Re: [PATCH v3 1/2] mtd: spi-nor: Add support for MX25L12833F and MX25L12845G

[Cheng Ming Lin]

Hi,

Shiji Yang <yangshiji66@xxxxxxxxxxx> 於 2026年8月22日週六 下午8:07寫道：
>
> On Fri,  5 Jun 2026 16:48:36 +0800, Cheng Ming Lin wrote:
>
> > From: Cheng Ming Lin <chengminglin@xxxxxxxxxxx>
> >
> > Add support for Macronix MX25L12833F and MX25L12845G SPI NOR flashes.
> > These parts share the same JEDEC ID (0xc2, 0x20, 0x18) as the legacy
> > MX25L12805D.
> >
> > The newer flashes support SFDP and 1-4-4 Page Program in 3-byte address
> > mode, but this 4PP capability is not defined in their SFDP tables.
> > Conversely, the legacy MX25L12805D lacks SFDP support entirely and does
> > not support 4PP.
> >
> > To safely enable 4PP for the newer flashes without breaking the legacy
> > part, introduce a post_sfdp fixup. Since the legacy MX25L12805D does
> > not support SFDP, it falls back to static parameters and will never
> > execute the post_sfdp hook. The newer flashes will successfully parse
> > the SFDP, trigger the hook, and safely append the SNOR_HWCAPS_PP_1_4_4
> > capability.
> >
> > Signed-off-by: Cheng Ming Lin <chengminglin@xxxxxxxxxxx>
> > ---
> >  drivers/mtd/spi-nor/macronix.c | 26 +++++++++++++++++++++++++-
> >  1 file changed, 25 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mtd/spi-nor/macronix.c b/drivers/mtd/spi-nor/macronix.c
> > index e97f5cbd9..1adb79832 100644
> > --- a/drivers/mtd/spi-nor/macronix.c
> > +++ b/drivers/mtd/spi-nor/macronix.c
> > @@ -83,6 +83,25 @@ mx25l3255e_late_init_fixups(struct spi_nor *nor)
> >       return 0;
> >  }
> >
> > +static int
> > +mx25l12805d_4pp3b_post_sfdp_fixups(struct spi_nor *nor)
> > +{
> > +     struct spi_nor_flash_parameter *params = nor->params;
> > +
> > +     /*
> > +      * JEDEC ID 0xc22018 is shared by MX25L12805D (no SFDP, no 4PP) and
> > +      * MX25L12833F/MX25L12845G (support SFDP and 4PP in 3-byte mode).
> > +      * The legacy 05D lacks SFDP and will not execute this hook. For
> > +      * the newer flashes, 3-byte 1-4-4 PP is not defined in SFDP, so
> > +      * we safely enable it here.
> > +      */
> > +     params->hwcaps.mask |= SNOR_HWCAPS_PP_1_4_4;
> > +     spi_nor_set_pp_settings(&params->page_programs[SNOR_CMD_PP_1_4_4],
> > +                             SPINOR_OP_PP_1_4_4, SNOR_PROTO_1_4_4);
> > +
> > +     return 0;
> > +}
> > +
> >  static const struct spi_nor_fixups mx25l25635_fixups = {
> >       .post_bfpt = mx25l25635_post_bfpt_fixups,
> >       .post_sfdp = macronix_qpp4b_post_sfdp_fixups,
> > @@ -96,6 +115,10 @@ static const struct spi_nor_fixups mx25l3255e_fixups = {
> >       .late_init = mx25l3255e_late_init_fixups,
> >  };
> >
> > +static const struct spi_nor_fixups mx25l12805d_4pp3b_fixups = {
> > +     .post_sfdp = mx25l12805d_4pp3b_post_sfdp_fixups,
>
> It seems that this fixup won't be called at all because the dual/quad
> io support is missing. See:

Since the MX25L12805D only supports single I/O read, these flags cannot
be added. Please refer to the datasheet for details:

Link: https://www.alldatasheet.com/datasheet-pdf/view/267916/MCNIX/MX25L12805D.html

Additionally, please refer to this patch, which mainly addresses the
deprecated SFDP parsing issue:

Link: https://patchwork.ozlabs.org/project/linux-mtd/cover/20260713091206.2414400-1-mwalle@xxxxxxxxxx/";

Therefore, my patch is expected to be merged alongside the 'Rework flash
parameter initialization' patch, which should resolve the issue you brought
up.

>
>         if (nor->info->no_sfdp_flags & (SPI_NOR_DUAL_READ |
>                                         SPI_NOR_QUAD_READ |
>                                         SPI_NOR_OCTAL_READ |
>                                         SPI_NOR_OCTAL_DTR_READ))
>                 spi_nor_sfdp_init_params_deprecated(nor);
>
> > +};
> > +
> >  static const struct flash_info macronix_nor_parts[] = {
> >       {
> >               .id = SNOR_ID(0xc2, 0x20, 0x10),
> > @@ -130,9 +153,10 @@ static const struct flash_info macronix_nor_parts[] = {
> >               .size = SZ_8M,
> >               .no_sfdp_flags = SECT_4K,
> >       }, {
> > -             /* MX25L12805D */
> > +             /* MX25L12805D, MX25L12833F, MX25L12845G */
> >               .id = SNOR_ID(0xc2, 0x20, 0x18),
> >               .flags = SPI_NOR_HAS_LOCK | SPI_NOR_4BIT_BP,
> > +             .fixups = &mx25l12805d_4pp3b_fixups,
> >       }, {
> >               /* MX25L25635E, MX25L25645G */
> >               .id = SNOR_ID(0xc2, 0x20, 0x19),
> > --
> > 2.25.1
> >
>
> Regards,
> Shiji Yang

Best Regards,
Cheng Ming Lin