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, 10 insertions, 3 deletions

diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
index 3f441096a14c..e6879d4d53ca 100644
--- a/drivers/mtd/nand/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/brcmnand/brcmnand.c
@@ -1689,7 +1689,6 @@ static int brcmstb_nand_verify_erased_page(struct mtd_info *mtd,
 	sas = mtd->oobsize / chip->ecc.steps;
 
 	/* read without ecc for verification */
-	nand_read_page_op(chip, page, 0, NULL, 0);
 	ret = chip->ecc.read_page_raw(mtd, chip, buf, true, page);
 	if (ret)
 		return ret;
@@ -1793,6 +1792,8 @@ static int brcmnand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 	struct brcmnand_host *host = nand_get_controller_data(chip);
 	u8 *oob = oob_required ? (u8 *)chip->oob_poi : NULL;
 
+	nand_read_page_op(chip, page, 0, NULL, 0);
+
 	return brcmnand_read(mtd, chip, host->last_addr,
 			mtd->writesize >> FC_SHIFT, (u32 *)buf, oob);
 }
@@ -1804,6 +1805,8 @@ static int brcmnand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 	u8 *oob = oob_required ? (u8 *)chip->oob_poi : NULL;
 	int ret;
 
+	nand_read_page_op(chip, page, 0, NULL, 0);
+
 	brcmnand_set_ecc_enabled(host, 0);
 	ret = brcmnand_read(mtd, chip, host->last_addr,
 			mtd->writesize >> FC_SHIFT, (u32 *)buf, oob);
@@ -1909,8 +1912,10 @@ static int brcmnand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	struct brcmnand_host *host = nand_get_controller_data(chip);
 	void *oob = oob_required ? chip->oob_poi : NULL;
 
+	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
 	brcmnand_write(mtd, chip, host->last_addr, (const u32 *)buf, oob);
-	return 0;
+
+	return nand_prog_page_end_op(chip);
 }
 
 static int brcmnand_write_page_raw(struct mtd_info *mtd,
@@ -1920,10 +1925,12 @@ static int brcmnand_write_page_raw(struct mtd_info *mtd,
 	struct brcmnand_host *host = nand_get_controller_data(chip);
 	void *oob = oob_required ? chip->oob_poi : NULL;
 
+	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
 	brcmnand_set_ecc_enabled(host, 0);
 	brcmnand_write(mtd, chip, host->last_addr, (const u32 *)buf, oob);
 	brcmnand_set_ecc_enabled(host, 1);
-	return 0;
+
+	return nand_prog_page_end_op(chip);
 }
 
 static int brcmnand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,