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>

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 4d099d4f442cf42410895431d1da3c3c242fc617..96d242e2fe3479087e5d6ceb4bc224a2bae0fba4 100644 (file)
--- 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);

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 970ceb948835dc5ab41c1bbfcf9bd39624df9737..ed6fd1993be117ccba27075e99ad28c404594ad4 100644 (file)
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -142,6 +142,12 @@ enum nand_ecc_algo {
  */
 #define NAND_ECC_GENERIC_ERASED_CHECK  BIT(0)
 #define NAND_ECC_MAXIMIZE              BIT(1)
+/*
+ * 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.
+ */
+#define NAND_ECC_CUSTOM_PAGE_ACCESS    BIT(2)
 
 /* Bit mask for flags passed to do_nand_read_ecc */
 #define NAND_GET_DEVICE                0x80
@@ -186,6 +192,7 @@ enum nand_ecc_algo {
 /* Macros to identify the above */
 #define NAND_HAS_CACHEPROG(chip) ((chip->options & NAND_CACHEPRG))
 #define NAND_HAS_SUBPAGE_READ(chip) ((chip->options & NAND_SUBPAGE_READ))
+#define NAND_HAS_SUBPAGE_WRITE(chip) !((chip)->options & NAND_NO_SUBPAGE_WRITE)
 
 /* Non chip related options */
 /* This option skips the bbt scan during initialization. */
@@ -568,6 +575,11 @@ struct nand_ecc_ctrl {
                        int page);
 };
 
+static inline int nand_standard_page_accessors(struct nand_ecc_ctrl *ecc)
+{
+       return !(ecc->options & NAND_ECC_CUSTOM_PAGE_ACCESS);
+}
+
 /**
  * struct nand_buffers - buffer structure for read/write
  * @ecccalc:   buffer pointer for calculated ECC, size is oobsize.