Messages in this thread Patch in this message | | | From | Michael Walle <> | Subject | [PATCH 5/6] mtd: spi-nor: add generic flash driver | Date | Fri, 13 May 2022 15:35:19 +0200 |
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Our SFDP is 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.
It is still recommended to add the flash to the in-kernel database. First, we get a proper partname and secondly, for all features not described by the SFDP like OTP we need the entry anyway.
Signed-off-by: Michael Walle <michael@walle.cc> --- drivers/mtd/spi-nor/core.c | 13 +++++++++++++ drivers/mtd/spi-nor/core.h | 1 + drivers/mtd/spi-nor/sfdp.c | 27 +++++++++++++++++++++++++++ 3 files changed, 41 insertions(+)
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 65cd8e668579..ee193a61310a 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -1632,6 +1632,11 @@ static const struct spi_nor_manufacturer *manufacturers[] = { &spi_nor_xmc, }; +static const struct flash_info spi_nor_generic_flash = { + .name = "spi-nor-generic", + .parse_sfdp = true, +}; + static const struct flash_info *spi_nor_match_id(struct spi_nor *nor, const u8 *id) { @@ -1670,6 +1675,14 @@ static const struct flash_info *spi_nor_detect(struct spi_nor *nor) return ERR_PTR(-ENOMEM); info = spi_nor_match_id(nor, id); + + /* Fallback to a generic flash described only by its SFDP data. */ + if (!info) { + ret = spi_nor_check_sfdp_signature(nor); + if (!ret) + info = &spi_nor_generic_flash; + } + if (!info) { dev_err(nor->dev, "unrecognized JEDEC id bytes: %*ph\n", SPI_NOR_MAX_ID_LEN, id); diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h index 3a19b8092ab8..aa9f218245a5 100644 --- a/drivers/mtd/spi-nor/core.h +++ b/drivers/mtd/spi-nor/core.h @@ -694,6 +694,7 @@ int spi_nor_controller_ops_read_reg(struct spi_nor *nor, u8 opcode, int spi_nor_controller_ops_write_reg(struct spi_nor *nor, u8 opcode, const u8 *buf, size_t len); +int spi_nor_check_sfdp_signature(struct spi_nor *nor); int spi_nor_parse_sfdp(struct spi_nor *nor); static inline struct spi_nor *mtd_to_spi_nor(struct mtd_info *mtd) diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c index a5211543d30d..9bdb3d5dc7e8 100644 --- a/drivers/mtd/spi-nor/sfdp.c +++ b/drivers/mtd/spi-nor/sfdp.c @@ -1247,6 +1247,33 @@ static void spi_nor_post_sfdp_fixups(struct spi_nor *nor) nor->info->fixups->post_sfdp(nor); } +/** + * spi_nor_check_sfdp_header() - check for a valid SFDP header + * @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. + */ +int spi_nor_check_sfdp_signature(struct spi_nor *nor) +{ + u32 signature; + int err; + + /* Get the SFDP header. */ + err = spi_nor_read_sfdp_dma_unsafe(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' -- 2.30.2
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