[PATCH 2/2] mtd: spi-nor-core: add 4-byte OPCODE support for Winbond W25Q256JV

[Tudor Ambarus]

On 25.04.2024 17:36, Robert Marko wrote:
> Winbond W25Q256FV and W25Q256JV share the same JEDEC ID, but only
> W25Q256JV fully supports 4-byte OPCODE-s.
> 
> In order to differentiate between them we can use the SFDP header version
> and apply a fixup post BFPT.
> 
> Based on upstream Linux commit ("mtd: spi-nor: winbond: Fix 4-byte opcode
> support for w25q256").

Linux commit info shall be the first info in the commit message. And
please give the sha1 of the commit, it spares me of grepping the log.

How about something along the lines:

Backport linux upstream commit e8aec15dd5842b5b11b0e621a2293348d3574a61 [1].

The copy the upstream commit message here.

Introduce a new paragraph if you need to add your comments.

And then add a link to the commit in torvalds's git:

Link:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e8aec15dd5842b5b11b0e621a2293348d3574a61
[1]
	("mtd: spi-nor: winbond: Fix 4-byte opcode support for w25q256")

Looking good otherwise.
> 
> Signed-off-by: Robert Marko <robert.marko at sartura.hr>
> ---
>  drivers/mtd/spi/spi-nor-core.c | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
> 
> diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
> index 7615ba602f..8882b045ce 100644
> --- a/drivers/mtd/spi/spi-nor-core.c
> +++ b/drivers/mtd/spi/spi-nor-core.c
> @@ -3816,6 +3816,32 @@ static struct spi_nor_fixups macronix_octal_fixups = {
>  };
>  #endif /* CONFIG_SPI_FLASH_MACRONIX */
>  
> +#if CONFIG_IS_ENABLED(SPI_FLASH_WINBOND)
> +static int w25q256_post_bfpt_fixup(struct spi_nor *nor,
> +				   const struct sfdp_parameter_header *header,
> +				   const struct sfdp_bfpt *bfpt,
> +				   struct spi_nor_flash_parameter *params)
> +{
> +	/*
> +	 * W25Q256JV supports 4B opcodes but W25Q256FV does not.
> +	 * Unfortunately, Winbond has re-used the same JEDEC ID for both
> +	 * variants which prevents us from defining a new entry in the parts
> +	 * table.
> +	 * To differentiate between W25Q256JV and W25Q256FV check SFDP header
> +	 * version: only JV has JESD216A compliant structure (version 5).
> +	 */
> +	if(header->major == SFDP_JESD216_MAJOR &&
> +	   header->minor == SFDP_JESD216A_MINOR)
> +		nor->flags |= SNOR_F_4B_OPCODES;
> +
> +	return 0;
> +}
> +
> +static struct spi_nor_fixups w25q256_fixups = {
> +	.post_bfpt = w25q256_post_bfpt_fixup,
> +};
> +#endif /* CONFIG_SPI_FLASH_WINBOND */
> +
>  /** spi_nor_octal_dtr_enable() - enable Octal DTR I/O if needed
>   * @nor:                 pointer to a 'struct spi_nor'
>   *
> @@ -4004,6 +4030,11 @@ void spi_nor_set_fixups(struct spi_nor *nor)
>  #if CONFIG_IS_ENABLED(SPI_FLASH_MACRONIX)
>  	nor->fixups = &macronix_octal_fixups;
>  #endif /* SPI_FLASH_MACRONIX */
> +
> +#if CONFIG_IS_ENABLED(SPI_FLASH_WINBOND)
> +	if (!strcmp(nor->info->name, "w25q256"))
> +		nor->fixups = &w25q256_fixups;
> +#endif /* SPI_FLASH_WINBOND */
>  }
>  
>  int spi_nor_scan(struct spi_nor *nor)