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, 4 deletions

diff --git a/drivers/mtd/nand/docg4.c b/drivers/mtd/nand/docg4.c
index 5a27f56dafdc..72f1327c4430 100644
--- a/drivers/mtd/nand/docg4.c
+++ b/drivers/mtd/nand/docg4.c
@@ -785,6 +785,8 @@ static int read_page(struct mtd_info *mtd, struct nand_chip *nand,
 
 	dev_dbg(doc->dev, "%s: page %08x\n", __func__, page);
 
+	nand_read_page_op(nand, page, 0, NULL, 0);
+
 	writew(DOC_ECCCONF0_READ_MODE |
 	       DOC_ECCCONF0_ECC_ENABLE |
 	       DOC_ECCCONF0_UNKNOWN |
@@ -948,7 +950,7 @@ static int docg4_erase_block(struct mtd_info *mtd, int page)
 }
 
 static int write_page(struct mtd_info *mtd, struct nand_chip *nand,
-		       const uint8_t *buf, bool use_ecc)
+		      const uint8_t *buf, int page, bool use_ecc)
 {
 	struct docg4_priv *doc = nand_get_controller_data(nand);
 	void __iomem *docptr = doc->virtadr;
@@ -956,6 +958,8 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *nand,
 
 	dev_dbg(doc->dev, "%s...\n", __func__);
 
+	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
+
 	writew(DOC_ECCCONF0_ECC_ENABLE |
 	       DOC_ECCCONF0_UNKNOWN |
 	       DOCG4_BCH_SIZE,
@@ -1000,19 +1004,19 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *nand,
 	writew(0, docptr + DOC_DATAEND);
 	write_nop(docptr);
 
-	return 0;
+	return nand_prog_page_end_op(nand);
 }
 
 static int docg4_write_page_raw(struct mtd_info *mtd, struct nand_chip *nand,
 				const uint8_t *buf, int oob_required, int page)
 {
-	return write_page(mtd, nand, buf, false);
+	return write_page(mtd, nand, buf, page, false);
 }
 
 static int docg4_write_page(struct mtd_info *mtd, struct nand_chip *nand,
 			     const uint8_t *buf, int oob_required, int page)
 {
-	return write_page(mtd, nand, buf, true);
+	return write_page(mtd, nand, buf, page, true);
 }
 
 static int docg4_write_oob(struct mtd_info *mtd, struct nand_chip *nand,