On Wed, Sep 11, 2024 at 10:31:40PM +0200, Marek Vasut wrote:
> On 9/10/24 9:07 PM, Frank Li wrote:
> > From: Liu Ying <victor.liu@xxxxxxx>
> >
> > PWM in i.MX8QXP MIPI subsystem needs the clock '32k'. Use it if the DTS
> > provides that.
> >
> > Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
> > Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> > ---
> > Change from v2 to v3
> > - use buck clk API
> >
> > Change from v1 to v2
> > - remove if check for clk
> > - use dev_err_probe
> > - remove int val
> > ---
> > drivers/pwm/pwm-imx27.c | 13 ++++++++++++-
> > 1 file changed, 12 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c
> > index ce9208540f1b8..2a9fba6f9d0a8 100644
> > --- a/drivers/pwm/pwm-imx27.c
> > +++ b/drivers/pwm/pwm-imx27.c
> > @@ -81,10 +81,11 @@
> > #define MX3_PWMPR_MAX 0xfffe
> > static const char * const pwm_imx27_clks[] = {"ipg", "per"};
> > +static const char * const pwm_imx27_opt_clks[] = {"32k"};
> > #define PWM_IMX27_PER 1
> > struct pwm_imx27_chip {
> > - struct clk_bulk_data clks[ARRAY_SIZE(pwm_imx27_clks)];
> > + struct clk_bulk_data clks[ARRAY_SIZE(pwm_imx27_clks) + ARRAY_SIZE(pwm_imx27_opt_clks)];
> > int clks_cnt;
> > void __iomem *mmio_base;
> > @@ -371,6 +372,16 @@ static int pwm_imx27_probe(struct platform_device *pdev)
> > return dev_err_probe(&pdev->dev, ret,
> > "getting clocks failed\n");
> > + for (i = 0; i < ARRAY_SIZE(pwm_imx27_opt_clks); i++)
> > + imx->clks[i + imx->clks_cnt].id = pwm_imx27_opt_clks[i];
> > +
> > + ret = devm_clk_bulk_get_optional(&pdev->dev, ARRAY_SIZE(pwm_imx27_opt_clks),
> > + imx->clks + imx->clks_cnt);
> > + if (ret)
> > + return dev_err_probe(&pdev->dev, ret, "get optional clocks failed\n");
> > +
> > + imx->clks_cnt += ARRAY_SIZE(pwm_imx27_opt_clks);
> > +
>
> This will succeed even if the regular PWM clock are invalid or not present,
> wouldn't it? I don't think removing that protection is an improvement.
I have not touch regular PWM clock's code. Just add more optional clocks.
devm_clk_bulk_get(imx->clks);
devm_clk_bulk_get_optional(imx->clks + required_cnt);
so imx->clks have two part {required_part, optional_part};
require part is the same as the before. If it invalidate or not present,
driver will fail probe.
>
> Also, it is not clear whether the 32kHz clock are really supplying the PWM,
> see my comment on 1/3 in this series.
Yes, it is for pwm.
