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/tech/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 *
28 * This program is free software; you can redistribute it and/or modify
29 * it under the terms of the GNU General Public License version 2 as
30 * published by the Free Software Foundation.
31 *
32 */
33
34#include <linux/module.h>
35#include <linux/delay.h>
36#include <linux/errno.h>
37#include <linux/err.h>
38#include <linux/sched.h>
39#include <linux/slab.h>
40#include <linux/types.h>
41#include <linux/mtd/mtd.h>
42#include <linux/mtd/nand.h>
43#include <linux/mtd/nand_ecc.h>
44#include <linux/mtd/compatmac.h>
45#include <linux/interrupt.h>
46#include <linux/bitops.h>
47#include <linux/leds.h>
48#include <asm/io.h>
49
50#ifdef CONFIG_MTD_PARTITIONS
51#include <linux/mtd/partitions.h>
52#endif
53
54/* Define default oob placement schemes for large and small page devices */
55static struct nand_ecclayout nand_oob_8 = {
56	.eccbytes = 3,
57	.eccpos = {0, 1, 2},
58	.oobfree = {
59		{.offset = 3,
60		 .length = 2},
61		{.offset = 6,
62		 .length = 2}}
63};
64
65static struct nand_ecclayout nand_oob_16 = {
66	.eccbytes = 6,
67	.eccpos = {0, 1, 2, 3, 6, 7},
68	.oobfree = {
69		{.offset = 8,
70		 . length = 8}}
71};
72
73static struct nand_ecclayout nand_oob_64 = {
74	.eccbytes = 24,
75	.eccpos = {
76		   40, 41, 42, 43, 44, 45, 46, 47,
77		   48, 49, 50, 51, 52, 53, 54, 55,
78		   56, 57, 58, 59, 60, 61, 62, 63},
79	.oobfree = {
80		{.offset = 2,
81		 .length = 38}}
82};
83
84static int nand_get_device(struct nand_chip *chip, struct mtd_info *mtd,
85			   int new_state);
86
87static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
88			     struct mtd_oob_ops *ops);
89
90/*
91 * For devices which display every fart in the system on a seperate LED. Is
92 * compiled away when LED support is disabled.
93 */
94DEFINE_LED_TRIGGER(nand_led_trigger);
95
96/**
97 * nand_release_device - [GENERIC] release chip
98 * @mtd:	MTD device structure
99 *
100 * Deselect, release chip lock and wake up anyone waiting on the device
101 */
102static void nand_release_device(struct mtd_info *mtd)
103{
104	struct nand_chip *chip = mtd->priv;
105
106#ifdef CONFIG_MTD_BRCMNAND
107	if (chip->release_device) {
108		chip->release_device(mtd);
109		return;
110	}
111#endif /* CONFIG_MTD_BRCMNAND */
112
113	/* De-select the NAND device */
114	chip->select_chip(mtd, -1);
115
116	/* Release the controller and the chip */
117	spin_lock(&chip->controller->lock);
118	chip->controller->active = NULL;
119	chip->state = FL_READY;
120	wake_up(&chip->controller->wq);
121	spin_unlock(&chip->controller->lock);
122}
123
124/**
125 * nand_read_byte - [DEFAULT] read one byte from the chip
126 * @mtd:	MTD device structure
127 *
128 * Default read function for 8bit buswith
129 */
130static uint8_t nand_read_byte(struct mtd_info *mtd)
131{
132	struct nand_chip *chip = mtd->priv;
133	return readb(chip->IO_ADDR_R);
134}
135
136/**
137 * nand_read_byte16 - [DEFAULT] read one byte endianess aware from the chip
138 * @mtd:	MTD device structure
139 *
140 * Default read function for 16bit buswith with
141 * endianess conversion
142 */
143static uint8_t nand_read_byte16(struct mtd_info *mtd)
144{
145	struct nand_chip *chip = mtd->priv;
146	return (uint8_t) cpu_to_le16(readw(chip->IO_ADDR_R));
147}
148
149/**
150 * nand_read_word - [DEFAULT] read one word from the chip
151 * @mtd:	MTD device structure
152 *
153 * Default read function for 16bit buswith without
154 * endianess conversion
155 */
156static u16 nand_read_word(struct mtd_info *mtd)
157{
158	struct nand_chip *chip = mtd->priv;
159	return readw(chip->IO_ADDR_R);
160}
161
162/**
163 * nand_select_chip - [DEFAULT] control CE line
164 * @mtd:	MTD device structure
165 * @chipnr:	chipnumber to select, -1 for deselect
166 *
167 * Default select function for 1 chip devices.
168 */
169static void nand_select_chip(struct mtd_info *mtd, int chipnr)
170{
171	struct nand_chip *chip = mtd->priv;
172
173	switch (chipnr) {
174	case -1:
175		chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0 | NAND_CTRL_CHANGE);
176		break;
177	case 0:
178		break;
179
180	default:
181		BUG();
182	}
183}
184
185/**
186 * nand_write_buf - [DEFAULT] write buffer to chip
187 * @mtd:	MTD device structure
188 * @buf:	data buffer
189 * @len:	number of bytes to write
190 *
191 * Default write function for 8bit buswith
192 */
193static void nand_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
194{
195	int i;
196	struct nand_chip *chip = mtd->priv;
197
198	for (i = 0; i < len; i++)
199		writeb(buf[i], chip->IO_ADDR_W);
200}
201
202/**
203 * nand_read_buf - [DEFAULT] read chip data into buffer
204 * @mtd:	MTD device structure
205 * @buf:	buffer to store date
206 * @len:	number of bytes to read
207 *
208 * Default read function for 8bit buswith
209 */
210static void nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
211{
212	int i;
213	struct nand_chip *chip = mtd->priv;
214
215	for (i = 0; i < len; i++)
216		buf[i] = readb(chip->IO_ADDR_R);
217}
218
219/**
220 * nand_verify_buf - [DEFAULT] Verify chip data against buffer
221 * @mtd:	MTD device structure
222 * @buf:	buffer containing the data to compare
223 * @len:	number of bytes to compare
224 *
225 * Default verify function for 8bit buswith
226 */
227static int nand_verify_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
228{
229	int i;
230	struct nand_chip *chip = mtd->priv;
231
232	for (i = 0; i < len; i++)
233		if (buf[i] != readb(chip->IO_ADDR_R))
234			return -EFAULT;
235	return 0;
236}
237
238/**
239 * nand_write_buf16 - [DEFAULT] write buffer to chip
240 * @mtd:	MTD device structure
241 * @buf:	data buffer
242 * @len:	number of bytes to write
243 *
244 * Default write function for 16bit buswith
245 */
246static void nand_write_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
247{
248	int i;
249	struct nand_chip *chip = mtd->priv;
250	u16 *p = (u16 *) buf;
251	len >>= 1;
252
253	for (i = 0; i < len; i++)
254		writew(p[i], chip->IO_ADDR_W);
255
256}
257
258/**
259 * nand_read_buf16 - [DEFAULT] read chip data into buffer
260 * @mtd:	MTD device structure
261 * @buf:	buffer to store date
262 * @len:	number of bytes to read
263 *
264 * Default read function for 16bit buswith
265 */
266static void nand_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
267{
268	int i;
269	struct nand_chip *chip = mtd->priv;
270	u16 *p = (u16 *) buf;
271	len >>= 1;
272
273	for (i = 0; i < len; i++)
274		p[i] = readw(chip->IO_ADDR_R);
275}
276
277/**
278 * nand_verify_buf16 - [DEFAULT] Verify chip data against buffer
279 * @mtd:	MTD device structure
280 * @buf:	buffer containing the data to compare
281 * @len:	number of bytes to compare
282 *
283 * Default verify function for 16bit buswith
284 */
285static int nand_verify_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
286{
287	int i;
288	struct nand_chip *chip = mtd->priv;
289	u16 *p = (u16 *) buf;
290	len >>= 1;
291
292	for (i = 0; i < len; i++)
293		if (p[i] != readw(chip->IO_ADDR_R))
294			return -EFAULT;
295
296	return 0;
297}
298
299/**
300 * nand_block_bad - [DEFAULT] Read bad block marker from the chip
301 * @mtd:	MTD device structure
302 * @ofs:	offset from device start
303 * @getchip:	0, if the chip is already selected
304 *
305 * Check, if the block is bad.
306 */
307static int nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
308{
309	int page, chipnr, res = 0;
310	struct nand_chip *chip = mtd->priv;
311	u16 bad;
312
313	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
314
315	if (getchip) {
316		chipnr = (int)(ofs >> chip->chip_shift);
317
318		nand_get_device(chip, mtd, FL_READING);
319
320		/* Select the NAND device */
321		chip->select_chip(mtd, chipnr);
322	}
323
324	if (chip->options & NAND_BUSWIDTH_16) {
325		chip->cmdfunc(mtd, NAND_CMD_READOOB, chip->badblockpos & 0xFE,
326			      page);
327		bad = cpu_to_le16(chip->read_word(mtd));
328		if (chip->badblockpos & 0x1)
329			bad >>= 8;
330		if ((bad & 0xFF) != 0xff)
331			res = 1;
332	} else {
333		chip->cmdfunc(mtd, NAND_CMD_READOOB, chip->badblockpos, page);
334		if (chip->read_byte(mtd) != 0xff)
335			res = 1;
336	}
337
338	if (getchip)
339		nand_release_device(mtd);
340
341	return res;
342}
343
344/**
345 * nand_default_block_markbad - [DEFAULT] mark a block bad
346 * @mtd:	MTD device structure
347 * @ofs:	offset from device start
348 *
349 * This is the default implementation, which can be overridden by
350 * a hardware specific driver.
351*/
352static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
353{
354	struct nand_chip *chip = mtd->priv;
355	uint8_t buf[2] = { 0, 0 };
356	int block, ret;
357
358	/* Get block number */
359	block = (int)(ofs >> chip->bbt_erase_shift);
360	if (chip->bbt)
361		chip->bbt[block >> 2] |= 0x01 << ((block & 0x03) << 1);
362
363	/* Do we have a flash based bad block table ? */
364	if (chip->options & NAND_USE_FLASH_BBT)
365		ret = nand_update_bbt(mtd, ofs);
366	else {
367		/* We write two bytes, so we dont have to mess with 16 bit
368		 * access
369		 */
370		/* Patched from Linux 2.6.27.57 */
371		nand_get_device(chip, mtd, FL_WRITING);
372
373		ofs += mtd->oobsize;
374		chip->ops.len = chip->ops.ooblen = 2;
375		chip->ops.datbuf = NULL;
376		chip->ops.oobbuf = buf;
377		chip->ops.ooboffs = chip->badblockpos & ~0x01;
378
379		ret = nand_do_write_oob(mtd, ofs, &chip->ops);
380
381		/* Patched from Linux 2.6.27.57 */
382		nand_release_device(mtd);
383	}
384	if (!ret)
385		mtd->ecc_stats.badblocks++;
386	return ret;
387}
388
389/**
390 * nand_check_wp - [GENERIC] check if the chip is write protected
391 * @mtd:	MTD device structure
392 * Check, if the device is write protected
393 *
394 * The function expects, that the device is already selected
395 */
396static int nand_check_wp(struct mtd_info *mtd)
397{
398	struct nand_chip *chip = mtd->priv;
399	/* Check the WP bit */
400	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
401	return (chip->read_byte(mtd) & NAND_STATUS_WP) ? 0 : 1;
402}
403
404/**
405 * nand_block_checkbad - [GENERIC] Check if a block is marked bad
406 * @mtd:	MTD device structure
407 * @ofs:	offset from device start
408 * @getchip:	0, if the chip is already selected
409 * @allowbbt:	1, if its allowed to access the bbt area
410 *
411 * Check, if the block is bad. Either by reading the bad block table or
412 * calling of the scan function.
413 */
414static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip,
415			       int allowbbt)
416{
417	struct nand_chip *chip = mtd->priv;
418
419	if (!chip->bbt)
420		return chip->block_bad(mtd, ofs, getchip);
421
422	/* Return info from the table */
423	return nand_isbad_bbt(mtd, ofs, allowbbt);
424}
425
426/*
427 * Wait for the ready pin, after a command
428 * The timeout is catched later.
429 */
430void nand_wait_ready(struct mtd_info *mtd)
431{
432	struct nand_chip *chip = mtd->priv;
433	unsigned long timeo = jiffies + 2;
434
435	led_trigger_event(nand_led_trigger, LED_FULL);
436	/* wait until command is processed or timeout occures */
437	do {
438		if (chip->dev_ready(mtd))
439			break;
440		touch_softlockup_watchdog();
441	} while (time_before(jiffies, timeo));
442	led_trigger_event(nand_led_trigger, LED_OFF);
443}
444EXPORT_SYMBOL_GPL(nand_wait_ready);
445
446/**
447 * nand_command - [DEFAULT] Send command to NAND device
448 * @mtd:	MTD device structure
449 * @command:	the command to be sent
450 * @column:	the column address for this command, -1 if none
451 * @page_addr:	the page address for this command, -1 if none
452 *
453 * Send command to NAND device. This function is used for small page
454 * devices (256/512 Bytes per page)
455 */
456static void nand_command(struct mtd_info *mtd, unsigned int command,
457			 int column, int page_addr)
458{
459	register struct nand_chip *chip = mtd->priv;
460	int ctrl = NAND_CTRL_CLE | NAND_CTRL_CHANGE;
461
462	/*
463	 * Write out the command to the device.
464	 */
465	if (command == NAND_CMD_SEQIN) {
466		int readcmd;
467
468		if (column >= mtd->writesize) {
469			/* OOB area */
470			column -= mtd->writesize;
471			readcmd = NAND_CMD_READOOB;
472		} else if (column < 256) {
473			/* First 256 bytes --> READ0 */
474			readcmd = NAND_CMD_READ0;
475		} else {
476			column -= 256;
477			readcmd = NAND_CMD_READ1;
478		}
479		chip->cmd_ctrl(mtd, readcmd, ctrl);
480		ctrl &= ~NAND_CTRL_CHANGE;
481	}
482	chip->cmd_ctrl(mtd, command, ctrl);
483
484	/*
485	 * Address cycle, when necessary
486	 */
487	ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE;
488	/* Serially input address */
489	if (column != -1) {
490		/* Adjust columns for 16 bit buswidth */
491		if (chip->options & NAND_BUSWIDTH_16)
492			column >>= 1;
493		chip->cmd_ctrl(mtd, column, ctrl);
494		ctrl &= ~NAND_CTRL_CHANGE;
495	}
496	if (page_addr != -1) {
497		chip->cmd_ctrl(mtd, page_addr, ctrl);
498		ctrl &= ~NAND_CTRL_CHANGE;
499		chip->cmd_ctrl(mtd, page_addr >> 8, ctrl);
500		/* One more address cycle for devices > 32MiB */
501		if (chip->chipsize > (32 << 20))
502			chip->cmd_ctrl(mtd, page_addr >> 16, ctrl);
503	}
504	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
505
506	/*
507	 * program and erase have their own busy handlers
508	 * status and sequential in needs no delay
509	 */
510	switch (command) {
511
512	case NAND_CMD_PAGEPROG:
513	case NAND_CMD_ERASE1:
514	case NAND_CMD_ERASE2:
515	case NAND_CMD_SEQIN:
516	case NAND_CMD_STATUS:
517		return;
518
519	case NAND_CMD_RESET:
520		if (chip->dev_ready)
521			break;
522		udelay(chip->chip_delay);
523		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
524			       NAND_CTRL_CLE | NAND_CTRL_CHANGE);
525		chip->cmd_ctrl(mtd,
526			       NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
527		while (!(chip->read_byte(mtd) & NAND_STATUS_READY)) ;
528		return;
529
530		/* This applies to read commands */
531	default:
532		/*
533		 * If we don't have access to the busy pin, we apply the given
534		 * command delay
535		 */
536		if (!chip->dev_ready) {
537			udelay(chip->chip_delay);
538			return;
539		}
540	}
541	/* Apply this short delay always to ensure that we do wait tWB in
542	 * any case on any machine. */
543	ndelay(100);
544
545	nand_wait_ready(mtd);
546}
547
548/**
549 * nand_command_lp - [DEFAULT] Send command to NAND large page device
550 * @mtd:	MTD device structure
551 * @command:	the command to be sent
552 * @column:	the column address for this command, -1 if none
553 * @page_addr:	the page address for this command, -1 if none
554 *
555 * Send command to NAND device. This is the version for the new large page
556 * devices We dont have the separate regions as we have in the small page
557 * devices.  We must emulate NAND_CMD_READOOB to keep the code compatible.
558 */
559static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
560			    int column, int page_addr)
561{
562	register struct nand_chip *chip = mtd->priv;
563
564	/* Emulate NAND_CMD_READOOB */
565	if (command == NAND_CMD_READOOB) {
566		column += mtd->writesize;
567		command = NAND_CMD_READ0;
568	}
569
570	/* Command latch cycle */
571	chip->cmd_ctrl(mtd, command & 0xff,
572		       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
573
574	if (column != -1 || page_addr != -1) {
575		int ctrl = NAND_CTRL_CHANGE | NAND_NCE | NAND_ALE;
576
577		/* Serially input address */
578		if (column != -1) {
579			/* Adjust columns for 16 bit buswidth */
580			if (chip->options & NAND_BUSWIDTH_16)
581				column >>= 1;
582			chip->cmd_ctrl(mtd, column, ctrl);
583			ctrl &= ~NAND_CTRL_CHANGE;
584			chip->cmd_ctrl(mtd, column >> 8, ctrl);
585		}
586		if (page_addr != -1) {
587			chip->cmd_ctrl(mtd, page_addr, ctrl);
588			chip->cmd_ctrl(mtd, page_addr >> 8,
589				       NAND_NCE | NAND_ALE);
590			/* One more address cycle for devices > 128MiB */
591			if (chip->chipsize > (128 << 20))
592				chip->cmd_ctrl(mtd, page_addr >> 16,
593					       NAND_NCE | NAND_ALE);
594		}
595	}
596	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
597
598	/*
599	 * program and erase have their own busy handlers
600	 * status, sequential in, and deplete1 need no delay
601	 */
602	switch (command) {
603
604	case NAND_CMD_CACHEDPROG:
605	case NAND_CMD_PAGEPROG:
606	case NAND_CMD_ERASE1:
607	case NAND_CMD_ERASE2:
608	case NAND_CMD_SEQIN:
609	case NAND_CMD_RNDIN:
610	case NAND_CMD_STATUS:
611	case NAND_CMD_DEPLETE1:
612		return;
613
614		/*
615		 * read error status commands require only a short delay
616		 */
617	case NAND_CMD_STATUS_ERROR:
618	case NAND_CMD_STATUS_ERROR0:
619	case NAND_CMD_STATUS_ERROR1:
620	case NAND_CMD_STATUS_ERROR2:
621	case NAND_CMD_STATUS_ERROR3:
622		udelay(chip->chip_delay);
623		return;
624
625	case NAND_CMD_RESET:
626		if (chip->dev_ready)
627			break;
628		udelay(chip->chip_delay);
629		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
630			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
631		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
632			       NAND_NCE | NAND_CTRL_CHANGE);
633		while (!(chip->read_byte(mtd) & NAND_STATUS_READY)) ;
634		return;
635
636	case NAND_CMD_RNDOUT:
637		/* No ready / busy check necessary */
638		chip->cmd_ctrl(mtd, NAND_CMD_RNDOUTSTART,
639			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
640		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
641			       NAND_NCE | NAND_CTRL_CHANGE);
642		return;
643
644	case NAND_CMD_READ0:
645		chip->cmd_ctrl(mtd, NAND_CMD_READSTART,
646			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
647		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
648			       NAND_NCE | NAND_CTRL_CHANGE);
649
650		/* This applies to read commands */
651	default:
652		/*
653		 * If we don't have access to the busy pin, we apply the given
654		 * command delay
655		 */
656		if (!chip->dev_ready) {
657			udelay(chip->chip_delay);
658			return;
659		}
660	}
661
662	/* Apply this short delay always to ensure that we do wait tWB in
663	 * any case on any machine. */
664	ndelay(100);
665
666	nand_wait_ready(mtd);
667}
668
669/**
670 * nand_get_device - [GENERIC] Get chip for selected access
671 * @chip:	the nand chip descriptor
672 * @mtd:	MTD device structure
673 * @new_state:	the state which is requested
674 *
675 * Get the device and lock it for exclusive access
676 */
677static int
678nand_get_device(struct nand_chip *chip, struct mtd_info *mtd, int new_state)
679{
680	spinlock_t *lock = &chip->controller->lock;
681	wait_queue_head_t *wq = &chip->controller->wq;
682	DECLARE_WAITQUEUE(wait, current);
683
684#ifdef CONFIG_MTD_BRCMNAND
685	if (chip->get_device) {
686		return (chip->get_device(chip, mtd, new_state));
687	}
688#endif /* CONFIG_MTD_BRCMNAND */
689
690 retry:
691	spin_lock(lock);
692
693	/* Hardware controller shared among independend devices */
694	/* Hardware controller shared among independend devices */
695	if (!chip->controller->active)
696		chip->controller->active = chip;
697
698	if (chip->controller->active == chip && chip->state == FL_READY) {
699		chip->state = new_state;
700		spin_unlock(lock);
701		return 0;
702	}
703	if (new_state == FL_PM_SUSPENDED) {
704		spin_unlock(lock);
705		return (chip->state == FL_PM_SUSPENDED) ? 0 : -EAGAIN;
706	}
707	set_current_state(TASK_UNINTERRUPTIBLE);
708	add_wait_queue(wq, &wait);
709	spin_unlock(lock);
710	schedule();
711	remove_wait_queue(wq, &wait);
712	goto retry;
713}
714
715/**
716 * nand_wait - [DEFAULT]  wait until the command is done
717 * @mtd:	MTD device structure
718 * @chip:	NAND chip structure
719 *
720 * Wait for command done. This applies to erase and program only
721 * Erase can take up to 400ms and program up to 20ms according to
722 * general NAND and SmartMedia specs
723 */
724static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
725{
726
727	unsigned long timeo = jiffies;
728	int status, state = chip->state;
729
730	if (state == FL_ERASING)
731		timeo += (HZ * 400) / 1000;
732	else
733		timeo += (HZ * 20) / 1000;
734
735	led_trigger_event(nand_led_trigger, LED_FULL);
736
737	/* Apply this short delay always to ensure that we do wait tWB in
738	 * any case on any machine. */
739	ndelay(100);
740
741	if ((state == FL_ERASING) && (chip->options & NAND_IS_AND))
742		chip->cmdfunc(mtd, NAND_CMD_STATUS_MULTI, -1, -1);
743	else
744		chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
745
746	while (time_before(jiffies, timeo)) {
747		if (chip->dev_ready) {
748			if (chip->dev_ready(mtd))
749				break;
750		} else {
751			if (chip->read_byte(mtd) & NAND_STATUS_READY)
752				break;
753		}
754		cond_resched();
755	}
756	led_trigger_event(nand_led_trigger, LED_OFF);
757
758	status = (int)chip->read_byte(mtd);
759	return status;
760}
761
762/**
763 * nand_read_page_raw - [Intern] read raw page data without ecc
764 * @mtd:	mtd info structure
765 * @chip:	nand chip info structure
766 * @buf:	buffer to store read data
767 */
768static int nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
769			      uint8_t *buf)
770{
771	chip->read_buf(mtd, buf, mtd->writesize);
772	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
773	return 0;
774}
775
776/**
777 * nand_read_page_swecc - [REPLACABLE] software ecc based page read function
778 * @mtd:	mtd info structure
779 * @chip:	nand chip info structure
780 * @buf:	buffer to store read data
781 */
782static int nand_read_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
783				uint8_t *buf)
784{
785	int i, eccsize = chip->ecc.size;
786	int eccbytes = chip->ecc.bytes;
787	int eccsteps = chip->ecc.steps;
788	uint8_t *p = buf;
789	uint8_t *ecc_calc = chip->buffers->ecccalc;
790	uint8_t *ecc_code = chip->buffers->ecccode;
791	int *eccpos = chip->ecc.layout->eccpos;
792
793	chip->ecc.read_page_raw(mtd, chip, buf);
794
795	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
796		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
797
798	for (i = 0; i < chip->ecc.total; i++)
799		ecc_code[i] = chip->oob_poi[eccpos[i]];
800
801	eccsteps = chip->ecc.steps;
802	p = buf;
803
804	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
805		int stat;
806
807		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
808		if (stat == -1)
809			mtd->ecc_stats.failed++;
810		else
811			mtd->ecc_stats.corrected += stat;
812	}
813	return 0;
814}
815
816/**
817 * nand_read_subpage - [REPLACABLE] software ecc based sub-page read function
818 * @mtd:	mtd info structure
819 * @chip:	nand chip info structure
820 * @dataofs	offset of requested data within the page
821 * @readlen	data length
822 * @buf:	buffer to store read data
823 * Note: 	This function is patched from Linux 2.6.27.57
824 */
825static int nand_read_subpage(struct mtd_info *mtd, struct nand_chip *chip, uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi)
826{
827	int start_step, end_step, num_steps;
828	uint32_t *eccpos = chip->ecc.layout->eccpos;
829	uint8_t *p;
830	int data_col_addr, i, gaps = 0;
831	int datafrag_len, eccfrag_len, aligned_len, aligned_pos;
832	int busw = (chip->options & NAND_BUSWIDTH_16) ? 2 : 1;
833
834	/* Column address wihin the page aligned to ECC size (256bytes). */
835	start_step = data_offs / chip->ecc.size;
836	end_step = (data_offs + readlen - 1) / chip->ecc.size;
837	num_steps = end_step - start_step + 1;
838
839	/* Data size aligned to ECC ecc.size*/
840	datafrag_len = num_steps * chip->ecc.size;
841	eccfrag_len = num_steps * chip->ecc.bytes;
842
843	data_col_addr = start_step * chip->ecc.size;
844	/* If we read not a page aligned data */
845	if (data_col_addr != 0)
846		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, data_col_addr, -1);
847
848	p = bufpoi + data_col_addr;
849	chip->read_buf(mtd, p, datafrag_len);
850
851	/* Calculate  ECC */
852	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size)
853		chip->ecc.calculate(mtd, p, &chip->buffers->ecccalc[i]);
854
855	/* The performance is faster if to position offsets
856	   according to ecc.pos. Let make sure here that
857	   there are no gaps in ecc positions */
858	for (i = 0; i < eccfrag_len - 1; i++) {
859		if (eccpos[i + start_step * chip->ecc.bytes] + 1 !=
860			eccpos[i + start_step * chip->ecc.bytes + 1]) {
861			gaps = 1;
862			break;
863		}
864	}
865	if (gaps) {
866		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);
867		chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
868	} else {
869		/* send the command to read the particular ecc bytes */
870		/* take care about buswidth alignment in read_buf */
871		aligned_pos = eccpos[start_step * chip->ecc.bytes] & ~(busw - 1);
872		aligned_len = eccfrag_len;
873		if (eccpos[start_step * chip->ecc.bytes] & (busw - 1))
874			aligned_len++;
875		if (eccpos[(start_step + num_steps) * chip->ecc.bytes] & (busw - 1))
876			aligned_len++;
877
878		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize + aligned_pos, -1);
879		chip->read_buf(mtd, &chip->oob_poi[aligned_pos], aligned_len);
880	}
881
882	for (i = 0; i < eccfrag_len; i++)
883		chip->buffers->ecccode[i] = chip->oob_poi[eccpos[i + start_step * chip->ecc.bytes]];
884
885	p = bufpoi + data_col_addr;
886	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size) {
887		int stat;
888
889		stat = chip->ecc.correct(mtd, p, &chip->buffers->ecccode[i], &chip->buffers->ecccalc[i]);
890		if (stat == -1)
891			mtd->ecc_stats.failed++;
892		else
893			mtd->ecc_stats.corrected += stat;
894	}
895	return 0;
896}
897
898/**
899 * nand_read_page_hwecc - [REPLACABLE] hardware ecc based page read function
900 * @mtd:	mtd info structure
901 * @chip:	nand chip info structure
902 * @buf:	buffer to store read data
903 *
904 * Not for syndrome calculating ecc controllers which need a special oob layout
905 */
906static int nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
907				uint8_t *buf)
908{
909	int i, eccsize = chip->ecc.size;
910	int eccbytes = chip->ecc.bytes;
911	int eccsteps = chip->ecc.steps;
912	uint8_t *p = buf;
913	uint8_t *ecc_calc = chip->buffers->ecccalc;
914	uint8_t *ecc_code = chip->buffers->ecccode;
915	int *eccpos = chip->ecc.layout->eccpos;
916
917	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
918		chip->ecc.hwctl(mtd, NAND_ECC_READ);
919		chip->read_buf(mtd, p, eccsize);
920		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
921	}
922	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
923
924	for (i = 0; i < chip->ecc.total; i++)
925		ecc_code[i] = chip->oob_poi[eccpos[i]];
926
927	eccsteps = chip->ecc.steps;
928	p = buf;
929
930	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
931		int stat;
932
933		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
934		if (stat == -1)
935			mtd->ecc_stats.failed++;
936		else
937			mtd->ecc_stats.corrected += stat;
938	}
939	return 0;
940}
941
942/**
943 * nand_read_page_syndrome - [REPLACABLE] hardware ecc syndrom based page read
944 * @mtd:	mtd info structure
945 * @chip:	nand chip info structure
946 * @buf:	buffer to store read data
947 *
948 * The hw generator calculates the error syndrome automatically. Therefor
949 * we need a special oob layout and handling.
950 */
951static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
952				   uint8_t *buf)
953{
954	int i, eccsize = chip->ecc.size;
955	int eccbytes = chip->ecc.bytes;
956	int eccsteps = chip->ecc.steps;
957	uint8_t *p = buf;
958	uint8_t *oob = chip->oob_poi;
959
960	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
961		int stat;
962
963		chip->ecc.hwctl(mtd, NAND_ECC_READ);
964		chip->read_buf(mtd, p, eccsize);
965
966		if (chip->ecc.prepad) {
967			chip->read_buf(mtd, oob, chip->ecc.prepad);
968			oob += chip->ecc.prepad;
969		}
970
971		chip->ecc.hwctl(mtd, NAND_ECC_READSYN);
972		chip->read_buf(mtd, oob, eccbytes);
973		stat = chip->ecc.correct(mtd, p, oob, NULL);
974
975		if (stat == -1)
976			mtd->ecc_stats.failed++;
977		else
978			mtd->ecc_stats.corrected += stat;
979
980		oob += eccbytes;
981
982		if (chip->ecc.postpad) {
983			chip->read_buf(mtd, oob, chip->ecc.postpad);
984			oob += chip->ecc.postpad;
985		}
986	}
987
988	/* Calculate remaining oob bytes */
989	i = mtd->oobsize - (oob - chip->oob_poi);
990	if (i)
991		chip->read_buf(mtd, oob, i);
992
993	return 0;
994}
995
996/**
997 * nand_transfer_oob - [Internal] Transfer oob to client buffer
998 * @chip:	nand chip structure
999 * @oob:	oob destination address
1000 * @ops:	oob ops structure
1001 * @len:	size of oob to transfer
1002 */
1003static uint8_t *nand_transfer_oob(struct nand_chip *chip, uint8_t *oob,
1004				  struct mtd_oob_ops *ops, size_t len)
1005{
1006	switch(ops->mode) {
1007
1008	case MTD_OOB_PLACE:
1009	case MTD_OOB_RAW:
1010		memcpy(oob, chip->oob_poi + ops->ooboffs, len);
1011		return oob + len;
1012
1013	case MTD_OOB_AUTO: {
1014		struct nand_oobfree *free = chip->ecc.layout->oobfree;
1015		uint32_t boffs = 0, roffs = ops->ooboffs;
1016		size_t bytes = 0;
1017
1018		for(; free->length && len; free++, len -= bytes) {
1019			/* Read request not from offset 0 ? */
1020			if (unlikely(roffs)) {
1021				if (roffs >= free->length) {
1022					roffs -= free->length;
1023					continue;
1024				}
1025				boffs = free->offset + roffs;
1026				bytes = min_t(size_t, len,
1027					      (free->length - roffs));
1028				roffs = 0;
1029			} else {
1030				bytes = min_t(size_t, len, free->length);
1031				boffs = free->offset;
1032			}
1033			memcpy(oob, chip->oob_poi + boffs, bytes);
1034			oob += bytes;
1035		}
1036		return oob;
1037	}
1038	default:
1039		BUG();
1040	}
1041	return NULL;
1042}
1043
1044/**
1045 * nand_do_read_ops - [Internal] Read data with ECC
1046 *
1047 * @mtd:	MTD device structure
1048 * @from:	offset to read from
1049 * @ops:	oob ops structure
1050 *
1051 * Internal function. Called with chip held.
1052 */
1053static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
1054			    struct mtd_oob_ops *ops)
1055{
1056	int chipnr, page, realpage, col, bytes, aligned;
1057	struct nand_chip *chip = mtd->priv;
1058	struct mtd_ecc_stats stats;
1059	int blkcheck = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
1060	int sndcmd = 1;
1061	int ret = 0;
1062	uint32_t readlen = ops->len;
1063	uint32_t oobreadlen = ops->ooblen;
1064	uint8_t *bufpoi, *oob, *buf;
1065
1066	stats = mtd->ecc_stats;
1067
1068	chipnr = (int)(from >> chip->chip_shift);
1069	chip->select_chip(mtd, chipnr);
1070
1071	realpage = (int)(from >> chip->page_shift);
1072	page = realpage & chip->pagemask;
1073
1074	col = (int)(from & (mtd->writesize - 1));
1075
1076	buf = ops->datbuf;
1077	oob = ops->oobbuf;
1078
1079	while(1) {
1080		bytes = min(mtd->writesize - col, readlen);
1081		aligned = (bytes == mtd->writesize);
1082
1083		/* Is the current page in the buffer ? */
1084		if (realpage != chip->pagebuf || oob) {
1085			bufpoi = aligned ? buf : chip->buffers->databuf;
1086
1087			if (likely(sndcmd)) {
1088				chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
1089				sndcmd = 0;
1090			}
1091
1092			/* Now read the page into the buffer */
1093			if (unlikely(ops->mode == MTD_OOB_RAW))
1094				ret = chip->ecc.read_page_raw(mtd, chip, bufpoi);
1095			/* Patched from Linux 2.6.27.57 */
1096			else if (!aligned && NAND_SUBPAGE_READ(chip) && !oob)
1097				ret = chip->ecc.read_subpage(mtd, chip, col, bytes, bufpoi);
1098			else
1099				ret = chip->ecc.read_page(mtd, chip, bufpoi);
1100			if (ret < 0)
1101				break;
1102
1103			/* Transfer not aligned data */
1104			if (!aligned) {
1105				/* Patched from Linux 2.6.27.57 */
1106				if (!NAND_SUBPAGE_READ(chip) && !oob)
1107					chip->pagebuf = realpage;
1108				memcpy(buf, chip->buffers->databuf + col, bytes);
1109			}
1110
1111			buf += bytes;
1112
1113			if (unlikely(oob)) {
1114				/* Raw mode does data:oob:data:oob */
1115				if (ops->mode != MTD_OOB_RAW) {
1116					int toread = min(oobreadlen,
1117						chip->ecc.layout->oobavail);
1118					if (toread) {
1119						oob = nand_transfer_oob(chip,
1120							oob, ops, toread);
1121						oobreadlen -= toread;
1122					}
1123				} else
1124					buf = nand_transfer_oob(chip,
1125						buf, ops, mtd->oobsize);
1126			}
1127
1128			if (!(chip->options & NAND_NO_READRDY)) {
1129				/*
1130				 * Apply delay or wait for ready/busy pin. Do
1131				 * this before the AUTOINCR check, so no
1132				 * problems arise if a chip which does auto
1133				 * increment is marked as NOAUTOINCR by the
1134				 * board driver.
1135				 */
1136				if (!chip->dev_ready)
1137					udelay(chip->chip_delay);
1138				else
1139					nand_wait_ready(mtd);
1140			}
1141		} else {
1142			memcpy(buf, chip->buffers->databuf + col, bytes);
1143			buf += bytes;
1144		}
1145
1146		readlen -= bytes;
1147
1148		if (!readlen)
1149			break;
1150
1151		/* For subsequent reads align to page boundary. */
1152		col = 0;
1153		/* Increment page address */
1154		realpage++;
1155
1156		page = realpage & chip->pagemask;
1157		/* Check, if we cross a chip boundary */
1158		if (!page) {
1159			chipnr++;
1160			chip->select_chip(mtd, -1);
1161			chip->select_chip(mtd, chipnr);
1162		}
1163
1164		/* Check, if the chip supports auto page increment
1165		 * or if we have hit a block boundary.
1166		 */
1167		if (!NAND_CANAUTOINCR(chip) || !(page & blkcheck))
1168			sndcmd = 1;
1169	}
1170
1171	ops->retlen = ops->len - (size_t) readlen;
1172	if (oob)
1173		ops->oobretlen = ops->ooblen - oobreadlen;
1174
1175	if (ret)
1176		return ret;
1177
1178	if (mtd->ecc_stats.failed - stats.failed)
1179		return -EBADMSG;
1180
1181	return  mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
1182}
1183
1184/**
1185 * nand_read - [MTD Interface] MTD compability function for nand_do_read_ecc
1186 * @mtd:	MTD device structure
1187 * @from:	offset to read from
1188 * @len:	number of bytes to read
1189 * @retlen:	pointer to variable to store the number of read bytes
1190 * @buf:	the databuffer to put data
1191 *
1192 * Get hold of the chip and call nand_do_read
1193 */
1194static int nand_read(struct mtd_info *mtd, loff_t from, size_t len,
1195		     size_t *retlen, uint8_t *buf)
1196{
1197	struct nand_chip *chip = mtd->priv;
1198	int ret;
1199
1200	/* Do not allow reads past end of device */
1201	if ((from + len) > mtd->size)
1202		return -EINVAL;
1203	if (!len)
1204		return 0;
1205
1206	nand_get_device(chip, mtd, FL_READING);
1207
1208	chip->ops.len = len;
1209	chip->ops.datbuf = buf;
1210	chip->ops.oobbuf = NULL;
1211
1212	ret = nand_do_read_ops(mtd, from, &chip->ops);
1213
1214	*retlen = chip->ops.retlen;
1215
1216	nand_release_device(mtd);
1217
1218	return ret;
1219}
1220
1221/**
1222 * nand_read_oob_std - [REPLACABLE] the most common OOB data read function
1223 * @mtd:	mtd info structure
1224 * @chip:	nand chip info structure
1225 * @page:	page number to read
1226 * @sndcmd:	flag whether to issue read command or not
1227 */
1228static int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
1229			     int page, int sndcmd)
1230{
1231	if (sndcmd) {
1232		chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
1233		sndcmd = 0;
1234	}
1235	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1236	return sndcmd;
1237}
1238
1239/**
1240 * nand_read_oob_syndrome - [REPLACABLE] OOB data read function for HW ECC
1241 *			    with syndromes
1242 * @mtd:	mtd info structure
1243 * @chip:	nand chip info structure
1244 * @page:	page number to read
1245 * @sndcmd:	flag whether to issue read command or not
1246 */
1247static int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
1248				  int page, int sndcmd)
1249{
1250	uint8_t *buf = chip->oob_poi;
1251	int length = mtd->oobsize;
1252	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
1253	int eccsize = chip->ecc.size;
1254	uint8_t *bufpoi = buf;
1255	int i, toread, sndrnd = 0, pos;
1256
1257	chip->cmdfunc(mtd, NAND_CMD_READ0, chip->ecc.size, page);
1258	for (i = 0; i < chip->ecc.steps; i++) {
1259		if (sndrnd) {
1260			pos = eccsize + i * (eccsize + chunk);
1261			if (mtd->writesize > 512)
1262				chip->cmdfunc(mtd, NAND_CMD_RNDOUT, pos, -1);
1263			else
1264				chip->cmdfunc(mtd, NAND_CMD_READ0, pos, page);
1265		} else
1266			sndrnd = 1;
1267		toread = min_t(int, length, chunk);
1268		chip->read_buf(mtd, bufpoi, toread);
1269		bufpoi += toread;
1270		length -= toread;
1271	}
1272	if (length > 0)
1273		chip->read_buf(mtd, bufpoi, length);
1274
1275	return 1;
1276}
1277
1278/**
1279 * nand_write_oob_std - [REPLACABLE] the most common OOB data write function
1280 * @mtd:	mtd info structure
1281 * @chip:	nand chip info structure
1282 * @page:	page number to write
1283 */
1284static int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
1285			      int page)
1286{
1287	int status = 0;
1288	const uint8_t *buf = chip->oob_poi;
1289	int length = mtd->oobsize;
1290
1291	chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, page);
1292	chip->write_buf(mtd, buf, length);
1293	/* Send command to program the OOB data */
1294	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1295
1296	status = chip->waitfunc(mtd, chip);
1297
1298	return status & NAND_STATUS_FAIL ? -EIO : 0;
1299}
1300
1301/**
1302 * nand_write_oob_syndrome - [REPLACABLE] OOB data write function for HW ECC
1303 *			     with syndrome - only for large page flash !
1304 * @mtd:	mtd info structure
1305 * @chip:	nand chip info structure
1306 * @page:	page number to write
1307 */
1308static int nand_write_oob_syndrome(struct mtd_info *mtd,
1309				   struct nand_chip *chip, int page)
1310{
1311	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
1312	int eccsize = chip->ecc.size, length = mtd->oobsize;
1313	int i, len, pos, status = 0, sndcmd = 0, steps = chip->ecc.steps;
1314	const uint8_t *bufpoi = chip->oob_poi;
1315
1316	/*
1317	 * data-ecc-data-ecc ... ecc-oob
1318	 * or
1319	 * data-pad-ecc-pad-data-pad .... ecc-pad-oob
1320	 */
1321	if (!chip->ecc.prepad && !chip->ecc.postpad) {
1322		pos = steps * (eccsize + chunk);
1323		steps = 0;
1324	} else
1325		pos = eccsize;
1326
1327	chip->cmdfunc(mtd, NAND_CMD_SEQIN, pos, page);
1328	for (i = 0; i < steps; i++) {
1329		if (sndcmd) {
1330			if (mtd->writesize <= 512) {
1331				uint32_t fill = 0xFFFFFFFF;
1332
1333				len = eccsize;
1334				while (len > 0) {
1335					int num = min_t(int, len, 4);
1336					chip->write_buf(mtd, (uint8_t *)&fill,
1337							num);
1338					len -= num;
1339				}
1340			} else {
1341				pos = eccsize + i * (eccsize + chunk);
1342				chip->cmdfunc(mtd, NAND_CMD_RNDIN, pos, -1);
1343			}
1344		} else
1345			sndcmd = 1;
1346		len = min_t(int, length, chunk);
1347		chip->write_buf(mtd, bufpoi, len);
1348		bufpoi += len;
1349		length -= len;
1350	}
1351	if (length > 0)
1352		chip->write_buf(mtd, bufpoi, length);
1353
1354	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1355	status = chip->waitfunc(mtd, chip);
1356
1357	return status & NAND_STATUS_FAIL ? -EIO : 0;
1358}
1359
1360/**
1361 * nand_do_read_oob - [Intern] NAND read out-of-band
1362 * @mtd:	MTD device structure
1363 * @from:	offset to read from
1364 * @ops:	oob operations description structure
1365 *
1366 * NAND read out-of-band data from the spare area
1367 */
1368static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
1369			    struct mtd_oob_ops *ops)
1370{
1371	int page, realpage, chipnr, sndcmd = 1;
1372	struct nand_chip *chip = mtd->priv;
1373	int blkcheck = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
1374	int readlen = ops->ooblen;
1375	int len;
1376	uint8_t *buf = ops->oobbuf;
1377
1378	DEBUG(MTD_DEBUG_LEVEL3, "nand_read_oob: from = 0x%08Lx, len = %i\n",
1379	      (unsigned long long)from, readlen);
1380
1381	if (ops->mode == MTD_OOB_AUTO)
1382		len = chip->ecc.layout->oobavail;
1383	else
1384		len = mtd->oobsize;
1385
1386	if (unlikely(ops->ooboffs >= len)) {
1387		DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: "
1388			"Attempt to start read outside oob\n");
1389		return -EINVAL;
1390	}
1391
1392	/* Do not allow reads past end of device */
1393	if (unlikely(from >= mtd->size ||
1394		     ops->ooboffs + readlen > ((mtd->size >> chip->page_shift) -
1395					(from >> chip->page_shift)) * len)) {
1396		DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: "
1397			"Attempt read beyond end of device\n");
1398		return -EINVAL;
1399	}
1400
1401	chipnr = (int)(from >> chip->chip_shift);
1402	chip->select_chip(mtd, chipnr);
1403
1404	/* Shift to get page */
1405	realpage = (int)(from >> chip->page_shift);
1406	page = realpage & chip->pagemask;
1407
1408	while(1) {
1409		sndcmd = chip->ecc.read_oob(mtd, chip, page, sndcmd);
1410
1411		len = min(len, readlen);
1412		buf = nand_transfer_oob(chip, buf, ops, len);
1413
1414		if (!(chip->options & NAND_NO_READRDY)) {
1415			/*
1416			 * Apply delay or wait for ready/busy pin. Do this
1417			 * before the AUTOINCR check, so no problems arise if a
1418			 * chip which does auto increment is marked as
1419			 * NOAUTOINCR by the board driver.
1420			 */
1421			if (!chip->dev_ready)
1422				udelay(chip->chip_delay);
1423			else
1424				nand_wait_ready(mtd);
1425		}
1426
1427		readlen -= len;
1428		if (!readlen)
1429			break;
1430
1431		/* Increment page address */
1432		realpage++;
1433
1434		page = realpage & chip->pagemask;
1435		/* Check, if we cross a chip boundary */
1436		if (!page) {
1437			chipnr++;
1438			chip->select_chip(mtd, -1);
1439			chip->select_chip(mtd, chipnr);
1440		}
1441
1442		/* Check, if the chip supports auto page increment
1443		 * or if we have hit a block boundary.
1444		 */
1445		if (!NAND_CANAUTOINCR(chip) || !(page & blkcheck))
1446			sndcmd = 1;
1447	}
1448
1449	ops->oobretlen = ops->ooblen;
1450	return 0;
1451}
1452
1453/**
1454 * nand_read_oob - [MTD Interface] NAND read data and/or out-of-band
1455 * @mtd:	MTD device structure
1456 * @from:	offset to read from
1457 * @ops:	oob operation description structure
1458 *
1459 * NAND read data and/or out-of-band data
1460 */
1461static int nand_read_oob(struct mtd_info *mtd, loff_t from,
1462			 struct mtd_oob_ops *ops)
1463{
1464	struct nand_chip *chip = mtd->priv;
1465	int ret = -ENOTSUPP;
1466
1467	ops->retlen = 0;
1468
1469	/* Do not allow reads past end of device */
1470	if (ops->datbuf && (from + ops->len) > mtd->size) {
1471		DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: "
1472		      "Attempt read beyond end of device\n");
1473		return -EINVAL;
1474	}
1475
1476	nand_get_device(chip, mtd, FL_READING);
1477
1478	switch(ops->mode) {
1479	case MTD_OOB_PLACE:
1480	case MTD_OOB_AUTO:
1481	case MTD_OOB_RAW:
1482		break;
1483
1484	default:
1485		goto out;
1486	}
1487
1488	if (!ops->datbuf)
1489		ret = nand_do_read_oob(mtd, from, ops);
1490	else
1491		ret = nand_do_read_ops(mtd, from, ops);
1492
1493 out:
1494	nand_release_device(mtd);
1495	return ret;
1496}
1497
1498
1499/**
1500 * nand_write_page_raw - [Intern] raw page write function
1501 * @mtd:	mtd info structure
1502 * @chip:	nand chip info structure
1503 * @buf:	data buffer
1504 */
1505static void nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
1506				const uint8_t *buf)
1507{
1508	chip->write_buf(mtd, buf, mtd->writesize);
1509	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
1510}
1511
1512/**
1513 * nand_write_page_swecc - [REPLACABLE] software ecc based page write function
1514 * @mtd:	mtd info structure
1515 * @chip:	nand chip info structure
1516 * @buf:	data buffer
1517 */
1518static void nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
1519				  const uint8_t *buf)
1520{
1521	int i, eccsize = chip->ecc.size;
1522	int eccbytes = chip->ecc.bytes;
1523	int eccsteps = chip->ecc.steps;
1524	uint8_t *ecc_calc = chip->buffers->ecccalc;
1525	const uint8_t *p = buf;
1526	int *eccpos = chip->ecc.layout->eccpos;
1527
1528	/* Software ecc calculation */
1529	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
1530		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1531
1532	for (i = 0; i < chip->ecc.total; i++)
1533		chip->oob_poi[eccpos[i]] = ecc_calc[i];
1534
1535	chip->ecc.write_page_raw(mtd, chip, buf);
1536}
1537
1538/**
1539 * nand_write_page_hwecc - [REPLACABLE] hardware ecc based page write function
1540 * @mtd:	mtd info structure
1541 * @chip:	nand chip info structure
1542 * @buf:	data buffer
1543 */
1544static void nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
1545				  const uint8_t *buf)
1546{
1547	int i, eccsize = chip->ecc.size;
1548	int eccbytes = chip->ecc.bytes;
1549	int eccsteps = chip->ecc.steps;
1550	uint8_t *ecc_calc = chip->buffers->ecccalc;
1551	const uint8_t *p = buf;
1552	int *eccpos = chip->ecc.layout->eccpos;
1553
1554	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1555		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
1556		chip->write_buf(mtd, p, eccsize);
1557		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1558	}
1559
1560	for (i = 0; i < chip->ecc.total; i++)
1561		chip->oob_poi[eccpos[i]] = ecc_calc[i];
1562
1563	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
1564}
1565
1566/**
1567 * nand_write_page_syndrome - [REPLACABLE] hardware ecc syndrom based page write
1568 * @mtd:	mtd info structure
1569 * @chip:	nand chip info structure
1570 * @buf:	data buffer
1571 *
1572 * The hw generator calculates the error syndrome automatically. Therefor
1573 * we need a special oob layout and handling.
1574 */
1575static void nand_write_page_syndrome(struct mtd_info *mtd,
1576				    struct nand_chip *chip, const uint8_t *buf)
1577{
1578	int i, eccsize = chip->ecc.size;
1579	int eccbytes = chip->ecc.bytes;
1580	int eccsteps = chip->ecc.steps;
1581	const uint8_t *p = buf;
1582	uint8_t *oob = chip->oob_poi;
1583
1584	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1585
1586		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
1587		chip->write_buf(mtd, p, eccsize);
1588
1589		if (chip->ecc.prepad) {
1590			chip->write_buf(mtd, oob, chip->ecc.prepad);
1591			oob += chip->ecc.prepad;
1592		}
1593
1594		chip->ecc.calculate(mtd, p, oob);
1595		chip->write_buf(mtd, oob, eccbytes);
1596		oob += eccbytes;
1597
1598		if (chip->ecc.postpad) {
1599			chip->write_buf(mtd, oob, chip->ecc.postpad);
1600			oob += chip->ecc.postpad;
1601		}
1602	}
1603
1604	/* Calculate remaining oob bytes */
1605	i = mtd->oobsize - (oob - chip->oob_poi);
1606	if (i)
1607		chip->write_buf(mtd, oob, i);
1608}
1609
1610/**
1611 * nand_write_page - [REPLACEABLE] write one page
1612 * @mtd:	MTD device structure
1613 * @chip:	NAND chip descriptor
1614 * @buf:	the data to write
1615 * @page:	page number to write
1616 * @cached:	cached programming
1617 * @raw:	use _raw version of write_page
1618 */
1619static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
1620			   const uint8_t *buf, int page, int cached, int raw)
1621{
1622	int status;
1623
1624	chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
1625
1626	if (unlikely(raw))
1627		chip->ecc.write_page_raw(mtd, chip, buf);
1628	else
1629		chip->ecc.write_page(mtd, chip, buf);
1630
1631	/*
1632	 * Cached progamming disabled for now, Not sure if its worth the
1633	 * trouble. The speed gain is not very impressive. (2.3->2.6Mib/s)
1634	 */
1635	cached = 0;
1636
1637	if (!cached || !(chip->options & NAND_CACHEPRG)) {
1638
1639		chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1640		status = chip->waitfunc(mtd, chip);
1641		/*
1642		 * See if operation failed and additional status checks are
1643		 * available
1644		 */
1645		if ((status & NAND_STATUS_FAIL) && (chip->errstat))
1646			status = chip->errstat(mtd, chip, FL_WRITING, status,
1647					       page);
1648
1649		if (status & NAND_STATUS_FAIL)
1650			return -EIO;
1651	} else {
1652		chip->cmdfunc(mtd, NAND_CMD_CACHEDPROG, -1, -1);
1653		status = chip->waitfunc(mtd, chip);
1654	}
1655
1656#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
1657	/* Send command to read back the data */
1658	chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
1659
1660	if (chip->verify_buf(mtd, buf, mtd->writesize))
1661		return -EIO;
1662#endif
1663	return 0;
1664}
1665
1666/**
1667 * nand_fill_oob - [Internal] Transfer client buffer to oob
1668 * @chip:	nand chip structure
1669 * @oob:	oob data buffer
1670 * @ops:	oob ops structure
1671 */
1672static uint8_t *nand_fill_oob(struct nand_chip *chip, uint8_t *oob,
1673				  struct mtd_oob_ops *ops)
1674{
1675	size_t len = ops->ooblen;
1676
1677	switch(ops->mode) {
1678
1679	case MTD_OOB_PLACE:
1680	case MTD_OOB_RAW:
1681		memcpy(chip->oob_poi + ops->ooboffs, oob, len);
1682		return oob + len;
1683
1684	case MTD_OOB_AUTO: {
1685		struct nand_oobfree *free = chip->ecc.layout->oobfree;
1686		uint32_t boffs = 0, woffs = ops->ooboffs;
1687		size_t bytes = 0;
1688
1689		for(; free->length && len; free++, len -= bytes) {
1690			/* Write request not from offset 0 ? */
1691			if (unlikely(woffs)) {
1692				if (woffs >= free->length) {
1693					woffs -= free->length;
1694					continue;
1695				}
1696				boffs = free->offset + woffs;
1697				bytes = min_t(size_t, len,
1698					      (free->length - woffs));
1699				woffs = 0;
1700			} else {
1701				bytes = min_t(size_t, len, free->length);
1702				boffs = free->offset;
1703			}
1704			memcpy(chip->oob_poi + boffs, oob, bytes);
1705			oob += bytes;
1706		}
1707		return oob;
1708	}
1709	default:
1710		BUG();
1711	}
1712	return NULL;
1713}
1714
1715#define NOTALIGNED(x)	(x & (chip->subpagesize - 1)) != 0
1716
1717/**
1718 * nand_do_write_ops - [Internal] NAND write with ECC
1719 * @mtd:	MTD device structure
1720 * @to:		offset to write to
1721 * @ops:	oob operations description structure
1722 *
1723 * NAND write with ECC
1724 */
1725static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
1726			     struct mtd_oob_ops *ops)
1727{
1728	int chipnr, realpage, page, blockmask, column;
1729	struct nand_chip *chip = mtd->priv;
1730	uint32_t writelen = ops->len;
1731	uint8_t *oob = ops->oobbuf;
1732	uint8_t *buf = ops->datbuf;
1733	int ret, subpage;
1734
1735	ops->retlen = 0;
1736	if (!writelen)
1737		return 0;
1738
1739	/* reject writes, which are not page aligned */
1740	if (NOTALIGNED(to) || NOTALIGNED(ops->len)) {
1741		printk(KERN_NOTICE "nand_write: "
1742		       "Attempt to write not page aligned data\n");
1743		return -EINVAL;
1744	}
1745
1746	column = to & (mtd->writesize - 1);
1747	subpage = column || (writelen & (mtd->writesize - 1));
1748
1749	if (subpage && oob)
1750		return -EINVAL;
1751
1752	chipnr = (int)(to >> chip->chip_shift);
1753	chip->select_chip(mtd, chipnr);
1754
1755	/* Check, if it is write protected */
1756	if (nand_check_wp(mtd))
1757		return -EIO;
1758
1759	realpage = (int)(to >> chip->page_shift);
1760	page = realpage & chip->pagemask;
1761	blockmask = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
1762
1763	/* Invalidate the page cache, when we write to the cached page */
1764	if (to <= (chip->pagebuf << chip->page_shift) &&
1765	    (chip->pagebuf << chip->page_shift) < (to + ops->len))
1766		chip->pagebuf = -1;
1767
1768	/* If we're not given explicit OOB data, let it be 0xFF */
1769	if (likely(!oob))
1770		memset(chip->oob_poi, 0xff, mtd->oobsize);
1771
1772	while(1) {
1773		int bytes = mtd->writesize;
1774		int cached = writelen > bytes && page != blockmask;
1775		uint8_t *wbuf = buf;
1776
1777		/* Partial page write ? */
1778		if (unlikely(column || writelen < (mtd->writesize - 1))) {
1779			cached = 0;
1780			bytes = min_t(int, bytes - column, (int) writelen);
1781			chip->pagebuf = -1;
1782			memset(chip->buffers->databuf, 0xff, mtd->writesize);
1783			memcpy(&chip->buffers->databuf[column], buf, bytes);
1784			wbuf = chip->buffers->databuf;
1785		}
1786
1787		if (unlikely(oob))
1788			oob = nand_fill_oob(chip, oob, ops);
1789
1790		ret = chip->write_page(mtd, chip, wbuf, page, cached,
1791				       (ops->mode == MTD_OOB_RAW));
1792		if (ret)
1793			break;
1794
1795		writelen -= bytes;
1796		if (!writelen)
1797			break;
1798
1799		column = 0;
1800		buf += bytes;
1801		realpage++;
1802
1803		page = realpage & chip->pagemask;
1804		/* Check, if we cross a chip boundary */
1805		if (!page) {
1806			chipnr++;
1807			chip->select_chip(mtd, -1);
1808			chip->select_chip(mtd, chipnr);
1809		}
1810	}
1811
1812	ops->retlen = ops->len - writelen;
1813	if (unlikely(oob))
1814		ops->oobretlen = ops->ooblen;
1815	return ret;
1816}
1817
1818/**
1819 * nand_write - [MTD Interface] NAND write with ECC
1820 * @mtd:	MTD device structure
1821 * @to:		offset to write to
1822 * @len:	number of bytes to write
1823 * @retlen:	pointer to variable to store the number of written bytes
1824 * @buf:	the data to write
1825 *
1826 * NAND write with ECC
1827 */
1828static int nand_write(struct mtd_info *mtd, loff_t to, size_t len,
1829			  size_t *retlen, const uint8_t *buf)
1830{
1831	struct nand_chip *chip = mtd->priv;
1832	int ret;
1833
1834	/* Do not allow reads past end of device */
1835	if ((to + len) > mtd->size)
1836		return -EINVAL;
1837	if (!len)
1838		return 0;
1839
1840	nand_get_device(chip, mtd, FL_WRITING);
1841
1842	chip->ops.len = len;
1843	chip->ops.datbuf = (uint8_t *)buf;
1844	chip->ops.oobbuf = NULL;
1845
1846	ret = nand_do_write_ops(mtd, to, &chip->ops);
1847
1848	*retlen = chip->ops.retlen;
1849
1850	nand_release_device(mtd);
1851
1852	return ret;
1853}
1854
1855/**
1856 * nand_do_write_oob - [MTD Interface] NAND write out-of-band
1857 * @mtd:	MTD device structure
1858 * @to:		offset to write to
1859 * @ops:	oob operation description structure
1860 *
1861 * NAND write out-of-band
1862 */
1863static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
1864			     struct mtd_oob_ops *ops)
1865{
1866	int chipnr, page, status, len;
1867	struct nand_chip *chip = mtd->priv;
1868
1869	DEBUG(MTD_DEBUG_LEVEL3, "nand_write_oob: to = 0x%08x, len = %i\n",
1870	      (unsigned int)to, (int)ops->ooblen);
1871
1872	if (ops->mode == MTD_OOB_AUTO)
1873		len = chip->ecc.layout->oobavail;
1874	else
1875		len = mtd->oobsize;
1876
1877	/* Do not allow write past end of page */
1878	if ((ops->ooboffs + ops->ooblen) > len) {
1879		DEBUG(MTD_DEBUG_LEVEL0, "nand_write_oob: "
1880		      "Attempt to write past end of page\n");
1881		return -EINVAL;
1882	}
1883
1884	if (unlikely(ops->ooboffs >= len)) {
1885		DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: "
1886			"Attempt to start write outside oob\n");
1887		return -EINVAL;
1888	}
1889
1890	/* Do not allow reads past end of device */
1891	if (unlikely(to >= mtd->size ||
1892		     ops->ooboffs + ops->ooblen >
1893			((mtd->size >> chip->page_shift) -
1894			 (to >> chip->page_shift)) * len)) {
1895		DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: "
1896			"Attempt write beyond end of device\n");
1897		return -EINVAL;
1898	}
1899
1900	chipnr = (int)(to >> chip->chip_shift);
1901	chip->select_chip(mtd, chipnr);
1902
1903	/* Shift to get page */
1904	page = (int)(to >> chip->page_shift);
1905
1906	/*
1907	 * Reset the chip. Some chips (like the Toshiba TC5832DC found in one
1908	 * of my DiskOnChip 2000 test units) will clear the whole data page too
1909	 * if we don't do this. I have no clue why, but I seem to have 'fixed'
1910	 * it in the doc2000 driver in August 1999.  dwmw2.
1911	 */
1912	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
1913
1914	/* Check, if it is write protected */
1915	if (nand_check_wp(mtd))
1916		return -EROFS;
1917
1918	/* Invalidate the page cache, if we write to the cached page */
1919	if (page == chip->pagebuf)
1920		chip->pagebuf = -1;
1921
1922	memset(chip->oob_poi, 0xff, mtd->oobsize);
1923	nand_fill_oob(chip, ops->oobbuf, ops);
1924	status = chip->ecc.write_oob(mtd, chip, page & chip->pagemask);
1925	memset(chip->oob_poi, 0xff, mtd->oobsize);
1926
1927	if (status)
1928		return status;
1929
1930	ops->oobretlen = ops->ooblen;
1931
1932	return 0;
1933}
1934
1935/**
1936 * nand_write_oob - [MTD Interface] NAND write data and/or out-of-band
1937 * @mtd:	MTD device structure
1938 * @to:		offset to write to
1939 * @ops:	oob operation description structure
1940 */
1941static int nand_write_oob(struct mtd_info *mtd, loff_t to,
1942			  struct mtd_oob_ops *ops)
1943{
1944	struct nand_chip *chip = mtd->priv;
1945	int ret = -ENOTSUPP;
1946
1947	ops->retlen = 0;
1948
1949	/* Do not allow writes past end of device */
1950	if (ops->datbuf && (to + ops->len) > mtd->size) {
1951		DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: "
1952		      "Attempt read beyond end of device\n");
1953		return -EINVAL;
1954	}
1955
1956	nand_get_device(chip, mtd, FL_WRITING);
1957
1958	switch(ops->mode) {
1959	case MTD_OOB_PLACE:
1960	case MTD_OOB_AUTO:
1961	case MTD_OOB_RAW:
1962		break;
1963
1964	default:
1965		goto out;
1966	}
1967
1968	if (!ops->datbuf)
1969		ret = nand_do_write_oob(mtd, to, ops);
1970	else
1971		ret = nand_do_write_ops(mtd, to, ops);
1972
1973 out:
1974	nand_release_device(mtd);
1975	return ret;
1976}
1977
1978/**
1979 * single_erease_cmd - [GENERIC] NAND standard block erase command function
1980 * @mtd:	MTD device structure
1981 * @page:	the page address of the block which will be erased
1982 *
1983 * Standard erase command for NAND chips
1984 */
1985static void single_erase_cmd(struct mtd_info *mtd, int page)
1986{
1987	struct nand_chip *chip = mtd->priv;
1988	/* Send commands to erase a block */
1989	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
1990	chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
1991}
1992
1993/**
1994 * multi_erease_cmd - [GENERIC] AND specific block erase command function
1995 * @mtd:	MTD device structure
1996 * @page:	the page address of the block which will be erased
1997 *
1998 * AND multi block erase command function
1999 * Erase 4 consecutive blocks
2000 */
2001static void multi_erase_cmd(struct mtd_info *mtd, int page)
2002{
2003	struct nand_chip *chip = mtd->priv;
2004	/* Send commands to erase a block */
2005	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
2006	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
2007	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
2008	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
2009	chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
2010}
2011
2012/**
2013 * nand_erase - [MTD Interface] erase block(s)
2014 * @mtd:	MTD device structure
2015 * @instr:	erase instruction
2016 *
2017 * Erase one ore more blocks
2018 */
2019static int nand_erase(struct mtd_info *mtd, struct erase_info *instr)
2020{
2021	return nand_erase_nand(mtd, instr, 0);
2022}
2023
2024#define BBT_PAGE_MASK	0xffffff3f
2025/**
2026 * nand_erase_nand - [Internal] erase block(s)
2027 * @mtd:	MTD device structure
2028 * @instr:	erase instruction
2029 * @allowbbt:	allow erasing the bbt area
2030 *
2031 * Erase one ore more blocks
2032 */
2033int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
2034		    int allowbbt)
2035{
2036	int page, len, status, pages_per_block, ret, chipnr;
2037	struct nand_chip *chip = mtd->priv;
2038	int rewrite_bbt[NAND_MAX_CHIPS]={0};
2039	unsigned int bbt_masked_page = 0xffffffff;
2040
2041	DEBUG(MTD_DEBUG_LEVEL3, "nand_erase: start = 0x%08x, len = %i\n",
2042	      (unsigned int)instr->addr, (unsigned int)instr->len);
2043
2044	/* Start address must align on block boundary */
2045	if (instr->addr & ((1 << chip->phys_erase_shift) - 1)) {
2046		DEBUG(MTD_DEBUG_LEVEL0, "nand_erase: Unaligned address\n");
2047		return -EINVAL;
2048	}
2049
2050	/* Length must align on block boundary */
2051	if (instr->len & ((1 << chip->phys_erase_shift) - 1)) {
2052		DEBUG(MTD_DEBUG_LEVEL0, "nand_erase: "
2053		      "Length not block aligned\n");
2054		return -EINVAL;
2055	}
2056
2057	/* Do not allow erase past end of device */
2058	if ((instr->len + instr->addr) > mtd->size) {
2059		DEBUG(MTD_DEBUG_LEVEL0, "nand_erase: "
2060		      "Erase past end of device\n");
2061		return -EINVAL;
2062	}
2063
2064	instr->fail_addr = 0xffffffff;
2065
2066	/* Grab the lock and see if the device is available */
2067	nand_get_device(chip, mtd, FL_ERASING);
2068
2069	/* Shift to get first page */
2070	page = (int)(instr->addr >> chip->page_shift);
2071	chipnr = (int)(instr->addr >> chip->chip_shift);
2072
2073	/* Calculate pages in each block */
2074	pages_per_block = 1 << (chip->phys_erase_shift - chip->page_shift);
2075
2076	/* Select the NAND device */
2077	chip->select_chip(mtd, chipnr);
2078
2079	/* Check, if it is write protected */
2080	if (nand_check_wp(mtd)) {
2081		DEBUG(MTD_DEBUG_LEVEL0, "nand_erase: "
2082		      "Device is write protected!!!\n");
2083		instr->state = MTD_ERASE_FAILED;
2084		goto erase_exit;
2085	}
2086
2087	/*
2088	 * If BBT requires refresh, set the BBT page mask to see if the BBT
2089	 * should be rewritten. Otherwise the mask is set to 0xffffffff which
2090	 * can not be matched. This is also done when the bbt is actually
2091	 * erased to avoid recusrsive updates
2092	 */
2093	if (chip->options & BBT_AUTO_REFRESH && !allowbbt)
2094		bbt_masked_page = chip->bbt_td->pages[chipnr] & BBT_PAGE_MASK;
2095
2096	/* Loop through the pages */
2097	len = instr->len;
2098
2099	instr->state = MTD_ERASING;
2100
2101	while (len) {
2102		/*
2103		 * heck if we have a bad block, we do not erase bad blocks !
2104		 */
2105		if (nand_block_checkbad(mtd, ((loff_t) page) <<
2106					chip->page_shift, 0, allowbbt)) {
2107			printk(KERN_WARNING "nand_erase: attempt to erase a "
2108			       "bad block at page 0x%08x\n", page);
2109			instr->state = MTD_ERASE_FAILED;
2110			goto erase_exit;
2111		}
2112
2113		/*
2114		 * Invalidate the page cache, if we erase the block which
2115		 * contains the current cached page
2116		 */
2117		if (page <= chip->pagebuf && chip->pagebuf <
2118		    (page + pages_per_block))
2119			chip->pagebuf = -1;
2120
2121		chip->erase_cmd(mtd, page & chip->pagemask);
2122
2123		status = chip->waitfunc(mtd, chip);
2124
2125		/*
2126		 * See if operation failed and additional status checks are
2127		 * available
2128		 */
2129		if ((status & NAND_STATUS_FAIL) && (chip->errstat))
2130			status = chip->errstat(mtd, chip, FL_ERASING,
2131					       status, page);
2132
2133		/* See if block erase succeeded */
2134		if (status & NAND_STATUS_FAIL) {
2135			DEBUG(MTD_DEBUG_LEVEL0, "nand_erase: "
2136			      "Failed erase, page 0x%08x\n", page);
2137			instr->state = MTD_ERASE_FAILED;
2138			instr->fail_addr = (page << chip->page_shift);
2139			goto erase_exit;
2140		}
2141
2142		/*
2143		 * If BBT requires refresh, set the BBT rewrite flag to the
2144		 * page being erased
2145		 */
2146		if (bbt_masked_page != 0xffffffff &&
2147		    (page & BBT_PAGE_MASK) == bbt_masked_page)
2148			    rewrite_bbt[chipnr] = (page << chip->page_shift);
2149
2150		/* Increment page address and decrement length */
2151		len -= (1 << chip->phys_erase_shift);
2152		page += pages_per_block;
2153
2154		/* Check, if we cross a chip boundary */
2155		if (len && !(page & chip->pagemask)) {
2156			chipnr++;
2157			chip->select_chip(mtd, -1);
2158			chip->select_chip(mtd, chipnr);
2159
2160			/*
2161			 * If BBT requires refresh and BBT-PERCHIP, set the BBT
2162			 * page mask to see if this BBT should be rewritten
2163			 */
2164			if (bbt_masked_page != 0xffffffff &&
2165			    (chip->bbt_td->options & NAND_BBT_PERCHIP))
2166				bbt_masked_page = chip->bbt_td->pages[chipnr] &
2167					BBT_PAGE_MASK;
2168		}
2169	}
2170	instr->state = MTD_ERASE_DONE;
2171
2172 erase_exit:
2173
2174	ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
2175	/* Do call back function */
2176	if (!ret)
2177		mtd_erase_callback(instr);
2178
2179	/* Deselect and wake up anyone waiting on the device */
2180	nand_release_device(mtd);
2181
2182	/*
2183	 * If BBT requires refresh and erase was successful, rewrite any
2184	 * selected bad block tables
2185	 */
2186	if (bbt_masked_page == 0xffffffff || ret)
2187		return ret;
2188
2189	for (chipnr = 0; chipnr < chip->numchips; chipnr++) {
2190		if (!rewrite_bbt[chipnr])
2191			continue;
2192		/* update the BBT for chip */
2193		DEBUG(MTD_DEBUG_LEVEL0, "nand_erase_nand: nand_update_bbt "
2194		      "(%d:0x%0x 0x%0x)\n", chipnr, rewrite_bbt[chipnr],
2195		      chip->bbt_td->pages[chipnr]);
2196		nand_update_bbt(mtd, rewrite_bbt[chipnr]);
2197	}
2198
2199	/* Return more or less happy */
2200	return ret;
2201}
2202
2203/**
2204 * nand_sync - [MTD Interface] sync
2205 * @mtd:	MTD device structure
2206 *
2207 * Sync is actually a wait for chip ready function
2208 */
2209static void nand_sync(struct mtd_info *mtd)
2210{
2211	struct nand_chip *chip = mtd->priv;
2212
2213	DEBUG(MTD_DEBUG_LEVEL3, "nand_sync: called\n");
2214
2215	/* Grab the lock and see if the device is available */
2216	nand_get_device(chip, mtd, FL_SYNCING);
2217	/* Release it and go back */
2218	nand_release_device(mtd);
2219}
2220
2221/**
2222 * nand_block_isbad - [MTD Interface] Check if block at offset is bad
2223 * @mtd:	MTD device structure
2224 * @offs:	offset relative to mtd start
2225 */
2226static int nand_block_isbad(struct mtd_info *mtd, loff_t offs)
2227{
2228	/* Check for invalid offset */
2229	if (offs > mtd->size)
2230		return -EINVAL;
2231
2232	return nand_block_checkbad(mtd, offs, 1, 0);
2233}
2234
2235/**
2236 * nand_block_markbad - [MTD Interface] Mark block at the given offset as bad
2237 * @mtd:	MTD device structure
2238 * @ofs:	offset relative to mtd start
2239 */
2240static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
2241{
2242	struct nand_chip *chip = mtd->priv;
2243	int ret;
2244
2245	if ((ret = nand_block_isbad(mtd, ofs))) {
2246		/* If it was bad already, return success and do nothing. */
2247		if (ret > 0)
2248			return 0;
2249		return ret;
2250	}
2251
2252	return chip->block_markbad(mtd, ofs);
2253}
2254
2255/**
2256 * nand_suspend - [MTD Interface] Suspend the NAND flash
2257 * @mtd:	MTD device structure
2258 */
2259static int nand_suspend(struct mtd_info *mtd)
2260{
2261	struct nand_chip *chip = mtd->priv;
2262
2263	return nand_get_device(chip, mtd, FL_PM_SUSPENDED);
2264}
2265
2266/**
2267 * nand_resume - [MTD Interface] Resume the NAND flash
2268 * @mtd:	MTD device structure
2269 */
2270static void nand_resume(struct mtd_info *mtd)
2271{
2272	struct nand_chip *chip = mtd->priv;
2273
2274	if (chip->state == FL_PM_SUSPENDED)
2275		nand_release_device(mtd);
2276	else
2277		printk(KERN_ERR "nand_resume() called for a chip which is not "
2278		       "in suspended state\n");
2279}
2280
2281/*
2282 * Set default functions
2283 */
2284static void nand_set_defaults(struct nand_chip *chip, int busw)
2285{
2286	/* check for proper chip_delay setup, set 20us if not */
2287	if (!chip->chip_delay)
2288		chip->chip_delay = 20;
2289
2290	/* check, if a user supplied command function given */
2291	if (chip->cmdfunc == NULL)
2292		chip->cmdfunc = nand_command;
2293
2294	/* check, if a user supplied wait function given */
2295	if (chip->waitfunc == NULL)
2296		chip->waitfunc = nand_wait;
2297
2298	if (!chip->select_chip)
2299		chip->select_chip = nand_select_chip;
2300	if (!chip->read_byte)
2301		chip->read_byte = busw ? nand_read_byte16 : nand_read_byte;
2302	if (!chip->read_word)
2303		chip->read_word = nand_read_word;
2304	if (!chip->block_bad)
2305		chip->block_bad = nand_block_bad;
2306	if (!chip->block_markbad)
2307		chip->block_markbad = nand_default_block_markbad;
2308	if (!chip->write_buf)
2309		chip->write_buf = busw ? nand_write_buf16 : nand_write_buf;
2310	if (!chip->read_buf)
2311		chip->read_buf = busw ? nand_read_buf16 : nand_read_buf;
2312	if (!chip->verify_buf)
2313		chip->verify_buf = busw ? nand_verify_buf16 : nand_verify_buf;
2314	if (!chip->scan_bbt)
2315		chip->scan_bbt = nand_default_bbt;
2316
2317	if (!chip->controller) {
2318		chip->controller = &chip->hwcontrol;
2319		spin_lock_init(&chip->controller->lock);
2320		init_waitqueue_head(&chip->controller->wq);
2321	}
2322
2323}
2324
2325/*
2326 * Get the flash and manufacturer id and lookup if the type is supported
2327 */
2328static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
2329						  struct nand_chip *chip,
2330						  int busw, int *maf_id)
2331{
2332	struct nand_flash_dev *type = NULL;
2333	int i, dev_id, maf_idx;
2334	int tmp_id, tmp_manf;
2335
2336	/* Select the device */
2337	chip->select_chip(mtd, 0);
2338
2339	/* Send the command for reading device ID */
2340	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
2341
2342	/* Read manufacturer and device IDs */
2343	*maf_id = chip->read_byte(mtd);
2344	dev_id = chip->read_byte(mtd);
2345
2346	/* Try again to make sure, as some systems the bus-hold or other
2347	 * interface concerns can cause random data which looks like a
2348	 * possibly credible NAND flash to appear. If the two results do
2349	 * not match, ignore the device completely.
2350	 * Patched from Linux 2.6.27.57.
2351	 */
2352
2353	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
2354
2355	/* Read manufacturer and device IDs */
2356
2357	tmp_manf = chip->read_byte(mtd);
2358	tmp_id = chip->read_byte(mtd);
2359
2360	if (tmp_manf != *maf_id || tmp_id != dev_id) {
2361		printk(KERN_INFO "%s: second ID read did not match "
2362		       "%02x,%02x against %02x,%02x\n", __func__,
2363		       *maf_id, dev_id, tmp_manf, tmp_id);
2364		return ERR_PTR(-ENODEV);
2365	}
2366
2367	/* Lookup the flash id */
2368	for (i = 0; nand_flash_ids[i].name != NULL; i++) {
2369		if (dev_id == nand_flash_ids[i].id) {
2370			type =  &nand_flash_ids[i];
2371			break;
2372		}
2373	}
2374
2375	if (!type)
2376		return ERR_PTR(-ENODEV);
2377
2378	if (!mtd->name)
2379		mtd->name = type->name;
2380
2381	chip->chipsize = type->chipsize << 20;
2382
2383	/* Newer devices have all the information in additional id bytes */
2384	if (!type->pagesize) {
2385		int extid;
2386		/* The 3rd id byte holds MLC / multichip data */
2387		chip->cellinfo = chip->read_byte(mtd);
2388		/* The 4th id byte is the important one */
2389		extid = chip->read_byte(mtd);
2390		/* Calc pagesize */
2391		mtd->writesize = 1024 << (extid & 0x3);
2392		extid >>= 2;
2393		/* Calc oobsize */
2394		mtd->oobsize = (8 << (extid & 0x01)) * (mtd->writesize >> 9);
2395		extid >>= 2;
2396		/* Calc blocksize. Blocksize is multiples of 64KiB */
2397		mtd->erasesize = (64 * 1024) << (extid & 0x03);
2398		extid >>= 2;
2399		/* Get buswidth information */
2400		busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0;
2401
2402	} else {
2403		/*
2404		 * Old devices have chip data hardcoded in the device id table
2405		 */
2406		mtd->erasesize = type->erasesize;
2407		mtd->writesize = type->pagesize;
2408		mtd->oobsize = mtd->writesize / 32;
2409		busw = type->options & NAND_BUSWIDTH_16;
2410	}
2411
2412	/* Try to identify manufacturer */
2413	for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_idx++) {
2414		if (nand_manuf_ids[maf_idx].id == *maf_id)
2415			break;
2416	}
2417
2418	/*
2419	 * Check, if buswidth is correct. Hardware drivers should set
2420	 * chip correct !
2421	 */
2422	if (busw != (chip->options & NAND_BUSWIDTH_16)) {
2423		printk(KERN_INFO "NAND device: Manufacturer ID:"
2424		       " 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id,
2425		       dev_id, nand_manuf_ids[maf_idx].name, mtd->name);
2426		printk(KERN_WARNING "NAND bus width %d instead %d bit\n",
2427		       (chip->options & NAND_BUSWIDTH_16) ? 16 : 8,
2428		       busw ? 16 : 8);
2429		return ERR_PTR(-EINVAL);
2430	}
2431
2432	/* Calculate the address shift from the page size */
2433	chip->page_shift = ffs(mtd->writesize) - 1;
2434	/* Convert chipsize to number of pages per chip -1. */
2435	chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
2436
2437	chip->bbt_erase_shift = chip->phys_erase_shift =
2438		ffs(mtd->erasesize) - 1;
2439	chip->chip_shift = ffs(chip->chipsize) - 1;
2440
2441	/* Set the bad block position */
2442	chip->badblockpos = mtd->writesize > 512 ?
2443		NAND_LARGE_BADBLOCK_POS : NAND_SMALL_BADBLOCK_POS;
2444
2445	/* Get chip options, preserve non chip based options */
2446	chip->options &= ~NAND_CHIPOPTIONS_MSK;
2447	chip->options |= type->options & NAND_CHIPOPTIONS_MSK;
2448
2449	/*
2450	 * Set chip as a default. Board drivers can override it, if necessary
2451	 */
2452	chip->options |= NAND_NO_AUTOINCR;
2453
2454	/* Check if chip is a not a samsung device. Do not clear the
2455	 * options for chips which are not having an extended id.
2456	 */
2457	if (*maf_id != NAND_MFR_SAMSUNG && !type->pagesize)
2458		chip->options &= ~NAND_SAMSUNG_LP_OPTIONS;
2459
2460	/* Check for AND chips with 4 page planes */
2461	if (chip->options & NAND_4PAGE_ARRAY)
2462		chip->erase_cmd = multi_erase_cmd;
2463	else
2464		chip->erase_cmd = single_erase_cmd;
2465
2466	/* Do not replace user supplied command function ! */
2467	if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
2468		chip->cmdfunc = nand_command_lp;
2469
2470	printk(KERN_INFO "NAND device: Manufacturer ID:"
2471	       " 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id, dev_id,
2472	       nand_manuf_ids[maf_idx].name, type->name);
2473
2474#ifdef CONFIG_MTD_BRCMNAND
2475	DEBUG(MTD_DEBUG_LEVEL3, "NAND device: mtd->writesize=%d mtd->oobsize=%d "
2476		   "mtd->erasesize=%d busw=%d\n",
2477		   mtd->writesize, mtd->oobsize, mtd->erasesize, busw);
2478
2479	DEBUG(MTD_DEBUG_LEVEL3, "NAND device: page_shift=%d pagemask=%d bbt_erase_shift=%d "
2480		   "chip_shift=%d badblockpos=%d options=%02x\n",
2481		   chip->page_shift, chip->pagemask, chip->bbt_erase_shift,
2482		   chip->chip_shift, chip->badblockpos, chip->options);
2483#endif /* CONFIG_MTD_BRCMNAND */
2484
2485	return type;
2486}
2487
2488/**
2489 * nand_scan_ident - [NAND Interface] Scan for the NAND device
2490 * @mtd:	     MTD device structure
2491 * @maxchips:	     Number of chips to scan for
2492 *
2493 * This is the first phase of the normal nand_scan() function. It
2494 * reads the flash ID and sets up MTD fields accordingly.
2495 *
2496 * The mtd->owner field must be set to the module of the caller.
2497 */
2498int nand_scan_ident(struct mtd_info *mtd, int maxchips)
2499{
2500	int i, busw, nand_maf_id;
2501	struct nand_chip *chip = mtd->priv;
2502	struct nand_flash_dev *type;
2503
2504	/* Get buswidth to select the correct functions */
2505	busw = chip->options & NAND_BUSWIDTH_16;
2506	/* Set the default functions */
2507	nand_set_defaults(chip, busw);
2508
2509	/* Read the flash type */
2510	type = nand_get_flash_type(mtd, chip, busw, &nand_maf_id);
2511
2512	if (IS_ERR(type)) {
2513		printk(KERN_WARNING "No NAND device found!!!\n");
2514		chip->select_chip(mtd, -1);
2515		return PTR_ERR(type);
2516	}
2517
2518	/* Check for a chip array */
2519	for (i = 1; i < maxchips; i++) {
2520		chip->select_chip(mtd, i);
2521		/* Send the command for reading device ID */
2522		chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
2523		/* Read manufacturer and device IDs */
2524		if (nand_maf_id != chip->read_byte(mtd) ||
2525		    type->id != chip->read_byte(mtd))
2526			break;
2527	}
2528	if (i > 1)
2529		printk(KERN_INFO "%d NAND chips detected\n", i);
2530
2531	/* Store the number of chips and calc total size for mtd */
2532	chip->numchips = i;
2533	mtd->size = i * chip->chipsize;
2534
2535	return 0;
2536}
2537
2538
2539/**
2540 * nand_scan_tail - [NAND Interface] Scan for the NAND device
2541 * @mtd:	    MTD device structure
2542 * @maxchips:	    Number of chips to scan for
2543 *
2544 * This is the second phase of the normal nand_scan() function. It
2545 * fills out all the uninitialized function pointers with the defaults
2546 * and scans for a bad block table if appropriate.
2547 */
2548int nand_scan_tail(struct mtd_info *mtd)
2549{
2550	int i;
2551	struct nand_chip *chip = mtd->priv;
2552
2553	if (!(chip->options & NAND_OWN_BUFFERS))
2554		chip->buffers = kmalloc(sizeof(*chip->buffers), GFP_KERNEL);
2555	if (!chip->buffers)
2556		return -ENOMEM;
2557
2558	/* Set the internal oob buffer location, just after the page data */
2559	chip->oob_poi = chip->buffers->databuf + mtd->writesize;
2560
2561	/*
2562	 * If no default placement scheme is given, select an appropriate one
2563	 */
2564	if (!chip->ecc.layout) {
2565		switch (mtd->oobsize) {
2566		case 8:
2567			chip->ecc.layout = &nand_oob_8;
2568			break;
2569		case 16:
2570			chip->ecc.layout = &nand_oob_16;
2571			break;
2572		case 64:
2573			chip->ecc.layout = &nand_oob_64;
2574			break;
2575		default:
2576			printk(KERN_WARNING "No oob scheme defined for "
2577			       "oobsize %d\n", mtd->oobsize);
2578			BUG();
2579		}
2580	}
2581
2582	if (!chip->write_page)
2583		chip->write_page = nand_write_page;
2584
2585	/*
2586	 * check ECC mode, default to software if 3byte/512byte hardware ECC is
2587	 * selected and we have 256 byte pagesize fallback to software ECC
2588	 */
2589	if (!chip->ecc.read_page_raw)
2590		chip->ecc.read_page_raw = nand_read_page_raw;
2591	if (!chip->ecc.write_page_raw)
2592		chip->ecc.write_page_raw = nand_write_page_raw;
2593
2594	switch (chip->ecc.mode) {
2595	case NAND_ECC_HW:
2596		/* Use standard hwecc read page function ? */
2597		if (!chip->ecc.read_page)
2598			chip->ecc.read_page = nand_read_page_hwecc;
2599		if (!chip->ecc.write_page)
2600			chip->ecc.write_page = nand_write_page_hwecc;
2601		if (!chip->ecc.read_oob)
2602			chip->ecc.read_oob = nand_read_oob_std;
2603		if (!chip->ecc.write_oob)
2604			chip->ecc.write_oob = nand_write_oob_std;
2605
2606	case NAND_ECC_HW_SYNDROME:
2607		if (!chip->ecc.calculate || !chip->ecc.correct ||
2608		    !chip->ecc.hwctl) {
2609			printk(KERN_WARNING "No ECC functions supplied, "
2610			       "Hardware ECC not possible\n");
2611			BUG();
2612		}
2613		/* Use standard syndrome read/write page function ? */
2614		if (!chip->ecc.read_page)
2615			chip->ecc.read_page = nand_read_page_syndrome;
2616		if (!chip->ecc.write_page)
2617			chip->ecc.write_page = nand_write_page_syndrome;
2618		if (!chip->ecc.read_oob)
2619			chip->ecc.read_oob = nand_read_oob_syndrome;
2620		if (!chip->ecc.write_oob)
2621			chip->ecc.write_oob = nand_write_oob_syndrome;
2622
2623		if (mtd->writesize >= chip->ecc.size)
2624			break;
2625		printk(KERN_WARNING "%d byte HW ECC not possible on "
2626		       "%d byte page size, fallback to SW ECC\n",
2627		       chip->ecc.size, mtd->writesize);
2628		chip->ecc.mode = NAND_ECC_SOFT;
2629
2630	case NAND_ECC_SOFT:
2631		chip->ecc.calculate = nand_calculate_ecc;
2632		chip->ecc.correct = nand_correct_data;
2633		chip->ecc.read_page = nand_read_page_swecc;
2634		/* Patched from Linux 2.6.27.57 */
2635		chip->ecc.read_subpage = nand_read_subpage;
2636		chip->ecc.write_page = nand_write_page_swecc;
2637		chip->ecc.read_oob = nand_read_oob_std;
2638		chip->ecc.write_oob = nand_write_oob_std;
2639		chip->ecc.size = 256;
2640		chip->ecc.bytes = 3;
2641		break;
2642
2643	case NAND_ECC_NONE:
2644		printk(KERN_WARNING "NAND_ECC_NONE selected by board driver. "
2645		       "This is not recommended !!\n");
2646		chip->ecc.read_page = nand_read_page_raw;
2647		chip->ecc.write_page = nand_write_page_raw;
2648		chip->ecc.read_oob = nand_read_oob_std;
2649		chip->ecc.write_oob = nand_write_oob_std;
2650		chip->ecc.size = mtd->writesize;
2651		chip->ecc.bytes = 0;
2652		break;
2653
2654	default:
2655		printk(KERN_WARNING "Invalid NAND_ECC_MODE %d\n",
2656		       chip->ecc.mode);
2657		BUG();
2658	}
2659
2660	/*
2661	 * The number of bytes available for a client to place data into
2662	 * the out of band area
2663	 */
2664	chip->ecc.layout->oobavail = 0;
2665	for (i = 0; chip->ecc.layout->oobfree[i].length; i++)
2666		chip->ecc.layout->oobavail +=
2667			chip->ecc.layout->oobfree[i].length;
2668	mtd->oobavail = chip->ecc.layout->oobavail;
2669
2670	/*
2671	 * Set the number of read / write steps for one page depending on ECC
2672	 * mode
2673	 */
2674	chip->ecc.steps = mtd->writesize / chip->ecc.size;
2675	if(chip->ecc.steps * chip->ecc.size != mtd->writesize) {
2676		printk(KERN_WARNING "Invalid ecc parameters\n");
2677		BUG();
2678	}
2679	chip->ecc.total = chip->ecc.steps * chip->ecc.bytes;
2680
2681	/*
2682	 * Allow subpage writes up to ecc.steps. Not possible for MLC
2683	 * FLASH.
2684	 */
2685	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) &&
2686	    !(chip->cellinfo & NAND_CI_CELLTYPE_MSK)) {
2687		switch(chip->ecc.steps) {
2688		case 2:
2689			mtd->subpage_sft = 1;
2690			break;
2691		case 4:
2692		case 8:
2693			mtd->subpage_sft = 2;
2694			break;
2695		}
2696	}
2697	chip->subpagesize = mtd->writesize >> mtd->subpage_sft;
2698
2699	/* Initialize state */
2700	chip->state = FL_READY;
2701
2702	/* De-select the device */
2703	chip->select_chip(mtd, -1);
2704
2705	/* Invalidate the pagebuffer reference */
2706	chip->pagebuf = -1;
2707
2708	/* Fill in remaining MTD driver data */
2709	mtd->type = MTD_NANDFLASH;
2710	mtd->flags = MTD_CAP_NANDFLASH;
2711	mtd->erase = nand_erase;
2712	mtd->point = NULL;
2713	mtd->unpoint = NULL;
2714	mtd->read = nand_read;
2715	mtd->write = nand_write;
2716	mtd->read_oob = nand_read_oob;
2717	mtd->write_oob = nand_write_oob;
2718	mtd->sync = nand_sync;
2719	mtd->lock = NULL;
2720	mtd->unlock = NULL;
2721	mtd->suspend = nand_suspend;
2722	mtd->resume = nand_resume;
2723	mtd->block_isbad = nand_block_isbad;
2724	mtd->block_markbad = nand_block_markbad;
2725
2726	/* propagate ecc.layout to mtd_info */
2727	mtd->ecclayout = chip->ecc.layout;
2728
2729	/* Check, if we should skip the bad block table scan */
2730	if (chip->options & NAND_SKIP_BBTSCAN)
2731		return 0;
2732
2733	/* Build bad block table */
2734	return chip->scan_bbt(mtd);
2735}
2736
2737/* module_text_address() isn't exported, and it's mostly a pointless
2738   test if this is a module _anyway_ -- they'd have to try _really_ hard
2739   to call us from in-kernel code if the core NAND support is modular. */
2740#ifdef MODULE
2741#define caller_is_module() (1)
2742#else
2743#define caller_is_module() \
2744	module_text_address((unsigned long)__builtin_return_address(0))
2745#endif
2746
2747/**
2748 * nand_scan - [NAND Interface] Scan for the NAND device
2749 * @mtd:	MTD device structure
2750 * @maxchips:	Number of chips to scan for
2751 *
2752 * This fills out all the uninitialized function pointers
2753 * with the defaults.
2754 * The flash ID is read and the mtd/chip structures are
2755 * filled with the appropriate values.
2756 * The mtd->owner field must be set to the module of the caller
2757 *
2758 */
2759int nand_scan(struct mtd_info *mtd, int maxchips)
2760{
2761	int ret;
2762
2763	/* Many callers got this wrong, so check for it for a while... */
2764	if (!mtd->owner && caller_is_module()) {
2765		printk(KERN_CRIT "nand_scan() called with NULL mtd->owner!\n");
2766		BUG();
2767	}
2768
2769	ret = nand_scan_ident(mtd, maxchips);
2770	if (!ret)
2771		ret = nand_scan_tail(mtd);
2772	return ret;
2773}
2774
2775/**
2776 * nand_release - [NAND Interface] Free resources held by the NAND device
2777 * @mtd:	MTD device structure
2778*/
2779void nand_release(struct mtd_info *mtd)
2780{
2781	struct nand_chip *chip = mtd->priv;
2782
2783#ifdef CONFIG_MTD_PARTITIONS
2784	/* Deregister partitions */
2785	del_mtd_partitions(mtd);
2786#endif
2787	/* Deregister the device */
2788	del_mtd_device(mtd);
2789
2790	/* Free bad block table memory */
2791	kfree(chip->bbt);
2792	if (!(chip->options & NAND_OWN_BUFFERS))
2793		kfree(chip->buffers);
2794}
2795
2796EXPORT_SYMBOL_GPL(nand_scan);
2797EXPORT_SYMBOL_GPL(nand_scan_ident);
2798EXPORT_SYMBOL_GPL(nand_scan_tail);
2799EXPORT_SYMBOL_GPL(nand_release);
2800
2801static int __init nand_base_init(void)
2802{
2803	led_trigger_register_simple("nand-disk", &nand_led_trigger);
2804	return 0;
2805}
2806
2807static void __exit nand_base_exit(void)
2808{
2809	led_trigger_unregister_simple(nand_led_trigger);
2810}
2811
2812module_init(nand_base_init);
2813module_exit(nand_base_exit);
2814
2815MODULE_LICENSE("GPL");
2816MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>, Thomas Gleixner <tglx@linutronix.de>");
2817MODULE_DESCRIPTION("Generic NAND flash driver code");
2818