[PATCH v1] spi: cadence_qspi: Probe fail if QSPI clock is not set

[Ang, Chee Hong]

> Hi,
> 
> On 05/08/20 3:48 pm, Chee Hong Ang wrote:
> > If the QSPI clock is not set (read as 0), QSPI driver probe shall fail
> > and prevent further QSPI access.
> >
> > Signed-off-by: Chee Hong Ang <chee.hong.ang at intel.com>
> > ---
> >   drivers/spi/cadence_qspi.c | 3 +++
> >   1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c
> > index 1e85749209..3bb5c7031d 100644
> > --- a/drivers/spi/cadence_qspi.c
> > +++ b/drivers/spi/cadence_qspi.c
> > @@ -170,6 +170,9 @@ static int cadence_spi_probe(struct udevice *bus)
> >   	struct clk clk;
> >   	int ret;
> >
> > +	if (!CONFIG_CQSPI_REF_CLK)
> > +		return -ENODEV;
> > +
> 
> This seems broken to me...
> 
> Most platforms have moved away from passing clk freq via CONFIG_ and are
> using more scalable DT or platdata approach where freq is obtained via

I think the proper way to resolve this is to change our clock driver to DM. Thanks.

> clk_get_*() APIs... See few lines below:
> 
>          if (plat->ref_clk_hz == 0) {
>                  ret = clk_get_by_index(bus, 0, &clk);
>                  if (ret) {
> #ifdef CONFIG_CQSPI_REF_CLK
>                          plat->ref_clk_hz = CONFIG_CQSPI_REF_CLK; #else
>                          return ret;
> #endif
>                  } else {
>                          plat->ref_clk_hz = clk_get_rate(&clk);
>                          clk_free(&clk);
>                          if (IS_ERR_VALUE(plat->ref_clk_hz))
>                                  return plat->ref_clk_hz;
>                  }
>          }
> 
> So there is no need to make CONFIG_CQSPI_REF_CLK mandatory.
> Probe may fail only when CONFIG_CQSPI_REF_CLK is undefined and there is
> no reference to a valid clk device either.
> 
> 
> >   	priv->regbase = plat->regbase;
> >   	priv->ahbbase = plat->ahbbase;
> >
> >
> 
> Regards
> Vignesh