Re: [PATCH v7 04/14] spi: cadence: Provide a capability structure

Miquel Raynal
2021-12-21T10:17:03Z

Hi Pratyush,

p.yadav@ti.com wrote on Tue, 21 Dec 2021 00:25:18 +0530:

> > Subject: [PATCH v7 04/14] spi: cadence: Provide a capability structure
>
> s/cadence/cadence-quadspi/

Right.

>
> On 17/12/21 05:16PM, Miquel Raynal wrote:
> > This controller has DTR support, so advertize it with a capability now
> > that the spi_controller_mem_ops structure contains this new field. This
> > will later be used by the core to discriminate whether an operation is
> > supported or not, in a more generic way than having different helpers.
> >
> > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > ---
> > drivers/spi/spi-cadence-quadspi.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
> > index 101cc71bffa7..98e0cc4236e3 100644
> > --- a/drivers/spi/spi-cadence-quadspi.c
> > +++ b/drivers/spi/spi-cadence-quadspi.c
> > @@ -1388,10 +1388,15 @@ static const char *cqspi_get_name(struct spi_mem *mem)
> > return devm_kasprintf(dev, GFP_KERNEL, "%s.%d", dev_name(dev), mem->spi->chip_select);
> > }
> >
> > +static const struct spi_controller_mem_caps cqspi_mem_caps = {
> > + .dtr = true,
> > +};
> > +
> > static const struct spi_controller_mem_ops cqspi_mem_ops = {
> > .exec_op = cqspi_exec_mem_op,
> > .get_name = cqspi_get_name,
> > .supports_op = cqspi_supports_mem_op,
> > + .caps = &cqspi_mem_caps,
>
> I just noticed you put it under struct spi_mem_ops, not under struct
> spi_mem. This is not an operation per se so wouldn't it be better if it
> is moved to struct spi_mem?

I had a hard time taking a decision but my conclusion was that these
caps are static controller capabilities and exclusively tight to the
controller. The spi_mem structure defines a SPI peripheral. The
spi_mem_ops structure is the only spi-mem related field of the
spi-controller structure. I could have added my own field there but
as these caps are only meant to be used by the spi_mem_ops anyway
(exclusively ->supports_op() for now), it seemed to be a good location,
at least better than the spi-mem structure.

> Anyway, the change itself looks good to me. The cqspi_supports_mem_op()
> already checks for mixed DTR modes so we should be good.

Yep!

>
> > };
> >
> > static int cqspi_setup_flash(struct cqspi_st *cqspi)
> > --
> > 2.27.0
> >
>

Thanks,
Miquèl