Re: [PATCH 1/3] TI QSPI: Fix fclk frequency

[Jean Pihet <jean.pihet@xxxxxxxxxxxxxx>]

Hi Vignesh,

On Mon, Dec 9, 2019 at 10:59 AM Vignesh Raghavendra <vigneshr@xxxxxx> wrote:
>
>
>
> On 06/12/19 9:30 pm, Jean Pihet wrote:
> > The QSPI IP is clocked by two clocks:
> > - CORE_CLKOUTM4 / 2 (L3) as interface clock,
> > - PER_CLKOUTM2 / 4 (L4) as functional clock, which is PER_CLKOUTM2
> >   divided by 4, so at 192Mhz / 4 = 48MHz.
> >
> > Fix the use of the correct fclk by the driver and fix the frequency
> > value so that the divider is correctly programmed to generate the
> > desired frequency of QSPI_CLK.
> > ---
> >  drivers/spi/spi-ti-qspi.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
> > index 3cb65371ae3b..4680dad38ab2 100644
> > --- a/drivers/spi/spi-ti-qspi.c
> > +++ b/drivers/spi/spi-ti-qspi.c
> > @@ -79,7 +79,7 @@ struct ti_qspi {
> >
> >  #define QSPI_COMPLETION_TIMEOUT              msecs_to_jiffies(2000)
> >
> > -#define QSPI_FCLK                    192000000
> > +#define QSPI_FCLK                    48000000
> >
>
> This macro is unused and should be dropped.
That is correct. It is a left over from older versions. Will remove it.

Thanks,
Jean

>
> >  /* Clock Control */
> >  #define QSPI_CLK_EN                  (1 << 31)
> > @@ -748,7 +748,7 @@ static int ti_qspi_probe(struct platform_device *pdev)
> >               }
> >       }
> >
> > -     qspi->fclk = devm_clk_get(&pdev->dev, "fck");
> > +     qspi->fclk = devm_clk_get(&pdev->dev, "dpll_per_m2_div4_ck");
> >       if (IS_ERR(qspi->fclk)) {
> >               ret = PTR_ERR(qspi->fclk);
> >               dev_err(&pdev->dev, "could not get clk: %d\n", ret);
> >
>
> --
> Regards
> Vignesh