bf5xx_nand.c 19.6 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856
/* linux/drivers/mtd/nand/bf5xx_nand.c
 *
 * Copyright 2006-2008 Analog Devices Inc.
 *	http://blackfin.uclinux.org/
 *	Bryan Wu <bryan.wu@analog.com>
 *
 * Blackfin BF5xx on-chip NAND flash controller driver
 *
 * Derived from drivers/mtd/nand/s3c2410.c
 * Copyright (c) 2007 Ben Dooks <ben@simtec.co.uk>
 *
 * Derived from drivers/mtd/nand/cafe.c
 * Copyright © 2006 Red Hat, Inc.
 * Copyright © 2006 David Woodhouse <dwmw2@infradead.org>
 *
 * Changelog:
 *	12-Jun-2007  Bryan Wu:  Initial version
 *	18-Jul-2007  Bryan Wu:
 *		- ECC_HW and ECC_SW supported
 *		- DMA supported in ECC_HW
 *		- YAFFS tested as rootfs in both ECC_HW and ECC_SW
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/bitops.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/partitions.h>

#include <asm/blackfin.h>
#include <asm/dma.h>
#include <asm/cacheflush.h>
#include <asm/nand.h>
#include <asm/portmux.h>

#define DRV_NAME	"bf5xx-nand"
#define DRV_VERSION	"1.2"
#define DRV_AUTHOR	"Bryan Wu <bryan.wu@analog.com>"
#define DRV_DESC	"BF5xx on-chip NAND FLash Controller Driver"

/* NFC_STAT Masks */
#define NBUSY       0x01  /* Not Busy */
#define WB_FULL     0x02  /* Write Buffer Full */
#define PG_WR_STAT  0x04  /* Page Write Pending */
#define PG_RD_STAT  0x08  /* Page Read Pending */
#define WB_EMPTY    0x10  /* Write Buffer Empty */

/* NFC_IRQSTAT Masks */
#define NBUSYIRQ    0x01  /* Not Busy IRQ */
#define WB_OVF      0x02  /* Write Buffer Overflow */
#define WB_EDGE     0x04  /* Write Buffer Edge Detect */
#define RD_RDY      0x08  /* Read Data Ready */
#define WR_DONE     0x10  /* Page Write Done */

/* NFC_RST Masks */
#define ECC_RST     0x01  /* ECC (and NFC counters) Reset */

/* NFC_PGCTL Masks */
#define PG_RD_START 0x01  /* Page Read Start */
#define PG_WR_START 0x02  /* Page Write Start */

#ifdef CONFIG_MTD_NAND_BF5XX_HWECC
static int hardware_ecc = 1;
#else
static int hardware_ecc;
#endif

static const unsigned short bfin_nfc_pin_req[] =
	{P_NAND_CE,
	 P_NAND_RB,
	 P_NAND_D0,
	 P_NAND_D1,
	 P_NAND_D2,
	 P_NAND_D3,
	 P_NAND_D4,
	 P_NAND_D5,
	 P_NAND_D6,
	 P_NAND_D7,
	 P_NAND_WE,
	 P_NAND_RE,
	 P_NAND_CLE,
	 P_NAND_ALE,
	 0};

#ifdef CONFIG_MTD_NAND_BF5XX_BOOTROM_ECC
static struct nand_ecclayout bootrom_ecclayout = {
	.eccbytes = 24,
	.eccpos = {
		0x8 * 0, 0x8 * 0 + 1, 0x8 * 0 + 2,
		0x8 * 1, 0x8 * 1 + 1, 0x8 * 1 + 2,
		0x8 * 2, 0x8 * 2 + 1, 0x8 * 2 + 2,
		0x8 * 3, 0x8 * 3 + 1, 0x8 * 3 + 2,
		0x8 * 4, 0x8 * 4 + 1, 0x8 * 4 + 2,
		0x8 * 5, 0x8 * 5 + 1, 0x8 * 5 + 2,
		0x8 * 6, 0x8 * 6 + 1, 0x8 * 6 + 2,
		0x8 * 7, 0x8 * 7 + 1, 0x8 * 7 + 2
	},
	.oobfree = {
		{ 0x8 * 0 + 3, 5 },
		{ 0x8 * 1 + 3, 5 },
		{ 0x8 * 2 + 3, 5 },
		{ 0x8 * 3 + 3, 5 },
		{ 0x8 * 4 + 3, 5 },
		{ 0x8 * 5 + 3, 5 },
		{ 0x8 * 6 + 3, 5 },
		{ 0x8 * 7 + 3, 5 },
	}
};
#endif

/*
 * Data structures for bf5xx nand flash controller driver
 */

/* bf5xx nand info */
struct bf5xx_nand_info {
	/* mtd info */
	struct nand_hw_control		controller;
	struct mtd_info			mtd;
	struct nand_chip		chip;

	/* platform info */
	struct bf5xx_nand_platform	*platform;

	/* device info */
	struct device			*device;

	/* DMA stuff */
	struct completion		dma_completion;
};

/*
 * Conversion functions
 */
static struct bf5xx_nand_info *mtd_to_nand_info(struct mtd_info *mtd)
{
	return container_of(mtd, struct bf5xx_nand_info, mtd);
}

static struct bf5xx_nand_info *to_nand_info(struct platform_device *pdev)
{
	return platform_get_drvdata(pdev);
}

static struct bf5xx_nand_platform *to_nand_plat(struct platform_device *pdev)
{
	return dev_get_platdata(&pdev->dev);
}

/*
 * struct nand_chip interface function pointers
 */

/*
 * bf5xx_nand_hwcontrol
 *
 * Issue command and address cycles to the chip
 */
static void bf5xx_nand_hwcontrol(struct mtd_info *mtd, int cmd,
				   unsigned int ctrl)
{
	if (cmd == NAND_CMD_NONE)
		return;

	while (bfin_read_NFC_STAT() & WB_FULL)
		cpu_relax();

	if (ctrl & NAND_CLE)
		bfin_write_NFC_CMD(cmd);
	else if (ctrl & NAND_ALE)
		bfin_write_NFC_ADDR(cmd);
	SSYNC();
}

/*
 * bf5xx_nand_devready()
 *
 * returns 0 if the nand is busy, 1 if it is ready
 */
static int bf5xx_nand_devready(struct mtd_info *mtd)
{
	unsigned short val = bfin_read_NFC_STAT();

	if ((val & NBUSY) == NBUSY)
		return 1;
	else
		return 0;
}

/*
 * ECC functions
 * These allow the bf5xx to use the controller's ECC
 * generator block to ECC the data as it passes through
 */

/*
 * ECC error correction function
 */
static int bf5xx_nand_correct_data_256(struct mtd_info *mtd, u_char *dat,
					u_char *read_ecc, u_char *calc_ecc)
{
	struct bf5xx_nand_info *info = mtd_to_nand_info(mtd);
	u32 syndrome[5];
	u32 calced, stored;
	int i;
	unsigned short failing_bit, failing_byte;
	u_char data;

	calced = calc_ecc[0] | (calc_ecc[1] << 8) | (calc_ecc[2] << 16);
	stored = read_ecc[0] | (read_ecc[1] << 8) | (read_ecc[2] << 16);

	syndrome[0] = (calced ^ stored);

	/*
	 * syndrome 0: all zero
	 * No error in data
	 * No action
	 */
	if (!syndrome[0] || !calced || !stored)
		return 0;

	/*
	 * sysdrome 0: only one bit is one
	 * ECC data was incorrect
	 * No action
	 */
	if (hweight32(syndrome[0]) == 1) {
		dev_err(info->device, "ECC data was incorrect!\n");
		return -EBADMSG;
	}

	syndrome[1] = (calced & 0x7FF) ^ (stored & 0x7FF);
	syndrome[2] = (calced & 0x7FF) ^ ((calced >> 11) & 0x7FF);
	syndrome[3] = (stored & 0x7FF) ^ ((stored >> 11) & 0x7FF);
	syndrome[4] = syndrome[2] ^ syndrome[3];

	for (i = 0; i < 5; i++)
		dev_info(info->device, "syndrome[%d] 0x%08x\n", i, syndrome[i]);

	dev_info(info->device,
		"calced[0x%08x], stored[0x%08x]\n",
		calced, stored);

	/*
	 * sysdrome 0: exactly 11 bits are one, each parity
	 * and parity' pair is 1 & 0 or 0 & 1.
	 * 1-bit correctable error
	 * Correct the error
	 */
	if (hweight32(syndrome[0]) == 11 && syndrome[4] == 0x7FF) {
		dev_info(info->device,
			"1-bit correctable error, correct it.\n");
		dev_info(info->device,
			"syndrome[1] 0x%08x\n", syndrome[1]);

		failing_bit = syndrome[1] & 0x7;
		failing_byte = syndrome[1] >> 0x3;
		data = *(dat + failing_byte);
		data = data ^ (0x1 << failing_bit);
		*(dat + failing_byte) = data;

		return 1;
	}

	/*
	 * sysdrome 0: random data
	 * More than 1-bit error, non-correctable error
	 * Discard data, mark bad block
	 */
	dev_err(info->device,
		"More than 1-bit error, non-correctable error.\n");
	dev_err(info->device,
		"Please discard data, mark bad block\n");

	return -EBADMSG;
}

static int bf5xx_nand_correct_data(struct mtd_info *mtd, u_char *dat,
					u_char *read_ecc, u_char *calc_ecc)
{
	struct nand_chip *chip = mtd->priv;
	int ret, bitflips = 0;

	ret = bf5xx_nand_correct_data_256(mtd, dat, read_ecc, calc_ecc);
	if (ret < 0)
		return ret;

	bitflips = ret;

	/* If ecc size is 512, correct second 256 bytes */
	if (chip->ecc.size == 512) {
		dat += 256;
		read_ecc += 3;
		calc_ecc += 3;
		ret = bf5xx_nand_correct_data_256(mtd, dat, read_ecc, calc_ecc);
		if (ret < 0)
			return ret;

		bitflips += ret;
	}

	return bitflips;
}

static void bf5xx_nand_enable_hwecc(struct mtd_info *mtd, int mode)
{
	return;
}

static int bf5xx_nand_calculate_ecc(struct mtd_info *mtd,
		const u_char *dat, u_char *ecc_code)
{
	struct bf5xx_nand_info *info = mtd_to_nand_info(mtd);
	struct nand_chip *chip = mtd->priv;
	u16 ecc0, ecc1;
	u32 code[2];
	u8 *p;

	/* first 3 bytes ECC code for 256 page size */
	ecc0 = bfin_read_NFC_ECC0();
	ecc1 = bfin_read_NFC_ECC1();

	code[0] = (ecc0 & 0x7ff) | ((ecc1 & 0x7ff) << 11);

	dev_dbg(info->device, "returning ecc 0x%08x\n", code[0]);

	p = (u8 *) code;
	memcpy(ecc_code, p, 3);

	/* second 3 bytes ECC code for 512 ecc size */
	if (chip->ecc.size == 512) {
		ecc0 = bfin_read_NFC_ECC2();
		ecc1 = bfin_read_NFC_ECC3();
		code[1] = (ecc0 & 0x7ff) | ((ecc1 & 0x7ff) << 11);

		/* second 3 bytes in ecc_code for second 256
		 * bytes of 512 page size
		 */
		p = (u8 *) (code + 1);
		memcpy((ecc_code + 3), p, 3);
		dev_dbg(info->device, "returning ecc 0x%08x\n", code[1]);
	}

	return 0;
}

/*
 * PIO mode for buffer writing and reading
 */
static void bf5xx_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
{
	int i;
	unsigned short val;

	/*
	 * Data reads are requested by first writing to NFC_DATA_RD
	 * and then reading back from NFC_READ.
	 */
	for (i = 0; i < len; i++) {
		while (bfin_read_NFC_STAT() & WB_FULL)
			cpu_relax();

		/* Contents do not matter */
		bfin_write_NFC_DATA_RD(0x0000);
		SSYNC();

		while ((bfin_read_NFC_IRQSTAT() & RD_RDY) != RD_RDY)
			cpu_relax();

		buf[i] = bfin_read_NFC_READ();

		val = bfin_read_NFC_IRQSTAT();
		val |= RD_RDY;
		bfin_write_NFC_IRQSTAT(val);
		SSYNC();
	}
}

static uint8_t bf5xx_nand_read_byte(struct mtd_info *mtd)
{
	uint8_t val;

	bf5xx_nand_read_buf(mtd, &val, 1);

	return val;
}

static void bf5xx_nand_write_buf(struct mtd_info *mtd,
				const uint8_t *buf, int len)
{
	int i;

	for (i = 0; i < len; i++) {
		while (bfin_read_NFC_STAT() & WB_FULL)
			cpu_relax();

		bfin_write_NFC_DATA_WR(buf[i]);
		SSYNC();
	}
}

static void bf5xx_nand_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
{
	int i;
	u16 *p = (u16 *) buf;
	len >>= 1;

	/*
	 * Data reads are requested by first writing to NFC_DATA_RD
	 * and then reading back from NFC_READ.
	 */
	bfin_write_NFC_DATA_RD(0x5555);

	SSYNC();

	for (i = 0; i < len; i++)
		p[i] = bfin_read_NFC_READ();
}

static void bf5xx_nand_write_buf16(struct mtd_info *mtd,
				const uint8_t *buf, int len)
{
	int i;
	u16 *p = (u16 *) buf;
	len >>= 1;

	for (i = 0; i < len; i++)
		bfin_write_NFC_DATA_WR(p[i]);

	SSYNC();
}

/*
 * DMA functions for buffer writing and reading
 */
static irqreturn_t bf5xx_nand_dma_irq(int irq, void *dev_id)
{
	struct bf5xx_nand_info *info = dev_id;

	clear_dma_irqstat(CH_NFC);
	disable_dma(CH_NFC);
	complete(&info->dma_completion);

	return IRQ_HANDLED;
}

static void bf5xx_nand_dma_rw(struct mtd_info *mtd,
				uint8_t *buf, int is_read)
{
	struct bf5xx_nand_info *info = mtd_to_nand_info(mtd);
	struct nand_chip *chip = mtd->priv;
	unsigned short val;

	dev_dbg(info->device, " mtd->%p, buf->%p, is_read %d\n",
			mtd, buf, is_read);

	/*
	 * Before starting a dma transfer, be sure to invalidate/flush
	 * the cache over the address range of your DMA buffer to
	 * prevent cache coherency problems. Otherwise very subtle bugs
	 * can be introduced to your driver.
	 */
	if (is_read)
		invalidate_dcache_range((unsigned int)buf,
				(unsigned int)(buf + chip->ecc.size));
	else
		flush_dcache_range((unsigned int)buf,
				(unsigned int)(buf + chip->ecc.size));

	/*
	 * This register must be written before each page is
	 * transferred to generate the correct ECC register
	 * values.
	 */
	bfin_write_NFC_RST(ECC_RST);
	SSYNC();
	while (bfin_read_NFC_RST() & ECC_RST)
		cpu_relax();

	disable_dma(CH_NFC);
	clear_dma_irqstat(CH_NFC);

	/* setup DMA register with Blackfin DMA API */
	set_dma_config(CH_NFC, 0x0);
	set_dma_start_addr(CH_NFC, (unsigned long) buf);

	/* The DMAs have different size on BF52x and BF54x */
#ifdef CONFIG_BF52x
	set_dma_x_count(CH_NFC, (chip->ecc.size >> 1));
	set_dma_x_modify(CH_NFC, 2);
	val = DI_EN | WDSIZE_16;
#endif

#ifdef CONFIG_BF54x
	set_dma_x_count(CH_NFC, (chip->ecc.size >> 2));
	set_dma_x_modify(CH_NFC, 4);
	val = DI_EN | WDSIZE_32;
#endif
	/* setup write or read operation */
	if (is_read)
		val |= WNR;
	set_dma_config(CH_NFC, val);
	enable_dma(CH_NFC);

	/* Start PAGE read/write operation */
	if (is_read)
		bfin_write_NFC_PGCTL(PG_RD_START);
	else
		bfin_write_NFC_PGCTL(PG_WR_START);
	wait_for_completion(&info->dma_completion);
}

static void bf5xx_nand_dma_read_buf(struct mtd_info *mtd,
					uint8_t *buf, int len)
{
	struct bf5xx_nand_info *info = mtd_to_nand_info(mtd);
	struct nand_chip *chip = mtd->priv;

	dev_dbg(info->device, "mtd->%p, buf->%p, int %d\n", mtd, buf, len);

	if (len == chip->ecc.size)
		bf5xx_nand_dma_rw(mtd, buf, 1);
	else
		bf5xx_nand_read_buf(mtd, buf, len);
}

static void bf5xx_nand_dma_write_buf(struct mtd_info *mtd,
				const uint8_t *buf, int len)
{
	struct bf5xx_nand_info *info = mtd_to_nand_info(mtd);
	struct nand_chip *chip = mtd->priv;

	dev_dbg(info->device, "mtd->%p, buf->%p, len %d\n", mtd, buf, len);

	if (len == chip->ecc.size)
		bf5xx_nand_dma_rw(mtd, (uint8_t *)buf, 0);
	else
		bf5xx_nand_write_buf(mtd, buf, len);
}

static int bf5xx_nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
		uint8_t *buf, int oob_required, int page)
{
	bf5xx_nand_read_buf(mtd, buf, mtd->writesize);
	bf5xx_nand_read_buf(mtd, chip->oob_poi, mtd->oobsize);

	return 0;
}

static int bf5xx_nand_write_page_raw(struct mtd_info *mtd,
		struct nand_chip *chip,	const uint8_t *buf, int oob_required,
		int page)
{
	bf5xx_nand_write_buf(mtd, buf, mtd->writesize);
	bf5xx_nand_write_buf(mtd, chip->oob_poi, mtd->oobsize);

	return 0;
}

/*
 * System initialization functions
 */
static int bf5xx_nand_dma_init(struct bf5xx_nand_info *info)
{
	int ret;

	/* Do not use dma */
	if (!hardware_ecc)
		return 0;

	init_completion(&info->dma_completion);

	/* Request NFC DMA channel */
	ret = request_dma(CH_NFC, "BF5XX NFC driver");
	if (ret < 0) {
		dev_err(info->device, " unable to get DMA channel\n");
		return ret;
	}

#ifdef CONFIG_BF54x
	/* Setup DMAC1 channel mux for NFC which shared with SDH */
	bfin_write_DMAC1_PERIMUX(bfin_read_DMAC1_PERIMUX() & ~1);
	SSYNC();
#endif

	set_dma_callback(CH_NFC, bf5xx_nand_dma_irq, info);

	/* Turn off the DMA channel first */
	disable_dma(CH_NFC);
	return 0;
}

static void bf5xx_nand_dma_remove(struct bf5xx_nand_info *info)
{
	/* Free NFC DMA channel */
	if (hardware_ecc)
		free_dma(CH_NFC);
}

/*
 * BF5XX NFC hardware initialization
 *  - pin mux setup
 *  - clear interrupt status
 */
static int bf5xx_nand_hw_init(struct bf5xx_nand_info *info)
{
	int err = 0;
	unsigned short val;
	struct bf5xx_nand_platform *plat = info->platform;

	/* setup NFC_CTL register */
	dev_info(info->device,
		"data_width=%d, wr_dly=%d, rd_dly=%d\n",
		(plat->data_width ? 16 : 8),
		plat->wr_dly, plat->rd_dly);

	val = (1 << NFC_PG_SIZE_OFFSET) |
		(plat->data_width << NFC_NWIDTH_OFFSET) |
		(plat->rd_dly << NFC_RDDLY_OFFSET) |
		(plat->wr_dly << NFC_WRDLY_OFFSET);
	dev_dbg(info->device, "NFC_CTL is 0x%04x\n", val);

	bfin_write_NFC_CTL(val);
	SSYNC();

	/* clear interrupt status */
	bfin_write_NFC_IRQMASK(0x0);
	SSYNC();
	val = bfin_read_NFC_IRQSTAT();
	bfin_write_NFC_IRQSTAT(val);
	SSYNC();

	/* DMA initialization  */
	if (bf5xx_nand_dma_init(info))
		err = -ENXIO;

	return err;
}

/*
 * Device management interface
 */
static int bf5xx_nand_add_partition(struct bf5xx_nand_info *info)
{
	struct mtd_info *mtd = &info->mtd;
	struct mtd_partition *parts = info->platform->partitions;
	int nr = info->platform->nr_partitions;

	return mtd_device_register(mtd, parts, nr);
}

static int bf5xx_nand_remove(struct platform_device *pdev)
{
	struct bf5xx_nand_info *info = to_nand_info(pdev);

	/* first thing we need to do is release all our mtds
	 * and their partitions, then go through freeing the
	 * resources used
	 */
	nand_release(&info->mtd);

	peripheral_free_list(bfin_nfc_pin_req);
	bf5xx_nand_dma_remove(info);

	return 0;
}

static int bf5xx_nand_scan(struct mtd_info *mtd)
{
	struct nand_chip *chip = mtd->priv;
	int ret;

	ret = nand_scan_ident(mtd, 1, NULL);
	if (ret)
		return ret;

	if (hardware_ecc) {
		/*
		 * for nand with page size > 512B, think it as several sections with 512B
		 */
		if (likely(mtd->writesize >= 512)) {
			chip->ecc.size = 512;
			chip->ecc.bytes = 6;
			chip->ecc.strength = 2;
		} else {
			chip->ecc.size = 256;
			chip->ecc.bytes = 3;
			chip->ecc.strength = 1;
			bfin_write_NFC_CTL(bfin_read_NFC_CTL() & ~(1 << NFC_PG_SIZE_OFFSET));
			SSYNC();
		}
	}

	return	nand_scan_tail(mtd);
}

/*
 * bf5xx_nand_probe
 *
 * called by device layer when it finds a device matching
 * one our driver can handled. This code checks to see if
 * it can allocate all necessary resources then calls the
 * nand layer to look for devices
 */
static int bf5xx_nand_probe(struct platform_device *pdev)
{
	struct bf5xx_nand_platform *plat = to_nand_plat(pdev);
	struct bf5xx_nand_info *info = NULL;
	struct nand_chip *chip = NULL;
	struct mtd_info *mtd = NULL;
	int err = 0;

	dev_dbg(&pdev->dev, "(%p)\n", pdev);

	if (!plat) {
		dev_err(&pdev->dev, "no platform specific information\n");
		return -EINVAL;
	}

	if (peripheral_request_list(bfin_nfc_pin_req, DRV_NAME)) {
		dev_err(&pdev->dev, "requesting Peripherals failed\n");
		return -EFAULT;
	}

	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
	if (info == NULL) {
		err = -ENOMEM;
		goto out_err;
	}

	platform_set_drvdata(pdev, info);

	spin_lock_init(&info->controller.lock);
	init_waitqueue_head(&info->controller.wq);

	info->device     = &pdev->dev;
	info->platform   = plat;

	/* initialise chip data struct */
	chip = &info->chip;

	if (plat->data_width)
		chip->options |= NAND_BUSWIDTH_16;

	chip->options |= NAND_CACHEPRG | NAND_SKIP_BBTSCAN;

	chip->read_buf = (plat->data_width) ?
		bf5xx_nand_read_buf16 : bf5xx_nand_read_buf;
	chip->write_buf = (plat->data_width) ?
		bf5xx_nand_write_buf16 : bf5xx_nand_write_buf;

	chip->read_byte    = bf5xx_nand_read_byte;

	chip->cmd_ctrl     = bf5xx_nand_hwcontrol;
	chip->dev_ready    = bf5xx_nand_devready;

	chip->priv	   = &info->mtd;
	chip->controller   = &info->controller;

	chip->IO_ADDR_R    = (void __iomem *) NFC_READ;
	chip->IO_ADDR_W    = (void __iomem *) NFC_DATA_WR;

	chip->chip_delay   = 0;

	/* initialise mtd info data struct */
	mtd 		= &info->mtd;
	mtd->priv	= chip;
	mtd->dev.parent = &pdev->dev;

	/* initialise the hardware */
	err = bf5xx_nand_hw_init(info);
	if (err)
		goto out_err;

	/* setup hardware ECC data struct */
	if (hardware_ecc) {
#ifdef CONFIG_MTD_NAND_BF5XX_BOOTROM_ECC
		chip->ecc.layout = &bootrom_ecclayout;
#endif
		chip->read_buf      = bf5xx_nand_dma_read_buf;
		chip->write_buf     = bf5xx_nand_dma_write_buf;
		chip->ecc.calculate = bf5xx_nand_calculate_ecc;
		chip->ecc.correct   = bf5xx_nand_correct_data;
		chip->ecc.mode	    = NAND_ECC_HW;
		chip->ecc.hwctl	    = bf5xx_nand_enable_hwecc;
		chip->ecc.read_page_raw = bf5xx_nand_read_page_raw;
		chip->ecc.write_page_raw = bf5xx_nand_write_page_raw;
	} else {
		chip->ecc.mode	    = NAND_ECC_SOFT;
	}

	/* scan hardware nand chip and setup mtd info data struct */
	if (bf5xx_nand_scan(mtd)) {
		err = -ENXIO;
		goto out_err_nand_scan;
	}

#ifdef CONFIG_MTD_NAND_BF5XX_BOOTROM_ECC
	chip->badblockpos = 63;
#endif

	/* add NAND partition */
	bf5xx_nand_add_partition(info);

	dev_dbg(&pdev->dev, "initialised ok\n");
	return 0;

out_err_nand_scan:
	bf5xx_nand_dma_remove(info);
out_err:
	peripheral_free_list(bfin_nfc_pin_req);

	return err;
}

/* driver device registration */
static struct platform_driver bf5xx_nand_driver = {
	.probe		= bf5xx_nand_probe,
	.remove		= bf5xx_nand_remove,
	.driver		= {
		.name	= DRV_NAME,
	},
};

module_platform_driver(bf5xx_nand_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION(DRV_DESC);
MODULE_ALIAS("platform:" DRV_NAME);