mtd: spi-nor: spansion: Enable JFFS2 write buffer for Infineon s28hx SEMPER flash

Infineon(Cypress) SEMPER NOR flash family has on-die ECC and its program
granularity is 16-byte ECC data unit size. JFFS2 supports write buffer
mode for ECC'd NOR flash. Provide a way to clear the MTD_BIT_WRITEABLE
flag in order to enable JFFS2 write buffer mode support.

A new SNOR_F_ECC flag is introduced to determine if the part has on-die
ECC and if it has, MTD_BIT_WRITEABLE is unset.

In vendor specific driver, a common cypress_nor_ecc_init() helper is
added. This helper takes care for ECC related initialization for SEMPER
flash family by setting up params->writesize and SNOR_F_ECC.

Fixes: c3266af101f2 ("mtd: spi-nor: spansion: add support for Cypress Semper flash")
Suggested-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/d586723f6f12aaff44fbcd7b51e674b47ed554ed.1680760742.git.Takahiro.Kuwano@infineon.com
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 1e30737b607b446f8dc0ddd01354c64cbed1aa08..143ca3c9b4772e21f5659d9750b1d78c53f401a3 100644 (file)
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -3407,6 +3407,9 @@ static void spi_nor_set_mtd_info(struct spi_nor *nor)
                mtd->name = dev_name(dev);
        mtd->type = MTD_NORFLASH;
        mtd->flags = MTD_CAP_NORFLASH;
+       /* Unset BIT_WRITEABLE to enable JFFS2 write buffer for ECC'd NOR */
+       if (nor->flags & SNOR_F_ECC)
+               mtd->flags &= ~MTD_BIT_WRITEABLE;
        if (nor->info->flags & SPI_NOR_NO_ERASE)
                mtd->flags |= MTD_NO_ERASE;
        else

diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index ea9033cb0a012bf4b67cba857e562b043785f342..8cfa82ed06c73726896ef1090023846b4f1a1035 100644 (file)
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -131,6 +131,7 @@ enum spi_nor_option_flags {
        SNOR_F_SOFT_RESET       = BIT(12),
        SNOR_F_SWP_IS_VOLATILE  = BIT(13),
        SNOR_F_RWW              = BIT(14),
+       SNOR_F_ECC              = BIT(15),
 };
 
 struct spi_nor_read_command {

diff --git a/drivers/mtd/spi-nor/debugfs.c b/drivers/mtd/spi-nor/debugfs.c
index e200f5b9234cfd104ef96ef02ef3a047fc6431a4..082c0c5a8626dba9cf1574833ed6b33b2d97f58b 100644 (file)
--- a/drivers/mtd/spi-nor/debugfs.c
+++ b/drivers/mtd/spi-nor/debugfs.c
@@ -26,6 +26,7 @@ static const char *const snor_f_names[] = {
        SNOR_F_NAME(SOFT_RESET),
        SNOR_F_NAME(SWP_IS_VOLATILE),
        SNOR_F_NAME(RWW),
+       SNOR_F_NAME(ECC),
 };
 #undef SNOR_F_NAME
 

diff --git a/drivers/mtd/spi-nor/spansion.c b/drivers/mtd/spi-nor/spansion.c
index 352c40dd3864f6974e439ae2c8a5c76553076bf5..19b1436f36eac858f5bfa62b6ab793aae654f7cc 100644 (file)
--- a/drivers/mtd/spi-nor/spansion.c
+++ b/drivers/mtd/spi-nor/spansion.c
@@ -332,6 +332,17 @@ static int cypress_nor_set_page_size(struct spi_nor *nor)
        return 0;
 }
 
+static void cypress_nor_ecc_init(struct spi_nor *nor)
+{
+       /*
+        * Programming is supported only in 16-byte ECC data unit granularity.
+        * Byte-programming, bit-walking, or multiple program operations to the
+        * same ECC data unit without an erase are not allowed.
+        */
+       nor->params->writesize = 16;
+       nor->flags |= SNOR_F_ECC;
+}
+
 static int
 s25fs256t_post_bfpt_fixup(struct spi_nor *nor,
                          const struct sfdp_parameter_header *bfpt_header,
@@ -506,7 +517,7 @@ static int s28hx_t_post_bfpt_fixup(struct spi_nor *nor,
 static void s28hx_t_late_init(struct spi_nor *nor)
 {
        nor->params->octal_dtr_enable = cypress_nor_octal_dtr_enable;
-       nor->params->writesize = 16;
+       cypress_nor_ecc_init(nor);
 }
 
 static const struct spi_nor_fixups s28hx_t_fixups = {