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>
diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index da5cc36..5c176de 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -1245,6 +1245,8 @@
 	int ret, i, cur_off = 0;
 	bool raw_mode = false;
 
+	nand_read_page_op(chip, page, 0, NULL, 0);
+
 	sunxi_nfc_hw_ecc_enable(mtd);
 
 	for (i = 0; i < ecc->steps; i++) {
@@ -1278,14 +1280,14 @@
 {
 	int ret;
 
+	nand_read_page_op(chip, page, 0, NULL, 0);
+
 	ret = sunxi_nfc_hw_ecc_read_chunks_dma(mtd, buf, oob_required, page,
 					       chip->ecc.steps);
 	if (ret >= 0)
 		return ret;
 
 	/* Fallback to PIO mode */
-	nand_change_read_column_op(chip, 0, NULL, 0, false);
-
 	return sunxi_nfc_hw_ecc_read_page(mtd, chip, buf, oob_required, page);
 }
 
@@ -1298,6 +1300,8 @@
 	int ret, i, cur_off = 0;
 	unsigned int max_bitflips = 0;
 
+	nand_read_page_op(chip, page, 0, NULL, 0);
+
 	sunxi_nfc_hw_ecc_enable(mtd);
 
 	for (i = data_offs / ecc->size;
@@ -1329,13 +1333,13 @@
 	int nchunks = DIV_ROUND_UP(data_offs + readlen, chip->ecc.size);
 	int ret;
 
+	nand_read_page_op(chip, page, 0, NULL, 0);
+
 	ret = sunxi_nfc_hw_ecc_read_chunks_dma(mtd, buf, false, page, nchunks);
 	if (ret >= 0)
 		return ret;
 
 	/* Fallback to PIO mode */
-	nand_change_read_column_op(chip, 0, NULL, 0, false);
-
 	return sunxi_nfc_hw_ecc_read_subpage(mtd, chip, data_offs, readlen,
 					     buf, page);
 }
@@ -1348,6 +1352,8 @@
 	struct nand_ecc_ctrl *ecc = &chip->ecc;
 	int ret, i, cur_off = 0;
 
+	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+
 	sunxi_nfc_hw_ecc_enable(mtd);
 
 	for (i = 0; i < ecc->steps; i++) {
@@ -1369,7 +1375,7 @@
 
 	sunxi_nfc_hw_ecc_disable(mtd);
 
-	return 0;
+	return nand_prog_page_end_op(chip);
 }
 
 static int sunxi_nfc_hw_ecc_write_subpage(struct mtd_info *mtd,
@@ -1381,6 +1387,8 @@
 	struct nand_ecc_ctrl *ecc = &chip->ecc;
 	int ret, i, cur_off = 0;
 
+	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+
 	sunxi_nfc_hw_ecc_enable(mtd);
 
 	for (i = data_offs / ecc->size;
@@ -1399,7 +1407,7 @@
 
 	sunxi_nfc_hw_ecc_disable(mtd);
 
-	return 0;
+	return nand_prog_page_end_op(chip);
 }
 
 static int sunxi_nfc_hw_ecc_write_page_dma(struct mtd_info *mtd,
@@ -1429,6 +1437,8 @@
 		sunxi_nfc_hw_ecc_set_prot_oob_bytes(mtd, oob, i, !i, page);
 	}
 
+	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+
 	sunxi_nfc_hw_ecc_enable(mtd);
 	sunxi_nfc_randomizer_config(mtd, page, false);
 	sunxi_nfc_randomizer_enable(mtd);
@@ -1459,7 +1469,7 @@
 		sunxi_nfc_hw_ecc_write_extra_oob(mtd, chip->oob_poi,
 						 NULL, page);
 
-	return 0;
+	return nand_prog_page_end_op(chip);
 
 pio_fallback:
 	return sunxi_nfc_hw_ecc_write_page(mtd, chip, buf, oob_required, page);
@@ -1475,6 +1485,8 @@
 	int ret, i, cur_off = 0;
 	bool raw_mode = false;
 
+	nand_read_page_op(chip, page, 0, NULL, 0);
+
 	sunxi_nfc_hw_ecc_enable(mtd);
 
 	for (i = 0; i < ecc->steps; i++) {
@@ -1511,6 +1523,8 @@
 	struct nand_ecc_ctrl *ecc = &chip->ecc;
 	int ret, i, cur_off = 0;
 
+	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+
 	sunxi_nfc_hw_ecc_enable(mtd);
 
 	for (i = 0; i < ecc->steps; i++) {
@@ -1532,15 +1546,13 @@
 
 	sunxi_nfc_hw_ecc_disable(mtd);
 
-	return 0;
+	return nand_prog_page_end_op(chip);
 }
 
 static int sunxi_nfc_hw_common_ecc_read_oob(struct mtd_info *mtd,
 					    struct nand_chip *chip,
 					    int page)
 {
-	nand_read_page_op(chip, page, 0, NULL, 0);
-
 	chip->pagebuf = -1;
 
 	return chip->ecc.read_page(mtd, chip, chip->buffers->databuf, 1, page);
@@ -1552,8 +1564,6 @@
 {
 	int ret;
 
-	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
-
 	chip->pagebuf = -1;
 
 	memset(chip->buffers->databuf, 0xff, mtd->writesize);