instr->state = MTD_ERASE_FAILED;
2623			instr->fail_addr =
2624				((loff_t)page << chip->page_shift);
2625			goto erase_exit;
2626		}
2627
2628		/*
2629		 * If BBT requires refresh, set the BBT rewrite flag to the
2630		 * page being erased.
2631		 */
2632		if (bbt_masked_page != 0xffffffff &&
2633		    (page & BBT_PAGE_MASK) == bbt_masked_page)
2634			    rewrite_bbt[chipnr] =
2635					((loff_t)page << chip->page_shift);
2636
2637		/* Increment page address and decrement length */
2638		len -= (1 << chip->phys_erase_shift);
2639		page += pages_per_block;
2640
2641		/* Check, if we cross a chip boundary */
2642		if (len && !(page & chip->pagemask)) {
2643			chipnr++;
2644			chip->select_chip(mtd, -1);
2645			chip->select_chip(mtd, chipnr);
2646
2647			/*
2648			 * If BBT requires refresh and BBT-PERCHIP, set the BBT
2649			 * page mask to see if this BBT should be rewritten.
2650			 */
2651			if (bbt_masked_page != 0xffffffff &&
2652			    (chip->bbt_td->options & NAND_BBT_PERCHIP))
2653				bbt_masked_page = chip->bbt_td->pages[chipnr] &
2654					BBT_PAGE_MASK;
2655		}
2656	}
2657	instr->state = MTD_ERASE_DONE;
2658
2659erase_exit:
2660
2661	ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
2662
2663	/* Deselect and wake up anyone waiting on the device */
2664	nand_release_device(mtd);
2665
2666	/* Do call back function */
2667	if (!ret)
2668		mtd_erase_callback(instr);
2669
2670	/*
2671	 * If BBT requires refresh and erase was successful, rewrite any
2672	 * selected bad block tables.
2673	 */
2674	if (bbt_masked_page == 0xffffffff || ret)
2675		return ret;
2676
2677	for (chipnr = 0; chipnr < chip->numchips; chipnr++) {
2678		if (!rewrite_bbt[chipnr])
2679			continue;
2680		/* Update the BBT for chip */
2681		pr_debug("%s: nand_update_bbt (%d:0x%0llx 0x%0x)\n",
2682				__func__, chipnr, rewrite_bbt[chipnr],
2683				chip->bbt_td->pages[chipnr]);
2684		nand_update_bbt(mtd, rewrite_bbt[chipnr]);
2685	}
2686
2687	/* Return more or less happy */
2688	return ret;
2689}
2690
2691/**
2692 * nand_sync - [MTD Interface] sync
2693 * @mtd: MTD device structure
2694 *
2695 * Sync is actually a wait for chip ready function.
2696 */
2697static void nand_sync(struct mtd_info *mtd)
2698{
2699	struct nand_chip *chip = mtd->priv;
2700
2701	pr_debug("%s: called\n", __func__);
2702
2703	/* Grab the lock and see if the device is available */
2704	nand_get_device(chip, mtd, FL_SYNCING);
2705	/* Release it and go back */
2706	nand_release_device(mtd);
2707}
2708
2709/**
2710 * nand_block_isbad - [MTD Interface] Check if block at offset is bad
2711 * @mtd: MTD device structure
2712 * @offs: offset relative to mtd start
2713 */
2714static int nand_block_isbad(struct mtd_info *mtd, loff_t offs)
2715{
2716	return nand_block_checkbad(mtd, offs, 1, 0);
2717}
2718
2719/**
2720 * nand_block_markbad - [MTD Interface] Mark block at the given offset as bad
2721 * @mtd: MTD device structure
2722 * @ofs: offset relative to mtd start
2723 */
2724static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
2725{
2726	struct nand_chip *chip = mtd->priv;
2727	int ret;
2728
2729	ret = nand_block_isbad(mtd, ofs);
2730	if (ret) {
2731		/* If it was bad already, return success and do nothing */
2732		if (ret > 0)
2733			return 0;
2734		return ret;
2735	}
2736
2737	return chip->block_markbad(mtd, ofs);
2738}
2739
2740/**
2741 * nand_suspend - [MTD Interface] Suspend the NAND flash
2742 * @mtd: MTD device structure
2743 */
2744static int nand_suspend(struct mtd_info *mtd)
2745{
2746	struct nand_chip *chip = mtd->priv;
2747
2748	return nand_get_device(chip, mtd, FL_PM_SUSPENDED);
2749}
2750
2751/**
2752 * nand_resume - [MTD Interface] Resume the NAND flash
2753 * @mtd: MTD device structure
2754 */
2755static void nand_resume(struct mtd_info *mtd)
2756{
2757	struct nand_chip *chip = mtd->priv;
2758
2759	if (chip->state == FL_PM_SUSPENDED)
2760		nand_release_device(mtd);
2761	else
2762		pr_err("%s called for a chip which is not in suspended state\n",
2763			__func__);
2764}
2765
2766/* Set default functions */
2767static void nand_set_defaults(struct nand_chip *chip, int busw)
2768{
2769	/* check for proper chip_delay setup, set 20us if not */
2770	if (!chip->chip_delay)
2771		chip->chip_delay = 20;
2772
2773	/* check, if a user supplied command function given */
2774	if (chip->cmdfunc == NULL)
2775		chip->cmdfunc = nand_command;
2776
2777	/* check, if a user supplied wait function given */
2778	if (chip->waitfunc == NULL)
2779		chip->waitfunc = nand_wait;
2780
2781	if (!chip->select_chip)
2782		chip->select_chip = nand_select_chip;
2783	if (!chip->read_byte)
2784		chip->read_byte = busw ? nand_read_byte16 : nand_read_byte;
2785	if (!chip->read_word)
2786		chip->read_word = nand_read_word;
2787	if (!chip->block_bad)
2788		chip->block_bad = nand_block_bad;
2789	if (!chip->block_markbad)
2790		chip->block_markbad = nand_default_block_markbad;
2791	if (!chip->write_buf)
2792		chip->write_buf = busw ? nand_write_buf16 : nand_write_buf;
2793	if (!chip->read_buf)
2794		chip->read_buf = busw ? nand_read_buf16 : nand_read_buf;
2795	if (!chip->verify_buf)
2796		chip->verify_buf = busw ? nand_verify_buf16 : nand_verify_buf;
2797	if (!chip->scan_bbt)
2798		chip->scan_bbt = nand_default_bbt;
2799
2800	if (!chip->controller) {
2801		chip->controller = &chip->hwcontrol;
2802		spin_lock_init(&chip->controller->lock);
2803		init_waitqueue_head(&chip->controller->wq);
2804	}
2805
2806}
2807
2808/* Sanitize ONFI strings so we can safely print them */
2809static void sanitize_string(uint8_t *s, size_t len)
2810{
2811	ssize_t i;
2812
2813	/* Null terminate */
2814	s[len - 1] = 0;
2815
2816	/* Remove non printable chars */
2817	for (i = 0; i < len - 1; i++) {
2818		if (s[i] < ' ' || s[i] > 127)
2819			s[i] = '?';
2820	}
2821
2822	/* Remove trailing spaces */
2823	strim(s);
2824}
2825
2826static u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
2827{
2828	int i;
2829	while (len--) {
2830		crc ^= *p++ << 8;
2831		for (i = 0; i < 8; i++)
2832			crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
2833	}
2834
2835	return crc;
2836}
2837
2838/*
2839 * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
2840 */
2841static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
2842					int *busw)
2843{
2844	struct nand_onfi_params *p = &chip->onfi_params;
2845	int i;
2846	int val;
2847
2848	/* Try ONFI for unknown chip or LP */
2849	chip->cmdfunc(mtd, NAND_CMD_READID, 0x20, -1);
2850	if (chip->read_byte(mtd) != 'O' || chip->read_byte(mtd) != 'N' ||
2851		chip->read_byte(mtd) != 'F' || chip->read_byte(mtd) != 'I')
2852		return 0;
2853
2854	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
2855	for (i = 0; i < 3; i++) {
2856		chip->read_buf(mtd, (uint8_t *)p, sizeof(*p));
2857		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
2858				le16_to_cpu(p->crc)) {
2859			pr_info("ONFI param page %d valid\n", i);
2860			break;
2861		}
2862	}
2863
2864	if (i == 3)
2865		return 0;
2866
2867	/* Check version */
2868	val = le16_to_cpu(p->revision);
2869	if (val & (1 << 5))
2870		chip->onfi_version = 23;
2871	else if (val & (1 << 4))
2872		chip->onfi_version = 22;
2873	else if (val & (1 << 3))
2874		chip->onfi_version = 21;
2875	else if (val & (1 << 2))
2876		chip->onfi_version = 20;
2877	else if (val & (1 << 1))
2878		chip->onfi_version = 10;
2879	else
2880		chip->onfi_version = 0;
2881
2882	if (!chip->onfi_version) {
2883		pr_info("%s: unsupported ONFI version: %d\n", __func__, val);
2884		return 0;
2885	}
2886
2887	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
2888	sanitize_string(p->model, sizeof(p->model));
2889	if (!mtd->name)
2890		mtd->name = p->model;
2891	mtd->writesize = le32_to_cpu(p->byte_per_page);
2892	mtd->erasesize = le32_to_cpu(p->pages_per_block) * mtd->writesize;
2893	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
2894	chip->chipsize = le32_to_cpu(p->blocks_per_lun);
2895	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
2896	*busw = 0;
2897	if (le16_to_cpu(p->features) & 1)
2898		*busw = NAND_BUSWIDTH_16;
2899
2900	chip->options &= ~NAND_CHIPOPTIONS_MSK;
2901	chip->options |= (NAND_NO_READRDY |
2902			NAND_NO_AUTOINCR) & NAND_CHIPOPTIONS_MSK;
2903
2904	pr_info("ONFI flash detected\n");
2905	return 1;
2906}
2907
2908/*
2909 * Get the flash and manufacturer id and lookup if the type is supported.
2910 */
2911static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
2912						  struct nand_chip *chip,
2913						  int busw,
2914						  int *maf_id, int *dev_id,
2915						  struct nand_flash_dev *type)
2916{
2917	int i, maf_idx;
2918	u8 id_data[8];
2919	int ret;
2920
2921	/* Select the device */
2922	chip->select_chip(mtd, 0);
2923
2924	/*
2925	 * Reset the chip, required by some chips (e.g. Micron MT29FxGxxxxx)
2926	 * after power-up.
2927	 */
2928	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
2929
2930	/* Send the command for reading device ID */
2931	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
2932
2933	/* Read manufacturer and device IDs */
2934	*maf_id = chip->read_byte(mtd);
2935	*dev_id = chip->read_byte(mtd);
2936
2937	/*
2938	 * Try again to make sure, as some systems the bus-hold or other
2939	 * interface concerns can cause random data which looks like a
2940	 * possibly credible NAND flash to appear. If the two results do
2941	 * not match, ignore the device completely.
2942	 */
2943
2944	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
2945
2946	for (i = 0; i < 2; i++)
2947		id_data[i] = chip->read_byte(mtd);
2948
2949	if (id_data[0] != *maf_id || id_data[1] != *dev_id) {
2950		pr_info("%s: second ID read did not match "
2951			"%02x,%02x against %02x,%02x\n", __func__,
2952			*maf_id, *dev_id, id_data[0], id_data[1]);
2953		return ERR_PTR(-ENODEV);
2954	}
2955
2956	if (!type)
2957		type = nand_flash_ids;
2958
2959	for (; type->name != NULL; type++)
2960		if (*dev_id == type->id)
2961			break;
2962
2963	chip->onfi_version = 0;
2964	if (!type->name || !type->pagesize) {
2965		/* Check is chip is ONFI compliant */
2966		ret = nand_flash_detect_onfi(mtd, chip, &busw);
2967		if (ret)
2968			goto ident_done;
2969	}
2970
2971	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
2972
2973	/* Read entire ID string */
2974
2975	for (i = 0; i < 8; i++)
2976		id_data[i] = chip->read_byte(mtd);
2977
2978	if (!type->name)
2979		return ERR_PTR(-ENODEV);
2980
2981	if (!mtd->name)
2982		mtd->name = type->name;
2983
2984	chip->chipsize = (uint64_t)type->chipsize << 20;
2985
2986	if (!type->pagesize && chip->init_size) {
2987		/* Set the pagesize, oobsize, erasesize by the driver */
2988		busw = chip->init_size(mtd, chip, id_data);
2989	} else if (!type->pagesize) {
2990		int extid;
2991		/* The 3rd id byte holds MLC / multichip data */
2992		chip->cellinfo = id_data[2];
2993		/* The 4th id byte is the important one */
2994		extid = id_data[3];
2995
2996		/*
2997		 * Field definitions are in the following datasheets:
2998		 * Old style (4,5 byte ID): Samsung K9GAG08U0M (p.32)
2999		 * New style   (6 byte ID): Samsung K9GBG08U0M (p.40)
3000		 *
3001		 * Check for wraparound + Samsung ID + nonzero 6th byte
3002		 * to decide what to do.
3003		 */
3004		if (id_data[0] == id_data[6] && id_data[1] == id_data[7] &&
3005				id_data[0] == NAND_MFR_SAMSUNG &&
3006				(chip->cellinfo & NAND_CI_CELLTYPE_MSK) &&
3007				id_data[5] != 0x00) {
3008			/* Calc pagesize */
3009			mtd->writesize = 2048 << (extid & 0x03);
3010			extid >>= 2;
3011			/* Calc oobsize */
3012			switch (extid & 0x03) {
3013			case 1:
3014				mtd->oobsize = 128;
3015				break;
3016			case 2:
3017				mtd->oobsize = 218;
3018				break;
3019			case 3:
3020				mtd->oobsize = 400;
3021				break;
3022			default:
3023				mtd->oobsize = 436;
3024				break;
3025			}
3026			extid >>= 2;
3027			/* Calc blocksize */
3028			mtd->erasesize = (128 * 1024) <<
3029				(((extid >> 1) & 0x04) | (extid & 0x03));
3030			busw = 0;
3031		} else {
3032			/* Calc pagesize */
3033			mtd->writesize = 1024 << (extid & 0x03);
3034			extid >>= 2;
3035			/* Calc oobsize */
3036			mtd->oobsize = (8 << (extid & 0x01)) *
3037				(mtd->writesize >> 9);
3038			extid >>= 2;
3039			/* Calc blocksize. Blocksize is multiples of 64KiB */
3040			mtd->erasesize = (64 * 1024) << (extid & 0x03);
3041			extid >>= 2;
3042			/* Get buswidth information */
3043			busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0;
3044		}
3045	} else {
3046		/*
3047		 * Old devices have chip data hardcoded in the device id table.
3048		 */
3049		mtd->erasesize = type->erasesize;
3050		mtd->writesize = type->pagesize;
3051		mtd->oobsize = mtd->writesize / 32;
3052		busw = type->options & NAND_BUSWIDTH_16;
3053
3054		/*
3055		 * Check for Spansion/AMD ID + repeating 5th, 6th byte since
3056		 * some Spansion chips have erasesize that conflicts with size
3057		 * listed in nand_ids table.
3058		 * Data sheet (5 byte ID): Spansion S30ML-P ORNAND (p.39)
3059		 */
3060		if (*maf_id == NAND_MFR_AMD && id_data[4] != 0x00 &&
3061				id_data[5] == 0x00 && id_data[6] == 0x00 &&
3062				id_data[7] == 0x00 && mtd->writesize == 512) {
3063			mtd->erasesize = 128 * 1024;
3064			mtd->erasesize <<= ((id_data[3] & 0x03) << 1);
3065		}
3066	}
3067	/* Get chip options, preserve non chip based options */
3068	chip->options &= ~NAND_CHIPOPTIONS_MSK;
3069	chip->options |= type->options & NAND_CHIPOPTIONS_MSK;
3070
3071	/*
3072	 * Check if chip is not a Samsung device. Do not clear the
3073	 * options for chips which do not have an extended id.
3074	 */
3075	if (*maf_id != NAND_MFR_SAMSUNG && !type->pagesize)
3076		chip->options &= ~NAND_SAMSUNG_LP_OPTIONS;
3077ident_done:
3078
3079	/*
3080	 * Set chip as a default. Board drivers can override it, if necessary.
3081	 */
3082	chip->options |= NAND_NO_AUTOINCR;
3083
3084	/* Try to identify manufacturer */
3085	for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_idx++) {
3086		if (nand_manuf_ids[maf_idx].id == *maf_id)
3087			break;
3088	}
3089
3090	/*
3091	 * Check, if buswidth is correct. Hardware drivers should set
3092	 * chip correct!
3093	 */
3094	if (busw != (chip->options & NAND_BUSWIDTH_16)) {
3095		pr_info("NAND device: Manufacturer ID:"
3096			" 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id,
3097			*dev_id, nand_manuf_ids[maf_idx].name, mtd->name);
3098		pr_warn("NAND bus width %d instead %d bit\n",
3099			   (chip->options & NAND_BUSWIDTH_16) ? 16 : 8,
3100			   busw ? 16 : 8);
3101		return ERR_PTR(-EINVAL);
3102	}
3103
3104	/* Calculate the address shift from the page size */
3105	chip->page_shift = ffs(mtd->writesize) - 1;
3106	/* Convert chipsize to number of pages per chip -1 */
3107	chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
3108
3109	chip->bbt_erase_shift = chip->phys_erase_shift =
3110		ffs(mtd->erasesize) - 1;
3111	if (chip->chipsize & 0xffffffff)
3112		chip->chip_shift = ffs((unsigned)chip->chipsize) - 1;
3113	else {
3114		chip->chip_shift = ffs((unsigned)(chip->chipsize >> 32));
3115		chip->chip_shift += 32 - 1;
3116	}
3117
3118	chip->badblockbits = 8;
3119
3120	/* Set the bad block position */
3121	if (mtd->writesize > 512 || (busw & NAND_BUSWIDTH_16))
3122		chip->badblockpos = NAND_LARGE_BADBLOCK_POS;
3123	else
3124		chip->badblockpos = NAND_SMALL_BADBLOCK_POS;
3125
3126	/*
3127	 * Bad block marker is stored in the last page of each block
3128	 * on Samsung and Hynix MLC devices; stored in first two pages
3129	 * of each block on Micron devices with 2KiB pages and on
3130	 * SLC Samsung, Hynix, Toshiba, AMD/Spansion, and Macronix.
3131	 * All others scan only the first page.
3132	 */
3133	if ((chip->cellinfo & NAND_CI_CELLTYPE_MSK) &&
3134			(*maf_id == NAND_MFR_SAMSUNG ||
3135			 *maf_id == NAND_MFR_HYNIX))
3136		chip->bbt_options |= NAND_BBT_SCANLASTPAGE;
3137	else if ((!(chip->cellinfo & NAND_CI_CELLTYPE_MSK) &&
3138				(*maf_id == NAND_MFR_SAMSUNG ||
3139				 *maf_id == NAND_MFR_HYNIX ||
3140				 *maf_id == NAND_MFR_TOSHIBA ||
3141				 *maf_id == NAND_MFR_AMD ||
3142				 *maf_id == NAND_MFR_MACRONIX)) ||
3143			(mtd->writesize == 2048 &&
3144			 *maf_id == NAND_MFR_MICRON))
3145		chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
3146
3147	/* Check for AND chips with 4 page planes */
3148	if (chip->options & NAND_4PAGE_ARRAY)
3149		chip->erase_cmd = multi_erase_cmd;
3150	else
3151		chip->erase_cmd = single_erase_cmd;
3152
3153	/* Do not replace user supplied command function! */
3154	if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
3155		chip->cmdfunc = nand_command_lp;
3156
3157	pr_info("NAND device: Manufacturer ID:"
3158		" 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id, *dev_id,
3159		nand_manuf_ids[maf_idx].name,
3160		chip->onfi_version ? chip->onfi_params.model : type->name);
3161
3162	return type;
3163}
3164
3165/**
3166 * nand_scan_ident - [NAND Interface] Scan for the NAND device
3167 * @mtd: MTD device structure
3168 * @maxchips: number of chips to scan for
3169 * @table: alternative NAND ID table
3170 *
3171 * This is the first phase of the normal nand_scan() function. It reads the
3172 * flash ID and sets up MTD fields accordingly.
3173 *
3174 * The mtd->owner field must be set to the module of the caller.
3175 */
3176int nand_scan_ident(struct mtd_info *mtd, int maxchips,
3177		    struct nand_flash_dev *table)
3178{
3179	int i, busw, nand_maf_id, nand_dev_id;
3180	struct nand_chip *chip = mtd->priv;
3181	struct nand_flash_dev *type;
3182
3183	/* Get buswidth to select the correct functions */
3184	busw = chip->options & NAND_BUSWIDTH_16;
3185	/* Set the default functions */
3186	nand_set_defaults(chip, busw);
3187
3188	/* Read the flash type */
3189	type = nand_get_flash_type(mtd, chip, busw,
3190				&nand_maf_id, &nand_dev_id, table);
3191
3192	if (IS_ERR(type)) {
3193		if (!(chip->options & NAND_SCAN_SILENT_NODEV))
3194			pr_warn("No NAND device found\n");
3195		chip->select_chip(mtd, -1);
3196		return PTR_ERR(type);
3197	}
3198
3199	/* Check for a chip array */
3200	for (i = 1; i < maxchips; i++) {
3201		chip->select_chip(mtd, i);
3202		/* See comment in nand_get_flash_type for reset */
3203		chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
3204		/* Send the command for reading device ID */
3205		chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
3206		/* Read manufacturer and device IDs */
3207		if (nand_maf_id != chip->read_byte(mtd) ||
3208		    nand_dev_id != chip->read_byte(mtd))
3209			break;
3210	}
3211	if (i > 1)
3212		pr_info("%d NAND chips detected\n", i);
3213
3214	/* Store the number of chips and calc total size for mtd */
3215	chip->numchips = i;
3216	mtd->size = i * chip->chipsize;
3217
3218	return 0;
3219}
3220EXPORT_SYMBOL(nand_scan_ident);
3221
3222
3223/**
3224 * nand_scan_tail - [NAND Interface] Scan for the NAND device
3225 * @mtd: MTD device structure
3226 *
3227 * This is the second phase of the normal nand_scan() function. It fills out
3228 * all the uninitialized function pointers with the defaults and scans for a
3229 * bad block table if appropriate.
3230 */
3231int nand_scan_tail(struct mtd_info *mtd)
3232{
3233	int i;
3234	struct nand_chip *chip = mtd->priv;
3235
3236	/* New bad blocks should be marked in OOB, flash-based BBT, or both */
3237	BUG_ON((chip->bbt_options & NAND_BBT_NO_OOB_BBM) &&
3238			!(chip->bbt_options & NAND_BBT_USE_FLASH));
3239
3240	if (!(chip->options & NAND_OWN_BUFFERS))
3241		chip->buffers = kmalloc(sizeof(*chip->buffers), GFP_KERNEL);
3242	if (!chip->buffers)
3243		return -ENOMEM;
3244
3245	/* Set the internal oob buffer location, just after the page data */
3246	chip->oob_poi = chip->buffers->databuf + mtd->writesize;
3247
3248	/*
3249	 * If no default placement scheme is given, select an appropriate one.
3250	 */
3251	if (!chip->ecc.layout && (chip->ecc.mode != NAND_ECC_SOFT_BCH)) {
3252		switch (mtd->oobsize) {
3253		case 8:
3254			chip->ecc.layout = &nand_oob_8;
3255			break;
3256		case 16:
3257			chip->ecc.layout = &nand_oob_16;
3258			break;
3259		case 64:
3260			chip->ecc.layout = &nand_oob_64;
3261			break;
3262		case 128:
3263			chip->ecc.layout = &nand_oob_128;
3264			break;
3265		default:
3266			pr_warn("No oob scheme defined for oobsize %d\n",
3267				   mtd->oobsize);
3268			BUG();
3269		}
3270	}
3271
3272	if (!chip->write_page)
3273		chip->write_page = nand_write_page;
3274
3275	/*
3276	 * Check ECC mode, default to software if 3byte/512byte hardware ECC is
3277	 * selected and we have 256 byte pagesize fallback to software ECC
3278	 */
3279
3280	switch (chip->ecc.mode) {
3281	case NAND_ECC_HW_OOB_FIRST:
3282		/* Similar to NAND_ECC_HW, but a separate read_page handle */
3283		if (!chip->ecc.calculate || !chip->ecc.correct ||
3284		     !chip->ecc.hwctl) {
3285			pr_warn("No ECC functions supplied; "
3286				   "hardware ECC not possible\n");
3287			BUG();
3288		}
3289		if (!chip->ecc.read_page)
3290			chip->ecc.read_page = nand_read_page_hwecc_oob_first;
3291
3292	case NAND_ECC_HW:
3293		/* Use standard hwecc read page function? */
3294		if (!chip->ecc.read_page)
3295			chip->ecc.read_page = nand_read_page_hwecc;
3296		if (!chip->ecc.write_page)
3297			chip->ecc.write_page = nand_write_page_hwecc;
3298		if (!chip->ecc.read_page_raw)
3299			chip->ecc.read_page_raw = nand_read_page_raw;
3300		if (!chip->ecc.write_page_raw)
3301			chip->ecc.write_page_raw = nand_write_page_raw;
3302		if (!chip->ecc.read_oob)
3303			chip->ecc.read_oob = nand_read_oob_std;
3304		if (!chip->ecc.write_oob)
3305			chip->ecc.write_oob = nand_write_oob_std;
3306
3307	case NAND_ECC_HW_SYNDROME:
3308		if ((!chip->ecc.calculate || !chip->ecc.correct ||
3309		     !chip->ecc.hwctl) &&
3310		    (!chip->ecc.read_page ||
3311		     chip->ecc.read_page == nand_read_page_hwecc ||
3312		     !chip->ecc.write_page ||
3313		     chip->ecc.write_page == nand_write_page_hwecc)) {
3314			pr_warn("No ECC functions supplied; "
3315				   "hardware ECC not possible\n");
3316			BUG();
3317		}
3318		/* Use standard syndrome read/write page function? */
3319		if (!chip->ecc.read_page)
3320			chip->ecc.read_page = nand_read_page_syndrome;
3321		if (!chip->ecc.write_page)
3322			chip->ecc.write_page = nand_write_page_syndrome;
3323		if (!chip->ecc.read_page_raw)
3324			chip->ecc.read_page_raw = nand_read_page_raw_syndrome;
3325		if (!chip->ecc.write_page_raw)
3326			chip->ecc.write_page_raw = nand_write_page_raw_syndrome;
3327		if (!chip->ecc.read_oob)
3328			chip->ecc.read_oob = nand_read_oob_syndrome;
3329		if (!chip->ecc.write_oob)
3330			chip->ecc.write_oob = nand_write_oob_syndrome;
3331
3332		if (mtd->writesize >= chip->ecc.size)
3333			break;
3334		pr_warn("%d byte HW ECC not possible on "
3335			   "%d byte page size, fallback to SW ECC\n",
3336			   chip->ecc.size, mtd->writesize);
3337		chip->ecc.mode = NAND_ECC_SOFT;
3338
3339	case NAND_ECC_SOFT:
3340		chip->ecc.calculate = nand_calculate_ecc;
3341		chip->ecc.correct = nand_correct_data;
3342		chip->ecc.read_page = nand_read_page_swecc;
3343		chip->ecc.read_subpage = nand_read_subpage;
3344		chip->ecc.write_page = nand_write_page_swecc;
3345		chip->ecc.read_page_raw = nand_read_page_raw;
3346		chip->ecc.write_page_raw = nand_write_page_raw;
3347		chip->ecc.read_oob = nand_read_oob_std;
3348		chip->ecc.write_oob = nand_write_oob_std;
3349		if (!chip->ecc.size)
3350			chip->ecc.size = 256;
3351		chip->ecc.bytes = 3;
3352		chip->ecc.strength = 1;
3353		break;
3354
3355	case NAND_ECC_SOFT_BCH:
3356		if (!mtd_nand_has_bch()) {
3357			pr_warn("CONFIG_MTD_ECC_BCH not enabled\n");
3358			BUG();
3359		}
3360		chip->ecc.calculate = nand_bch_calculate_ecc;
3361		chip->ecc.correct = nand_bch_correct_data;
3362		chip->ecc.read_page = nand_read_page_swecc;
3363		chip->ecc.read_subpage = nand_read_subpage;
3364		chip->ecc.write_page = nand_write_page_swecc;
3365		chip->ecc.read_page_raw = nand_read_page_raw;
3366		chip->ecc.write_page_raw = nand_write_page_raw;
3367		chip->ecc.read_oob = nand_read_oob_std;
3368		chip->ecc.write_oob = nand_write_oob_std;
3369		/*
3370		 * Board driver should supply ecc.size and ecc.bytes values to
3371		 * select how many bits are correctable; see nand_bch_init()
3372		 * for details. Otherwise, default to 4 bits for large page
3373		 * devices.
3374		 */
3375		if (!chip->ecc.size && (mtd->oobsize >= 64)) {
3376			chip->ecc.size = 512;
3377			chip->ecc.bytes = 7;
3378		}
3379		chip->ecc.priv = nand_bch_init(mtd,
3380					       chip->ecc.size,
3381					       chip->ecc.bytes,
3382					       &chip->ecc.layout);
3383		if (!chip->ecc.priv) {
3384			pr_warn("BCH ECC initialization failed!\n");
3385			BUG();
3386		}
3387		chip->ecc.strength =
3388			chip->ecc.bytes*8 / fls(8*chip->ecc.size);
3389		break;
3390
3391	case NAND_ECC_NONE:
3392		pr_warn("NAND_ECC_NONE selected by board driver. "
3393			   "This is not recommended!\n");
3394		chip->ecc.read_page = nand_read_page_raw;
3395		chip->ecc.write_page = nand_write_page_raw;
3396		chip->ecc.read_oob = nand_read_oob_std;
3397		chip->ecc.read_page_raw = nand_read_page_raw;
3398		chip->ecc.write_page_raw = nand_write_page_raw;
3399		chip->ecc.write_oob = nand_write_oob_std;
3400		chip->ecc.size = mtd->writesize;
3401		chip->ecc.bytes = 0;
3402		chip->ecc.strength = 0;
3403		break;
3404
3405	default:
3406		pr_warn("Invalid NAND_ECC_MODE %d\n", chip->ecc.mode);
3407		BUG();
3408	}
3409
3410	/* For many systems, the standard OOB write also works for raw */
3411	if (!chip->ecc.read_oob_raw)
3412		chip->ecc.read_oob_raw = chip->ecc.read_oob;
3413	if (!chip->ecc.write_oob_raw)
3414		chip->ecc.write_oob_raw = chip->ecc.write_oob;
3415
3416	/*
3417	 * The number of bytes available for a client to place data into
3418	 * the out of band area.
3419	 */
3420	chip->ecc.layout->oobavail = 0;
3421	for (i = 0; chip->ecc.layout->oobfree[i].length
3422			&& i < ARRAY_SIZE(chip->ecc.layout->oobfree); i++)
3423		chip->ecc.layout->oobavail +=
3424			chip->ecc.layout->oobfree[i].length;
3425	mtd->oobavail = chip->ecc.layout->oobavail;
3426
3427	/*
3428	 * Set the number of read / write steps for one page depending on ECC
3429	 * mode.
3430	 */
3431	chip->ecc.steps = mtd->writesize / chip->ecc.size;
3432	if (chip->ecc.steps * chip->ecc.size != mtd->writesize) {
3433		pr_warn("Invalid ECC parameters\n");
3434		BUG();
3435	}
3436	chip->ecc.total = chip->ecc.steps * chip->ecc.bytes;
3437
3438	/* Allow subpage writes up to ecc.steps. Not possible for MLC flash */
3439	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) &&
3440	    !(chip->cellinfo & NAND_CI_CELLTYPE_MSK)) {
3441		switch (chip->ecc.steps) {
3442		case 2:
3443			mtd->subpage_sft = 1;
3444			break;
3445		case 4:
3446		case 8:
3447		case 16:
3448			mtd->subpage_sft = 2;
3449			break;
3450		}
3451	}
3452	chip->subpagesize = mtd->writesize >> mtd->subpage_sft;
3453
3454	/* Initialize state */
3455	chip->state = FL_READY;
3456
3457	/* De-select the device */
3458	chip->select_chip(mtd, -1);
3459
3460	/* Invalidate the pagebuffer reference */
3461	chip->pagebuf = -1;
3462
3463	/* Fill in remaining MTD driver data */
3464	mtd->type = MTD_NANDFLASH;
3465	mtd->flags = (chip->options & NAND_ROM) ? MTD_CAP_ROM :
3466						MTD_CAP_NANDFLASH;
3467	mtd->_erase = nand_erase;
3468	mtd->_point = NULL;
3469	mtd->_unpoint = NULL;
3470	mtd->_read = nand_read;
3471	mtd->_write = nand_write;
3472	mtd->_panic_write = panic_nand_write;
3473	mtd->_read_oob = nand_read_oob;
3474	mtd->_write_oob = nand_write_oob;
3475	mtd->_sync = nand_sync;
3476	mtd->_lock = NULL;
3477	mtd->_unlock = NULL;
3478	mtd->_suspend = nand_suspend;
3479	mtd->_resume = nand_resume;
3480	mtd->_block_isbad = nand_block_isbad;
3481	mtd->_block_markbad = nand_block_markbad;
3482	mtd->writebufsize = mtd->writesize;
3483
3484	/* propagate ecc info to mtd_info */
3485	mtd->ecclayout = chip->ecc.layout;
3486	mtd->ecc_strength = chip->ecc.strength * chip->ecc.steps;
3487
3488	/* Check, if we should skip the bad block table scan */
3489	if (chip->options & NAND_SKIP_BBTSCAN)
3490		return 0;
3491
3492	/* Build bad block table */
3493	return chip->scan_bbt(mtd);
3494}
3495EXPORT_SYMBOL(nand_scan_tail);
3496
3497/*
3498 * is_module_text_address() isn't exported, and it's mostly a pointless
3499 * test if this is a module _anyway_ -- they'd have to try _really_ hard
3500 * to call us from in-kernel code if the core NAND support is modular.
3501 */
3502#ifdef MODULE
3503#define caller_is_module() (1)
3504#else
3505#define caller_is_module() \
3506	is_module_text_address((unsigned long)__builtin_return_address(0))
3507#endif
3508
3509/**
3510 * nand_scan - [NAND Interface] Scan for the NAND device
3511 * @mtd: MTD device structure
3512 * @maxchips: number of chips to scan for
3513 *
3514 * This fills out all the uninitialized function pointers with the defaults.
3515 * The flash ID is read and the mtd/chip structures are filled with the
3516 * appropriate values. The mtd->owner field must be set to the module of the
3517 * caller.
3518 */
3519int nand_scan(struct mtd_info *mtd, int maxchips)
3520{
3521	int ret;
3522
3523	/* Many callers got this wrong, so check for it for a while... */
3524	if (!mtd->owner && caller_is_module()) {
3525		pr_crit("%s called with NULL mtd->owner!\n", __func__);
3526		BUG();
3527	}
3528
3529	ret = nand_scan_ident(mtd, maxchips, NULL);
3530	if (!ret)
3531		ret = nand_scan_tail(mtd);
3532	return ret;
3533}
3534EXPORT_SYMBOL(nand_scan);
3535
3536/**
3537 * nand_release - [NAND Interface] Free resources held by the NAND device
3538 * @mtd: MTD device structure
3539 */
3540void nand_release(struct mtd_info *mtd)
3541{
3542	struct nand_chip *chip = mtd->priv;
3543
3544	if (chip->ecc.mode == NAND_ECC_SOFT_BCH)
3545		nand_bch_free((struct nand_bch_control *)chip->ecc.priv);
3546
3547	mtd_device_unregister(mtd);
3548
3549	/* Free bad block table memory */
3550	kfree(chip->bbt);
3551	if (!(chip->options & NAND_OWN_BUFFERS))
3552		kfree(chip->buffers);
3553
3554	/* Free bad block descriptor memory */
3555	if (chip->badblock_pattern && chip->badblock_pattern->options
3556			& NAND_BBT_DYNAMICSTRUCT)
3557		kfree(chip->badblock_pattern);
3558}
3559EXPORT_SYMBOL_GPL(nand_release);
3560
3561static int __init nand_base_init(void)
3562{
3563	led_trigger_register_simple("nand-disk", &nand_led_trigger);
3564	return 0;
3565}
3566
3567static void __exit nand_base_exit(void)
3568{
3569	led_trigger_unregister_simple(nand_led_trigger);
3570}
3571
3572module_init(nand_base_init);
3573module_exit(nand_base_exit);
3574
3575MODULE_LICENSE("GPL");
3576MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>");
3577MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
3578MODULE_DESCRIPTION("Generic NAND flash driver code");
3579