[PATCH v2 1/2] mtd: nand: Support controllers with custom page
Marc Gonzalez
marc_gonzalez at sigmadesigns.com
Mon Nov 14 09:01:27 PST 2016
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 at sigmadesigns.com>
---
v2:
(chip) in NAND_HAS_SUBPAGE_WRITE macro
s/nand_default_page_accessors/nand_standard_page_accessors/
scripts/checkpatch.pl --strict v2-0001-mtd-nand-Support-controllers-with-custom-page-acc.patch
total: 0 errors, 0 warnings, 0 checks, 91 lines checked
---
drivers/mtd/nand/nand_base.c | 31 ++++++++++++++++++++++++++++---
include/linux/mtd/nand.h | 12 ++++++++++++
2 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 50cdf37cb8e4..db5f27db3748 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1970,7 +1970,8 @@ 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,
@@ -2658,7 +2659,8 @@ 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,
@@ -2681,7 +2683,8 @@ 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
@@ -4539,6 +4542,25 @@ 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));
+}
+
/**
* nand_scan_tail - [NAND Interface] Scan for the NAND device
* @mtd: MTD device structure
@@ -4559,6 +4581,9 @@ int nand_scan_tail(struct mtd_info *mtd)
!(chip->bbt_options & NAND_BBT_USE_FLASH)))
return -EINVAL;
+ if (WARN_ON(invalid_ecc_page_accessors(chip)))
+ 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 06d0c9d740f7..c5f3a012ae62 100644
--- 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.
--
2.9.0
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