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

[Jean Pihet <jean.pihet@xxxxxxxxxxxxxx>]

Hi Tony,

On Fri, Dec 6, 2019 at 5:24 PM Tony Lindgren <tony@xxxxxxxxxxx> wrote:
>
> Hi Jean,
>
> * Jean Pihet <jean.pihet@xxxxxxxxxxxxxx> [191206 16:01]:
> > 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.
>
> This source clock can be different between the SoC models, the
> related fck probably needs to be fixed in the SoC specific dtsi
> file.
>
> Currently qspi it's there only in dra7.dtsi, sounds like you
> are using it on am3/am4 based on the clock name?

I am using the AM4376 chipset. Only the interface is fixed in the
hwmod data as fck.
What is the best solution to add the extra fck?

Thank you for reviewing.
Regards,
Jean

>
> Regards,
>
> Tony
>
> > ---
> >  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
> >
> >  /* 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);
> > --
> > 2.23.0
> >