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, 6 insertions, 50 deletions

diff --git a/drivers/mtd/nand/nand_micron.c b/drivers/mtd/nand/nand_micron.c
index bf2dc23e1c32..02e109ae73f1 100644
--- a/drivers/mtd/nand/nand_micron.c
+++ b/drivers/mtd/nand/nand_micron.c
@@ -149,7 +149,10 @@ micron_nand_read_page_on_die_ecc(struct mtd_info *mtd, struct nand_chip *chip,
 	else if (status & NAND_STATUS_WRITE_RECOMMENDED)
 		max_bitflips = chip->ecc.strength;
 
-	ret = nand_read_page_raw(mtd, chip, buf, oob_required, page);
+	ret = nand_read_data_op(chip, buf, mtd->writesize, false);
+	if (!ret && oob_required)
+		ret = nand_read_data_op(chip, chip->oob_poi, mtd->oobsize,
+					false);
 
 out:
 	micron_nand_on_die_ecc_setup(chip, false);
@@ -168,56 +171,12 @@ micron_nand_write_page_on_die_ecc(struct mtd_info *mtd, struct nand_chip *chip,
 	if (ret)
 		return ret;
 
-	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
-	if (ret)
-		goto out;
-
 	ret = nand_write_page_raw(mtd, chip, buf, oob_required, page);
-	if (ret)
-		return ret;
-
-	ret = nand_prog_page_end_op(chip);
-
-out:
 	micron_nand_on_die_ecc_setup(chip, false);
 
 	return ret;
 }
 
-static int
-micron_nand_read_page_raw_on_die_ecc(struct mtd_info *mtd,
-				     struct nand_chip *chip,
-				     uint8_t *buf, int oob_required,
-				     int page)
-{
-	int ret;
-
-	ret = nand_read_page_op(chip, page, 0, NULL, 0);
-	if (ret)
-		return ret;
-
-	return nand_read_page_raw(mtd, chip, buf, oob_required, page);
-}
-
-static int
-micron_nand_write_page_raw_on_die_ecc(struct mtd_info *mtd,
-				      struct nand_chip *chip,
-				      const uint8_t *buf, int oob_required,
-				      int page)
-{
-	int ret;
-
-	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
-	if (ret)
-		return ret;
-
-	ret = nand_write_page_raw(mtd, chip, buf, oob_required, page);
-	if (ret)
-		return ret;
-
-	return nand_prog_page_end_op(chip);
-}
-
 enum {
 	/* The NAND flash doesn't support on-die ECC */
 	MICRON_ON_DIE_UNSUPPORTED,
@@ -310,17 +269,14 @@ static int micron_nand_init(struct nand_chip *chip)
 			return -EINVAL;
 		}
 
-		chip->ecc.options = NAND_ECC_CUSTOM_PAGE_ACCESS;
 		chip->ecc.bytes = 8;
 		chip->ecc.size = 512;
 		chip->ecc.strength = 4;
 		chip->ecc.algo = NAND_ECC_BCH;
 		chip->ecc.read_page = micron_nand_read_page_on_die_ecc;
 		chip->ecc.write_page = micron_nand_write_page_on_die_ecc;
-		chip->ecc.read_page_raw =
-			micron_nand_read_page_raw_on_die_ecc;
-		chip->ecc.write_page_raw =
-			micron_nand_write_page_raw_on_die_ecc;
+		chip->ecc.read_page_raw = nand_read_page_raw;
+		chip->ecc.write_page_raw = nand_write_page_raw;
 
 		mtd_set_ooblayout(mtd, &micron_nand_on_die_ooblayout_ops);
 	}