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   1/*
   2 *  drivers/mtd/nand.c
   3 *
   4 *  Overview:
   5 *   This is the generic MTD driver for NAND flash devices. It should be
   6 *   capable of working with almost all NAND chips currently available.
   7 *
   8 *	Additional technical information is available on
   9 *	http://www.linux-mtd.infradead.org/doc/nand.html
  10 *
  11 *  Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
  12 *		  2002-2006 Thomas Gleixner (tglx@linutronix.de)
  13 *
  14 *  Credits:
  15 *	David Woodhouse for adding multichip support
  16 *
  17 *	Aleph One Ltd. and Toby Churchill Ltd. for supporting the
  18 *	rework for 2K page size chips
  19 *
  20 *  TODO:
  21 *	Enable cached programming for 2k page size chips
  22 *	Check, if mtd->ecctype should be set to MTD_ECC_HW
  23 *	if we have HW ECC support.
  24 *	BBT table is not serialized, has to be fixed
  25 *
  26 * This program is free software; you can redistribute it and/or modify
  27 * it under the terms of the GNU General Public License version 2 as
  28 * published by the Free Software Foundation.
  29 *
  30 */
  31
  32#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  33
  34#include <linux/module.h>
  35#include <linux/delay.h>
  36#include <linux/errno.h>
  37#include <linux/err.h>
  38#include <linux/sched.h>
  39#include <linux/slab.h>
  40#include <linux/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/nand_bch.h>
  45#include <linux/interrupt.h>
  46#include <linux/bitops.h>
  47#include <linux/leds.h>
  48#include <linux/io.h>
  49#include <linux/mtd/partitions.h>
  50
  51/* Define default oob placement schemes for large and small page devices */
  52static struct nand_ecclayout nand_oob_8 = {
  53	.eccbytes = 3,
  54	.eccpos = {0, 1, 2},
  55	.oobfree = {
  56		{.offset = 3,
  57		 .length = 2},
  58		{.offset = 6,
  59		 .length = 2} }
  60};
  61
  62static struct nand_ecclayout nand_oob_16 = {
  63	.eccbytes = 6,
  64	.eccpos = {0, 1, 2, 3, 6, 7},
  65	.oobfree = {
  66		{.offset = 8,
  67		 . length = 8} }
  68};
  69
  70static struct nand_ecclayout nand_oob_64 = {
  71	.eccbytes = 24,
  72	.eccpos = {
  73		   40, 41, 42, 43, 44, 45, 46, 47,
  74		   48, 49, 50, 51, 52, 53, 54, 55,
  75		   56, 57, 58, 59, 60, 61, 62, 63},
  76	.oobfree = {
  77		{.offset = 2,
  78		 .length = 38} }
  79};
  80
  81static struct nand_ecclayout nand_oob_128 = {
  82	.eccbytes = 48,
  83	.eccpos = {
  84		   80, 81, 82, 83, 84, 85, 86, 87,
  85		   88, 89, 90, 91, 92, 93, 94, 95,
  86		   96, 97, 98, 99, 100, 101, 102, 103,
  87		   104, 105, 106, 107, 108, 109, 110, 111,
  88		   112, 113, 114, 115, 116, 117, 118, 119,
  89		   120, 121, 122, 123, 124, 125, 126, 127},
  90	.oobfree = {
  91		{.offset = 2,
  92		 .length = 78} }
  93};
  94
  95static int nand_get_device(struct mtd_info *mtd, int new_state);
  96
  97static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
  98			     struct mtd_oob_ops *ops);
  99
 100/*
 101 * For devices which display every fart in the system on a separate LED. Is
 102 * compiled away when LED support is disabled.
 103 */
 104DEFINE_LED_TRIGGER(nand_led_trigger);
 105
 106static int check_offs_len(struct mtd_info *mtd,
 107					loff_t ofs, uint64_t len)
 108{
 109	struct nand_chip *chip = mtd->priv;
 110	int ret = 0;
 111
 112	/* Start address must align on block boundary */
 113	if (ofs & ((1ULL << chip->phys_erase_shift) - 1)) {
 114		pr_debug("%s: unaligned address\n", __func__);
 115		ret = -EINVAL;
 116	}
 117
 118	/* Length must align on block boundary */
 119	if (len & ((1ULL << chip->phys_erase_shift) - 1)) {
 120		pr_debug("%s: length not block aligned\n", __func__);
 121		ret = -EINVAL;
 122	}
 123
 124	return ret;
 125}
 126
 127/**
 128 * nand_release_device - [GENERIC] release chip
 129 * @mtd: MTD device structure
 130 *
 131 * Release chip lock and wake up anyone waiting on the device.
 132 */
 133static void nand_release_device(struct mtd_info *mtd)
 134{
 135	struct nand_chip *chip = mtd->priv;
 136
 137	/* Release the controller and the chip */
 138	spin_lock(&chip->controller->lock);
 139	chip->controller->active = NULL;
 140	chip->state = FL_READY;
 141	wake_up(&chip->controller->wq);
 142	spin_unlock(&chip->controller->lock);
 143}
 144
 145/**
 146 * nand_read_byte - [DEFAULT] read one byte from the chip
 147 * @mtd: MTD device structure
 148 *
 149 * Default read function for 8bit buswidth
 150 */
 151static uint8_t nand_read_byte(struct mtd_info *mtd)
 152{
 153	struct nand_chip *chip = mtd->priv;
 154	return readb(chip->IO_ADDR_R);
 155}
 156
 157/**
 158 * nand_read_byte16 - [DEFAULT] read one byte endianness aware from the chip
 159 * nand_read_byte16 - [DEFAULT] read one byte endianness aware from the chip
 160 * @mtd: MTD device structure
 161 *
 162 * Default read function for 16bit buswidth with endianness conversion.
 163 *
 164 */
 165static uint8_t nand_read_byte16(struct mtd_info *mtd)
 166{
 167	struct nand_chip *chip = mtd->priv;
 168	return (uint8_t) cpu_to_le16(readw(chip->IO_ADDR_R));
 169}
 170
 171/**
 172 * nand_read_word - [DEFAULT] read one word from the chip
 173 * @mtd: MTD device structure
 174 *
 175 * Default read function for 16bit buswidth without endianness conversion.
 176 */
 177static u16 nand_read_word(struct mtd_info *mtd)
 178{
 179	struct nand_chip *chip = mtd->priv;
 180	return readw(chip->IO_ADDR_R);
 181}
 182
 183/**
 184 * nand_select_chip - [DEFAULT] control CE line
 185 * @mtd: MTD device structure
 186 * @chipnr: chipnumber to select, -1 for deselect
 187 *
 188 * Default select function for 1 chip devices.
 189 */
 190static void nand_select_chip(struct mtd_info *mtd, int chipnr)
 191{
 192	struct nand_chip *chip = mtd->priv;
 193
 194	switch (chipnr) {
 195	case -1:
 196		chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0 | NAND_CTRL_CHANGE);
 197		break;
 198	case 0:
 199		break;
 200
 201	default:
 202		BUG();
 203	}
 204}
 205
 206/**
 207 * nand_write_byte - [DEFAULT] write single byte to chip
 208 * @mtd: MTD device structure
 209 * @byte: value to write
 210 *
 211 * Default function to write a byte to I/O[7:0]
 212 */
 213static void nand_write_byte(struct mtd_info *mtd, uint8_t byte)
 214{
 215	struct nand_chip *chip = mtd->priv;
 216
 217	chip->write_buf(mtd, &byte, 1);
 218}
 219
 220/**
 221 * nand_write_byte16 - [DEFAULT] write single byte to a chip with width 16
 222 * @mtd: MTD device structure
 223 * @byte: value to write
 224 *
 225 * Default function to write a byte to I/O[7:0] on a 16-bit wide chip.
 226 */
 227static void nand_write_byte16(struct mtd_info *mtd, uint8_t byte)
 228{
 229	struct nand_chip *chip = mtd->priv;
 230	uint16_t word = byte;
 231
 232	/*
 233	 * It's not entirely clear what should happen to I/O[15:8] when writing
 234	 * a byte. The ONFi spec (Revision 3.1; 2012-09-19, Section 2.16) reads:
 235	 *
 236	 *    When the host supports a 16-bit bus width, only data is
 237	 *    transferred at the 16-bit width. All address and command line
 238	 *    transfers shall use only the lower 8-bits of the data bus. During
 239	 *    command transfers, the host may place any value on the upper
 240	 *    8-bits of the data bus. During address transfers, the host shall
 241	 *    set the upper 8-bits of the data bus to 00h.
 242	 *
 243	 * One user of the write_byte callback is nand_onfi_set_features. The
 244	 * four parameters are specified to be written to I/O[7:0], but this is
 245	 * neither an address nor a command transfer. Let's assume a 0 on the
 246	 * upper I/O lines is OK.
 247	 */
 248	chip->write_buf(mtd, (uint8_t *)&word, 2);
 249}
 250
 251/**
 252 * nand_write_buf - [DEFAULT] write buffer to chip
 253 * @mtd: MTD device structure
 254 * @buf: data buffer
 255 * @len: number of bytes to write
 256 *
 257 * Default write function for 8bit buswidth.
 258 */
 259static void nand_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
 260{
 261	struct nand_chip *chip = mtd->priv;
 262
 263	iowrite8_rep(chip->IO_ADDR_W, buf, len);
 264}
 265
 266/**
 267 * nand_read_buf - [DEFAULT] read chip data into buffer
 268 * @mtd: MTD device structure
 269 * @buf: buffer to store date
 270 * @len: number of bytes to read
 271 *
 272 * Default read function for 8bit buswidth.
 273 */
 274static void nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
 275{
 276	struct nand_chip *chip = mtd->priv;
 277
 278	ioread8_rep(chip->IO_ADDR_R, buf, len);
 279}
 280
 281/**
 282 * nand_write_buf16 - [DEFAULT] write buffer to chip
 283 * @mtd: MTD device structure
 284 * @buf: data buffer
 285 * @len: number of bytes to write
 286 *
 287 * Default write function for 16bit buswidth.
 288 */
 289static void nand_write_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
 290{
 291	struct nand_chip *chip = mtd->priv;
 292	u16 *p = (u16 *) buf;
 293
 294	iowrite16_rep(chip->IO_ADDR_W, p, len >> 1);
 295}
 296
 297/**
 298 * nand_read_buf16 - [DEFAULT] read chip data into buffer
 299 * @mtd: MTD device structure
 300 * @buf: buffer to store date
 301 * @len: number of bytes to read
 302 *
 303 * Default read function for 16bit buswidth.
 304 */
 305static void nand_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
 306{
 307	struct nand_chip *chip = mtd->priv;
 308	u16 *p = (u16 *) buf;
 309
 310	ioread16_rep(chip->IO_ADDR_R, p, len >> 1);
 311}
 312
 313/**
 314 * nand_block_bad - [DEFAULT] Read bad block marker from the chip
 315 * @mtd: MTD device structure
 316 * @ofs: offset from device start
 317 * @getchip: 0, if the chip is already selected
 318 *
 319 * Check, if the block is bad.
 320 */
 321static int nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
 322{
 323	int page, chipnr, res = 0, i = 0;
 324	struct nand_chip *chip = mtd->priv;
 325	u16 bad;
 326
 327	if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
 328		ofs += mtd->erasesize - mtd->writesize;
 329
 330	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
 331
 332	if (getchip) {
 333		chipnr = (int)(ofs >> chip->chip_shift);
 334
 335		nand_get_device(mtd, FL_READING);
 336
 337		/* Select the NAND device */
 338		chip->select_chip(mtd, chipnr);
 339	}
 340
 341	do {
 342		if (chip->options & NAND_BUSWIDTH_16) {
 343			chip->cmdfunc(mtd, NAND_CMD_READOOB,
 344					chip->badblockpos & 0xFE, page);
 345			bad = cpu_to_le16(chip->read_word(mtd));
 346			if (chip->badblockpos & 0x1)
 347				bad >>= 8;
 348			else
 349				bad &= 0xFF;
 350		} else {
 351			chip->cmdfunc(mtd, NAND_CMD_READOOB, chip->badblockpos,
 352					page);
 353			bad = chip->read_byte(mtd);
 354		}
 355
 356		if (likely(chip->badblockbits == 8))
 357			res = bad != 0xFF;
 358		else
 359			res = hweight8(bad) < chip->badblockbits;
 360		ofs += mtd->writesize;
 361		page = (int)(ofs >> chip->page_shift) & chip->pagemask;
 362		i++;
 363	} while (!res && i < 2 && (chip->bbt_options & NAND_BBT_SCAN2NDPAGE));
 364
 365	if (getchip) {
 366		chip->select_chip(mtd, -1);
 367		nand_release_device(mtd);
 368	}
 369
 370	return res;
 371}
 372
 373/**
 374 * nand_default_block_markbad - [DEFAULT] mark a block bad via bad block marker
 375 * @mtd: MTD device structure
 376 * @ofs: offset from device start
 377 *
 378 * This is the default implementation, which can be overridden by a hardware
 379 * specific driver. It provides the details for writing a bad block marker to a
 380 * block.
 381 */
 382static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
 383{
 384	struct nand_chip *chip = mtd->priv;
 385	struct mtd_oob_ops ops;
 386	uint8_t buf[2] = { 0, 0 };
 387	int ret = 0, res, i = 0;
 388
 389	ops.datbuf = NULL;
 390	ops.oobbuf = buf;
 391	ops.ooboffs = chip->badblockpos;
 392	if (chip->options & NAND_BUSWIDTH_16) {
 393		ops.ooboffs &= ~0x01;
 394		ops.len = ops.ooblen = 2;
 395	} else {
 396		ops.len = ops.ooblen = 1;
 397	}
 398	ops.mode = MTD_OPS_PLACE_OOB;
 399
 400	/* Write to first/last page(s) if necessary */
 401	if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
 402		ofs += mtd->erasesize - mtd->writesize;
 403	do {
 404		res = nand_do_write_oob(mtd, ofs, &ops);
 405		if (!ret)
 406			ret = res;
 407
 408		i++;
 409		ofs += mtd->writesize;
 410	} while ((chip->bbt_options & NAND_BBT_SCAN2NDPAGE) && i < 2);
 411
 412	return ret;
 413}
 414
 415/**
 416 * nand_block_markbad_lowlevel - mark a block bad
 417 * @mtd: MTD device structure
 418 * @ofs: offset from device start
 419 *
 420 * This function performs the generic NAND bad block marking steps (i.e., bad
 421 * block table(s) and/or marker(s)). We only allow the hardware driver to
 422 * specify how to write bad block markers to OOB (chip->block_markbad).
 423 *
 424 * We try operations in the following order:
 425 *  (1) erase the affected block, to allow OOB marker to be written cleanly
 426 *  (2) write bad block marker to OOB area of affected block (unless flag
 427 *      NAND_BBT_NO_OOB_BBM is present)
 428 *  (3) update the BBT
 429 * Note that we retain the first error encountered in (2) or (3), finish the
 430 * procedures, and dump the error in the end.
 431*/
 432static int nand_block_markbad_lowlevel(struct mtd_info *mtd, loff_t ofs)
 433{
 434	struct nand_chip *chip = mtd->priv;
 435	int res, ret = 0;
 436
 437	if (!(chip->bbt_options & NAND_BBT_NO_OOB_BBM)) {
 438		struct erase_info einfo;
 439
 440		/* Attempt erase before marking OOB */
 441		memset(&einfo, 0, sizeof(einfo));
 442		einfo.mtd = mtd;
 443		einfo.addr = ofs;
 444		einfo.len = 1ULL << chip->phys_erase_shift;
 445		nand_erase_nand(mtd, &einfo, 0);
 446
 447		/* Write bad block marker to OOB */
 448		nand_get_device(mtd, FL_WRITING);
 449		ret = chip->block_markbad(mtd, ofs);
 450		nand_release_device(mtd);
 451	}
 452
 453	/* Mark block bad in BBT */
 454	if (chip->bbt) {
 455		res = nand_markbad_bbt(mtd, ofs);
 456		if (!ret)
 457			ret = res;
 458	}
 459
 460	if (!ret)
 461		mtd->ecc_stats.badblocks++;
 462
 463	return ret;
 464}
 465
 466/**
 467 * nand_check_wp - [GENERIC] check if the chip is write protected
 468 * @mtd: MTD device structure
 469 *
 470 * Check, if the device is write protected. The function expects, that the
 471 * device is already selected.
 472 */
 473static int nand_check_wp(struct mtd_info *mtd)
 474{
 475	struct nand_chip *chip = mtd->priv;
 476
 477	/* Broken xD cards report WP despite being writable */
 478	if (chip->options & NAND_BROKEN_XD)
 479		return 0;
 480
 481	/* Check the WP bit */
 482	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
 483	return (chip->read_byte(mtd) & NAND_STATUS_WP) ? 0 : 1;
 484}
 485
 486/**
 487 * nand_block_checkbad - [GENERIC] Check if a block is marked bad
 488 * @mtd: MTD device structure
 489 * @ofs: offset from device start
 490 * @getchip: 0, if the chip is already selected
 491 * @allowbbt: 1, if its allowed to access the bbt area
 492 *
 493 * Check, if the block is bad. Either by reading the bad block table or
 494 * calling of the scan function.
 495 */
 496static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip,
 497			       int allowbbt)
 498{
 499	struct nand_chip *chip = mtd->priv;
 500
 501	if (!chip->bbt)
 502		return chip->block_bad(mtd, ofs, getchip);
 503
 504	/* Return info from the table */
 505	return nand_isbad_bbt(mtd, ofs, allowbbt);
 506}
 507
 508/**
 509 * panic_nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
 510 * @mtd: MTD device structure
 511 * @timeo: Timeout
 512 *
 513 * Helper function for nand_wait_ready used when needing to wait in interrupt
 514 * context.
 515 */
 516static void panic_nand_wait_ready(struct mtd_info *mtd, unsigned long timeo)
 517{
 518	struct nand_chip *chip = mtd->priv;
 519	int i;
 520
 521	/* Wait for the device to get ready */
 522	for (i = 0; i < timeo; i++) {
 523		if (chip->dev_ready(mtd))
 524			break;
 525		touch_softlockup_watchdog();
 526		mdelay(1);
 527	}
 528}
 529
 530/* Wait for the ready pin, after a command. The timeout is caught later. */
 531void nand_wait_ready(struct mtd_info *mtd)
 532{
 533	struct nand_chip *chip = mtd->priv;
 534	unsigned long timeo = jiffies + msecs_to_jiffies(20);
 535
 536	/* 400ms timeout */
 537	if (in_interrupt() || oops_in_progress)
 538		return panic_nand_wait_ready(mtd, 400);
 539
 540	led_trigger_event(nand_led_trigger, LED_FULL);
 541	/* Wait until command is processed or timeout occurs */
 542	do {
 543		if (chip->dev_ready(mtd))
 544			break;
 545		touch_softlockup_watchdog();
 546	} while (time_before(jiffies, timeo));
 547	led_trigger_event(nand_led_trigger, LED_OFF);
 548}
 549EXPORT_SYMBOL_GPL(nand_wait_ready);
 550
 551/**
 552 * nand_command - [DEFAULT] Send command to NAND device
 553 * @mtd: MTD device structure
 554 * @command: the command to be sent
 555 * @column: the column address for this command, -1 if none
 556 * @page_addr: the page address for this command, -1 if none
 557 *
 558 * Send command to NAND device. This function is used for small page devices
 559 * (512 Bytes per page).
 560 */
 561static void nand_command(struct mtd_info *mtd, unsigned int command,
 562			 int column, int page_addr)
 563{
 564	register struct nand_chip *chip = mtd->priv;
 565	int ctrl = NAND_CTRL_CLE | NAND_CTRL_CHANGE;
 566
 567	/* Write out the command to the device */
 568	if (command == NAND_CMD_SEQIN) {
 569		int readcmd;
 570
 571		if (column >= mtd->writesize) {
 572			/* OOB area */
 573			column -= mtd->writesize;
 574			readcmd = NAND_CMD_READOOB;
 575		} else if (column < 256) {
 576			/* First 256 bytes --> READ0 */
 577			readcmd = NAND_CMD_READ0;
 578		} else {
 579			column -= 256;
 580			readcmd = NAND_CMD_READ1;
 581		}
 582		chip->cmd_ctrl(mtd, readcmd, ctrl);
 583		ctrl &= ~NAND_CTRL_CHANGE;
 584	}
 585	chip->cmd_ctrl(mtd, command, ctrl);
 586
 587	/* Address cycle, when necessary */
 588	ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE;
 589	/* Serially input address */
 590	if (column != -1) {
 591		/* Adjust columns for 16 bit buswidth */
 592		if (chip->options & NAND_BUSWIDTH_16 &&
 593				!nand_opcode_8bits(command))
 594			column >>= 1;
 595		chip->cmd_ctrl(mtd, column, ctrl);
 596		ctrl &= ~NAND_CTRL_CHANGE;
 597	}
 598	if (page_addr != -1) {
 599		chip->cmd_ctrl(mtd, page_addr, ctrl);
 600		ctrl &= ~NAND_CTRL_CHANGE;
 601		chip->cmd_ctrl(mtd, page_addr >> 8, ctrl);
 602		/* One more address cycle for devices > 32MiB */
 603		if (chip->chipsize > (32 << 20))
 604			chip->cmd_ctrl(mtd, page_addr >> 16, ctrl);
 605	}
 606	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
 607
 608	/*
 609	 * Program and erase have their own busy handlers status and sequential
 610	 * in needs no delay
 611	 */
 612	switch (command) {
 613
 614	case NAND_CMD_PAGEPROG:
 615	case NAND_CMD_ERASE1:
 616	case NAND_CMD_ERASE2:
 617	case NAND_CMD_SEQIN:
 618	case NAND_CMD_STATUS:
 619		return;
 620
 621	case NAND_CMD_RESET:
 622		if (chip->dev_ready)
 623			break;
 624		udelay(chip->chip_delay);
 625		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
 626			       NAND_CTRL_CLE | NAND_CTRL_CHANGE);
 627		chip->cmd_ctrl(mtd,
 628			       NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
 629		while (!(chip->read_byte(mtd) & NAND_STATUS_READY))
 630				;
 631		return;
 632
 633		/* This applies to read commands */
 634	default:
 635		/*
 636		 * If we don't have access to the busy pin, we apply the given
 637		 * command delay
 638		 */
 639		if (!chip->dev_ready) {
 640			udelay(chip->chip_delay);
 641			return;
 642		}
 643	}
 644	/*
 645	 * Apply this short delay always to ensure that we do wait tWB in
 646	 * any case on any machine.
 647	 */
 648	ndelay(100);
 649
 650	nand_wait_ready(mtd);
 651}
 652
 653/**
 654 * nand_command_lp - [DEFAULT] Send command to NAND large page device
 655 * @mtd: MTD device structure
 656 * @command: the command to be sent
 657 * @column: the column address for this command, -1 if none
 658 * @page_addr: the page address for this command, -1 if none
 659 *
 660 * Send command to NAND device. This is the version for the new large page
 661 * devices. We don't have the separate regions as we have in the small page
 662 * devices. We must emulate NAND_CMD_READOOB to keep the code compatible.
 663 */
 664static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
 665			    int column, int page_addr)
 666{
 667	register struct nand_chip *chip = mtd->priv;
 668
 669	/* Emulate NAND_CMD_READOOB */
 670	if (command == NAND_CMD_READOOB) {
 671		column += mtd->writesize;
 672		command = NAND_CMD_READ0;
 673	}
 674
 675	/* Command latch cycle */
 676	chip->cmd_ctrl(mtd, command, NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
 677
 678	if (column != -1 || page_addr != -1) {
 679		int ctrl = NAND_CTRL_CHANGE | NAND_NCE | NAND_ALE;
 680
 681		/* Serially input address */
 682		if (column != -1) {
 683			/* Adjust columns for 16 bit buswidth */
 684			if (chip->options & NAND_BUSWIDTH_16 &&
 685					!nand_opcode_8bits(command))
 686				column >>= 1;
 687			chip->cmd_ctrl(mtd, column, ctrl);
 688			ctrl &= ~NAND_CTRL_CHANGE;
 689			chip->cmd_ctrl(mtd, column >> 8, ctrl);
 690		}
 691		if (page_addr != -1) {
 692			chip->cmd_ctrl(mtd, page_addr, ctrl);
 693			chip->cmd_ctrl(mtd, page_addr >> 8,
 694				       NAND_NCE | NAND_ALE);
 695			/* One more address cycle for devices > 128MiB */
 696			if (chip->chipsize > (128 << 20))
 697				chip->cmd_ctrl(mtd, page_addr >> 16,
 698					       NAND_NCE | NAND_ALE);
 699		}
 700	}
 701	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
 702
 703	/*
 704	 * Program and erase have their own busy handlers status, sequential
 705	 * in, and deplete1 need no delay.
 706	 */
 707	switch (command) {
 708
 709	case NAND_CMD_CACHEDPROG:
 710	case NAND_CMD_PAGEPROG:
 711	case NAND_CMD_ERASE1:
 712	case NAND_CMD_ERASE2:
 713	case NAND_CMD_SEQIN:
 714	case NAND_CMD_RNDIN:
 715	case NAND_CMD_STATUS:
 716		return;
 717
 718	case NAND_CMD_RESET:
 719		if (chip->dev_ready)
 720			break;
 721		udelay(chip->chip_delay);
 722		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
 723			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
 724		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
 725			       NAND_NCE | NAND_CTRL_CHANGE);
 726		while (!(chip->read_byte(mtd) & NAND_STATUS_READY))
 727				;
 728		return;
 729
 730	case NAND_CMD_RNDOUT:
 731		/* No ready / busy check necessary */
 732		chip->cmd_ctrl(mtd, NAND_CMD_RNDOUTSTART,
 733			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
 734		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
 735			       NAND_NCE | NAND_CTRL_CHANGE);
 736		return;
 737
 738	case NAND_CMD_READ0:
 739		chip->cmd_ctrl(mtd, NAND_CMD_READSTART,
 740			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
 741		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
 742			       NAND_NCE | NAND_CTRL_CHANGE);
 743
 744		/* This applies to read commands */
 745	default:
 746		/*
 747		 * If we don't have access to the busy pin, we apply the given
 748		 * command delay.
 749		 */
 750		if (!chip->dev_ready) {
 751			udelay(chip->chip_delay);
 752			return;
 753		}
 754	}
 755
 756	/*
 757	 * Apply this short delay always to ensure that we do wait tWB in
 758	 * any case on any machine.
 759	 */
 760	ndelay(100);
 761
 762	nand_wait_ready(mtd);
 763}
 764
 765/**
 766 * panic_nand_get_device - [GENERIC] Get chip for selected access
 767 * @chip: the nand chip descriptor
 768 * @mtd: MTD device structure
 769 * @new_state: the state which is requested
 770 *
 771 * Used when in panic, no locks are taken.
 772 */
 773static void panic_nand_get_device(struct nand_chip *chip,
 774		      struct mtd_info *mtd, int new_state)
 775{
 776	/* Hardware controller shared among independent devices */
 777	chip->controller->active = chip;
 778	chip->state = new_state;
 779}
 780
 781/**
 782 * nand_get_device - [GENERIC] Get chip for selected access
 783 * @mtd: MTD device structure
 784 * @new_state: the state which is requested
 785 *
 786 * Get the device and lock it for exclusive access
 787 */
 788static int
 789nand_get_device(struct mtd_info *mtd, int new_state)
 790{
 791	struct nand_chip *chip = mtd->priv;
 792	spinlock_t *lock = &chip->controller->lock;
 793	wait_queue_head_t *wq = &chip->controller->wq;
 794	DECLARE_WAITQUEUE(wait, current);
 795retry:
 796	spin_lock(lock);
 797
 798	/* Hardware controller shared among independent devices */
 799	if (!chip->controller->active)
 800		chip->controller->active = chip;
 801
 802	if (chip->controller->active == chip && chip->state == FL_READY) {
 803		chip->state = new_state;
 804		spin_unlock(lock);
 805		return 0;
 806	}
 807	if (new_state == FL_PM_SUSPENDED) {
 808		if (chip->controller->active->state == FL_PM_SUSPENDED) {
 809			chip->state = FL_PM_SUSPENDED;
 810			spin_unlock(lock);
 811			return 0;
 812		}
 813	}
 814	set_current_state(TASK_UNINTERRUPTIBLE);
 815	add_wait_queue(wq, &wait);
 816	spin_unlock(lock);
 817	schedule();
 818	remove_wait_queue(wq, &wait);
 819	goto retry;
 820}
 821
 822/**
 823 * panic_nand_wait - [GENERIC] wait until the command is done
 824 * @mtd: MTD device structure
 825 * @chip: NAND chip structure
 826 * @timeo: timeout
 827 *
 828 * Wait for command done. This is a helper function for nand_wait used when
 829 * we are in interrupt context. May happen when in panic and trying to write
 830 * an oops through mtdoops.
 831 */
 832static void panic_nand_wait(struct mtd_info *mtd, struct nand_chip *chip,
 833			    unsigned long timeo)
 834{
 835	int i;
 836	for (i = 0; i < timeo; i++) {
 837		if (chip->dev_ready) {
 838			if (chip->dev_ready(mtd))
 839				break;
 840		} else {
 841			if (chip->read_byte(mtd) & NAND_STATUS_READY)
 842				break;
 843		}
 844		mdelay(1);
 845	}
 846}
 847
 848/**
 849 * nand_wait - [DEFAULT] wait until the command is done
 850 * @mtd: MTD device structure
 851 * @chip: NAND chip structure
 852 *
 853 * Wait for command done. This applies to erase and program only. Erase can
 854 * take up to 400ms and program up to 20ms according to general NAND and
 855 * SmartMedia specs.
 856 */
 857static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
 858{
 859
 860	int status, state = chip->state;
 861	unsigned long timeo = (state == FL_ERASING ? 400 : 20);
 862
 863	led_trigger_event(nand_led_trigger, LED_FULL);
 864
 865	/*
 866	 * Apply this short delay always to ensure that we do wait tWB in any
 867	 * case on any machine.
 868	 */
 869	ndelay(100);
 870
 871	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
 872
 873	if (in_interrupt() || oops_in_progress)
 874		panic_nand_wait(mtd, chip, timeo);
 875	else {
 876		timeo = jiffies + msecs_to_jiffies(timeo);
 877		while (time_before(jiffies, timeo)) {
 878			if (chip->dev_ready) {
 879				if (chip->dev_ready(mtd))
 880					break;
 881			} else {
 882				if (chip->read_byte(mtd) & NAND_STATUS_READY)
 883					break;
 884			}
 885			cond_resched();
 886		}
 887	}
 888	led_trigger_event(nand_led_trigger, LED_OFF);
 889
 890	status = (int)chip->read_byte(mtd);
 891	/* This can happen if in case of timeout or buggy dev_ready */
 892	WARN_ON(!(status & NAND_STATUS_READY));
 893	return status;
 894}
 895
 896/**
 897 * __nand_unlock - [REPLACEABLE] unlocks specified locked blocks
 898 * @mtd: mtd info
 899 * @ofs: offset to start unlock from
 900 * @len: length to unlock
 901 * @invert: when = 0, unlock the range of blocks within the lower and
 902 *                    upper boundary address
 903 *          when = 1, unlock the range of blocks outside the boundaries
 904 *                    of the lower and upper boundary address
 905 *
 906 * Returs unlock status.
 907 */
 908static int __nand_unlock(struct mtd_info *mtd, loff_t ofs,
 909					uint64_t len, int invert)
 910{
 911	int ret = 0;
 912	int status, page;
 913	struct nand_chip *chip = mtd->priv;
 914
 915	/* Submit address of first page to unlock */
 916	page = ofs >> chip->page_shift;
 917	chip->cmdfunc(mtd, NAND_CMD_UNLOCK1, -1, page & chip->pagemask);
 918
 919	/* Submit address of last page to unlock */
 920	page = (ofs + len) >> chip->page_shift;
 921	chip->cmdfunc(mtd, NAND_CMD_UNLOCK2, -1,
 922				(page | invert) & chip->pagemask);
 923
 924	/* Call wait ready function */
 925	status = chip->waitfunc(mtd, chip);
 926	/* See if device thinks it succeeded */
 927	if (status & NAND_STATUS_FAIL) {
 928		pr_debug("%s: error status = 0x%08x\n",
 929					__func__, status);
 930		ret = -EIO;
 931	}
 932
 933	return ret;
 934}
 935
 936/**
 937 * nand_unlock - [REPLACEABLE] unlocks specified locked blocks
 938 * @mtd: mtd info
 939 * @ofs: offset to start unlock from
 940 * @len: length to unlock
 941 *
 942 * Returns unlock status.
 943 */
 944int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 945{
 946	int ret = 0;
 947	int chipnr;
 948	struct nand_chip *chip = mtd->priv;
 949
 950	pr_debug("%s: start = 0x%012llx, len = %llu\n",
 951			__func__, (unsigned long long)ofs, len);
 952
 953	if (check_offs_len(mtd, ofs, len))
 954		ret = -EINVAL;
 955
 956	/* Align to last block address if size addresses end of the device */
 957	if (ofs + len == mtd->size)
 958		len -= mtd->erasesize;
 959
 960	nand_get_device(mtd, FL_UNLOCKING);
 961
 962	/* Shift to get chip number */
 963	chipnr = ofs >> chip->chip_shift;
 964
 965	chip->select_chip(mtd, chipnr);
 966
 967	/* Check, if it is write protected */
 968	if (nand_check_wp(mtd)) {
 969		pr_debug("%s: device is write protected!\n",
 970					__func__);
 971		ret = -EIO;
 972		goto out;
 973	}
 974
 975	ret = __nand_unlock(mtd, ofs, len, 0);
 976
 977out:
 978	chip->select_chip(mtd, -1);
 979	nand_release_device(mtd);
 980
 981	return ret;
 982}
 983EXPORT_SYMBOL(nand_unlock);
 984
 985/**
 986 * nand_lock - [REPLACEABLE] locks all blocks present in the device
 987 * @mtd: mtd info
 988 * @ofs: offset to start unlock from
 989 * @len: length to unlock
 990 *
 991 * This feature is not supported in many NAND parts. 'Micron' NAND parts do
 992 * have this feature, but it allows only to lock all blocks, not for specified
 993 * range for block. Implementing 'lock' feature by making use of 'unlock', for
 994 * now.
 995 *
 996 * Returns lock status.
 997 */
 998int nand_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 999{
1000	int ret = 0;
1001	int chipnr, status, page;
1002	struct nand_chip *chip = mtd->priv;
1003
1004	pr_debug("%s: start = 0x%012llx, len = %llu\n",
1005			__func__, (unsigned long long)ofs, len);
1006
1007	if (check_offs_len(mtd, ofs, len))
1008		ret = -EINVAL;
1009
1010	nand_get_device(mtd, FL_LOCKING);
1011
1012	/* Shift to get chip number */
1013	chipnr = ofs >> chip->chip_shift;
1014
1015	chip->select_chip(mtd, chipnr);
1016
1017	/* Check, if it is write protected */
1018	if (nand_check_wp(mtd)) {
1019		pr_debug("%s: device is write protected!\n",
1020					__func__);
1021		status = MTD_ERASE_FAILED;
1022		ret = -EIO;
1023		goto out;
1024	}
1025
1026	/* Submit address of first page to lock */
1027	page = ofs >> chip->page_shift;
1028	chip->cmdfunc(mtd, NAND_CMD_LOCK, -1, page & chip->pagemask);
1029
1030	/* Call wait ready function */
1031	status = chip->waitfunc(mtd, chip);
1032	/* See if device thinks it succeeded */
1033	if (status & NAND_STATUS_FAIL) {
1034		pr_debug("%s: error status = 0x%08x\n",
1035					__func__, status);
1036		ret = -EIO;
1037		goto out;
1038	}
1039
1040	ret = __nand_unlock(mtd, ofs, len, 0x1);
1041
1042out:
1043	chip->select_chip(mtd, -1);
1044	nand_release_device(mtd);
1045
1046	return ret;
1047}
1048EXPORT_SYMBOL(nand_lock);
1049
1050/**
1051 * nand_read_page_raw - [INTERN] read raw page data without ecc
1052 * @mtd: mtd info structure
1053 * @chip: nand chip info structure
1054 * @buf: buffer to store read data
1055 * @oob_required: caller requires OOB data read to chip->oob_poi
1056 * @page: page number to read
1057 *
1058 * Not for syndrome calculating ECC controllers, which use a special oob layout.
1059 */
1060static int nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
1061			      uint8_t *buf, int oob_required, int page)
1062{
1063	chip->read_buf(mtd, buf, mtd->writesize);
1064	if (oob_required)
1065		chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1066	return 0;
1067}
1068
1069/**
1070 * nand_read_page_raw_syndrome - [INTERN] read raw page data without ecc
1071 * @mtd: mtd info structure
1072 * @chip: nand chip info structure
1073 * @buf: buffer to store read data
1074 * @oob_required: caller requires OOB data read to chip->oob_poi
1075 * @page: page number to read
1076 *
1077 * We need a special oob layout and handling even when OOB isn't used.
1078 */
1079static int nand_read_page_raw_syndrome(struct mtd_info *mtd,
1080				       struct nand_chip *chip, uint8_t *buf,
1081				       int oob_required, int page)
1082{
1083	int eccsize = chip->ecc.size;
1084	int eccbytes = chip->ecc.bytes;
1085	uint8_t *oob = chip->oob_poi;
1086	int steps, size;
1087
1088	for (steps = chip->ecc.steps; steps > 0; steps--) {
1089		chip->read_buf(mtd, buf, eccsize);
1090		buf += eccsize;
1091
1092		if (chip->ecc.prepad) {
1093			chip->read_buf(mtd, oob, chip->ecc.prepad);
1094			oob += chip->ecc.prepad;
1095		}
1096
1097		chip->read_buf(mtd, oob, eccbytes);
1098		oob += eccbytes;
1099
1100		if (chip->ecc.postpad) {
1101			chip->read_buf(mtd, oob, chip->ecc.postpad);
1102			oob += chip->ecc.postpad;
1103		}
1104	}
1105
1106	size = mtd->oobsize - (oob - chip->oob_poi);
1107	if (size)
1108		chip->read_buf(mtd, oob, size);
1109
1110	return 0;
1111}
1112
1113/**
1114 * nand_read_page_swecc - [REPLACEABLE] software ECC based page read function
1115 * @mtd: mtd info structure
1116 * @chip: nand chip info structure
1117 * @buf: buffer to store read data
1118 * @oob_required: caller requires OOB data read to chip->oob_poi
1119 * @page: page number to read
1120 */
1121static int nand_read_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
1122				uint8_t *buf, int oob_required, int page)
1123{
1124	int i, eccsize = chip->ecc.size;
1125	int eccbytes = chip->ecc.bytes;
1126	int eccsteps = chip->ecc.steps;
1127	uint8_t *p = buf;
1128	uint8_t *ecc_calc = chip->buffers->ecccalc;
1129	uint8_t *ecc_code = chip->buffers->ecccode;
1130	uint32_t *eccpos = chip->ecc.layout->eccpos;
1131	unsigned int max_bitflips = 0;
1132
1133	chip->ecc.read_page_raw(mtd, chip, buf, 1, page);
1134
1135	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
1136		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1137
1138	for (i = 0; i < chip->ecc.total; i++)
1139		ecc_code[i] = chip->oob_poi[eccpos[i]];
1140
1141	eccsteps = chip->ecc.steps;
1142	p = buf;
1143
1144	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1145		int stat;
1146
1147		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
1148		if (stat < 0) {
1149			mtd->ecc_stats.failed++;
1150		} else {
1151			mtd->ecc_stats.corrected += stat;
1152			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1153		}
1154	}
1155	return max_bitflips;
1156}
1157
1158/**
1159 * nand_read_subpage - [REPLACEABLE] ECC based sub-page read function
1160 * @mtd: mtd info structure
1161 * @chip: nand chip info structure
1162 * @data_offs: offset of requested data within the page
1163 * @readlen: data length
1164 * @bufpoi: buffer to store read data
1165 * @page: page number to read
1166 */
1167static int nand_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
1168			uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi,
1169			int page)
1170{
1171	int start_step, end_step, num_steps;
1172	uint32_t *eccpos = chip->ecc.layout->eccpos;
1173	uint8_t *p;
1174	int data_col_addr, i, gaps = 0;
1175	int datafrag_len, eccfrag_len, aligned_len, aligned_pos;
1176	int busw = (chip->options & NAND_BUSWIDTH_16) ? 2 : 1;
1177	int index;
1178	unsigned int max_bitflips = 0;
1179
1180	/* Column address within the page aligned to ECC size (256bytes) */
1181	start_step = data_offs / chip->ecc.size;
1182	end_step = (data_offs + readlen - 1) / chip->ecc.size;
1183	num_steps = end_step - start_step + 1;
1184	index = start_step * chip->ecc.bytes;
1185
1186	/* Data size aligned to ECC ecc.size */
1187	datafrag_len = num_steps * chip->ecc.size;
1188	eccfrag_len = num_steps * chip->ecc.bytes;
1189
1190	data_col_addr = start_step * chip->ecc.size;
1191	/* If we read not a page aligned data */
1192	if (data_col_addr != 0)
1193		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, data_col_addr, -1);
1194
1195	p = bufpoi + data_col_addr;
1196	chip->read_buf(mtd, p, datafrag_len);
1197
1198	/* Calculate ECC */
1199	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size)
1200		chip->ecc.calculate(mtd, p, &chip->buffers->ecccalc[i]);
1201
1202	/*
1203	 * The performance is faster if we position offsets according to
1204	 * ecc.pos. Let's make sure that there are no gaps in ECC positions.
1205	 */
1206	for (i = 0; i < eccfrag_len - 1; i++) {
1207		if (eccpos[i + start_step * chip->ecc.bytes] + 1 !=
1208			eccpos[i + start_step * chip->ecc.bytes + 1]) {
1209			gaps = 1;
1210			break;
1211		}
1212	}
1213	if (gaps) {
1214		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);
1215		chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1216	} else {
1217		/*
1218		 * Send the command to read the particular ECC bytes take care
1219		 * about buswidth alignment in read_buf.
1220		 */
1221		aligned_pos = eccpos[index] & ~(busw - 1);
1222		aligned_len = eccfrag_len;
1223		if (eccpos[index] & (busw - 1))
1224			aligned_len++;
1225		if (eccpos[index + (num_steps * chip->ecc.bytes)] & (busw - 1))
1226			aligned_len++;
1227
1228		chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
1229					mtd->writesize + aligned_pos, -1);
1230		chip->read_buf(mtd, &chip->oob_poi[aligned_pos], aligned_len);
1231	}
1232
1233	for (i = 0; i < eccfrag_len; i++)
1234		chip->buffers->ecccode[i] = chip->oob_poi[eccpos[i + index]];
1235
1236	p = bufpoi + data_col_addr;
1237	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size) {
1238		int stat;
1239
1240		stat = chip->ecc.correct(mtd, p,
1241			&chip->buffers->ecccode[i], &chip->buffers->ecccalc[i]);
1242		if (stat < 0) {
1243			mtd->ecc_stats.failed++;
1244		} else {
1245			mtd->ecc_stats.corrected += stat;
1246			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1247		}
1248	}
1249	return max_bitflips;
1250}
1251
1252/**
1253 * nand_read_page_hwecc - [REPLACEABLE] hardware ECC based page read function
1254 * @mtd: mtd info structure
1255 * @chip: nand chip info structure
1256 * @buf: buffer to store read data
1257 * @oob_required: caller requires OOB data read to chip->oob_poi
1258 * @page: page number to read
1259 *
1260 * Not for syndrome calculating ECC controllers which need a special oob layout.
1261 */
1262static int nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
1263				uint8_t *buf, int oob_required, int page)
1264{
1265	int i, eccsize = chip->ecc.size;
1266	int eccbytes = chip->ecc.bytes;
1267	int eccsteps = chip->ecc.steps;
1268	uint8_t *p = buf;
1269	uint8_t *ecc_calc = chip->buffers->ecccalc;
1270	uint8_t *ecc_code = chip->buffers->ecccode;
1271	uint32_t *eccpos = chip->ecc.layout->eccpos;
1272	unsigned int max_bitflips = 0;
1273
1274	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1275		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1276		chip->read_buf(mtd, p, eccsize);
1277		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1278	}
1279	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1280
1281	for (i = 0; i < chip->ecc.total; i++)
1282		ecc_code[i] = chip->oob_poi[eccpos[i]];
1283
1284	eccsteps = chip->ecc.steps;
1285	p = buf;
1286
1287	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1288		int stat;
1289
1290		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
1291		if (stat < 0) {
1292			mtd->ecc_stats.failed++;
1293		} else {
1294			mtd->ecc_stats.corrected += stat;
1295			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1296		}
1297	}
1298	return max_bitflips;
1299}
1300
1301/**
1302 * nand_read_page_hwecc_oob_first - [REPLACEABLE] hw ecc, read oob first
1303 * @mtd: mtd info structure
1304 * @chip: nand chip info structure
1305 * @buf: buffer to store read data
1306 * @oob_required: caller requires OOB data read to chip->oob_poi
1307 * @page: page number to read
1308 *
1309 * Hardware ECC for large page chips, require OOB to be read first. For this
1310 * ECC mode, the write_page method is re-used from ECC_HW. These methods
1311 * read/write ECC from the OOB area, unlike the ECC_HW_SYNDROME support with
1312 * multiple ECC steps, follows the "infix ECC" scheme and reads/writes ECC from
1313 * the data area, by overwriting the NAND manufacturer bad block markings.
1314 */
1315static int nand_read_page_hwecc_oob_first(struct mtd_info *mtd,
1316	struct nand_chip *chip, uint8_t *buf, int oob_required, int page)
1317{
1318	int i, eccsize = chip->ecc.size;
1319	int eccbytes = chip->ecc.bytes;
1320	int eccsteps = chip->ecc.steps;
1321	uint8_t *p = buf;
1322	uint8_t *ecc_code = chip->buffers->ecccode;
1323	uint32_t *eccpos = chip->ecc.layout->eccpos;
1324	uint8_t *ecc_calc = chip->buffers->ecccalc;
1325	unsigned int max_bitflips = 0;
1326
1327	/* Read the OOB area first */
1328	chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
1329	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1330	chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
1331
1332	for (i = 0; i < chip->ecc.total; i++)
1333		ecc_code[i] = chip->oob_poi[eccpos[i]];
1334
1335	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1336		int stat;
1337
1338		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1339		chip->read_buf(mtd, p, eccsize);
1340		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
1341
1342		stat = chip->ecc.correct(mtd, p, &ecc_code[i], NULL);
1343		if (stat < 0) {
1344			mtd->ecc_stats.failed++;
1345		} else {
1346			mtd->ecc_stats.corrected += stat;
1347			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1348		}
1349	}
1350	return max_bitflips;
1351}
1352
1353/**
1354 * nand_read_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page read
1355 * @mtd: mtd info structure
1356 * @chip: nand chip info structure
1357 * @buf: buffer to store read data
1358 * @oob_required: caller requires OOB data read to chip->oob_poi
1359 * @page: page number to read
1360 *
1361 * The hw generator calculates the error syndrome automatically. Therefore we
1362 * need a special oob layout and handling.
1363 */
1364static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
1365				   uint8_t *buf, int oob_required, int page)
1366{
1367	int i, eccsize = chip->ecc.size;
1368	int eccbytes = chip->ecc.bytes;
1369	int eccsteps = chip->ecc.steps;
1370	uint8_t *p = buf;
1371	uint8_t *oob = chip->oob_poi;
1372	unsigned int max_bitflips = 0;
1373
1374	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
1375		int stat;
1376
1377		chip->ecc.hwctl(mtd, NAND_ECC_READ);
1378		chip->read_buf(mtd, p, eccsize);
1379
1380		if (chip->ecc.prepad) {
1381			chip->read_buf(mtd, oob, chip->ecc.prepad);
1382			oob += chip->ecc.prepad;
1383		}
1384
1385		chip->ecc.hwctl(mtd, NAND_ECC_READSYN);
1386		chip->read_buf(mtd, oob, eccbytes);
1387		stat = chip->ecc.correct(mtd, p, oob, NULL);
1388
1389		if (stat < 0) {
1390			mtd->ecc_stats.failed++;
1391		} else {
1392			mtd->ecc_stats.corrected += stat;
1393			max_bitflips = max_t(unsigned int, max_bitflips, stat);
1394		}
1395
1396		oob += eccbytes;
1397
1398		if (chip->ecc.postpad) {
1399			chip->read_buf(mtd, oob, chip->ecc.postpad);
1400			oob += chip->ecc.postpad;
1401		}
1402	}
1403
1404	/* Calculate remaining oob bytes */
1405	i = mtd->oobsize - (oob - chip->oob_poi);
1406	if (i)
1407		chip->read_buf(mtd, oob, i);
1408
1409	return max_bitflips;
1410}
1411
1412/**
1413 * nand_transfer_oob - [INTERN] Transfer oob to client buffer
1414 * @chip: nand chip structure
1415 * @oob: oob destination address
1416 * @ops: oob ops structure
1417 * @len: size of oob to transfer
1418 */
1419static uint8_t *nand_transfer_oob(struct nand_chip *chip, uint8_t *oob,
1420				  struct mtd_oob_ops *ops, size_t len)
1421{
1422	switch (ops->mode) {
1423
1424	case MTD_OPS_PLACE_OOB:
1425	case MTD_OPS_RAW:
1426		memcpy(oob, chip->oob_poi + ops->ooboffs, len);
1427		return oob + len;
1428
1429	case MTD_OPS_AUTO_OOB: {
1430		struct nand_oobfree *free = chip->ecc.layout->oobfree;
1431		uint32_t boffs = 0, roffs = ops->ooboffs;
1432		size_t bytes = 0;
1433
1434		for (; free->length && len; free++, len -= bytes) {
1435			/* Read request not from offset 0? */
1436			if (unlikely(roffs)) {
1437				if (roffs >= free->length) {
1438					roffs -= free->length;
1439					continue;
1440				}
1441				boffs = free->offset + roffs;
1442				bytes = min_t(size_t, len,
1443					      (free->length - roffs));
1444				roffs = 0;
1445			} else {
1446				bytes = min_t(size_t, len, free->length);
1447				boffs = free->offset;
1448			}
1449			memcpy(oob, chip->oob_poi + boffs, bytes);
1450			oob += bytes;
1451		}
1452		return oob;
1453	}
1454	default:
1455		BUG();
1456	}
1457	return NULL;
1458}
1459
1460/**
1461 * nand_setup_read_retry - [INTERN] Set the READ RETRY mode
1462 * @mtd: MTD device structure
1463 * @retry_mode: the retry mode to use
1464 *
1465 * Some vendors supply a special command to shift the Vt threshold, to be used
1466 * when there are too many bitflips in a page (i.e., ECC error). After setting
1467 * a new threshold, the host should retry reading the page.
1468 */
1469static int nand_setup_read_retry(struct mtd_info *mtd, int retry_mode)
1470{
1471	struct nand_chip *chip = mtd->priv;
1472
1473	pr_debug("setting READ RETRY mode %d\n", retry_mode);
1474
1475	if (retry_mode >= chip->read_retries)
1476		return -EINVAL;
1477
1478	if (!chip->setup_read_retry)
1479		return -EOPNOTSUPP;
1480
1481	return chip->setup_read_retry(mtd, retry_mode);
1482}
1483
1484/**
1485 * nand_do_read_ops - [INTERN] Read data with ECC
1486 * @mtd: MTD device structure
1487 * @from: offset to read from
1488 * @ops: oob ops structure
1489 *
1490 * Internal function. Called with chip held.
1491 */
1492static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
1493			    struct mtd_oob_ops *ops)
1494{
1495	int chipnr, page, realpage, col, bytes, aligned, oob_required;
1496	struct nand_chip *chip = mtd->priv;
1497	int ret = 0;
1498	uint32_t readlen = ops->len;
1499	uint32_t oobreadlen = ops->ooblen;
1500	uint32_t max_oobsize = ops->mode == MTD_OPS_AUTO_OOB ?
1501		mtd->oobavail : mtd->oobsize;
1502
1503	uint8_t *bufpoi, *oob, *buf;
1504	unsigned int max_bitflips = 0;
1505	int retry_mode = 0;
1506	bool ecc_fail = false;
1507
1508	chipnr = (int)(from >> chip->chip_shift);
1509	chip->select_chip(mtd, chipnr);
1510
1511	realpage = (int)(from >> chip->page_shift);
1512	page = realpage & chip->pagemask;
1513
1514	col = (int)(from & (mtd->writesize - 1));
1515
1516	buf = ops->datbuf;
1517	oob = ops->oobbuf;
1518	oob_required = oob ? 1 : 0;
1519
1520	while (1) {
1521		unsigned int ecc_failures = mtd->ecc_stats.failed;
1522
1523		bytes = min(mtd->writesize - col, readlen);
1524		aligned = (bytes == mtd->writesize);
1525
1526		/* Is the current page in the buffer? */
1527		if (realpage != chip->pagebuf || oob) {
1528			bufpoi = aligned ? buf : chip->buffers->databuf;
1529
1530read_retry:
1531			chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
1532
1533			/*
1534			 * Now read the page into the buffer.  Absent an error,
1535			 * the read methods return max bitflips per ecc step.
1536			 */
1537			if (unlikely(ops->mode == MTD_OPS_RAW))
1538				ret = chip->ecc.read_page_raw(mtd, chip, bufpoi,
1539							      oob_required,
1540							      page);
1541			else if (!aligned && NAND_HAS_SUBPAGE_READ(chip) &&
1542				 !oob)
1543				ret = chip->ecc.read_subpage(mtd, chip,
1544							col, bytes, bufpoi,
1545							page);
1546			else
1547				ret = chip->ecc.read_page(mtd, chip, bufpoi,
1548							  oob_required, page);
1549			if (ret < 0) {
1550				if (!aligned)
1551					/* Invalidate page cache */
1552					chip->pagebuf = -1;
1553				break;
1554			}
1555
1556			max_bitflips = max_t(unsigned int, max_bitflips, ret);
1557
1558			/* Transfer not aligned data */
1559			if (!aligned) {
1560				if (!NAND_HAS_SUBPAGE_READ(chip) && !oob &&
1561				    !(mtd->ecc_stats.failed - ecc_failures) &&
1562				    (ops->mode != MTD_OPS_RAW)) {
1563					chip->pagebuf = realpage;
1564					chip->pagebuf_bitflips = ret;
1565				} else {
1566					/* Invalidate page cache */
1567					chip->pagebuf = -1;
1568				}
1569				memcpy(buf, chip->buffers->databuf + col, bytes);
1570			}
1571
1572			if (unlikely(oob)) {
1573				int toread = min(oobreadlen, max_oobsize);
1574
1575				if (toread) {
1576					oob = nand_transfer_oob(chip,
1577						oob, ops, toread);
1578					oobreadlen -= toread;
1579				}
1580			}
1581
1582			if (chip->options & NAND_NEED_READRDY) {
1583				/* Apply delay or wait for ready/busy pin */
1584				if (!chip->dev_ready)
1585					udelay(chip->chip_delay);
1586				else
1587					nand_wait_ready(mtd);
1588			}
1589
1590			if (mtd->ecc_stats.failed - ecc_failures) {
1591				if (retry_mode + 1 < chip->read_retries) {
1592					retry_mode++;
1593					ret = nand_setup_read_retry(mtd,
1594							retry_mode);
1595					if (ret < 0)
1596						break;
1597
1598					/* Reset failures; retry */
1599					mtd->ecc_stats.failed = ecc_failures;
1600					goto read_retry;
1601				} else {
1602					/* No more retry modes; real failure */
1603					ecc_fail = true;
1604				}
1605			}
1606
1607			buf += bytes;
1608		} else {
1609			memcpy(buf, chip->buffers->databuf + col, bytes);
1610			buf += bytes;
1611			max_bitflips = max_t(unsigned int, max_bitflips,
1612					     chip->pagebuf_bitflips);
1613		}
1614
1615		readlen -= bytes;
1616
1617		/* Reset to retry mode 0 */
1618		if (retry_mode) {
1619			ret = nand_setup_read_retry(mtd, 0);
1620			if (ret < 0)
1621				break;
1622			retry_mode = 0;
1623		}
1624
1625		if (!readlen)
1626			break;
1627
1628		/* For subsequent reads align to page boundary */
1629		col = 0;
1630		/* Increment page address */
1631		realpage++;
1632
1633		page = realpage & chip->pagemask;
1634		/* Check, if we cross a chip boundary */
1635		if (!page) {
1636			chipnr++;
1637			chip->select_chip(mtd, -1);
1638			chip->select_chip(mtd, chipnr);
1639		}
1640	}
1641	chip->select_chip(mtd, -1);
1642
1643	ops->retlen = ops->len - (size_t) readlen;
1644	if (oob)
1645		ops->oobretlen = ops->ooblen - oobreadlen;
1646
1647	if (ret < 0)
1648		return ret;
1649
1650	if (ecc_fail)
1651		return -EBADMSG;
1652
1653	return max_bitflips;
1654}
1655
1656/**
1657 * nand_read - [MTD Interface] MTD compatibility function for nand_do_read_ecc
1658 * @mtd: MTD device structure
1659 * @from: offset to read from
1660 * @len: number of bytes to read
1661 * @retlen: pointer to variable to store the number of read bytes
1662 * @buf: the databuffer to put data
1663 *
1664 * Get hold of the chip and call nand_do_read.
1665 */
1666static int nand_read(struct mtd_info *mtd, loff_t from, size_t len,
1667		     size_t *retlen, uint8_t *buf)
1668{
1669	struct mtd_oob_ops ops;
1670	int ret;
1671
1672	nand_get_device(mtd, FL_READING);
1673	ops.len = len;
1674	ops.datbuf = buf;
1675	ops.oobbuf = NULL;
1676	ops.mode = MTD_OPS_PLACE_OOB;
1677	ret = nand_do_read_ops(mtd, from, &ops);
1678	*retlen = ops.retlen;
1679	nand_release_device(mtd);
1680	return ret;
1681}
1682
1683/**
1684 * nand_read_oob_std - [REPLACEABLE] the most common OOB data read function
1685 * @mtd: mtd info structure
1686 * @chip: nand chip info structure
1687 * @page: page number to read
1688 */
1689static int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
1690			     int page)
1691{
1692	chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
1693	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
1694	return 0;
1695}
1696
1697/**
1698 * nand_read_oob_syndrome - [REPLACEABLE] OOB data read function for HW ECC
1699 *			    with syndromes
1700 * @mtd: mtd info structure
1701 * @chip: nand chip info structure
1702 * @page: page number to read
1703 */
1704static int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
1705				  int page)
1706{
1707	uint8_t *buf = chip->oob_poi;
1708	int length = mtd->oobsize;
1709	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
1710	int eccsize = chip->ecc.size;
1711	uint8_t *bufpoi = buf;
1712	int i, toread, sndrnd = 0, pos;
1713
1714	chip->cmdfunc(mtd, NAND_CMD_READ0, chip->ecc.size, page);
1715	for (i = 0; i < chip->ecc.steps; i++) {
1716		if (sndrnd) {
1717			pos = eccsize + i * (eccsize + chunk);
1718			if (mtd->writesize > 512)
1719				chip->cmdfunc(mtd, NAND_CMD_RNDOUT, pos, -1);
1720			else
1721				chip->cmdfunc(mtd, NAND_CMD_READ0, pos, page);
1722		} else
1723			sndrnd = 1;
1724		toread = min_t(int, length, chunk);
1725		chip->read_buf(mtd, bufpoi, toread);
1726		bufpoi += toread;
1727		length -= toread;
1728	}
1729	if (length > 0)
1730		chip->read_buf(mtd, bufpoi, length);
1731
1732	return 0;
1733}
1734
1735/**
1736 * nand_write_oob_std - [REPLACEABLE] the most common OOB data write function
1737 * @mtd: mtd info structure
1738 * @chip: nand chip info structure
1739 * @page: page number to write
1740 */
1741static int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
1742			      int page)
1743{
1744	int status = 0;
1745	const uint8_t *buf = chip->oob_poi;
1746	int length = mtd->oobsize;
1747
1748	chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, page);
1749	chip->write_buf(mtd, buf, length);
1750	/* Send command to program the OOB data */
1751	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1752
1753	status = chip->waitfunc(mtd, chip);
1754
1755	return status & NAND_STATUS_FAIL ? -EIO : 0;
1756}
1757
1758/**
1759 * nand_write_oob_syndrome - [REPLACEABLE] OOB data write function for HW ECC
1760 *			     with syndrome - only for large page flash
1761 * @mtd: mtd info structure
1762 * @chip: nand chip info structure
1763 * @page: page number to write
1764 */
1765static int nand_write_oob_syndrome(struct mtd_info *mtd,
1766				   struct nand_chip *chip, int page)
1767{
1768	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
1769	int eccsize = chip->ecc.size, length = mtd->oobsize;
1770	int i, len, pos, status = 0, sndcmd = 0, steps = chip->ecc.steps;
1771	const uint8_t *bufpoi = chip->oob_poi;
1772
1773	/*
1774	 * data-ecc-data-ecc ... ecc-oob
1775	 * or
1776	 * data-pad-ecc-pad-data-pad .... ecc-pad-oob
1777	 */
1778	if (!chip->ecc.prepad && !chip->ecc.postpad) {
1779		pos = steps * (eccsize + chunk);
1780		steps = 0;
1781	} else
1782		pos = eccsize;
1783
1784	chip->cmdfunc(mtd, NAND_CMD_SEQIN, pos, page);
1785	for (i = 0; i < steps; i++) {
1786		if (sndcmd) {
1787			if (mtd->writesize <= 512) {
1788				uint32_t fill = 0xFFFFFFFF;
1789
1790				len = eccsize;
1791				while (len > 0) {
1792					int num = min_t(int, len, 4);
1793					chip->write_buf(mtd, (uint8_t *)&fill,
1794							num);
1795					len -= num;
1796				}
1797			} else {
1798				pos = eccsize + i * (eccsize + chunk);
1799				chip->cmdfunc(mtd, NAND_CMD_RNDIN, pos, -1);
1800			}
1801		} else
1802			sndcmd = 1;
1803		len = min_t(int, length, chunk);
1804		chip->write_buf(mtd, bufpoi, len);
1805		bufpoi += len;
1806		length -= len;
1807	}
1808	if (length > 0)
1809		chip->write_buf(mtd, bufpoi, length);
1810
1811	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
1812	status = chip->waitfunc(mtd, chip);
1813
1814	return status & NAND_STATUS_FAIL ? -EIO : 0;
1815}
1816
1817/**
1818 * nand_do_read_oob - [INTERN] NAND read out-of-band
1819 * @mtd: MTD device structure
1820 * @from: offset to read from
1821 * @ops: oob operations description structure
1822 *
1823 * NAND read out-of-band data from the spare area.
1824 */
1825static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
1826			    struct mtd_oob_ops *ops)
1827{
1828	int page, realpage, chipnr;
1829	struct nand_chip *chip = mtd->priv;
1830	struct mtd_ecc_stats stats;
1831	int readlen = ops->ooblen;
1832	int len;
1833	uint8_t *buf = ops->oobbuf;
1834	int ret = 0;
1835
1836	pr_debug("%s: from = 0x%08Lx, len = %i\n",
1837			__func__, (unsigned long long)from, readlen);
1838
1839	stats = mtd->ecc_stats;
1840
1841	if (ops->mode == MTD_OPS_AUTO_OOB)
1842		len = chip->ecc.layout->oobavail;
1843	else
1844		len = mtd->oobsize;
1845
1846	if (unlikely(ops->ooboffs >= len)) {
1847		pr_debug("%s: attempt to start read outside oob\n",
1848				__func__);
1849		return -EINVAL;
1850	}
1851
1852	/* Do not allow reads past end of device */
1853	if (unlikely(from >= mtd->size ||
1854		     ops->ooboffs + readlen > ((mtd->size >> chip->page_shift) -
1855					(from >> chip->page_shift)) * len)) {
1856		pr_debug("%s: attempt to read beyond end of device\n",
1857				__func__);
1858		return -EINVAL;
1859	}
1860
1861	chipnr = (int)(from >> chip->chip_shift);
1862	chip->select_chip(mtd, chipnr);
1863
1864	/* Shift to get page */
1865	realpage = (int)(from >> chip->page_shift);
1866	page = realpage & chip->pagemask;
1867
1868	while (1) {
1869		if (ops->mode == MTD_OPS_RAW)
1870			ret = chip->ecc.read_oob_raw(mtd, chip, page);
1871		else
1872			ret = chip->ecc.read_oob(mtd, chip, page);
1873
1874		if (ret < 0)
1875			break;
1876
1877		len = min(len, readlen);
1878		buf = nand_transfer_oob(chip, buf, ops, len);
1879
1880		if (chip->options & NAND_NEED_READRDY) {
1881			/* Apply delay or wait for ready/busy pin */
1882			if (!chip->dev_ready)
1883				udelay(chip->chip_delay);
1884			else
1885				nand_wait_ready(mtd);
1886		}
1887
1888		readlen -= len;
1889		if (!readlen)
1890			break;
1891
1892		/* Increment page address */
1893		realpage++;
1894
1895		page = realpage & chip->pagemask;
1896		/* Check, if we cross a chip boundary */
1897		if (!page) {
1898			chipnr++;
1899			chip->select_chip(mtd, -1);
1900			chip->select_chip(mtd, chipnr);
1901		}
1902	}
1903	chip->select_chip(mtd, -1);
1904
1905	ops->oobretlen = ops->ooblen - readlen;
1906
1907	if (ret < 0)
1908		return ret;
1909
1910	if (mtd->ecc_stats.failed - stats.failed)
1911		return -EBADMSG;
1912
1913	return  mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0;
1914}
1915
1916/**
1917 * nand_read_oob - [MTD Interface] NAND read data and/or out-of-band
1918 * @mtd: MTD device structure
1919 * @from: offset to read from
1920 * @ops: oob operation description structure
1921 *
1922 * NAND read data and/or out-of-band data.
1923 */
1924static int nand_read_oob(struct mtd_info *mtd, loff_t from,
1925			 struct mtd_oob_ops *ops)
1926{
1927	int ret = -ENOTSUPP;
1928
1929	ops->retlen = 0;
1930
1931	/* Do not allow reads past end of device */
1932	if (ops->datbuf && (from + ops->len) > mtd->size) {
1933		pr_debug("%s: attempt to read beyond end of device\n",
1934				__func__);
1935		return -EINVAL;
1936	}
1937
1938	nand_get_device(mtd, FL_READING);
1939
1940	switch (ops->mode) {
1941	case MTD_OPS_PLACE_OOB:
1942	case MTD_OPS_AUTO_OOB:
1943	case MTD_OPS_RAW:
1944		break;
1945
1946	default:
1947		goto out;
1948	}
1949
1950	if (!ops->datbuf)
1951		ret = nand_do_read_oob(mtd, from, ops);
1952	else
1953		ret = nand_do_read_ops(mtd, from, ops);
1954
1955out:
1956	nand_release_device(mtd);
1957	return ret;
1958}
1959
1960
1961/**
1962 * nand_write_page_raw - [INTERN] raw page write function
1963 * @mtd: mtd info structure
1964 * @chip: nand chip info structure
1965 * @buf: data buffer
1966 * @oob_required: must write chip->oob_poi to OOB
1967 *
1968 * Not for syndrome calculating ECC controllers, which use a special oob layout.
1969 */
1970static int nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
1971				const uint8_t *buf, int oob_required)
1972{
1973	chip->write_buf(mtd, buf, mtd->writesize);
1974	if (oob_required)
1975		chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
1976
1977	return 0;
1978}
1979
1980/**
1981 * nand_write_page_raw_syndrome - [INTERN] raw page write function
1982 * @mtd: mtd info structure
1983 * @chip: nand chip info structure
1984 * @buf: data buffer
1985 * @oob_required: must write chip->oob_poi to OOB
1986 *
1987 * We need a special oob layout and handling even when ECC isn't checked.
1988 */
1989static int nand_write_page_raw_syndrome(struct mtd_info *mtd,
1990					struct nand_chip *chip,
1991					const uint8_t *buf, int oob_required)
1992{
1993	int eccsize = chip->ecc.size;
1994	int eccbytes = chip->ecc.bytes;
1995	uint8_t *oob = chip->oob_poi;
1996	int steps, size;
1997
1998	for (steps = chip->ecc.steps; steps > 0; steps--) {
1999		chip->write_buf(mtd, buf, eccsize);
2000		buf += eccsize;
2001
2002		if (chip->ecc.prepad) {
2003			chip->write_buf(mtd, oob, chip->ecc.prepad);
2004			oob += chip->ecc.prepad;
2005		}
2006
2007		chip->write_buf(mtd, oob, eccbytes);
2008		oob += eccbytes;
2009
2010		if (chip->ecc.postpad) {
2011			chip->write_buf(mtd, oob, chip->ecc.postpad);
2012			oob += chip->ecc.postpad;
2013		}
2014	}
2015
2016	size = mtd->oobsize - (oob - chip->oob_poi);
2017	if (size)
2018		chip->write_buf(mtd, oob, size);
2019
2020	return 0;
2021}
2022/**
2023 * nand_write_page_swecc - [REPLACEABLE] software ECC based page write function
2024 * @mtd: mtd info structure
2025 * @chip: nand chip info structure
2026 * @buf: data buffer
2027 * @oob_required: must write chip->oob_poi to OOB
2028 */
2029static int nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
2030				  const uint8_t *buf, int oob_required)
2031{
2032	int i, eccsize = chip->ecc.size;
2033	int eccbytes = chip->ecc.bytes;
2034	int eccsteps = chip->ecc.steps;
2035	uint8_t *ecc_calc = chip->buffers->ecccalc;
2036	const uint8_t *p = buf;
2037	uint32_t *eccpos = chip->ecc.layout->eccpos;
2038
2039	/* Software ECC calculation */
2040	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
2041		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
2042
2043	for (i = 0; i < chip->ecc.total; i++)
2044		chip->oob_poi[eccpos[i]] = ecc_calc[i];
2045
2046	return chip->ecc.write_page_raw(mtd, chip, buf, 1);
2047}
2048
2049/**
2050 * nand_write_page_hwecc - [REPLACEABLE] hardware ECC based page write function
2051 * @mtd: mtd info structure
2052 * @chip: nand chip info structure
2053 * @buf: data buffer
2054 * @oob_required: must write chip->oob_poi to OOB
2055 */
2056static int nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
2057				  const uint8_t *buf, int oob_required)
2058{
2059	int i, eccsize = chip->ecc.size;
2060	int eccbytes = chip->ecc.bytes;
2061	int eccsteps = chip->ecc.steps;
2062	uint8_t *ecc_calc = chip->buffers->ecccalc;
2063	const uint8_t *p = buf;
2064	uint32_t *eccpos = chip->ecc.layout->eccpos;
2065
2066	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
2067		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
2068		chip->write_buf(mtd, p, eccsize);
2069		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
2070	}
2071
2072	for (i = 0; i < chip->ecc.total; i++)
2073		chip->oob_poi[eccpos[i]] = ecc_calc[i];
2074
2075	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
2076
2077	return 0;
2078}
2079
2080
2081/**
2082 * nand_write_subpage_hwecc - [REPLACABLE] hardware ECC based subpage write
2083 * @mtd:	mtd info structure
2084 * @chip:	nand chip info structure
2085 * @offset:	column address of subpage within the page
2086 * @data_len:	data length
2087 * @buf:	data buffer
2088 * @oob_required: must write chip->oob_poi to OOB
2089 */
2090static int nand_write_subpage_hwecc(struct mtd_info *mtd,
2091				struct nand_chip *chip, uint32_t offset,
2092				uint32_t data_len, const uint8_t *buf,
2093				int oob_required)
2094{
2095	uint8_t *oob_buf  = chip->oob_poi;
2096	uint8_t *ecc_calc = chip->buffers->ecccalc;
2097	int ecc_size      = chip->ecc.size;
2098	int ecc_bytes     = chip->ecc.bytes;
2099	int ecc_steps     = chip->ecc.steps;
2100	uint32_t *eccpos  = chip->ecc.layout->eccpos;
2101	uint32_t start_step = offset / ecc_size;
2102	uint32_t end_step   = (offset + data_len - 1) / ecc_size;
2103	int oob_bytes       = mtd->oobsize / ecc_steps;
2104	int step, i;
2105
2106	for (step = 0; step < ecc_steps; step++) {
2107		/* configure controller for WRITE access */
2108		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
2109
2110		/* write data (untouched subpages already masked by 0xFF) */
2111		chip->write_buf(mtd, buf, ecc_size);
2112
2113		/* mask ECC of un-touched subpages by padding 0xFF */
2114		if ((step < start_step) || (step > end_step))
2115			memset(ecc_calc, 0xff, ecc_bytes);
2116		else
2117			chip->ecc.calculate(mtd, buf, ecc_calc);
2118
2119		/* mask OOB of un-touched subpages by padding 0xFF */
2120		/* if oob_required, preserve OOB metadata of written subpage */
2121		if (!oob_required || (step < start_step) || (step > end_step))
2122			memset(oob_buf, 0xff, oob_bytes);
2123
2124		buf += ecc_size;
2125		ecc_calc += ecc_bytes;
2126		oob_buf  += oob_bytes;
2127	}
2128
2129	/* copy calculated ECC for whole page to chip->buffer->oob */
2130	/* this include masked-value(0xFF) for unwritten subpages */
2131	ecc_calc = chip->buffers->ecccalc;
2132	for (i = 0; i < chip->ecc.total; i++)
2133		chip->oob_poi[eccpos[i]] = ecc_calc[i];
2134
2135	/* write OOB buffer to NAND device */
2136	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
2137
2138	return 0;
2139}
2140
2141
2142/**
2143 * nand_write_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page write
2144 * @mtd: mtd info structure
2145 * @chip: nand chip info structure
2146 * @buf: data buffer
2147 * @oob_required: must write chip->oob_poi to OOB
2148 *
2149 * The hw generator calculates the error syndrome automatically. Therefore we
2150 * need a special oob layout and handling.
2151 */
2152static int nand_write_page_syndrome(struct mtd_info *mtd,
2153				    struct nand_chip *chip,
2154				    const uint8_t *buf, int oob_required)
2155{
2156	int i, eccsize = chip->ecc.size;
2157	int eccbytes = chip->ecc.bytes;
2158	int eccsteps = chip->ecc.steps;
2159	const uint8_t *p = buf;
2160	uint8_t *oob = chip->oob_poi;
2161
2162	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
2163
2164		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
2165		chip->write_buf(mtd, p, eccsize);
2166
2167		if (chip->ecc.prepad) {
2168			chip->write_buf(mtd, oob, chip->ecc.prepad);
2169			oob += chip->ecc.prepad;
2170		}
2171
2172		chip->ecc.calculate(mtd, p, oob);
2173		chip->write_buf(mtd, oob, eccbytes);
2174		oob += eccbytes;
2175
2176		if (chip->ecc.postpad) {
2177			chip->write_buf(mtd, oob, chip->ecc.postpad);
2178			oob += chip->ecc.postpad;
2179		}
2180	}
2181
2182	/* Calculate remaining oob bytes */
2183	i = mtd->oobsize - (oob - chip->oob_poi);
2184	if (i)
2185		chip->write_buf(mtd, oob, i);
2186
2187	return 0;
2188}
2189
2190/**
2191 * nand_write_page - [REPLACEABLE] write one page
2192 * @mtd: MTD device structure
2193 * @chip: NAND chip descriptor
2194 * @offset: address offset within the page
2195 * @data_len: length of actual data to be written
2196 * @buf: the data to write
2197 * @oob_required: must write chip->oob_poi to OOB
2198 * @page: page number to write
2199 * @cached: cached programming
2200 * @raw: use _raw version of write_page
2201 */
2202static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
2203		uint32_t offset, int data_len, const uint8_t *buf,
2204		int oob_required, int page, int cached, int raw)
2205{
2206	int status, subpage;
2207
2208	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) &&
2209		chip->ecc.write_subpage)
2210		subpage = offset || (data_len < mtd->writesize);
2211	else
2212		subpage = 0;
2213
2214	chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
2215
2216	if (unlikely(raw))
2217		status = chip->ecc.write_page_raw(mtd, chip, buf,
2218							oob_required);
2219	else if (subpage)
2220		status = chip->ecc.write_subpage(mtd, chip, offset, data_len,
2221							 buf, oob_required);
2222	else
2223		status = chip->ecc.write_page(mtd, chip, buf, oob_required);
2224
2225	if (status < 0)
2226		return status;
2227
2228	/*
2229	 * Cached progamming disabled for now. Not sure if it's worth the
2230	 * trouble. The speed gain is not very impressive. (2.3->2.6Mib/s).
2231	 */
2232	cached = 0;
2233
2234	if (!cached || !NAND_HAS_CACHEPROG(chip)) {
2235
2236		chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
2237		status = chip->waitfunc(mtd, chip);
2238		/*
2239		 * See if operation failed and additional status checks are
2240		 * available.
2241		 */
2242		if ((status & NAND_STATUS_FAIL) && (chip->errstat))
2243			status = chip->errstat(mtd, chip, FL_WRITING, status,
2244					       page);
2245
2246		if (status & NAND_STATUS_FAIL)
2247			return -EIO;
2248	} else {
2249		chip->cmdfunc(mtd, NAND_CMD_CACHEDPROG, -1, -1);
2250		status = chip->waitfunc(mtd, chip);
2251	}
2252
2253	return 0;
2254}
2255
2256/**
2257 * nand_fill_oob - [INTERN] Transfer client buffer to oob
2258 * @mtd: MTD device structure
2259 * @oob: oob data buffer
2260 * @len: oob data write length
2261 * @ops: oob ops structure
2262 */
2263static uint8_t *nand_fill_oob(struct mtd_info *mtd, uint8_t *oob, size_t len,
2264			      struct mtd_oob_ops *ops)
2265{
2266	struct nand_chip *chip = mtd->priv;
2267
2268	/*
2269	 * Initialise to all 0xFF, to avoid the possibility of left over OOB
2270	 * data from a previous OOB read.
2271	 */
2272	memset(chip->oob_poi, 0xff, mtd->oobsize);
2273
2274	switch (ops->mode) {
2275
2276	case MTD_OPS_PLACE_OOB:
2277	case MTD_OPS_RAW:
2278		memcpy(chip->oob_poi + ops->ooboffs, oob, len);
2279		return oob + len;
2280
2281	case MTD_OPS_AUTO_OOB: {
2282		struct nand_oobfree *free = chip->ecc.layout->oobfree;
2283		uint32_t boffs = 0, woffs = ops->ooboffs;
2284		size_t bytes = 0;
2285
2286		for (; free->length && len; free++, len -= bytes) {
2287			/* Write request not from offset 0? */
2288			if (unlikely(woffs)) {
2289				if (woffs >= free->length) {
2290					woffs -= free->length;
2291					continue;
2292				}
2293				boffs = free->offset + woffs;
2294				bytes = min_t(size_t, len,
2295					      (free->length - woffs));
2296				woffs = 0;
2297			} else {
2298				bytes = min_t(size_t, len, free->length);
2299				boffs = free->offset;
2300			}
2301			memcpy(chip->oob_poi + boffs, oob, bytes);
2302			oob += bytes;
2303		}
2304		return oob;
2305	}
2306	default:
2307		BUG();
2308	}
2309	return NULL;
2310}
2311
2312#define NOTALIGNED(x)	((x & (chip->subpagesize - 1)) != 0)
2313
2314/**
2315 * nand_do_write_ops - [INTERN] NAND write with ECC
2316 * @mtd: MTD device structure
2317 * @to: offset to write to
2318 * @ops: oob operations description structure
2319 *
2320 * NAND write with ECC.
2321 */
2322static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
2323			     struct mtd_oob_ops *ops)
2324{
2325	int chipnr, realpage, page, blockmask, column;
2326	struct nand_chip *chip = mtd->priv;
2327	uint32_t writelen = ops->len;
2328
2329	uint32_t oobwritelen = ops->ooblen;
2330	uint32_t oobmaxlen = ops->mode == MTD_OPS_AUTO_OOB ?
2331				mtd->oobavail : mtd->oobsize;
2332
2333	uint8_t *oob = ops->oobbuf;
2334	uint8_t *buf = ops->datbuf;
2335	int ret;
2336	int oob_required = oob ? 1 : 0;
2337
2338	ops->retlen = 0;
2339	if (!writelen)
2340		return 0;
2341
2342	/* Reject writes, which are not page aligned */
2343	if (NOTALIGNED(to) || NOTALIGNED(ops->len)) {
2344		pr_notice("%s: attempt to write non page aligned data\n",
2345			   __func__);
2346		return -EINVAL;
2347	}
2348
2349	column = to & (mtd->writesize - 1);
2350
2351	chipnr = (int)(to >> chip->chip_shift);
2352	chip->select_chip(mtd, chipnr);
2353
2354	/* Check, if it is write protected */
2355	if (nand_check_wp(mtd)) {
2356		ret = -EIO;
2357		goto err_out;
2358	}
2359
2360	realpage = (int)(to >> chip->page_shift);
2361	page = realpage & chip->pagemask;
2362	blockmask = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
2363
2364	/* Invalidate the page cache, when we write to the cached page */
2365	if (to <= (chip->pagebuf << chip->page_shift) &&
2366	    (chip->pagebuf << chip->page_shift) < (to + ops->len))
2367		chip->pagebuf = -1;
2368
2369	/* Don't allow multipage oob writes with offset */
2370	if (oob && ops->ooboffs && (ops->ooboffs + ops->ooblen > oobmaxlen)) {
2371		ret = -EINVAL;
2372		goto err_out;
2373	}
2374
2375	while (1) {
2376		int bytes = mtd->writesize;
2377		int cached = writelen > bytes && page != blockmask;
2378		uint8_t *wbuf = buf;
2379
2380		/* Partial page write? */
2381		if (unlikely(column || writelen < (mtd->writesize - 1))) {
2382			cached = 0;
2383			bytes = min_t(int, bytes - column, (int) writelen);
2384			chip->pagebuf = -1;
2385			memset(chip->buffers->databuf, 0xff, mtd->writesize);
2386			memcpy(&chip->buffers->databuf[column], buf, bytes);
2387			wbuf = chip->buffers->databuf;
2388		}
2389
2390		if (unlikely(oob)) {
2391			size_t len = min(oobwritelen, oobmaxlen);
2392			oob = nand_fill_oob(mtd, oob, len, ops);
2393			oobwritelen -= len;
2394		} else {
2395			/* We still need to erase leftover OOB data */
2396			memset(chip->oob_poi, 0xff, mtd->oobsize);
2397		}
2398		ret = chip->write_page(mtd, chip, column, bytes, wbuf,
2399					oob_required, page, cached,
2400					(ops->mode == MTD_OPS_RAW));
2401		if (ret)
2402			break;
2403
2404		writelen -= bytes;
2405		if (!writelen)
2406			break;
2407
2408		column = 0;
2409		buf += bytes;
2410		realpage++;
2411
2412		page = realpage & chip->pagemask;
2413		/* Check, if we cross a chip boundary */
2414		if (!page) {
2415			chipnr++;
2416			chip->select_chip(mtd, -1);
2417			chip->select_chip(mtd, chipnr);
2418		}
2419	}
2420
2421	ops->retlen = ops->len - writelen;
2422	if (unlikely(oob))
2423		ops->oobretlen = ops->ooblen;
2424
2425err_out:
2426	chip->select_chip(mtd, -1);
2427	return ret;
2428}
2429
2430/**
2431 * panic_nand_write - [MTD Interface] NAND write with ECC
2432 * @mtd: MTD device structure
2433 * @to: offset to write to
2434 * @len: number of bytes to write
2435 * @retlen: pointer to variable to store the number of written bytes
2436 * @buf: the data to write
2437 *
2438 * NAND write with ECC. Used when performing writes in interrupt context, this
2439 * may for example be called by mtdoops when writing an oops while in panic.
2440 */
2441static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
2442			    size_t *retlen, const uint8_t *buf)
2443{
2444	struct nand_chip *chip = mtd->priv;
2445	struct mtd_oob_ops ops;
2446	int ret;
2447
2448	/* Wait for the device to get ready */
2449	panic_nand_wait(mtd, chip, 400);
2450
2451	/* Grab the device */
2452	panic_nand_get_device(chip, mtd, FL_WRITING);
2453
2454	ops.len = len;
2455	ops.datbuf = (uint8_t *)buf;
2456	ops.oobbuf = NULL;
2457	ops.mode = MTD_OPS_PLACE_OOB;
2458
2459	ret = nand_do_write_ops(mtd, to, &ops);
2460
2461	*retlen = ops.retlen;
2462	return ret;
2463}
2464
2465/**
2466 * nand_write - [MTD Interface] NAND write with ECC
2467 * @mtd: MTD device structure
2468 * @to: offset to write to
2469 * @len: number of bytes to write
2470 * @retlen: pointer to variable to store the number of written bytes
2471 * @buf: the data to write
2472 *
2473 * NAND write with ECC.
2474 */
2475static int nand_write(struct mtd_info *mtd, loff_t to, size_t len,
2476			  size_t *retlen, const uint8_t *buf)
2477{
2478	struct mtd_oob_ops ops;
2479	int ret;
2480
2481	nand_get_device(mtd, FL_WRITING);
2482	ops.len = len;
2483	ops.datbuf = (uint8_t *)buf;
2484	ops.oobbuf = NULL;
2485	ops.mode = MTD_OPS_PLACE_OOB;
2486	ret = nand_do_write_ops(mtd, to, &ops);
2487	*retlen = ops.retlen;
2488	nand_release_device(mtd);
2489	return ret;
2490}
2491
2492/**
2493 * nand_do_write_oob - [MTD Interface] NAND write out-of-band
2494 * @mtd: MTD device structure
2495 * @to: offset to write to
2496 * @ops: oob operation description structure
2497 *
2498 * NAND write out-of-band.
2499 */
2500static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
2501			     struct mtd_oob_ops *ops)
2502{
2503	int chipnr, page, status, len;
2504	struct nand_chip *chip = mtd->priv;
2505
2506	pr_debug("%s: to = 0x%08x, len = %i\n",
2507			 __func__, (unsigned int)to, (int)ops->ooblen);
2508
2509	if (ops->mode == MTD_OPS_AUTO_OOB)
2510		len = chip->ecc.layout->oobavail;
2511	else
2512		len = mtd->oobsize;
2513
2514	/* Do not allow write past end of page */
2515	if ((ops->ooboffs + ops->ooblen) > len) {
2516		pr_debug("%s: attempt to write past end of page\n",
2517				__func__);
2518		return -EINVAL;
2519	}
2520
2521	if (unlikely(ops->ooboffs >= len)) {
2522		pr_debug("%s: attempt to start write outside oob\n",
2523				__func__);
2524		return -EINVAL;
2525	}
2526
2527	/* Do not allow write past end of device */
2528	if (unlikely(to >= mtd->size ||
2529		     ops->ooboffs + ops->ooblen >
2530			((mtd->size >> chip->page_shift) -
2531			 (to >> chip->page_shift)) * len)) {
2532		pr_debug("%s: attempt to write beyond end of device\n",
2533				__func__);
2534		return -EINVAL;
2535	}
2536
2537	chipnr = (int)(to >> chip->chip_shift);
2538	chip->select_chip(mtd, chipnr);
2539
2540	/* Shift to get page */
2541	page = (int)(to >> chip->page_shift);
2542
2543	/*
2544	 * Reset the chip. Some chips (like the Toshiba TC5832DC found in one
2545	 * of my DiskOnChip 2000 test units) will clear the whole data page too
2546	 * if we don't do this. I have no clue why, but I seem to have 'fixed'
2547	 * it in the doc2000 driver in August 1999.  dwmw2.
2548	 */
2549	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
2550
2551	/* Check, if it is write protected */
2552	if (nand_check_wp(mtd)) {
2553		chip->select_chip(mtd, -1);
2554		return -EROFS;
2555	}
2556
2557	/* Invalidate the page cache, if we write to the cached page */
2558	if (page == chip->pagebuf)
2559		chip->pagebuf = -1;
2560
2561	nand_fill_oob(mtd, ops->oobbuf, ops->ooblen, ops);
2562
2563	if (ops->mode == MTD_OPS_RAW)
2564		status = chip->ecc.write_oob_raw(mtd, chip, page & chip->pagemask);
2565	else
2566		status = chip->ecc.write_oob(mtd, chip, page & chip->pagemask);
2567
2568	chip->select_chip(mtd, -1);
2569
2570	if (status)
2571		return status;
2572
2573	ops->oobretlen = ops->ooblen;
2574
2575	return 0;
2576}
2577
2578/**
2579 * nand_write_oob - [MTD Interface] NAND write data and/or out-of-band
2580 * @mtd: MTD device structure
2581 * @to: offset to write to
2582 * @ops: oob operation description structure
2583 */
2584static int nand_write_oob(struct mtd_info *mtd, loff_t to,
2585			  struct mtd_oob_ops *ops)
2586{
2587	int ret = -ENOTSUPP;
2588
2589	ops->retlen = 0;
2590
2591	/* Do not allow writes past end of device */
2592	if (ops->datbuf && (to + ops->len) > mtd->size) {
2593		pr_debug("%s: attempt to write beyond end of device\n",
2594				__func__);
2595		return -EINVAL;
2596	}
2597
2598	nand_get_device(mtd, FL_WRITING);
2599
2600	switch (ops->mode) {
2601	case MTD_OPS_PLACE_OOB:
2602	case MTD_OPS_AUTO_OOB:
2603	case MTD_OPS_RAW:
2604		break;
2605
2606	default:
2607		goto out;
2608	}
2609
2610	if (!ops->datbuf)
2611		ret = nand_do_write_oob(mtd, to, ops);
2612	else
2613		ret = nand_do_write_ops(mtd, to, ops);
2614
2615out:
2616	nand_release_device(mtd);
2617	return ret;
2618}
2619
2620/**
2621 * single_erase_cmd - [GENERIC] NAND standard block erase command function
2622 * @mtd: MTD device structure
2623 * @page: the page address of the block which will be erased
2624 *
2625 * Standard erase command for NAND chips.
2626 */
2627static void single_erase_cmd(struct mtd_info *mtd, int page)
2628{
2629	struct nand_chip *chip = mtd->priv;
2630	/* Send commands to erase a block */
2631	chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
2632	chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
2633}
2634
2635/**
2636 * nand_erase - [MTD Interface] erase block(s)
2637 * @mtd: MTD device structure
2638 * @instr: erase instruction
2639 *
2640 * Erase one ore more blocks.
2641 */
2642static int nand_erase(struct mtd_info *mtd, struct erase_info *instr)
2643{
2644	return nand_erase_nand(mtd, instr, 0);
2645}
2646
2647/**
2648 * nand_erase_nand - [INTERN] erase block(s)
2649 * @mtd: MTD device structure
2650 * @instr: erase instruction
2651 * @allowbbt: allow erasing the bbt area
2652 *
2653 * Erase one ore more blocks.
2654 */
2655int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
2656		    int allowbbt)
2657{
2658	int page, status, pages_per_block, ret, chipnr;
2659	struct nand_chip *chip = mtd->priv;
2660	loff_t len;
2661
2662	pr_debug("%s: start = 0x%012llx, len = %llu\n",
2663			__func__, (unsigned long long)instr->addr,
2664			(unsigned long long)instr->len);
2665
2666	if (check_offs_len(mtd, instr->addr, instr->len))
2667		return -EINVAL;
2668
2669	/* Grab the lock and see if the device is available */
2670	nand_get_device(mtd, FL_ERASING);
2671
2672	/* Shift to get first page */
2673	page = (int)(instr->addr >> chip->page_shift);
2674	chipnr = (int)(instr->addr >> chip->chip_shift);
2675
2676	/* Calculate pages in each block */
2677	pages_per_block = 1 << (chip->phys_erase_shift - chip->page_shift);
2678
2679	/* Select the NAND device */
2680	chip->select_chip(mtd, chipnr);
2681
2682	/* Check, if it is write protected */
2683	if (nand_check_wp(mtd)) {
2684		pr_debug("%s: device is write protected!\n",
2685				__func__);
2686		instr->state = MTD_ERASE_FAILED;
2687		goto erase_exit;
2688	}
2689
2690	/* Loop through the pages */
2691	len = instr->len;
2692
2693	instr->state = MTD_ERASING;
2694
2695	while (len) {
2696		/* Check if we have a bad block, we do not erase bad blocks! */
2697		if (nand_block_checkbad(mtd, ((loff_t) page) <<
2698					chip->page_shift, 0, allowbbt)) {
2699			pr_warn("%s: attempt to erase a bad block at page 0x%08x\n",
2700				    __func__, page);
2701			instr->state = MTD_ERASE_FAILED;
2702			goto erase_exit;
2703		}
2704
2705		/*
2706		 * Invalidate the page cache, if we erase the block which
2707		 * contains the current cached page.
2708		 */
2709		if (page <= chip->pagebuf && chip->pagebuf <
2710		    (page + pages_per_block))
2711			chip->pagebuf = -1;
2712
2713		chip->erase_cmd(mtd, page & chip->pagemask);
2714
2715		status = chip->waitfunc(mtd, chip);
2716
2717		/*
2718		 * See if operation failed and additional status checks are
2719		 * available
2720		 */
2721		if ((status & NAND_STATUS_FAIL) && (chip->errstat))
2722			status = chip->errstat(mtd, chip, FL_ERASING,
2723					       status, page);
2724
2725		/* See if block erase succeeded */
2726		if (status & NAND_STATUS_FAIL) {
2727			pr_debug("%s: failed erase, page 0x%08x\n",
2728					__func__, page);
2729			instr->state = MTD_ERASE_FAILED;
2730			instr->fail_addr =
2731				((loff_t)page << chip->page_shift);
2732			goto erase_exit;
2733		}
2734
2735		/* Increment page address and decrement length */
2736		len -= (1ULL << chip->phys_erase_shift);
2737		page += pages_per_block;
2738
2739		/* Check, if we cross a chip boundary */
2740		if (len && !(page & chip->pagemask)) {
2741			chipnr++;
2742			chip->select_chip(mtd, -1);
2743			chip->select_chip(mtd, chipnr);
2744		}
2745	}
2746	instr->state = MTD_ERASE_DONE;
2747
2748erase_exit:
2749
2750	ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
2751
2752	/* Deselect and wake up anyone waiting on the device */
2753	chip->select_chip(mtd, -1);
2754	nand_release_device(mtd);
2755
2756	/* Do call back function */
2757	if (!ret)
2758		mtd_erase_callback(instr);
2759
2760	/* Return more or less happy */
2761	return ret;
2762}
2763
2764/**
2765 * nand_sync - [MTD Interface] sync
2766 * @mtd: MTD device structure
2767 *
2768 * Sync is actually a wait for chip ready function.
2769 */
2770static void nand_sync(struct mtd_info *mtd)
2771{
2772	pr_debug("%s: called\n", __func__);
2773
2774	/* Grab the lock and see if the device is available */
2775	nand_get_device(mtd, FL_SYNCING);
2776	/* Release it and go back */
2777	nand_release_device(mtd);
2778}
2779
2780/**
2781 * nand_block_isbad - [MTD Interface] Check if block at offset is bad
2782 * @mtd: MTD device structure
2783 * @offs: offset relative to mtd start
2784 */
2785static int nand_block_isbad(struct mtd_info *mtd, loff_t offs)
2786{
2787	return nand_block_checkbad(mtd, offs, 1, 0);
2788}
2789
2790/**
2791 * nand_block_markbad - [MTD Interface] Mark block at the given offset as bad
2792 * @mtd: MTD device structure
2793 * @ofs: offset relative to mtd start
2794 */
2795static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
2796{
2797	int ret;
2798
2799	ret = nand_block_isbad(mtd, ofs);
2800	if (ret) {
2801		/* If it was bad already, return success and do nothing */
2802		if (ret > 0)
2803			return 0;
2804		return ret;
2805	}
2806
2807	return nand_block_markbad_lowlevel(mtd, ofs);
2808}
2809
2810/**
2811 * nand_onfi_set_features- [REPLACEABLE] set features for ONFI nand
2812 * @mtd: MTD device structure
2813 * @chip: nand chip info structure
2814 * @addr: feature address.
2815 * @subfeature_param: the subfeature parameters, a four bytes array.
2816 */
2817static int nand_onfi_set_features(struct mtd_info *mtd, struct nand_chip *chip,
2818			int addr, uint8_t *subfeature_param)
2819{
2820	int status;
2821	int i;
2822
2823	if (!chip->onfi_version ||
2824	    !(le16_to_cpu(chip->onfi_params.opt_cmd)
2825	      & ONFI_OPT_CMD_SET_GET_FEATURES))
2826		return -EINVAL;
2827
2828	chip->cmdfunc(mtd, NAND_CMD_SET_FEATURES, addr, -1);
2829	for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
2830		chip->write_byte(mtd, subfeature_param[i]);
2831
2832	status = chip->waitfunc(mtd, chip);
2833	if (status & NAND_STATUS_FAIL)
2834		return -EIO;
2835	return 0;
2836}
2837
2838/**
2839 * nand_onfi_get_features- [REPLACEABLE] get features for ONFI nand
2840 * @mtd: MTD device structure
2841 * @chip: nand chip info structure
2842 * @addr: feature address.
2843 * @subfeature_param: the subfeature parameters, a four bytes array.
2844 */
2845static int nand_onfi_get_features(struct mtd_info *mtd, struct nand_chip *chip,
2846			int addr, uint8_t *subfeature_param)
2847{
2848	int i;
2849
2850	if (!chip->onfi_version ||
2851	    !(le16_to_cpu(chip->onfi_params.opt_cmd)
2852	      & ONFI_OPT_CMD_SET_GET_FEATURES))
2853		return -EINVAL;
2854
2855	/* clear the sub feature parameters */
2856	memset(subfeature_param, 0, ONFI_SUBFEATURE_PARAM_LEN);
2857
2858	chip->cmdfunc(mtd, NAND_CMD_GET_FEATURES, addr, -1);
2859	for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
2860		*subfeature_param++ = chip->read_byte(mtd);
2861	return 0;
2862}
2863
2864/**
2865 * nand_suspend - [MTD Interface] Suspend the NAND flash
2866 * @mtd: MTD device structure
2867 */
2868static int nand_suspend(struct mtd_info *mtd)
2869{
2870	return nand_get_device(mtd, FL_PM_SUSPENDED);
2871}
2872
2873/**
2874 * nand_resume - [MTD Interface] Resume the NAND flash
2875 * @mtd: MTD device structure
2876 */
2877static void nand_resume(struct mtd_info *mtd)
2878{
2879	struct nand_chip *chip = mtd->priv;
2880
2881	if (chip->state == FL_PM_SUSPENDED)
2882		nand_release_device(mtd);
2883	else
2884		pr_err("%s called for a chip which is not in suspended state\n",
2885			__func__);
2886}
2887
2888/* Set default functions */
2889static void nand_set_defaults(struct nand_chip *chip, int busw)
2890{
2891	/* check for proper chip_delay setup, set 20us if not */
2892	if (!chip->chip_delay)
2893		chip->chip_delay = 20;
2894
2895	/* check, if a user supplied command function given */
2896	if (chip->cmdfunc == NULL)
2897		chip->cmdfunc = nand_command;
2898
2899	/* check, if a user supplied wait function given */
2900	if (chip->waitfunc == NULL)
2901		chip->waitfunc = nand_wait;
2902
2903	if (!chip->select_chip)
2904		chip->select_chip = nand_select_chip;
2905
2906	/* set for ONFI nand */
2907	if (!chip->onfi_set_features)
2908		chip->onfi_set_features = nand_onfi_set_features;
2909	if (!chip->onfi_get_features)
2910		chip->onfi_get_features = nand_onfi_get_features;
2911
2912	/* If called twice, pointers that depend on busw may need to be reset */
2913	if (!chip->read_byte || chip->read_byte == nand_read_byte)
2914		chip->read_byte = busw ? nand_read_byte16 : nand_read_byte;
2915	if (!chip->read_word)
2916		chip->read_word = nand_read_word;
2917	if (!chip->block_bad)
2918		chip->block_bad = nand_block_bad;
2919	if (!chip->block_markbad)
2920		chip->block_markbad = nand_default_block_markbad;
2921	if (!chip->write_buf || chip->write_buf == nand_write_buf)
2922		chip->write_buf = busw ? nand_write_buf16 : nand_write_buf;
2923	if (!chip->write_byte || chip->write_byte == nand_write_byte)
2924		chip->write_byte = busw ? nand_write_byte16 : nand_write_byte;
2925	if (!chip->read_buf || chip->read_buf == nand_read_buf)
2926		chip->read_buf = busw ? nand_read_buf16 : nand_read_buf;
2927	if (!chip->scan_bbt)
2928		chip->scan_bbt = nand_default_bbt;
2929
2930	if (!chip->controller) {
2931		chip->controller = &chip->hwcontrol;
2932		spin_lock_init(&chip->controller->lock);
2933		init_waitqueue_head(&chip->controller->wq);
2934	}
2935
2936}
2937
2938/* Sanitize ONFI strings so we can safely print them */
2939static void sanitize_string(uint8_t *s, size_t len)
2940{
2941	ssize_t i;
2942
2943	/* Null terminate */
2944	s[len - 1] = 0;
2945
2946	/* Remove non printable chars */
2947	for (i = 0; i < len - 1; i++) {
2948		if (s[i] < ' ' || s[i] > 127)
2949			s[i] = '?';
2950	}
2951
2952	/* Remove trailing spaces */
2953	strim(s);
2954}
2955
2956static u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
2957{
2958	int i;
2959	while (len--) {
2960		crc ^= *p++ << 8;
2961		for (i = 0; i < 8; i++)
2962			crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
2963	}
2964
2965	return crc;
2966}
2967
2968/* Parse the Extended Parameter Page. */
2969static int nand_flash_detect_ext_param_page(struct mtd_info *mtd,
2970		struct nand_chip *chip, struct nand_onfi_params *p)
2971{
2972	struct onfi_ext_param_page *ep;
2973	struct onfi_ext_section *s;
2974	struct onfi_ext_ecc_info *ecc;
2975	uint8_t *cursor;
2976	int ret = -EINVAL;
2977	int len;
2978	int i;
2979
2980	len = le16_to_cpu(p->ext_param_page_length) * 16;
2981	ep = kmalloc(len, GFP_KERNEL);
2982	if (!ep)
2983		return -ENOMEM;
2984
2985	/* Send our own NAND_CMD_PARAM. */
2986	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
2987
2988	/* Use the Change Read Column command to skip the ONFI param pages. */
2989	chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
2990			sizeof(*p) * p->num_of_param_pages , -1);
2991
2992	/* Read out the Extended Parameter Page. */
2993	chip->read_buf(mtd, (uint8_t *)ep, len);
2994	if ((onfi_crc16(ONFI_CRC_BASE, ((uint8_t *)ep) + 2, len - 2)
2995		!= le16_to_cpu(ep->crc))) {
2996		pr_debug("fail in the CRC.\n");
2997		goto ext_out;
2998	}
2999
3000	/*
3001	 * Check the signature.
3002	 * Do not strictly follow the ONFI spec, maybe changed in future.
3003	 */
3004	if (strncmp(ep->sig, "EPPS", 4)) {
3005		pr_debug("The signature is invalid.\n");
3006		goto ext_out;
3007	}
3008
3009	/* find the ECC section. */
3010	cursor = (uint8_t *)(ep + 1);
3011	for (i = 0; i < ONFI_EXT_SECTION_MAX; i++) {
3012		s = ep->sections + i;
3013		if (s->type == ONFI_SECTION_TYPE_2)
3014			break;
3015		cursor += s->length * 16;
3016	}
3017	if (i == ONFI_EXT_SECTION_MAX) {
3018		pr_debug("We can not find the ECC section.\n");
3019		goto ext_out;
3020	}
3021
3022	/* get the info we want. */
3023	ecc = (struct onfi_ext_ecc_info *)cursor;
3024
3025	if (!ecc->codeword_size) {
3026		pr_debug("Invalid codeword size\n");
3027		goto ext_out;
3028	}
3029
3030	chip->ecc_strength_ds = ecc->ecc_bits;
3031	chip->ecc_step_ds = 1 << ecc->codeword_size;
3032	ret = 0;
3033
3034ext_out:
3035	kfree(ep);
3036	return ret;
3037}
3038
3039static int nand_setup_read_retry_micron(struct mtd_info *mtd, int retry_mode)
3040{
3041	struct nand_chip *chip = mtd->priv;
3042	uint8_t feature[ONFI_SUBFEATURE_PARAM_LEN] = {retry_mode};
3043
3044	return chip->onfi_set_features(mtd, chip, ONFI_FEATURE_ADDR_READ_RETRY,
3045			feature);
3046}
3047
3048/*
3049 * Configure chip properties from Micron vendor-specific ONFI table
3050 */
3051static void nand_onfi_detect_micron(struct nand_chip *chip,
3052		struct nand_onfi_params *p)
3053{
3054	struct nand_onfi_vendor_micron *micron = (void *)p->vendor;
3055
3056	if (le16_to_cpu(p->vendor_revision) < 1)
3057		return;
3058
3059	chip->read_retries = micron->read_retry_options;
3060	chip->setup_read_retry = nand_setup_read_retry_micron;
3061}
3062
3063/*
3064 * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
3065 */
3066static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
3067					int *busw)
3068{
3069	struct nand_onfi_params *p = &chip->onfi_params;
3070	int i, j;
3071	int val;
3072
3073	/* Try ONFI for unknown chip or LP */
3074	chip->cmdfunc(mtd, NAND_CMD_READID, 0x20, -1);
3075	if (chip->read_byte(mtd) != 'O' || chip->read_byte(mtd) != 'N' ||
3076		chip->read_byte(mtd) != 'F' || chip->read_byte(mtd) != 'I')
3077		return 0;
3078
3079	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
3080	for (i = 0; i < 3; i++) {
3081		for (j = 0; j < sizeof(*p); j++)
3082			((uint8_t *)p)[j] = chip->read_byte(mtd);
3083		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
3084				le16_to_cpu(p->crc)) {
3085			break;
3086		}
3087	}
3088
3089	if (i == 3) {
3090		pr_err("Could not find valid ONFI parameter page; aborting\n");
3091		return 0;
3092	}
3093
3094	/* Check version */
3095	val = le16_to_cpu(p->revision);
3096	if (val & (1 << 5))
3097		chip->onfi_version = 23;
3098	else if (val & (1 << 4))
3099		chip->onfi_version = 22;
3100	else if (val & (1 << 3))
3101		chip->onfi_version = 21;
3102	else if (val & (1 << 2))
3103		chip->onfi_version = 20;
3104	else if (val & (1 << 1))
3105		chip->onfi_version = 10;
3106
3107	if (!chip->onfi_version) {
3108		pr_info("unsupported ONFI version: %d\n", val);
3109		return 0;
3110	}
3111
3112	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
3113	sanitize_string(p->model, sizeof(p->model));
3114	if (!mtd->name)
3115		mtd->name = p->model;
3116
3117	mtd->writesize = le32_to_cpu(p->byte_per_page);
3118
3119	/*
3120	 * pages_per_block and blocks_per_lun may not be a power-of-2 size
3121	 * (don't ask me who thought of this...). MTD assumes that these
3122	 * dimensions will be power-of-2, so just truncate the remaining area.
3123	 */
3124	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
3125	mtd->erasesize *= mtd->writesize;
3126
3127	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
3128
3129	/* See erasesize comment */
3130	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
3131	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
3132	chip->bits_per_cell = p->bits_per_cell;
3133
3134	if (onfi_feature(chip) & ONFI_FEATURE_16_BIT_BUS)
3135		*busw = NAND_BUSWIDTH_16;
3136	else
3137		*busw = 0;
3138
3139	if (p->ecc_bits != 0xff) {
3140		chip->ecc_strength_ds = p->ecc_bits;
3141		chip->ecc_step_ds = 512;
3142	} else if (chip->onfi_version >= 21 &&
3143		(onfi_feature(chip) & ONFI_FEATURE_EXT_PARAM_PAGE)) {
3144
3145		/*
3146		 * The nand_flash_detect_ext_param_page() uses the
3147		 * Change Read Column command which maybe not supported
3148		 * by the chip->cmdfunc. So try to update the chip->cmdfunc
3149		 * now. We do not replace user supplied command function.
3150		 */
3151		if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
3152			chip->cmdfunc = nand_command_lp;
3153
3154		/* The Extended Parameter Page is supported since ONFI 2.1. */
3155		if (nand_flash_detect_ext_param_page(mtd, chip, p))
3156			pr_warn("Failed to detect ONFI extended param page\n");
3157	} else {
3158		pr_warn("Could not retrieve ONFI ECC requirements\n");
3159	}
3160
3161	if (p->jedec_id == NAND_MFR_MICRON)
3162		nand_onfi_detect_micron(chip, p);
3163
3164	return 1;
3165}
3166
3167/*
3168 * Check if the NAND chip is JEDEC compliant, returns 1 if it is, 0 otherwise.
3169 */
3170static int nand_flash_detect_jedec(struct mtd_info *mtd, struct nand_chip *chip,
3171					int *busw)
3172{
3173	struct nand_jedec_params *p = &chip->jedec_params;
3174	struct jedec_ecc_info *ecc;
3175	int val;
3176	int i, j;
3177
3178	/* Try JEDEC for unknown chip or LP */
3179	chip->cmdfunc(mtd, NAND_CMD_READID, 0x40, -1);
3180	if (chip->read_byte(mtd) != 'J' || chip->read_byte(mtd) != 'E' ||
3181		chip->read_byte(mtd) != 'D' || chip->read_byte(mtd) != 'E' ||
3182		chip->read_byte(mtd) != 'C')
3183		return 0;
3184
3185	chip->cmdfunc(mtd, NAND_CMD_PARAM, 0x40, -1);
3186	for (i = 0; i < 3; i++) {
3187		for (j = 0; j < sizeof(*p); j++)
3188			((uint8_t *)p)[j] = chip->read_byte(mtd);
3189
3190		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 510) ==
3191				le16_to_cpu(p->crc))
3192			break;
3193	}
3194
3195	if (i == 3) {
3196		pr_err("Could not find valid JEDEC parameter page; aborting\n");
3197		return 0;
3198	}
3199
3200	/* Check version */
3201	val = le16_to_cpu(p->revision);
3202	if (val & (1 << 2))
3203		chip->jedec_version = 10;
3204	else if (val & (1 << 1))
3205		chip->jedec_version = 1; /* vendor specific version */
3206
3207	if (!chip->jedec_version) {
3208		pr_info("unsupported JEDEC version: %d\n", val);
3209		return 0;
3210	}
3211
3212	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
3213	sanitize_string(p->model, sizeof(p->model));
3214	if (!mtd->name)
3215		mtd->name = p->model;
3216
3217	mtd->writesize = le32_to_cpu(p->byte_per_page);
3218
3219	/* Please reference to the comment for nand_flash_detect_onfi. */
3220	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
3221	mtd->erasesize *= mtd->writesize;
3222
3223	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
3224
3225	/* Please reference to the comment for nand_flash_detect_onfi. */
3226	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
3227	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
3228	chip->bits_per_cell = p->bits_per_cell;
3229
3230	if (jedec_feature(chip) & JEDEC_FEATURE_16_BIT_BUS)
3231		*busw = NAND_BUSWIDTH_16;
3232	else
3233		*busw = 0;
3234
3235	/* ECC info */
3236	ecc = &p->ecc_info[0];
3237
3238	if (ecc->codeword_size >= 9) {
3239		chip->ecc_strength_ds = ecc->ecc_bits;
3240		chip->ecc_step_ds = 1 << ecc->codeword_size;
3241	} else {
3242		pr_warn("Invalid codeword size\n");
3243	}
3244
3245	return 1;
3246}
3247
3248/*
3249 * nand_id_has_period - Check if an ID string has a given wraparound period
3250 * @id_data: the ID string
3251 * @arrlen: the length of the @id_data array
3252 * @period: the period of repitition
3253 *
3254 * Check if an ID string is repeated within a given sequence of bytes at
3255 * specific repetition interval period (e.g., {0x20,0x01,0x7F,0x20} has a
3256 * period of 3). This is a helper function for nand_id_len(). Returns non-zero
3257 * if the repetition has a period of @period; otherwise, returns zero.
3258 */
3259static int nand_id_has_period(u8 *id_data, int arrlen, int period)
3260{
3261	int i, j;
3262	for (i = 0; i < period; i++)
3263		for (j = i + period; j < arrlen; j += period)
3264			if (id_data[i] != id_data[j])
3265				return 0;
3266	return 1;
3267}
3268
3269/*
3270 * nand_id_len - Get the length of an ID string returned by CMD_READID
3271 * @id_data: the ID string
3272 * @arrlen: the length of the @id_data array
3273
3274 * Returns the length of the ID string, according to known wraparound/trailing
3275 * zero patterns. If no pattern exists, returns the length of the array.
3276 */
3277static int nand_id_len(u8 *id_data, int arrlen)
3278{
3279	int last_nonzero, period;
3280
3281	/* Find last non-zero byte */
3282	for (last_nonzero = arrlen - 1; last_nonzero >= 0; last_nonzero--)
3283		if (id_data[last_nonzero])
3284			break;
3285
3286	/* All zeros */
3287	if (last_nonzero < 0)
3288		return 0;
3289
3290	/* Calculate wraparound period */
3291	for (period = 1; period < arrlen; period++)
3292		if (nand_id_has_period(id_data, arrlen, period))
3293			break;
3294
3295	/* There's a repeated pattern */
3296	if (period < arrlen)
3297		return period;
3298
3299	/* There are trailing zeros */
3300	if (last_nonzero < arrlen - 1)
3301		return last_nonzero + 1;
3302
3303	/* No pattern detected */
3304	return arrlen;
3305}
3306
3307/* Extract the bits of per cell from the 3rd byte of the extended ID */
3308static int nand_get_bits_per_cell(u8 cellinfo)
3309{
3310	int bits;
3311
3312	bits = cellinfo & NAND_CI_CELLTYPE_MSK;
3313	bits >>= NAND_CI_CELLTYPE_SHIFT;
3314	return bits + 1;
3315}
3316
3317/*
3318 * Many new NAND share similar device ID codes, which represent the size of the
3319 * chip. The rest of the parameters must be decoded according to generic or
3320 * manufacturer-specific "extended ID" decoding patterns.
3321 */
3322static void nand_decode_ext_id(struct mtd_info *mtd, struct nand_chip *chip,
3323				u8 id_data[8], int *busw)
3324{
3325	int extid, id_len;
3326	/* The 3rd id byte holds MLC / multichip data */
3327	chip->bits_per_cell = nand_get_bits_per_cell(id_data[2]);
3328	/* The 4th id byte is the important one */
3329	extid = id_data[3];
3330
3331	id_len = nand_id_len(id_data, 8);
3332
3333	/*
3334	 * Field definitions are in the following datasheets:
3335	 * Old style (4,5 byte ID): Samsung K9GAG08U0M (p.32)
3336	 * New Samsung (6 byte ID): Samsung K9GAG08U0F (p.44)
3337	 * Hynix MLC   (6 byte ID): Hynix H27UBG8T2B (p.22)
3338	 *
3339	 * Check for ID length, non-zero 6th byte, cell type, and Hynix/Samsung
3340	 * ID to decide what to do.
3341	 */
3342	if (id_len == 6 && id_data[0] == NAND_MFR_SAMSUNG &&
3343			!nand_is_slc(chip) && id_data[5] != 0x00) {
3344		/* Calc pagesize */
3345		mtd->writesize = 2048 << (extid & 0x03);
3346		extid >>= 2;
3347		/* Calc oobsize */
3348		switch (((extid >> 2) & 0x04) | (extid & 0x03)) {
3349		case 1:
3350			mtd->oobsize = 128;
3351			break;
3352		case 2:
3353			mtd->oobsize = 218;
3354			break;
3355		case 3:
3356			mtd->oobsize = 400;
3357			break;
3358		case 4:
3359			mtd->oobsize = 436;
3360			break;
3361		case 5:
3362			mtd->oobsize = 512;
3363			break;
3364		case 6:
3365			mtd->oobsize = 640;
3366			break;
3367		case 7:
3368		default: /* Other cases are "reserved" (unknown) */
3369			mtd->oobsize = 1024;
3370			break;
3371		}
3372		extid >>= 2;
3373		/* Calc blocksize */
3374		mtd->erasesize = (128 * 1024) <<
3375			(((extid >> 1) & 0x04) | (extid & 0x03));
3376		*busw = 0;
3377	} else if (id_len == 6 && id_data[0] == NAND_MFR_HYNIX &&
3378			!nand_is_slc(chip)) {
3379		unsigned int tmp;
3380
3381		/* Calc pagesize */
3382		mtd->writesize = 2048 << (extid & 0x03);
3383		extid >>= 2;
3384		/* Calc oobsize */
3385		switch (((extid >> 2) & 0x04) | (extid & 0x03)) {
3386		case 0:
3387			mtd->oobsize = 128;
3388			break;
3389		case 1:
3390			mtd->oobsize = 224;
3391			break;
3392		case 2:
3393			mtd->oobsize = 448;
3394			break;
3395		case 3:
3396			mtd->oobsize = 64;
3397			break;
3398		case 4:
3399			mtd->oobsize = 32;
3400			break;
3401		case 5:
3402			mtd->oobsize = 16;
3403			break;
3404		default:
3405			mtd->oobsize = 640;
3406			break;
3407		}
3408		extid >>= 2;
3409		/* Calc blocksize */
3410		tmp = ((extid >> 1) & 0x04) | (extid & 0x03);
3411		if (tmp < 0x03)
3412			mtd->erasesize = (128 * 1024) << tmp;
3413		else if (tmp == 0x03)
3414			mtd->erasesize = 768 * 1024;
3415		else
3416			mtd->erasesize = (64 * 1024) << tmp;
3417		*busw = 0;
3418	} else {
3419		/* Calc pagesize */
3420		mtd->writesize = 1024 << (extid & 0x03);
3421		extid >>= 2;
3422		/* Calc oobsize */
3423		mtd->oobsize = (8 << (extid & 0x01)) *
3424			(mtd->writesize >> 9);
3425		extid >>= 2;
3426		/* Calc blocksize. Blocksize is multiples of 64KiB */
3427		mtd->erasesize = (64 * 1024) << (extid & 0x03);
3428		extid >>= 2;
3429		/* Get buswidth information */
3430		*busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0;
3431
3432		/*
3433		 * Toshiba 24nm raw SLC (i.e., not BENAND) have 32B OOB per
3434		 * 512B page. For Toshiba SLC, we decode the 5th/6th byte as
3435		 * follows:
3436		 * - ID byte 6, bits[2:0]: 100b -> 43nm, 101b -> 32nm,
3437		 *                         110b -> 24nm
3438		 * - ID byte 5, bit[7]:    1 -> BENAND, 0 -> raw SLC
3439		 */
3440		if (id_len >= 6 && id_data[0] == NAND_MFR_TOSHIBA &&
3441				nand_is_slc(chip) &&
3442				(id_data[5] & 0x7) == 0x6 /* 24nm */ &&
3443				!(id_data[4] & 0x80) /* !BENAND */) {
3444			mtd->oobsize = 32 * mtd->writesize >> 9;
3445		}
3446
3447	}
3448}
3449
3450/*
3451 * Old devices have chip data hardcoded in the device ID table. nand_decode_id
3452 * decodes a matching ID table entry and assigns the MTD size parameters for
3453 * the chip.
3454 */
3455static void nand_decode_id(struct mtd_info *mtd, struct nand_chip *chip,
3456				struct nand_flash_dev *type, u8 id_data[8],
3457				int *busw)
3458{
3459	int maf_id = id_data[0];
3460
3461	mtd->erasesize = type->erasesize;
3462	mtd->writesize = type->pagesize;
3463	mtd->oobsize = mtd->writesize / 32;
3464	*busw = type->options & NAND_BUSWIDTH_16;
3465
3466	/* All legacy ID NAND are small-page, SLC */
3467	chip->bits_per_cell = 1;
3468
3469	/*
3470	 * Check for Spansion/AMD ID + repeating 5th, 6th byte since
3471	 * some Spansion chips have erasesize that conflicts with size
3472	 * listed in nand_ids table.
3473	 * Data sheet (5 byte ID): Spansion S30ML-P ORNAND (p.39)
3474	 */
3475	if (maf_id == NAND_MFR_AMD && id_data[4] != 0x00 && id_data[5] == 0x00
3476			&& id_data[6] == 0x00 && id_data[7] == 0x00
3477			&& mtd->writesize == 512) {
3478		mtd->erasesize = 128 * 1024;
3479		mtd->erasesize <<= ((id_data[3] & 0x03) << 1);
3480	}
3481}
3482
3483/*
3484 * Set the bad block marker/indicator (BBM/BBI) patterns according to some
3485 * heuristic patterns using various detected parameters (e.g., manufacturer,
3486 * page size, cell-type information).
3487 */
3488static void nand_decode_bbm_options(struct mtd_info *mtd,
3489				    struct nand_chip *chip, u8 id_data[8])
3490{
3491	int maf_id = id_data[0];
3492
3493	/* Set the bad block position */
3494	if (mtd->writesize > 512 || (chip->options & NAND_BUSWIDTH_16))
3495		chip->badblockpos = NAND_LARGE_BADBLOCK_POS;
3496	else
3497		chip->badblockpos = NAND_SMALL_BADBLOCK_POS;
3498
3499	/*
3500	 * Bad block marker is stored in the last page of each block on Samsung
3501	 * and Hynix MLC devices; stored in first two pages of each block on
3502	 * Micron devices with 2KiB pages and on SLC Samsung, Hynix, Toshiba,
3503	 * AMD/Spansion, and Macronix.  All others scan only the first page.
3504	 */
3505	if (!nand_is_slc(chip) &&
3506			(maf_id == NAND_MFR_SAMSUNG ||
3507			 maf_id == NAND_MFR_HYNIX))
3508		chip->bbt_options |= NAND_BBT_SCANLASTPAGE;
3509	else if ((nand_is_slc(chip) &&
3510				(maf_id == NAND_MFR_SAMSUNG ||
3511				 maf_id == NAND_MFR_HYNIX ||
3512				 maf_id == NAND_MFR_TOSHIBA ||
3513				 maf_id == NAND_MFR_AMD ||
3514				 maf_id == NAND_MFR_MACRONIX)) ||
3515			(mtd->writesize == 2048 &&
3516			 maf_id == NAND_MFR_MICRON))
3517		chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
3518}
3519
3520static inline bool is_full_id_nand(struct nand_flash_dev *type)
3521{
3522	return type->id_len;
3523}
3524
3525static bool find_full_id_nand(struct mtd_info *mtd, struct nand_chip *chip,
3526		   struct nand_flash_dev *type, u8 *id_data, int *busw)
3527{
3528	if (!strncmp(type->id, id_data, type->id_len)) {
3529		mtd->writesize = type->pagesize;
3530		mtd->erasesize = type->erasesize;
3531		mtd->oobsize = type->oobsize;
3532
3533		chip->bits_per_cell = nand_get_bits_per_cell(id_data[2]);
3534		chip->chipsize = (uint64_t)type->chipsize << 20;
3535		chip->options |= type->options;
3536		chip->ecc_strength_ds = NAND_ECC_STRENGTH(type);
3537		chip->ecc_step_ds = NAND_ECC_STEP(type);
3538
3539		*busw = type->options & NAND_BUSWIDTH_16;
3540
3541		if (!mtd->name)
3542			mtd->name = type->name;
3543
3544		return true;
3545	}
3546	return false;
3547}
3548
3549/*
3550 * Get the flash and manufacturer id and lookup if the type is supported.
3551 */
3552static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
3553						  struct nand_chip *chip,
3554						  int *maf_id, int *dev_id,
3555						  struct nand_flash_dev *type)
3556{
3557	int busw;
3558	int i, maf_idx;
3559	u8 id_data[8];
3560
3561	/* Select the device */
3562	chip->select_chip(mtd, 0);
3563
3564	/*
3565	 * Reset the chip, required by some chips (e.g. Micron MT29FxGxxxxx)
3566	 * after power-up.
3567	 */
3568	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
3569
3570	/* Send the command for reading device ID */
3571	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
3572
3573	/* Read manufacturer and device IDs */
3574	*maf_id = chip->read_byte(mtd);
3575	*dev_id = chip->read_byte(mtd);
3576
3577	/*
3578	 * Try again to make sure, as some systems the bus-hold or other
3579	 * interface concerns can cause random data which looks like a
3580	 * possibly credible NAND flash to appear. If the two results do
3581	 * not match, ignore the device completely.
3582	 */
3583
3584	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
3585
3586	/* Read entire ID string */
3587	for (i = 0; i < 8; i++)
3588		id_data[i] = chip->read_byte(mtd);
3589
3590	if (id_data[0] != *maf_id || id_data[1] != *dev_id) {
3591		pr_info("second ID read did not match %02x,%02x against %02x,%02x\n",
3592			*maf_id, *dev_id, id_data[0], id_data[1]);
3593		return ERR_PTR(-ENODEV);
3594	}
3595
3596	if (!type)
3597		type = nand_flash_ids;
3598
3599	for (; type->name != NULL; type++) {
3600		if (is_full_id_nand(type)) {
3601			if (find_full_id_nand(mtd, chip, type, id_data, &busw))
3602				goto ident_done;
3603		} else if (*dev_id == type->dev_id) {
3604				break;
3605		}
3606	}
3607
3608	chip->onfi_version = 0;
3609	if (!type->name || !type->pagesize) {
3610		/* Check is chip is ONFI compliant */
3611		if (nand_flash_detect_onfi(mtd, chip, &busw))
3612			goto ident_done;
3613
3614		/* Check if the chip is JEDEC compliant */
3615		if (nand_flash_detect_jedec(mtd, chip, &busw))
3616			goto ident_done;
3617	}
3618
3619	if (!type->name)
3620		return ERR_PTR(-ENODEV);
3621
3622	if (!mtd->name)
3623		mtd->name = type->name;
3624
3625	chip->chipsize = (uint64_t)type->chipsize << 20;
3626
3627	if (!type->pagesize && chip->init_size) {
3628		/* Set the pagesize, oobsize, erasesize by the driver */
3629		busw = chip->init_size(mtd, chip, id_data);
3630	} else if (!type->pagesize) {
3631		/* Decode parameters from extended ID */
3632		nand_decode_ext_id(mtd, chip, id_data, &busw);
3633	} else {
3634		nand_decode_id(mtd, chip, type, id_data, &busw);
3635	}
3636	/* Get chip options */
3637	chip->options |= type->options;
3638
3639	/*
3640	 * Check if chip is not a Samsung device. Do not clear the
3641	 * options for chips which do not have an extended id.
3642	 */
3643	if (*maf_id != NAND_MFR_SAMSUNG && !type->pagesize)
3644		chip->options &= ~NAND_SAMSUNG_LP_OPTIONS;
3645ident_done:
3646
3647	/* Try to identify manufacturer */
3648	for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_idx++) {
3649		if (nand_manuf_ids[maf_idx].id == *maf_id)
3650			break;
3651	}
3652
3653	if (chip->options & NAND_BUSWIDTH_AUTO) {
3654		WARN_ON(chip->options & NAND_BUSWIDTH_16);
3655		chip->options |= busw;
3656		nand_set_defaults(chip, busw);
3657	} else if (busw != (chip->options & NAND_BUSWIDTH_16)) {
3658		/*
3659		 * Check, if buswidth is correct. Hardware drivers should set
3660		 * chip correct!
3661		 */
3662		pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
3663			*maf_id, *dev_id);
3664		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name, mtd->name);
3665		pr_warn("bus width %d instead %d bit\n",
3666			   (chip->options & NAND_BUSWIDTH_16) ? 16 : 8,
3667			   busw ? 16 : 8);
3668		return ERR_PTR(-EINVAL);
3669	}
3670
3671	nand_decode_bbm_options(mtd, chip, id_data);
3672
3673	/* Calculate the address shift from the page size */
3674	chip->page_shift = ffs(mtd->writesize) - 1;
3675	/* Convert chipsize to number of pages per chip -1 */
3676	chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
3677
3678	chip->bbt_erase_shift = chip->phys_erase_shift =
3679		ffs(mtd->erasesize) - 1;
3680	if (chip->chipsize & 0xffffffff)
3681		chip->chip_shift = ffs((unsigned)chip->chipsize) - 1;
3682	else {
3683		chip->chip_shift = ffs((unsigned)(chip->chipsize >> 32));
3684		chip->chip_shift += 32 - 1;
3685	}
3686
3687	chip->badblockbits = 8;
3688	chip->erase_cmd = single_erase_cmd;
3689
3690	/* Do not replace user supplied command function! */
3691	if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
3692		chip->cmdfunc = nand_command_lp;
3693
3694	pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
3695		*maf_id, *dev_id);
3696
3697	if (chip->onfi_version)
3698		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3699				chip->onfi_params.model);
3700	else if (chip->jedec_version)
3701		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3702				chip->jedec_params.model);
3703	else
3704		pr_info("%s %s\n", nand_manuf_ids[maf_idx].name,
3705				type->name);
3706
3707	pr_info("%dMiB, %s, page size: %d, OOB size: %d\n",
3708		(int)(chip->chipsize >> 20), nand_is_slc(chip) ? "SLC" : "MLC",
3709		mtd->writesize, mtd->oobsize);
3710	return type;
3711}
3712
3713/**
3714 * nand_scan_ident - [NAND Interface] Scan for the NAND device
3715 * @mtd: MTD device structure
3716 * @maxchips: number of chips to scan for
3717 * @table: alternative NAND ID table
3718 *
3719 * This is the first phase of the normal nand_scan() function. It reads the
3720 * flash ID and sets up MTD fields accordingly.
3721 *
3722 * The mtd->owner field must be set to the module of the caller.
3723 */
3724int nand_scan_ident(struct mtd_info *mtd, int maxchips,
3725		    struct nand_flash_dev *table)
3726{
3727	int i, nand_maf_id, nand_dev_id;
3728	struct nand_chip *chip = mtd->priv;
3729	struct nand_flash_dev *type;
3730
3731	/* Set the default functions */
3732	nand_set_defaults(chip, chip->options & NAND_BUSWIDTH_16);
3733
3734	/* Read the flash type */
3735	type = nand_get_flash_type(mtd, chip, &nand_maf_id,
3736				   &nand_dev_id, table);
3737
3738	if (IS_ERR(type)) {
3739		if (!(chip->options & NAND_SCAN_SILENT_NODEV))
3740			pr_warn("No NAND device found\n");
3741		chip->select_chip(mtd, -1);
3742		return PTR_ERR(type);
3743	}
3744
3745	chip->select_chip(mtd, -1);
3746
3747	/* Check for a chip array */
3748	for (i = 1; i < maxchips; i++) {
3749		chip->select_chip(mtd, i);
3750		/* See comment in nand_get_flash_type for reset */
3751		chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
3752		/* Send the command for reading device ID */
3753		chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
3754		/* Read manufacturer and device IDs */
3755		if (nand_maf_id != chip->read_byte(mtd) ||
3756		    nand_dev_id != chip->read_byte(mtd)) {
3757			chip->select_chip(mtd, -1);
3758			break;
3759		}
3760		chip->select_chip(mtd, -1);
3761	}
3762	if (i > 1)
3763		pr_info("%d chips detected\n", i);
3764
3765	/* Store the number of chips and calc total size for mtd */
3766	chip->numchips = i;
3767	mtd->size = i * chip->chipsize;
3768
3769	return 0;
3770}
3771EXPORT_SYMBOL(nand_scan_ident);
3772
3773
3774/**
3775 * nand_scan_tail - [NAND Interface] Scan for the NAND device
3776 * @mtd: MTD device structure
3777 *
3778 * This is the second phase of the normal nand_scan() function. It fills out
3779 * all the uninitialized function pointers with the defaults and scans for a
3780 * bad block table if appropriate.
3781 */
3782int nand_scan_tail(struct mtd_info *mtd)
3783{
3784	int i;
3785	struct nand_chip *chip = mtd->priv;
3786	struct nand_ecc_ctrl *ecc = &chip->ecc;
3787	struct nand_buffers *nbuf;
3788
3789	/* New bad blocks should be marked in OOB, flash-based BBT, or both */
3790	BUG_ON((chip->bbt_options & NAND_BBT_NO_OOB_BBM) &&
3791			!(chip->bbt_options & NAND_BBT_USE_FLASH));
3792
3793	if (!(chip->options & NAND_OWN_BUFFERS)) {
3794		nbuf = kzalloc(sizeof(*nbuf) + mtd->writesize
3795				+ mtd->oobsize * 3, GFP_KERNEL);
3796		if (!nbuf)
3797			return -ENOMEM;
3798		nbuf->ecccalc = (uint8_t *)(nbuf + 1);
3799		nbuf->ecccode = nbuf->ecccalc + mtd->oobsize;
3800		nbuf->databuf = nbuf->ecccode + mtd->oobsize;
3801
3802		chip->buffers = nbuf;
3803	} else {
3804		if (!chip->buffers)
3805			return -ENOMEM;
3806	}
3807
3808	/* Set the internal oob buffer location, just after the page data */
3809	chip->oob_poi = chip->buffers->databuf + mtd->writesize;
3810
3811	/*
3812	 * If no default placement scheme is given, select an appropriate one.
3813	 */
3814	if (!ecc->layout && (ecc->mode != NAND_ECC_SOFT_BCH)) {
3815		switch (mtd->oobsize) {
3816		case 8:
3817			ecc->layout = &nand_oob_8;
3818			break;
3819		case 16:
3820			ecc->layout = &nand_oob_16;
3821			break;
3822		case 64:
3823			ecc->layout = &nand_oob_64;
3824			break;
3825		case 128:
3826			ecc->layout = &nand_oob_128;
3827			break;
3828		default:
3829			pr_warn("No oob scheme defined for oobsize %d\n",
3830				   mtd->oobsize);
3831			BUG();
3832		}
3833	}
3834
3835	if (!chip->write_page)
3836		chip->write_page = nand_write_page;
3837
3838	/*
3839	 * Check ECC mode, default to software if 3byte/512byte hardware ECC is
3840	 * selected and we have 256 byte pagesize fallback to software ECC
3841	 */
3842
3843	switch (ecc->mode) {
3844	case NAND_ECC_HW_OOB_FIRST:
3845		/* Similar to NAND_ECC_HW, but a separate read_page handle */
3846		if (!ecc->calculate || !ecc->correct || !ecc->hwctl) {
3847			pr_warn("No ECC functions supplied; "
3848				   "hardware ECC not possible\n");
3849			BUG();
3850		}
3851		if (!ecc->read_page)
3852			ecc->read_page = nand_read_page_hwecc_oob_first;
3853
3854	case NAND_ECC_HW:
3855		/* Use standard hwecc read page function? */
3856		if (!ecc->read_page)
3857			ecc->read_page = nand_read_page_hwecc;
3858		if (!ecc->write_page)
3859			ecc->write_page = nand_write_page_hwecc;
3860		if (!ecc->read_page_raw)
3861			ecc->read_page_raw = nand_read_page_raw;
3862		if (!ecc->write_page_raw)
3863			ecc->write_page_raw = nand_write_page_raw;
3864		if (!ecc->read_oob)
3865			ecc->read_oob = nand_read_oob_std;
3866		if (!ecc->write_oob)
3867			ecc->write_oob = nand_write_oob_std;
3868		if (!ecc->read_subpage)
3869			ecc->read_subpage = nand_read_subpage;
3870		if (!ecc->write_subpage)
3871			ecc->write_subpage = nand_write_subpage_hwecc;
3872
3873	case NAND_ECC_HW_SYNDROME:
3874		if ((!ecc->calculate || !ecc->correct || !ecc->hwctl) &&
3875		    (!ecc->read_page ||
3876		     ecc->read_page == nand_read_page_hwecc ||
3877		     !ecc->write_page ||
3878		     ecc->write_page == nand_write_page_hwecc)) {
3879			pr_warn("No ECC functions supplied; "
3880				   "hardware ECC not possible\n");
3881			BUG();
3882		}
3883		/* Use standard syndrome read/write page function? */
3884		if (!ecc->read_page)
3885			ecc->read_page = nand_read_page_syndrome;
3886		if (!ecc->write_page)
3887			ecc->write_page = nand_write_page_syndrome;
3888		if (!ecc->read_page_raw)
3889			ecc->read_page_raw = nand_read_page_raw_syndrome;
3890		if (!ecc->write_page_raw)
3891			ecc->write_page_raw = nand_write_page_raw_syndrome;
3892		if (!ecc->read_oob)
3893			ecc->read_oob = nand_read_oob_syndrome;
3894		if (!ecc->write_oob)
3895			ecc->write_oob = nand_write_oob_syndrome;
3896
3897		if (mtd->writesize >= ecc->size) {
3898			if (!ecc->strength) {
3899				pr_warn("Driver must set ecc.strength when using hardware ECC\n");
3900				BUG();
3901			}
3902			break;
3903		}
3904		pr_warn("%d byte HW ECC not possible on "
3905			   "%d byte page size, fallback to SW ECC\n",
3906			   ecc->size, mtd->writesize);
3907		ecc->mode = NAND_ECC_SOFT;
3908
3909	case NAND_ECC_SOFT:
3910		ecc->calculate = nand_calculate_ecc;
3911		ecc->correct = nand_correct_data;
3912		ecc->read_page = nand_read_page_swecc;
3913		ecc->read_subpage = nand_read_subpage;
3914		ecc->write_page = nand_write_page_swecc;
3915		ecc->read_page_raw = nand_read_page_raw;
3916		ecc->write_page_raw = nand_write_page_raw;
3917		ecc->read_oob = nand_read_oob_std;
3918		ecc->write_oob = nand_write_oob_std;
3919		if (!ecc->size)
3920			ecc->size = 256;
3921		ecc->bytes = 3;
3922		ecc->strength = 1;
3923		break;
3924
3925	case NAND_ECC_SOFT_BCH:
3926		if (!mtd_nand_has_bch()) {
3927			pr_warn("CONFIG_MTD_NAND_ECC_BCH not enabled\n");
3928			BUG();
3929		}
3930		ecc->calculate = nand_bch_calculate_ecc;
3931		ecc->correct = nand_bch_correct_data;
3932		ecc->read_page = nand_read_page_swecc;
3933		ecc->read_subpage = nand_read_subpage;
3934		ecc->write_page = nand_write_page_swecc;
3935		ecc->read_page_raw = nand_read_page_raw;
3936		ecc->write_page_raw = nand_write_page_raw;
3937		ecc->read_oob = nand_read_oob_std;
3938		ecc->write_oob = nand_write_oob_std;
3939		/*
3940		 * Board driver should supply ecc.size and ecc.bytes values to
3941		 * select how many bits are correctable; see nand_bch_init()
3942		 * for details. Otherwise, default to 4 bits for large page
3943		 * devices.
3944		 */
3945		if (!ecc->size && (mtd->oobsize >= 64)) {
3946			ecc->size = 512;
3947			ecc->bytes = 7;
3948		}
3949		ecc->priv = nand_bch_init(mtd, ecc->size, ecc->bytes,
3950					       &ecc->layout);
3951		if (!ecc->priv) {
3952			pr_warn("BCH ECC initialization failed!\n");
3953			BUG();
3954		}
3955		ecc->strength = ecc->bytes * 8 / fls(8 * ecc->size);
3956		break;
3957
3958	case NAND_ECC_NONE:
3959		pr_warn("NAND_ECC_NONE selected by board driver. "
3960			   "This is not recommended!\n");
3961		ecc->read_page = nand_read_page_raw;
3962		ecc->write_page = nand_write_page_raw;
3963		ecc->read_oob = nand_read_oob_std;
3964		ecc->read_page_raw = nand_read_page_raw;
3965		ecc->write_page_raw = nand_write_page_raw;
3966		ecc->write_oob = nand_write_oob_std;
3967		ecc->size = mtd->writesize;
3968		ecc->bytes = 0;
3969		ecc->strength = 0;
3970		break;
3971
3972	default:
3973		pr_warn("Invalid NAND_ECC_MODE %d\n", ecc->mode);
3974		BUG();
3975	}
3976
3977	/* For many systems, the standard OOB write also works for raw */
3978	if (!ecc->read_oob_raw)
3979		ecc->read_oob_raw = ecc->read_oob;
3980	if (!ecc->write_oob_raw)
3981		ecc->write_oob_raw = ecc->write_oob;
3982
3983	/*
3984	 * The number of bytes available for a client to place data into
3985	 * the out of band area.
3986	 */
3987	ecc->layout->oobavail = 0;
3988	for (i = 0; ecc->layout->oobfree[i].length
3989			&& i < ARRAY_SIZE(ecc->layout->oobfree); i++)
3990		ecc->layout->oobavail += ecc->layout->oobfree[i].length;
3991	mtd->oobavail = ecc->layout->oobavail;
3992
3993	/*
3994	 * Set the number of read / write steps for one page depending on ECC
3995	 * mode.
3996	 */
3997	ecc->steps = mtd->writesize / ecc->size;
3998	if (ecc->steps * ecc->size != mtd->writesize) {
3999		pr_warn("Invalid ECC parameters\n");
4000		BUG();
4001	}
4002	ecc->total = ecc->steps * ecc->bytes;
4003
4004	/* Allow subpage writes up to ecc.steps. Not possible for MLC flash */
4005	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) && nand_is_slc(chip)) {
4006		switch (ecc->steps) {
4007		case 2:
4008			mtd->subpage_sft = 1;
4009			break;
4010		case 4:
4011		case 8:
4012		case 16:
4013			mtd->subpage_sft = 2;
4014			break;
4015		}
4016	}
4017	chip->subpagesize = mtd->writesize >> mtd->subpage_sft;
4018
4019	/* Initialize state */
4020	chip->state = FL_READY;
4021
4022	/* Invalidate the pagebuffer reference */
4023	chip->pagebuf = -1;
4024
4025	/* Large page NAND with SOFT_ECC should support subpage reads */
4026	if ((ecc->mode == NAND_ECC_SOFT) && (chip->page_shift > 9))
4027		chip->options |= NAND_SUBPAGE_READ;
4028
4029	/* Fill in remaining MTD driver data */
4030	mtd->type = nand_is_slc(chip) ? MTD_NANDFLASH : MTD_MLCNANDFLASH;
4031	mtd->flags = (chip->options & NAND_ROM) ? MTD_CAP_ROM :
4032						MTD_CAP_NANDFLASH;
4033	mtd->_erase = nand_erase;
4034	mtd->_point = NULL;
4035	mtd->_unpoint = NULL;
4036	mtd->_read = nand_read;
4037	mtd->_write = nand_write;
4038	mtd->_panic_write = panic_nand_write;
4039	mtd->_read_oob = nand_read_oob;
4040	mtd->_write_oob = nand_write_oob;
4041	mtd->_sync = nand_sync;
4042	mtd->_lock = NULL;
4043	mtd->_unlock = NULL;
4044	mtd->_suspend = nand_suspend;
4045	mtd->_resume = nand_resume;
4046	mtd->_block_isbad = nand_block_isbad;
4047	mtd->_block_markbad = nand_block_markbad;
4048	mtd->writebufsize = mtd->writesize;
4049
4050	/* propagate ecc info to mtd_info */
4051	mtd->ecclayout = ecc->layout;
4052	mtd->ecc_strength = ecc->strength;
4053	mtd->ecc_step_size = ecc->size;
4054	/*
4055	 * Initialize bitflip_threshold to its default prior scan_bbt() call.
4056	 * scan_bbt() might invoke mtd_read(), thus bitflip_threshold must be
4057	 * properly set.
4058	 */
4059	if (!mtd->bitflip_threshold)
4060		mtd->bitflip_threshold = mtd->ecc_strength;
4061
4062	/* Check, if we should skip the bad block table scan */
4063	if (chip->options & NAND_SKIP_BBTSCAN)
4064		return 0;
4065
4066	/* Build bad block table */
4067	return chip->scan_bbt(mtd);
4068}
4069EXPORT_SYMBOL(nand_scan_tail);
4070
4071/*
4072 * is_module_text_address() isn't exported, and it's mostly a pointless
4073 * test if this is a module _anyway_ -- they'd have to try _really_ hard
4074 * to call us from in-kernel code if the core NAND support is modular.
4075 */
4076#ifdef MODULE
4077#define caller_is_module() (1)
4078#else
4079#define caller_is_module() \
4080	is_module_text_address((unsigned long)__builtin_return_address(0))
4081#endif
4082
4083/**
4084 * nand_scan - [NAND Interface] Scan for the NAND device
4085 * @mtd: MTD device structure
4086 * @maxchips: number of chips to scan for
4087 *
4088 * This fills out all the uninitialized function pointers with the defaults.
4089 * The flash ID is read and the mtd/chip structures are filled with the
4090 * appropriate values. The mtd->owner field must be set to the module of the
4091 * caller.
4092 */
4093int nand_scan(struct mtd_info *mtd, int maxchips)
4094{
4095	int ret;
4096
4097	/* Many callers got this wrong, so check for it for a while... */
4098	if (!mtd->owner && caller_is_module()) {
4099		pr_crit("%s called with NULL mtd->owner!\n", __func__);
4100		BUG();
4101	}
4102
4103	ret = nand_scan_ident(mtd, maxchips, NULL);
4104	if (!ret)
4105		ret = nand_scan_tail(mtd);
4106	return ret;
4107}
4108EXPORT_SYMBOL(nand_scan);
4109
4110/**
4111 * nand_release - [NAND Interface] Free resources held by the NAND device
4112 * @mtd: MTD device structure
4113 */
4114void nand_release(struct mtd_info *mtd)
4115{
4116	struct nand_chip *chip = mtd->priv;
4117
4118	if (chip->ecc.mode == NAND_ECC_SOFT_BCH)
4119		nand_bch_free((struct nand_bch_control *)chip->ecc.priv);
4120
4121	mtd_device_unregister(mtd);
4122
4123	/* Free bad block table memory */
4124	kfree(chip->bbt);
4125	if (!(chip->options & NAND_OWN_BUFFERS))
4126		kfree(chip->buffers);
4127
4128	/* Free bad block descriptor memory */
4129	if (chip->badblock_pattern && chip->badblock_pattern->options
4130			& NAND_BBT_DYNAMICSTRUCT)
4131		kfree(chip->badblock_pattern);
4132}
4133EXPORT_SYMBOL_GPL(nand_release);
4134
4135static int __init nand_base_init(void)
4136{
4137	led_trigger_register_simple("nand-disk", &nand_led_trigger);
4138	return 0;
4139}
4140
4141static void __exit nand_base_exit(void)
4142{
4143	led_trigger_unregister_simple(nand_led_trigger);
4144}
4145
4146module_init(nand_base_init);
4147module_exit(nand_base_exit);
4148
4149MODULE_LICENSE("GPL");
4150MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>");
4151MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
4152MODULE_DESCRIPTION("Generic NAND flash driver code");