[PATCH v2 2/2] mtd: spi-nor: Mask out fast read if not requested in DT

[Bin Meng]

Hi Pratyush,

On Fri, Jul 30, 2021 at 3:31 PM Pratyush Yadav <p.yadav at ti.com> wrote:
>
> On 30/07/21 03:20PM, Bin Meng wrote:
> > The DT bindings of "jedec,spi-nor" [1] defines "m25p,fast-read" property
> > to indicate that "fast read" opcode can be used to read data from the
> > chip instead of the usual "read" opcode.
> >
> > If this property is not present in DT, mask out fast read in
> > spi_nor_init_params(). This change mirrors the same logic in
> > spi_nor_info_init_params() in drivers/mtd/spi-nor/core.c in
> > the Linux kernel v5.14-rc3.
> >
> > [1] Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml in the kernel tree
> >
> > Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> >
> > ---
> >
> > Changes in v2:
> > - Guard changes with CONFIG_IS_ENABLED(DM_SPI)
>
> Hehe, I just commented about this on your v1, and I see the v2 in my
> inbox already ;-)
>
> So this will make sure that dev_ofnode() will be valid, right?

This is to avoid build error for non-DM_SPI platforms.

For dev_ofnode() I think it's always valid, as spi_nor_init_params()
is called by spi_nor_scan() in sf_probe.c which does not support
OF_PLATDATA.

>
> >
> >  drivers/mtd/spi/spi-nor-core.c | 16 +++++++++++++---
> >  1 file changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
> > index c8c3bdd890..d5d905fa5a 100644
> > --- a/drivers/mtd/spi/spi-nor-core.c
> > +++ b/drivers/mtd/spi/spi-nor-core.c
> > @@ -2604,18 +2604,28 @@ static int spi_nor_init_params(struct spi_nor *nor,
> >       params->size = info->sector_size * info->n_sectors;
> >       params->page_size = info->page_size;
> >
> > +     if (!(info->flags & SPI_NOR_NO_FR)) {
> > +             /* Default to Fast Read for DT and non-DT platform devices. */
> > +             params->hwcaps.mask |= SNOR_HWCAPS_READ_FAST;
> > +
> > +             /* Mask out Fast Read if not requested at DT instantiation. */
> > +#if CONFIG_IS_ENABLED(DM_SPI)
> > +             if (!ofnode_read_bool(dev_ofnode(nor->spi->dev),
>
> Let's avoid the #if here and do
>
>   if (CONFIG_IS_ENABLED(DM_SPI) && !ofnode_read_bool())

This does not work because nor->spi->dev has to be inside
CONFIG_IS_ENABLED(DM_SPI) as well.

>
> > +                                   "m25p,fast-read"))
> > +                     params->hwcaps.mask &= ~SNOR_HWCAPS_READ_FAST;
> > +#endif
> > +     }
> > +
> >       /* (Fast) Read settings. */
> >       params->hwcaps.mask |= SNOR_HWCAPS_READ;
> >       spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ],
> >                                 0, 0, SPINOR_OP_READ,
> >                                 SNOR_PROTO_1_1_1);
> >
> > -     if (!(info->flags & SPI_NOR_NO_FR)) {
> > -             params->hwcaps.mask |= SNOR_HWCAPS_READ_FAST;
> > +     if (params->hwcaps.mask & SNOR_HWCAPS_READ_FAST)
> >               spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_FAST],
> >                                         0, 8, SPINOR_OP_READ_FAST,
> >                                         SNOR_PROTO_1_1_1);
> > -     }
> >
> >       if (info->flags & SPI_NOR_DUAL_READ) {
> >               params->hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2;
>

Regards,
Bin