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>

1 files changed, 31 insertions, 3 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 4d099d4f442c..96d242e2fe34 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1961,7 +1961,8 @@ 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,
@@ -2649,7 +2650,8 @@ 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,
@@ -2672,7 +2674,8 @@ 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
@@ -4511,6 +4514,26 @@ 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
@@ -4531,6 +4554,11 @@ int nand_scan_tail(struct mtd_info *mtd)
                    !(chip->bbt_options & NAND_BBT_USE_FLASH)))
                 return -EINVAL;
 
+        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(*nbuf) + mtd->writesize
                                 + mtd->oobsize * 3, GFP_KERNEL);