mtd: nand: force drivers to explicitly send READ/PROG commands

The core currently send the READ0 and SEQIN+PAGEPROG commands in
nand_do_read/write_ops(). This is inconsistent with
->read/write_oob[_raw]() hooks behavior which are expected to send
these commands.

There's already a flag (NAND_ECC_CUSTOM_PAGE_ACCESS) to inform the core
that a specific controller wants to send the READ/SEQIN+PAGEPROG
commands on its own, but it's an opt-in flag, and existing drivers are
unlikely to be updated to pass it.

Moreover, some controllers cannot dissociate the READ/PAGEPROG commands
from the associated data transfer and ECC engine activation, and
developers have to hack things in their ->cmdfunc() implementation to
handle such complex cases, or have to accept the perf penalty of sending
twice the same command.
To address this problem we are planning on adding a new interface which
is passed all information about a NAND operation (including the amount
of data to transfer) and replacing all calls to ->cmdfunc() to calls to
this new ->exec_op() hook. But, in order to do that, we need to have all
->cmdfunc() calls placed near their associated ->read/write_buf/byte()
calls.

Modify the core and relevant drivers to make NAND_ECC_CUSTOM_PAGE_ACCESS
the default case, and remove this flag.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[miquel.raynal@free-electrons.com: tested, fixed and rebased on nand/next]
Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/drivers/mtd/nand/lpc32xx_slc.c b/drivers/mtd/nand/lpc32xx_slc.c
index 2b96c281b1a2..5f7cc6da0a7f 100644
--- a/drivers/mtd/nand/lpc32xx_slc.c
+++ b/drivers/mtd/nand/lpc32xx_slc.c
@@ -686,6 +686,8 @@ static int lpc32xx_nand_write_page_syndrome(struct mtd_info *mtd,
 	uint8_t *pb;
 	int error;
 
+	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+
 	/* Write data, calculate ECC on outbound data */
 	error = lpc32xx_xfer(mtd, (uint8_t *)buf, chip->ecc.steps, 0);
 	if (error)
@@ -704,7 +706,8 @@ static int lpc32xx_nand_write_page_syndrome(struct mtd_info *mtd,
 
 	/* Write ECC data to device */
 	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
-	return 0;
+
+	return nand_prog_page_end_op(chip);
 }
 
 /*
@@ -717,9 +720,11 @@ static int lpc32xx_nand_write_page_raw_syndrome(struct mtd_info *mtd,
 						int oob_required, int page)
 {
 	/* Raw writes can just use the FIFO interface */
-	chip->write_buf(mtd, buf, chip->ecc.size * chip->ecc.steps);
+	nand_prog_page_begin_op(chip, page, 0, buf,
+				chip->ecc.size * chip->ecc.steps);
 	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
-	return 0;
+
+	return nand_prog_page_end_op(chip);
 }
 
 static int lpc32xx_nand_dma_setup(struct lpc32xx_nand_host *host)