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, 2 insertions, 3 deletions

diff --git a/drivers/staging/mt29f_spinand/mt29f_spinand.c b/drivers/staging/mt29f_spinand/mt29f_spinand.c
index 87595c594b12..264ad362d858 100644
--- a/drivers/staging/mt29f_spinand/mt29f_spinand.c
+++ b/drivers/staging/mt29f_spinand/mt29f_spinand.c
@@ -637,8 +637,7 @@ static int spinand_write_page_hwecc(struct mtd_info *mtd,
 	int eccsteps = chip->ecc.steps;
 
 	enable_hw_ecc = 1;
-	chip->write_buf(mtd, p, eccsize * eccsteps);
-	return 0;
+	return nand_prog_page_op(chip, page, 0, p, eccsize * eccsteps);
 }
 
 static int spinand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
@@ -653,7 +652,7 @@ static int spinand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
 
 	enable_read_hw_ecc = 1;
 
-	chip->read_buf(mtd, p, eccsize * eccsteps);
+	nand_read_page_op(chip, page, 0, p, eccsize * eccsteps);
 	if (oob_required)
 		chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);