[PATCH 2/2 v4] mtd/nand : workaround for Freescale FCM to support large-page Nand chip

From: shuo.liu
Date: Fri Dec 09 2011 - 05:28:05 EST

From: Liu Shuo <shuo.liu@xxxxxxxxxxxxx>

Freescale FCM controller has a 2K size limitation of buffer RAM. In order
to support the Nand flash chip whose page size is larger than 2K bytes,
we read/write 2k data repeatedly by issuing FIR_OP_RB/FIR_OP_WB and save
them to a large buffer.

Signed-off-by: Liu Shuo <shuo.liu@xxxxxxxxxxxxx>
Signed-off-by: Shengzhou Liu <Shengzhou.Liu@xxxxxxxxxxxxx>
Signed-off-by: Li Yang <leoli@xxxxxxxxxxxxx>
---
v4 : allocate (8+1)k buffer for large page chip.

drivers/mtd/nand/fsl_elbc_nand.c | 246 ++++++++++++++++++++++++++++++++++----
1 files changed, 221 insertions(+), 25 deletions(-)

diff --git a/drivers/mtd/nand/fsl_elbc_nand.c b/drivers/mtd/nand/fsl_elbc_nand.c
index d29479a..9f58e78 100644
--- a/drivers/mtd/nand/fsl_elbc_nand.c
+++ b/drivers/mtd/nand/fsl_elbc_nand.c
@@ -55,7 +55,6 @@ struct fsl_elbc_mtd {
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 */
};

@@ -75,6 +74,8 @@ struct fsl_elbc_fcm_ctrl {
unsigned int use_mdr; /* Non zero if the MDR is to be set */
unsigned int oob; /* Non zero if operating on OOB data */
unsigned int counter; /* counter for the initializations */
+
+ char *buffer; /* just be used when pagesize > 2048 */
};

/* These map to the positions used by the FCM hardware ECC generator */
@@ -150,6 +151,42 @@ static struct nand_bbt_descr bbt_mirror_descr = {
};

/*=================================*/
+static void io_to_buffer(struct mtd_info *mtd, int subpage, int oob)
+{
+ struct nand_chip *chip = mtd->priv;
+ struct fsl_elbc_mtd *priv = chip->priv;
+ struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
+ void *src, *dst;
+ int len = (oob ? 64 : 2048);
+
+ if (oob)
+ dst = elbc_fcm_ctrl->buffer + mtd->writesize + subpage * 64;
+ else
+ dst = elbc_fcm_ctrl->buffer + subpage * 2048;
+
+ src = elbc_fcm_ctrl->addr + (oob ? 2048 : 0);
+ memcpy_fromio(dst, src, len);
+}
+
+static void buffer_to_io(struct mtd_info *mtd, int subpage, int oob)
+{
+ struct nand_chip *chip = mtd->priv;
+ struct fsl_elbc_mtd *priv = chip->priv;
+ struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;
+ void *src, *dst;
+ int len = (oob ? 64 : 2048);
+
+ if (oob)
+ src = elbc_fcm_ctrl->buffer + mtd->writesize + subpage * 64;
+ else
+ src = elbc_fcm_ctrl->buffer + subpage * 2048;
+
+ dst = elbc_fcm_ctrl->addr + (oob ? 2048 : 0);
+ memcpy_toio(dst, src, len);
+
+ /* See the in_8() in fsl_elbc_write_buf() */
+ in_8(elbc_fcm_ctrl->addr + (oob ? 2111 : 2047));
+}

/*
* Set up the FCM hardware block and page address fields, and the fcm
@@ -166,7 +203,7 @@ static void set_addr(struct mtd_info *mtd, int column, int page_addr, int oob)

elbc_fcm_ctrl->page = page_addr;

- if (priv->page_size) {
+ if (mtd->writesize >= 2048) {
/*
* large page size chip : FPAR[PI] save the lowest 6 bits,
* FBAR[BLK] save the other bits.
@@ -193,7 +230,7 @@ static void set_addr(struct mtd_info *mtd, int column, int page_addr, int oob)

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

dev_vdbg(priv->dev, "set_addr: bank=%d, "
"elbc_fcm_ctrl->addr=0x%p (0x%p), "
@@ -272,13 +309,14 @@ static int fsl_elbc_run_command(struct mtd_info *mtd)
return 0;
}

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

- if (priv->page_size) {
+ if (mtd->writesize >= 2048) {
out_be32(&lbc->fir,
(FIR_OP_CM0 << FIR_OP0_SHIFT) |
(FIR_OP_CA << FIR_OP1_SHIFT) |
@@ -311,6 +349,7 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
struct fsl_lbc_ctrl *ctrl = priv->ctrl;
struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = ctrl->nand;
struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
+ int i, n;

elbc_fcm_ctrl->use_mdr = 0;

@@ -337,8 +376,30 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
elbc_fcm_ctrl->read_bytes = mtd->writesize + mtd->oobsize;
elbc_fcm_ctrl->index += column;

- fsl_elbc_do_read(chip, 0);
+ fsl_elbc_do_read(mtd, 0);
fsl_elbc_run_command(mtd);
+
+ if (mtd->writesize <= 2048)
+ return;
+
+ /* Continue to read the rest bytes if writesize > 2048 */
+ io_to_buffer(mtd, 0, 0);
+ io_to_buffer(mtd, 0, 1);
+
+ /*
+ * Maybe there are some reasons of FCM hardware timing,
+ * we must insert a FIR_OP_NOP(0x00) before FIR_OP_RB.
+ */
+ out_be32(&lbc->fir, (FIR_OP_NOP << FIR_OP0_SHIFT) |
+ (FIR_OP_RB << FIR_OP1_SHIFT));
+
+ n = mtd->writesize / 2048;
+ for (i = 1; i < n; i++) {
+ fsl_elbc_run_command(mtd);
+ io_to_buffer(mtd, i, 0);
+ io_to_buffer(mtd, i, 1);
+ }
+
return;

/* READOOB reads only the OOB because no ECC is performed. */
@@ -347,13 +408,38 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
"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);
+ if (mtd->writesize <= 2048) {
+ out_be32(&lbc->fbcr, mtd->oobsize - column);
+ set_addr(mtd, column, page_addr, 1);
+ } else {
+ out_be32(&lbc->fbcr, 64);
+ set_addr(mtd, 0, page_addr, 1);
+ elbc_fcm_ctrl->index += column;
+ }

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

- fsl_elbc_do_read(chip, 1);
+ fsl_elbc_do_read(mtd, 1);
fsl_elbc_run_command(mtd);
+
+ if (mtd->writesize <= 2048)
+ return;
+
+ if (column < 64)
+ io_to_buffer(mtd, 0, 1);
+
+ out_be32(&lbc->fbcr, 2112);
+ out_be32(&lbc->fpar, in_be32(&lbc->fpar) & ~FPAR_LP_MS);
+ out_be32(&lbc->fir, (FIR_OP_NOP << FIR_OP0_SHIFT) |
+ (FIR_OP_RB << FIR_OP1_SHIFT));
+
+ n = mtd->writesize / 2048;
+ for (i = 1; i < n; i++) {
+ fsl_elbc_run_command(mtd);
+ if (column < (64 * (i + 1)))
+ io_to_buffer(mtd, i, 1);
+ }
+
return;

/* READID must read all 5 possible bytes while CEB is active */
@@ -429,7 +515,17 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
(NAND_CMD_SEQIN << FCR_CMD2_SHIFT) |
(NAND_CMD_PAGEPROG << FCR_CMD3_SHIFT);

- if (priv->page_size) {
+ if (mtd->writesize > 2048) {
+ /* writesize > 2048 */
+ out_be32(&lbc->fir,
+ (FIR_OP_CM2 << FIR_OP0_SHIFT) |
+ (FIR_OP_CA << FIR_OP1_SHIFT) |
+ (FIR_OP_PA << FIR_OP2_SHIFT) |
+ (FIR_OP_WB << FIR_OP3_SHIFT));
+
+ if (elbc_fcm_ctrl->oob)
+ fcr |= NAND_CMD_RNDIN << FCR_CMD0_SHIFT;
+ } else if (mtd->writesize == 2048) {
out_be32(&lbc->fir,
(FIR_OP_CM2 << FIR_OP0_SHIFT) |
(FIR_OP_CA << FIR_OP1_SHIFT) |
@@ -464,6 +560,7 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,

/* PAGEPROG reuses all of the setup from SEQIN and adds the length */
case NAND_CMD_PAGEPROG: {
+ int pos;
dev_vdbg(priv->dev,
"fsl_elbc_cmdfunc: NAND_CMD_PAGEPROG "
"writing %d bytes.\n", elbc_fcm_ctrl->index);
@@ -473,13 +570,74 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
* write so the HW generates the ECC.
*/
if (elbc_fcm_ctrl->oob || elbc_fcm_ctrl->column != 0 ||
- elbc_fcm_ctrl->index != mtd->writesize + mtd->oobsize)
- out_be32(&lbc->fbcr,
- elbc_fcm_ctrl->index - elbc_fcm_ctrl->column);
- else
+ elbc_fcm_ctrl->index != mtd->writesize + mtd->oobsize) {
+ if (elbc_fcm_ctrl->oob && mtd->writesize > 2048) {
+ out_be32(&lbc->fbcr, 64);
+ } else {
+ out_be32(&lbc->fbcr, elbc_fcm_ctrl->index
+ - elbc_fcm_ctrl->column);
+ }
+ } else {
out_be32(&lbc->fbcr, 0);
+ }
+
+ if (mtd->writesize > 2048) {
+ if (!elbc_fcm_ctrl->oob)
+ buffer_to_io(mtd, 0, 0);
+ buffer_to_io(mtd, 0, 1);
+ }

fsl_elbc_run_command(mtd);
+
+ if (mtd->writesize <= 2048)
+ return;
+
+ n = mtd->writesize / 2048;
+
+ if (elbc_fcm_ctrl->oob) {
+ pos = 2048;
+ out_be32(&lbc->fir,
+ (FIR_OP_CM0 << FIR_OP0_SHIFT) |
+ (FIR_OP_UA << FIR_OP1_SHIFT) |
+ (FIR_OP_UA << FIR_OP2_SHIFT) |
+ (FIR_OP_WB << FIR_OP3_SHIFT));
+
+ for (i = 1; i < n; i++) {
+ pos += 2112;
+ elbc_fcm_ctrl->mdr = pos;
+ elbc_fcm_ctrl->use_mdr = 1;
+ if (i == n - 1) {
+ out_be32(&lbc->fir,
+ (FIR_OP_NOP << FIR_OP0_SHIFT) |
+ (FIR_OP_CM0 << FIR_OP1_SHIFT) |
+ (FIR_OP_UA << FIR_OP2_SHIFT) |
+ (FIR_OP_UA << FIR_OP3_SHIFT) |
+ (FIR_OP_WB << FIR_OP4_SHIFT) |
+ (FIR_OP_CM3 << FIR_OP5_SHIFT) |
+ (FIR_OP_CW1 << FIR_OP6_SHIFT) |
+ (FIR_OP_RS << FIR_OP7_SHIFT));
+ }
+ buffer_to_io(mtd, i, 1);
+ fsl_elbc_run_command(mtd);
+ }
+ } else {
+ out_be32(&lbc->fir, FIR_OP_WB << FIR_OP1_SHIFT);
+ for (i = 1; i < n; i++) {
+ if (i == n - 1) {
+ elbc_fcm_ctrl->use_mdr = 1;
+ out_be32(&lbc->fir,
+ (FIR_OP_NOP << FIR_OP0_SHIFT) |
+ (FIR_OP_WB << FIR_OP1_SHIFT) |
+ (FIR_OP_CM3 << FIR_OP2_SHIFT) |
+ (FIR_OP_CW1 << FIR_OP3_SHIFT) |
+ (FIR_OP_RS << FIR_OP4_SHIFT));
+ }
+ buffer_to_io(mtd, i, 0);
+ buffer_to_io(mtd, i, 1);
+ fsl_elbc_run_command(mtd);
+ }
+ }
+
return;
}

@@ -500,6 +658,7 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
* write-protected, even when it is not.
*/
setbits8(elbc_fcm_ctrl->addr, NAND_STATUS_WP);
+ elbc_fcm_ctrl->buffer[0] = in_8(elbc_fcm_ctrl->addr);
return;

/* RESET without waiting for the ready line */
@@ -548,7 +707,14 @@ static void fsl_elbc_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
len = bufsize - elbc_fcm_ctrl->index;
}

- memcpy_toio(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index], buf, len);
+ if (mtd->writesize > 2048) {
+ memcpy(&elbc_fcm_ctrl->buffer[elbc_fcm_ctrl->index],
+ buf, len);
+ } else {
+ memcpy_toio(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index],
+ buf, len);
+ }
+
/*
* This is workaround for the weird elbc hangs during nand write,
* Scott Wood says: "...perhaps difference in how long it takes a
@@ -572,8 +738,13 @@ static u8 fsl_elbc_read_byte(struct mtd_info *mtd)
struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl = priv->ctrl->nand;

/* If there are still bytes in the FCM, then use the next byte. */
- if (elbc_fcm_ctrl->index < elbc_fcm_ctrl->read_bytes)
- return in_8(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index++]);
+ if (elbc_fcm_ctrl->index < elbc_fcm_ctrl->read_bytes) {
+ int index = elbc_fcm_ctrl->index++;
+ if (mtd->writesize > 2048)
+ return elbc_fcm_ctrl->buffer[index];
+ else
+ return in_8(&elbc_fcm_ctrl->addr[index]);
+ }

dev_err(priv->dev, "read_byte beyond end of buffer\n");
return ERR_BYTE;
@@ -594,7 +765,13 @@ static void fsl_elbc_read_buf(struct mtd_info *mtd, u8 *buf, int len)

avail = min((unsigned int)len,
elbc_fcm_ctrl->read_bytes - elbc_fcm_ctrl->index);
- memcpy_fromio(buf, &elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index], avail);
+ if (mtd->writesize > 2048) {
+ memcpy(buf, &elbc_fcm_ctrl->buffer[elbc_fcm_ctrl->index],
+ avail);
+ } else {
+ memcpy_fromio(buf, &elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index],
+ avail);
+ }
elbc_fcm_ctrl->index += avail;

if (len > avail)
@@ -630,10 +807,17 @@ static int fsl_elbc_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
return -EINVAL;
}

- for (i = 0; i < len; i++)
- if (in_8(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index + i])
- != buf[i])
- break;
+ if (mtd->writesize > 2048) {
+ for (i = 0; i < len; i++)
+ if (elbc_fcm_ctrl->buffer[elbc_fcm_ctrl->index + i]
+ != buf[i])
+ break;
+ } else {
+ for (i = 0; i < len; i++)
+ if (in_8(&elbc_fcm_ctrl->addr[elbc_fcm_ctrl->index + i])
+ != buf[i])
+ break;
+ }

elbc_fcm_ctrl->index += len;
return i == len && elbc_fcm_ctrl->status == LTESR_CC ? 0 : -EIO;
@@ -714,10 +898,8 @@ static int fsl_elbc_chip_init_tail(struct mtd_info *mtd)

/* adjust Option Register and ECC to match Flash page size */
if (mtd->writesize == 512) {
- priv->page_size = 0;
clrbits32(&lbc->bank[priv->bank].or, OR_FCM_PGS);
- } else if (mtd->writesize == 2048) {
- priv->page_size = 1;
+ } else if (mtd->writesize >= 2048 && mtd->writesize <= 8192) {
setbits32(&lbc->bank[priv->bank].or, OR_FCM_PGS);
/* adjust ecc setup if needed */
if ((in_be32(&lbc->bank[priv->bank].br) & BR_DECC) ==
@@ -891,6 +1073,19 @@ static int __devinit fsl_elbc_nand_probe(struct platform_device *pdev)
goto err;
}
elbc_fcm_ctrl->counter++;
+ /*
+ * Freescale FCM controller has a 2K size limitation of buffer
+ * RAM, so elbc_fcm_ctrl->buffer have to be used if writesize
+ * of chip is greater than 2048.
+ * We malloc a large enough buffer (maximum page size is 8K).
+ */
+ elbc_fcm_ctrl->buffer = kmalloc(1024 * 8 + 1024, GFP_KERNEL);
+ if (!elbc_fcm_ctrl->buffer) {
+ dev_err(dev, "failed to allocate memory\n");
+ mutex_unlock(&fsl_elbc_nand_mutex);
+ ret = -ENOMEM;
+ goto err;
+ }

spin_lock_init(&elbc_fcm_ctrl->controller.lock);
init_waitqueue_head(&elbc_fcm_ctrl->controller.wq);
@@ -960,6 +1155,7 @@ static int fsl_elbc_nand_remove(struct platform_device *pdev)
elbc_fcm_ctrl->counter--;
if (!elbc_fcm_ctrl->counter) {
fsl_lbc_ctrl_dev->nand = NULL;
+ kfree(elbc_fcm_ctrl->buffer);
kfree(elbc_fcm_ctrl);
}
mutex_unlock(&fsl_elbc_nand_mutex);
--
1.7.1


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