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@freescale.com>
Reported-by: Suchit Lepcha <suchit.lepcha@freescale.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/nand/fsl_elbc_nand.c b/drivers/mtd/nand/fsl_elbc_nand.c
index 58db278..5b51ed3c 100644
--- a/drivers/mtd/nand/fsl_elbc_nand.c
+++ b/drivers/mtd/nand/fsl_elbc_nand.c
@@ -253,17 +253,17 @@
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 @@
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 @@
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 @@
ctrl->column = column;
ctrl->oob = 0;
+ ctrl->use_mdr = 1;
+
+ fcr = (NAND_CMD_STATUS << FCR_CMD1_SHIFT) |
+ (NAND_CMD_SEQIN << FCR_CMD2_SHIFT) |
+ (NAND_CMD_PAGEPROG << FCR_CMD3_SHIFT);
if (priv->page_size) {
- fcr = (NAND_CMD_SEQIN << FCR_CMD0_SHIFT) |
- (NAND_CMD_PAGEPROG << FCR_CMD1_SHIFT);
-
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 @@
{
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 @@
/* 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)