From: Takahiro Kuwano <takahiro.kuw...@infineon.com>
Our SFDP parsing is everything we need to support all basic operations
of a flash device. If the flash isn't found in our in-kernel flash
database, gracefully fall back to a driver described solely by its SFDP
tables.
This patch ports the commit in Linux:
773bbe104497 ("mtd: spi-nor: add generic flash driver")
A new flag named SPI_NOR_PARSE_SFDP is defined to perform SFDP parse for
the spi-nor-generic. And spi_nor_read_id() is moved to later part than
SFDP functions.
Signed-off-by: Takahiro Kuwano <takahiro.kuw...@infineon.com>
---
drivers/mtd/spi/sf_internal.h | 1 +
drivers/mtd/spi/spi-nor-core.c | 95 ++++++++++++++++++++++++----------
2 files changed, 70 insertions(+), 26 deletions(-)
diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
index 57608750c9..f7b0cea983 100644
--- a/drivers/mtd/spi/sf_internal.h
+++ b/drivers/mtd/spi/sf_internal.h
@@ -68,6 +68,7 @@ struct flash_info {
#define SPI_NOR_HAS_SST26LOCK BIT(14) /* Flash supports lock/unlock via BPR */
#define SPI_NOR_OCTAL_READ BIT(15) /* Flash supports Octal Read */
#define SPI_NOR_OCTAL_DTR_READ BIT(16) /* Flash supports Octal DTR Read */
+#define SPI_NOR_PARSE_SFDP BIT(17) /* Parse SFDP tables */
};
extern const struct flash_info spi_nor_ids[];
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index feafc48a49..c1186271a4 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -1509,31 +1509,6 @@ static int stm_is_unlocked(struct spi_nor *nor, loff_t
ofs, uint64_t len)
#endif /* CONFIG_SPI_FLASH_STMICRO */
#endif
-static const struct flash_info *spi_nor_read_id(struct spi_nor *nor)
-{
- int tmp;
- u8 id[SPI_NOR_MAX_ID_LEN];
- const struct flash_info *info;
-
- tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, SPI_NOR_MAX_ID_LEN);
- if (tmp < 0) {
- dev_dbg(nor->dev, "error %d reading JEDEC ID\n", tmp);
- return ERR_PTR(tmp);
- }
-
- info = spi_nor_ids;
- for (; info->name; info++) {
- if (info->id_len) {
- if (!memcmp(info->id, id, info->id_len))
- return info;
- }
- }
-
- dev_err(nor->dev, "unrecognized JEDEC id bytes: %02x, %02x, %02x\n",
- id[0], id[1], id[2]);
- return ERR_PTR(-ENODEV);
-}
-
static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
@@ -2154,6 +2129,17 @@ spi_nor_set_pp_settings(struct spi_nor_pp_command *pp,
}
#if CONFIG_IS_ENABLED(SPI_FLASH_SFDP_SUPPORT)
+
+static const struct flash_info spi_nor_generic_flash = {
+ .name = "spi-nor-generic",
+ /*
+ * JESD216 rev A doesn't specify the page size, therefore we need a
+ * sane default.
+ */
+ .page_size = 256,
+ .flags = SPI_NOR_PARSE_SFDP,
+};
+
/*
* Serial Flash Discoverable Parameters (SFDP) parsing.
*/
@@ -2724,6 +2710,32 @@ out:
return ret;
}
+/**
+ * spi_nor_check_sfdp_signature() - check for a valid SFDP signature
+ * @nor: pointer to a 'struct spi_nor'
+ *
+ * Used to detect if the flash supports the RDSFDP command as well as the
+ * presence of a valid SFDP table.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_nor_check_sfdp_signature(struct spi_nor *nor)
+{
+ u32 signature;
+ int err;
+
+ /* Get the SFDP header. */
+ err = spi_nor_read_sfdp(nor, 0, sizeof(signature), &signature);
+ if (err < 0)
+ return err;
+
+ /* Check the SFDP signature. */
+ if (le32_to_cpu(signature) != SFDP_SIGNATURE)
+ return -EINVAL;
+
+ return 0;
+}
+
/**
* spi_nor_parse_sfdp() - parse the Serial Flash Discoverable Parameters.
* @nor: pointer to a 'struct spi_nor'
@@ -3014,7 +3026,7 @@ static int spi_nor_init_params(struct spi_nor *nor,
nor->addr_width = 0;
nor->mtd.erasesize = 0;
if (info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
- SPI_NOR_OCTAL_DTR_READ)) {
+ SPI_NOR_OCTAL_DTR_READ | SPI_NOR_PARSE_SFDP)) {
struct spi_nor_flash_parameter sfdp_params;
memcpy(&sfdp_params, params, sizeof(sfdp_params));
@@ -4170,6 +4182,37 @@ void spi_nor_set_fixups(struct spi_nor *nor)
#endif /* SPI_FLASH_MACRONIX */
}
+static const struct flash_info *spi_nor_read_id(struct spi_nor *nor)
+{
+ int tmp;
+ u8 id[SPI_NOR_MAX_ID_LEN];
+ const struct flash_info *info;
+
+ tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, SPI_NOR_MAX_ID_LEN);
+ if (tmp < 0) {
+ dev_dbg(nor->dev, "error %d reading JEDEC ID\n", tmp);
+ return ERR_PTR(tmp);
+ }
+
+ info = spi_nor_ids;
+ for (; info->name; info++) {
+ if (info->id_len) {
+ if (!memcmp(info->id, id, info->id_len))
+ return info;
+ }
+ }
+
+#if CONFIG_IS_ENABLED(SPI_FLASH_SFDP_SUPPORT)
+ /* Fallback to a generic flash described only by its SFDP data. */
+ if (!spi_nor_check_sfdp_signature(nor))
+ return &spi_nor_generic_flash;
+#endif
+
+ dev_err(nor->dev, "unrecognized JEDEC id bytes: %02x, %02x, %02x\n",
+ id[0], id[1], id[2]);
+ return ERR_PTR(-ENODEV);
+}
+
int spi_nor_scan(struct spi_nor *nor)
{
struct spi_nor_flash_parameter params;
--
2.34.1
