Re: [PATCH 2/2] mtd: spi-nor: issi: Add support for is25wx01g

[Michael Walle]

Hi,

On Fri Sep 11, 2026 at 5:36 PM CEST, Nuno Sá wrote:
> Add support for the ISSI IS25WX01G, a 1 Gbit octal NOR flash. The part
> is fully described by SFDP, so only the flash ID and two BFPT fixups are
> needed.

Adding a new flash involves minimum testing and an SFDP dump, see
[1].

Also please keep the following Link: tag in your next version:

Link: https://www.issi.com/WW/pdf/25LX-WX01GB.pdf

> The flash has no Status Register 2 and does not implement the 35h Read
> Configuration Register command, so the default assumption of a 16-bit
> Write Status command does not hold. Additionally, its BFPT Quad Enable
> Requirement field carries a reserved value, which makes
> spi_nor_parse_bfpt() keep the manufacturer default quad enable method;
> clear it, since this is an octal-only part with no quad mode at all.
>
> Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
> ---
>  drivers/mtd/spi-nor/issi.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
>
> diff --git a/drivers/mtd/spi-nor/issi.c b/drivers/mtd/spi-nor/issi.c
> index 2f057d731df2..aac9d19b90fc 100644
> --- a/drivers/mtd/spi-nor/issi.c
> +++ b/drivers/mtd/spi-nor/issi.c
> @@ -29,6 +29,29 @@ static const struct spi_nor_fixups is25lp256_fixups = {
>  	.post_bfpt = is25lp256_post_bfpt_fixups,
>  };
>  
> +static int is25wx01g_post_bfpt_fixups(struct spi_nor *nor,
> +				      const struct sfdp_parameter_header *bfpt_header,
> +				      const struct sfdp_bfpt *bfpt)
> +{
> +	/*
> +	 * There is no Status Register 2 and no 35h command. And WRITE STATUS
> +	 * REGISTER takes a single data byte.
> +	 */
> +	nor->flags &= ~SNOR_F_HAS_16BIT_SR;
> +
> +	/*
> +	 * The BFPT Quad Enable Requirement field is set to a reserved value, so
> +	 * spi_nor_parse_bfpt() leaves the quad enable method at its default.
> +	 * Make sure we disable it as there is no quad mode anyway.
> +	 */
> +	nor->params->quad_enable = NULL;
> +	return 0;
> +}
> +
> +static const struct spi_nor_fixups is25wx01g_fixups = {
> +	.post_bfpt = is25wx01g_post_bfpt_fixups,
> +};
> +
>  static int pm25lv_nor_late_init(struct spi_nor *nor)
>  {
>  	struct spi_nor_erase_map *map = &nor->params->erase_map;
> @@ -120,6 +143,10 @@ static const struct flash_info issi_nor_parts[] = {
>  		.id = SNOR_ID(0x9d, 0x70, 0x19),
>  		.name = "is25wp256",
>  		.flags = SPI_NOR_QUAD_PP,
> +	}, {
> +		.id = SNOR_ID(0x9d, 0x5b, 0x1b),
> +		.name = "is25wx01g",
No .name please.

-michael

[1] https://docs.kernel.org/driver-api/mtd/spi-nor.html

> +		.fixups = &is25wx01g_fixups,
>  	}
>  };
>