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, 2 deletions

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 6e1b209cd5a7..5cb4db6f88e3 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1532,6 +1532,8 @@ static int omap_write_page_bch(struct mtd_info *mtd, struct nand_chip *chip,
 	int ret;
 	uint8_t *ecc_calc = chip->buffers->ecccalc;
 
+	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+
 	/* Enable GPMC ecc engine */
 	chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
 
@@ -1548,7 +1550,8 @@ static int omap_write_page_bch(struct mtd_info *mtd, struct nand_chip *chip,
 
 	/* Write ecc vector to OOB area */
 	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
-	return 0;
+
+	return nand_prog_page_end_op(chip);
 }
 
 /**
@@ -1582,6 +1585,7 @@ static int omap_write_subpage_bch(struct mtd_info *mtd,
 	 * ECC is calculated for all subpages but we choose
 	 * only what we want.
 	 */
+	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
 
 	/* Enable GPMC ECC engine */
 	chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
@@ -1614,7 +1618,7 @@ static int omap_write_subpage_bch(struct mtd_info *mtd,
 	/* write OOB buffer to NAND device */
 	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
 
-	return 0;
+	return nand_prog_page_end_op(chip);
 }
 
 /**
@@ -1640,6 +1644,8 @@ static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip,
 	int stat, ret;
 	unsigned int max_bitflips = 0;
 
+	nand_read_page_op(chip, page, 0, NULL, 0);
+
 	/* Enable GPMC ecc engine */
 	chip->ecc.hwctl(mtd, NAND_ECC_READ);