mtd: eLBC NAND: use recommended command sequences
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linux-mtd at lists.infradead.org
Mon Nov 30 05:59:05 EST 2009
Gitweb: http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=476459a6cf46d20ec73d9b211f3894ced5f9871e
Commit: 476459a6cf46d20ec73d9b211f3894ced5f9871e
Parent: b3a70f0bc32d1b70584bcaa6019fa4260b0da92e
Author: Scott Wood <scottwood at freescale.com>
AuthorDate: Fri Nov 13 14:13:01 2009 -0600
Committer: David Woodhouse <David.Woodhouse at intel.com>
CommitDate: Mon Nov 30 09:53:49 2009 +0000
mtd: eLBC NAND: use recommended command sequences
Currently, the program and erase sequences do not wait for completion,
instead relying on a subsequent waitfunc() callback. However, this causes
the chipselect to be deasserted while the NAND chip is still asserting the
busy pin, which can corrupt activity on other chipselects.
This patch switches to using the sequences recommended by the manual,
in which a wait is performed within the initial command sequence. We can
now re-use the status byte from the initial command sequence, rather than
having to do another status read in the waitfunc.
Since we're already touching the command sequences, it also cleans up some
cruft in SEQIN that isn't needed since we cannot program partial pages
outside of OOB.
Signed-off-by: Scott Wood <scottwood at freescale.com>
Reported-by: Suchit Lepcha <suchit.lepcha at freescale.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy at nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
---
drivers/mtd/nand/fsl_elbc_nand.c | 66 +++++++++++++++----------------------
1 files changed, 27 insertions(+), 39 deletions(-)
diff --git a/drivers/mtd/nand/fsl_elbc_nand.c b/drivers/mtd/nand/fsl_elbc_nand.c
index 58db278..5b51ed3 100644
--- a/drivers/mtd/nand/fsl_elbc_nand.c
+++ b/drivers/mtd/nand/fsl_elbc_nand.c
@@ -253,17 +253,17 @@ static void fsl_elbc_do_read(struct nand_chip *chip, int oob)
if (priv->page_size) {
out_be32(&lbc->fir,
- (FIR_OP_CW0 << FIR_OP0_SHIFT) |
+ (FIR_OP_CM0 << FIR_OP0_SHIFT) |
(FIR_OP_CA << FIR_OP1_SHIFT) |
(FIR_OP_PA << FIR_OP2_SHIFT) |
- (FIR_OP_CW1 << FIR_OP3_SHIFT) |
+ (FIR_OP_CM1 << 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_CM0 << FIR_OP0_SHIFT) |
(FIR_OP_CA << FIR_OP1_SHIFT) |
(FIR_OP_PA << FIR_OP2_SHIFT) |
(FIR_OP_RBW << FIR_OP3_SHIFT));
@@ -332,7 +332,7 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
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) |
+ out_be32(&lbc->fir, (FIR_OP_CM0 << 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);
@@ -359,16 +359,20 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
dev_vdbg(ctrl->dev, "fsl_elbc_cmdfunc: NAND_CMD_ERASE2.\n");
out_be32(&lbc->fir,
- (FIR_OP_CW0 << FIR_OP0_SHIFT) |
+ (FIR_OP_CM0 << FIR_OP0_SHIFT) |
(FIR_OP_PA << FIR_OP1_SHIFT) |
- (FIR_OP_CM1 << FIR_OP2_SHIFT));
+ (FIR_OP_CM2 << FIR_OP2_SHIFT) |
+ (FIR_OP_CW1 << FIR_OP3_SHIFT) |
+ (FIR_OP_RS << FIR_OP4_SHIFT));
out_be32(&lbc->fcr,
(NAND_CMD_ERASE1 << FCR_CMD0_SHIFT) |
- (NAND_CMD_ERASE2 << FCR_CMD1_SHIFT));
+ (NAND_CMD_STATUS << FCR_CMD1_SHIFT) |
+ (NAND_CMD_ERASE2 << FCR_CMD2_SHIFT));
out_be32(&lbc->fbcr, 0);
ctrl->read_bytes = 0;
+ ctrl->use_mdr = 1;
fsl_elbc_run_command(mtd);
return;
@@ -383,40 +387,41 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
ctrl->column = column;
ctrl->oob = 0;
+ ctrl->use_mdr = 1;
- if (priv->page_size) {
- fcr = (NAND_CMD_SEQIN << FCR_CMD0_SHIFT) |
- (NAND_CMD_PAGEPROG << FCR_CMD1_SHIFT);
+ fcr = (NAND_CMD_STATUS << FCR_CMD1_SHIFT) |
+ (NAND_CMD_SEQIN << FCR_CMD2_SHIFT) |
+ (NAND_CMD_PAGEPROG << FCR_CMD3_SHIFT);
+ if (priv->page_size) {
out_be32(&lbc->fir,
- (FIR_OP_CW0 << FIR_OP0_SHIFT) |
+ (FIR_OP_CM2 << FIR_OP0_SHIFT) |
(FIR_OP_CA << FIR_OP1_SHIFT) |
(FIR_OP_PA << FIR_OP2_SHIFT) |
(FIR_OP_WB << FIR_OP3_SHIFT) |
- (FIR_OP_CW1 << FIR_OP4_SHIFT));
+ (FIR_OP_CM3 << FIR_OP4_SHIFT) |
+ (FIR_OP_CW1 << FIR_OP5_SHIFT) |
+ (FIR_OP_RS << FIR_OP6_SHIFT));
} else {
- fcr = (NAND_CMD_PAGEPROG << FCR_CMD1_SHIFT) |
- (NAND_CMD_SEQIN << FCR_CMD2_SHIFT);
-
out_be32(&lbc->fir,
- (FIR_OP_CW0 << FIR_OP0_SHIFT) |
+ (FIR_OP_CM0 << FIR_OP0_SHIFT) |
(FIR_OP_CM2 << FIR_OP1_SHIFT) |
(FIR_OP_CA << FIR_OP2_SHIFT) |
(FIR_OP_PA << FIR_OP3_SHIFT) |
(FIR_OP_WB << FIR_OP4_SHIFT) |
- (FIR_OP_CW1 << FIR_OP5_SHIFT));
+ (FIR_OP_CM3 << FIR_OP5_SHIFT) |
+ (FIR_OP_CW1 << FIR_OP6_SHIFT) |
+ (FIR_OP_RS << FIR_OP7_SHIFT));
if (column >= mtd->writesize) {
/* OOB area --> READOOB */
column -= mtd->writesize;
fcr |= NAND_CMD_READOOB << FCR_CMD0_SHIFT;
ctrl->oob = 1;
- } else if (column < 256) {
+ } else {
+ WARN_ON(column != 0);
/* First 256 bytes --> READ0 */
fcr |= NAND_CMD_READ0 << FCR_CMD0_SHIFT;
- } else {
- /* Second 256 bytes --> READ1 */
- fcr |= NAND_CMD_READ1 << FCR_CMD0_SHIFT;
}
}
@@ -628,22 +633,6 @@ static int fsl_elbc_wait(struct mtd_info *mtd, struct nand_chip *chip)
{
struct fsl_elbc_mtd *priv = chip->priv;
struct fsl_elbc_ctrl *ctrl = priv->ctrl;
- struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
-
- if (ctrl->status != LTESR_CC)
- return NAND_STATUS_FAIL;
-
- /* Use READ_STATUS command, but wait for the device to be ready */
- ctrl->use_mdr = 0;
- out_be32(&lbc->fir,
- (FIR_OP_CW0 << FIR_OP0_SHIFT) |
- (FIR_OP_RBW << FIR_OP1_SHIFT));
- out_be32(&lbc->fcr, NAND_CMD_STATUS << FCR_CMD0_SHIFT);
- out_be32(&lbc->fbcr, 1);
- set_addr(mtd, 0, 0, 0);
- ctrl->read_bytes = 1;
-
- fsl_elbc_run_command(mtd);
if (ctrl->status != LTESR_CC)
return NAND_STATUS_FAIL;
@@ -651,8 +640,7 @@ static int fsl_elbc_wait(struct mtd_info *mtd, struct nand_chip *chip)
/* The chip always seems to report that it is
* write-protected, even when it is not.
*/
- setbits8(ctrl->addr, NAND_STATUS_WP);
- return fsl_elbc_read_byte(mtd);
+ return (ctrl->mdr & 0xff) | NAND_STATUS_WP;
}
static int fsl_elbc_chip_init_tail(struct mtd_info *mtd)
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