mtd: nand: Support controllers with custom page

If your controller already sends the required NAND commands when
reading or writing a page, then the framework is not supposed to
send READ0 and SEQIN/PAGEPROG respectively.

Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[Linux commit: 3371d663bb4579f1b2003a92162edd6d90edd089]
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

1 files changed, 31 insertions, 3 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 5054c0e7ab..d9f0a752b5 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1732,7 +1732,8 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
 						 __func__, buf);
 
 read_retry:
-			chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
+			if (nand_standard_page_accessors(&chip->ecc))
+				chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
 
 			/*
 			 * Now read the page into the buffer.  Absent an error,
@@ -2423,7 +2424,8 @@ static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	else
 		subpage = 0;
 
-	chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
+	if (nand_standard_page_accessors(&chip->ecc))
+		chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
 
 	if (unlikely(raw))
 		status = chip->ecc.write_page_raw(mtd, chip, buf,
@@ -2446,7 +2448,8 @@ static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
 
 	if (!cached || !NAND_HAS_CACHEPROG(chip)) {
 
-		chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+		if (nand_standard_page_accessors(&chip->ecc))
+			chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
 		status = chip->waitfunc(mtd, chip);
 		/*
 		 * See if operation failed and additional status checks are
@@ -4126,6 +4129,26 @@ static bool nand_ecc_strength_good(struct mtd_info *mtd)
 	return corr >= ds_corr && ecc->strength >= chip->ecc_strength_ds;
 }
 
+static bool invalid_ecc_page_accessors(struct nand_chip *chip)
+{
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+
+	if (nand_standard_page_accessors(ecc))
+		return false;
+
+	/*
+	 * NAND_ECC_CUSTOM_PAGE_ACCESS flag is set, make sure the NAND
+	 * controller driver implements all the page accessors because
+	 * default helpers are not suitable when the core does not
+	 * send the READ0/PAGEPROG commands.
+	 */
+	return (!ecc->read_page || !ecc->write_page ||
+		!ecc->read_page_raw || !ecc->write_page_raw ||
+		(NAND_HAS_SUBPAGE_READ(chip) && !ecc->read_subpage) ||
+		(NAND_HAS_SUBPAGE_WRITE(chip) && !ecc->write_subpage &&
+		 ecc->hwctl && ecc->calculate));
+}
+
 /**
  * nand_scan_tail - [NAND Interface] Scan for the NAND device
  * @mtd: MTD device structure
@@ -4145,6 +4168,11 @@ int nand_scan_tail(struct mtd_info *mtd)
 	BUG_ON((chip->bbt_options & NAND_BBT_NO_OOB_BBM) &&
 			!(chip->bbt_options & NAND_BBT_USE_FLASH));
 
+	if (invalid_ecc_page_accessors(chip)) {
+		pr_err("Invalid ECC page accessors setup\n");
+		return -EINVAL;
+	}
+
 	if (!(chip->options & NAND_OWN_BUFFERS)) {
 		nbuf = kzalloc(sizeof(struct nand_buffers), GFP_KERNEL);
 		chip->buffers = nbuf;