Messages in this thread | | | Date | Fri, 29 Jul 2022 10:40:24 +0900 | Subject | Re: [PATCH 5/6] mtd: spi-nor: add generic flash driver | From | Takahiro Kuwano <> |
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On 5/13/2022 10:35 PM, Michael Walle wrote: > Our SFDP is parsing is everything we need to support all basic redundant "is"?
> 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; > +} > +
Nice to use this function from spi_nor_parse_sfdp() as well, but I found it's not straightforward...
Reviewed-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Thanks, Takahiro
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