fsl_elbc_nand.c

基于linux-2.6.28的mtd驱动

/* Freescale Enhanced Local Bus Controller NAND driver
 *
 * Copyright (c) 2006-2007 Freescale Semiconductor
 *
 * Authors: Nick Spence <[e-mail]>,
 *          Scott Wood <[e-mail]>
 *
 * 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/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <linux/interrupt.h>

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

#include <asm/io.h>
#include <asm/fsl_lbc.h>

#define MAX_BANKS 8
#define ERR_BYTE 0xFF /* Value returned for read bytes when read failed */
#define FCM_TIMEOUT_MSECS 500 /* Maximum number of mSecs to wait for FCM */

struct fsl_elbc_ctrl;

/* mtd information per set */

struct fsl_elbc_mtd {
	struct mtd_info mtd;
	struct nand_chip chip;
	struct fsl_elbc_ctrl *ctrl;

	struct device *dev;
	int bank;               /* Chip select bank number           */
	u8 __iomem *vbase;      /* Chip select base virtual address  */
	int page_size;          /* NAND page size (0=512, 1=2048)    */
	unsigned int fmr;       /* FCM Flash Mode Register value     */
};

/* overview of the fsl elbc controller */

struct fsl_elbc_ctrl {
	struct nand_hw_control controller;
	struct fsl_elbc_mtd *chips[MAX_BANKS];

	/* device info */
	struct device *dev;
	struct fsl_lbc_regs __iomem *regs;
	int irq;
	wait_queue_head_t irq_wait;
	unsigned int irq_status; /* status read from LTESR by irq handler */
	u8 __iomem *addr;        /* Address of assigned FCM buffer        */
	unsigned int page;       /* Last page written to / read from      */
	unsigned int read_bytes; /* Number of bytes read during command   */
	unsigned int column;     /* Saved column from SEQIN               */
	unsigned int index;      /* Pointer to next byte to 'read'        */
	unsigned int status;     /* status read from LTESR after last op  */
	unsigned int mdr;        /* UPM/FCM Data Register value           */
	unsigned int use_mdr;    /* Non zero if the MDR is to be set      */
	unsigned int oob;        /* Non zero if operating on OOB data     */
	char *oob_poi;           /* Place to write ECC after read back    */
};

/* These map to the positions used by the FCM hardware ECC generator */

/* Small Page FLASH with FMR[ECCM] = 0 */
static struct nand_ecclayout fsl_elbc_oob_sp_eccm0 = {
	.eccbytes = 3,
	.eccpos = {6, 7, 8},
	.oobfree = { {0, 5}, {9, 7} },
};

/* Small Page FLASH with FMR[ECCM] = 1 */
static struct nand_ecclayout fsl_elbc_oob_sp_eccm1 = {
	.eccbytes = 3,
	.eccpos = {8, 9, 10},
	.oobfree = { {0, 5}, {6, 2}, {11, 5} },
};

/* Large Page FLASH with FMR[ECCM] = 0 */
static struct nand_ecclayout fsl_elbc_oob_lp_eccm0 = {
	.eccbytes = 12,
	.eccpos = {6, 7, 8, 22, 23, 24, 38, 39, 40, 54, 55, 56},
	.oobfree = { {1, 5}, {9, 13}, {25, 13}, {41, 13}, {57, 7} },
};

/* Large Page FLASH with FMR[ECCM] = 1 */
static struct nand_ecclayout fsl_elbc_oob_lp_eccm1 = {
	.eccbytes = 12,
	.eccpos = {8, 9, 10, 24, 25, 26, 40, 41, 42, 56, 57, 58},
	.oobfree = { {1, 7}, {11, 13}, {27, 13}, {43, 13}, {59, 5} },
};

/*
 * fsl_elbc_oob_lp_eccm* specify that LP NAND's OOB free area starts at offset
 * 1, so we have to adjust bad block pattern. This pattern should be used for
 * x8 chips only. So far hardware does not support x16 chips anyway.
 */
static u8 scan_ff_pattern[] = { 0xff, };

static struct nand_bbt_descr largepage_memorybased = {
	.options = 0,
	.offs = 0,
	.len = 1,
	.pattern = scan_ff_pattern,
};

/*
 * ELBC may use HW ECC, so that OOB offsets, that NAND core uses for bbt,
 * interfere with ECC positions, that's why we implement our own descriptors.
 * OOB {11, 5}, works for both SP and LP chips, with ECCM = 1 and ECCM = 0.
 */
static u8 bbt_pattern[] = {'B', 'b', 't', '0' };
static u8 mirror_pattern[] = {'1', 't', 'b', 'B' };

static struct nand_bbt_descr bbt_main_descr = {
	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
		   NAND_BBT_2BIT | NAND_BBT_VERSION,
	.offs =	11,
	.len = 4,
	.veroffs = 15,
	.maxblocks = 4,
	.pattern = bbt_pattern,
};

static struct nand_bbt_descr bbt_mirror_descr = {
	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
		   NAND_BBT_2BIT | NAND_BBT_VERSION,
	.offs =	11,
	.len = 4,
	.veroffs = 15,
	.maxblocks = 4,
	.pattern = mirror_pattern,
};

/*=================================*/

/*
 * Set up the FCM hardware block and page address fields, and the fcm
 * structure addr field to point to the correct FCM buffer in memory
 */
static void set_addr(struct mtd_info *mtd, int column, int page_addr, int oob)
{
	struct nand_chip *chip = mtd->priv;
	struct fsl_elbc_mtd *priv = chip->priv;
	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
	int buf_num;

	ctrl->page = page_addr;

	out_be32(&lbc->fbar,
	         page_addr >> (chip->phys_erase_shift - chip->page_shift));

	if (priv->page_size) {
		out_be32(&lbc->fpar,
		         ((page_addr << FPAR_LP_PI_SHIFT) & FPAR_LP_PI) |
		         (oob ? FPAR_LP_MS : 0) | column);
		buf_num = (page_addr & 1) << 2;
	} else {
		out_be32(&lbc->fpar,
		         ((page_addr << FPAR_SP_PI_SHIFT) & FPAR_SP_PI) |
		         (oob ? FPAR_SP_MS : 0) | column);
		buf_num = page_addr & 7;
	}

	ctrl->addr = priv->vbase + buf_num * 1024;
	ctrl->index = column;

	/* for OOB data point to the second half of the buffer */
	if (oob)
		ctrl->index += priv->page_size ? 2048 : 512;

	dev_vdbg(ctrl->dev, "set_addr: bank=%d, ctrl->addr=0x%p (0x%p), "
	                    "index %x, pes %d ps %d\n",
	         buf_num, ctrl->addr, priv->vbase, ctrl->index,
	         chip->phys_erase_shift, chip->page_shift);
}

/*
 * execute FCM command and wait for it to complete
 */
static int fsl_elbc_run_command(struct mtd_info *mtd)
{
	struct nand_chip *chip = mtd->priv;
	struct fsl_elbc_mtd *priv = chip->priv;
	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;

	/* Setup the FMR[OP] to execute without write protection */
	out_be32(&lbc->fmr, priv->fmr | 3);
	if (ctrl->use_mdr)
		out_be32(&lbc->mdr, ctrl->mdr);

	dev_vdbg(ctrl->dev,
	         "fsl_elbc_run_command: fmr=%08x fir=%08x fcr=%08x\n",
	         in_be32(&lbc->fmr), in_be32(&lbc->fir), in_be32(&lbc->fcr));
	dev_vdbg(ctrl->dev,
	         "fsl_elbc_run_command: fbar=%08x fpar=%08x "
	         "fbcr=%08x bank=%d\n",
	         in_be32(&lbc->fbar), in_be32(&lbc->fpar),
	         in_be32(&lbc->fbcr), priv->bank);

	ctrl->irq_status = 0;
	/* execute special operation */
	out_be32(&lbc->lsor, priv->bank);

	/* wait for FCM complete flag or timeout */
	wait_event_timeout(ctrl->irq_wait, ctrl->irq_status,
	                   FCM_TIMEOUT_MSECS * HZ/1000);
	ctrl->status = ctrl->irq_status;

	/* store mdr value in case it was needed */
	if (ctrl->use_mdr)
		ctrl->mdr = in_be32(&lbc->mdr);

	ctrl->use_mdr = 0;

	dev_vdbg(ctrl->dev,
	         "fsl_elbc_run_command: stat=%08x mdr=%08x fmr=%08x\n",
	         ctrl->status, ctrl->mdr, in_be32(&lbc->fmr));

	/* returns 0 on success otherwise non-zero) */
	return ctrl->status == LTESR_CC ? 0 : -EIO;
}

static void fsl_elbc_do_read(struct nand_chip *chip, int oob)
{
	struct fsl_elbc_mtd *priv = chip->priv;
	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;

	if (priv->page_size) {
		out_be32(&lbc->fir,
		         (FIR_OP_CW0 << FIR_OP0_SHIFT) |
		         (FIR_OP_CA  << FIR_OP1_SHIFT) |
		         (FIR_OP_PA  << FIR_OP2_SHIFT) |
		         (FIR_OP_CW1 << FIR_OP3_SHIFT) |
		         (FIR_OP_RBW << FIR_OP4_SHIFT));

		out_be32(&lbc->fcr, (NAND_CMD_READ0 << FCR_CMD0_SHIFT) |
		                    (NAND_CMD_READSTART << FCR_CMD1_SHIFT));
	} else {
		out_be32(&lbc->fir,
		         (FIR_OP_CW0 << FIR_OP0_SHIFT) |
		         (FIR_OP_CA  << FIR_OP1_SHIFT) |
		         (FIR_OP_PA  << FIR_OP2_SHIFT) |
		         (FIR_OP_RBW << FIR_OP3_SHIFT));

		if (oob)
			out_be32(&lbc->fcr, NAND_CMD_READOOB << FCR_CMD0_SHIFT);
		else
			out_be32(&lbc->fcr, NAND_CMD_READ0 << FCR_CMD0_SHIFT);
	}
}

/* cmdfunc send commands to the FCM */
static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
                             int column, int page_addr)
{
	struct nand_chip *chip = mtd->priv;
	struct fsl_elbc_mtd *priv = chip->priv;
	struct fsl_elbc_ctrl *ctrl = priv->ctrl;
	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;

	ctrl->use_mdr = 0;

	/* clear the read buffer */
	ctrl->read_bytes = 0;
	if (command != NAND_CMD_PAGEPROG)
		ctrl->index = 0;

	switch (command) {
	/* READ0 and READ1 read the entire buffer to use hardware ECC. */
	case NAND_CMD_READ1:
		column += 256;

	/* fall-through */
	case NAND_CMD_READ0:
		dev_dbg(ctrl->dev,
		        "fsl_elbc_cmdfunc: NAND_CMD_READ0, page_addr:"
		        " 0x%x, column: 0x%x.\n", page_addr, column);


		out_be32(&lbc->fbcr, 0); /* read entire page to enable ECC */
		set_addr(mtd, 0, page_addr, 0);

		ctrl->read_bytes = mtd->writesize + mtd->oobsize;
		ctrl->index += column;

		fsl_elbc_do_read(chip, 0);
		fsl_elbc_run_command(mtd);
		return;

	/* READOOB reads only the OOB because no ECC is performed. */
	case NAND_CMD_READOOB:
		dev_vdbg(ctrl->dev,
		         "fsl_elbc_cmdfunc: NAND_CMD_READOOB, page_addr:"
			 " 0x%x, column: 0x%x.\n", page_addr, column);

		out_be32(&lbc->fbcr, mtd->oobsize - column);
		set_addr(mtd, column, page_addr, 1);

		ctrl->read_bytes = mtd->writesize + mtd->oobsize;

		fsl_elbc_do_read(chip, 1);
		fsl_elbc_run_command(mtd);
		return;

	/* READID must read all 5 possible bytes while CEB is active */
	case NAND_CMD_READID:
		dev_vdbg(ctrl->dev, "fsl_elbc_cmdfunc: NAND_CMD_READID.\n");

		out_be32(&lbc->fir, (FIR_OP_CW0 << FIR_OP0_SHIFT) |
		                    (FIR_OP_UA  << FIR_OP1_SHIFT) |
		                    (FIR_OP_RBW << FIR_OP2_SHIFT));
		out_be32(&lbc->fcr, NAND_CMD_READID << FCR_CMD0_SHIFT);
		/* 5 bytes for manuf, device and exts */
		out_be32(&lbc->fbcr, 5);
		ctrl->read_bytes = 5;
		ctrl->use_mdr = 1;
		ctrl->mdr = 0;

		set_addr(mtd, 0, 0, 0);
		fsl_elbc_run_command(mtd);
		return;

	/* ERASE1 stores the block and page address */
	case NAND_CMD_ERASE1:
		dev_vdbg(ctrl->dev,
		         "fsl_elbc_cmdfunc: NAND_CMD_ERASE1, "
		         "page_addr: 0x%x.\n", page_addr);
		set_addr(mtd, 0, page_addr, 0);
		return;

	/* ERASE2 uses the block and page address from ERASE1 */
	case NAND_CMD_ERASE2:
		dev_vdbg(ctrl->dev, "fsl_elbc_cmdfunc: NAND_CMD_ERASE2.\n");

		out_be32(&lbc->fir,
		         (FIR_OP_CW0 << FIR_OP0_SHIFT) |
		         (FIR_OP_PA  << FIR_OP1_SHIFT) |
		         (FIR_OP_CM1 << FIR_OP2_SHIFT));

		out_be32(&lbc->fcr,
		         (NAND_CMD_ERASE1 << FCR_CMD0_SHIFT) |
		         (NAND_CMD_ERASE2 << FCR_CMD1_SHIFT));