Re: [PATCH v3 6/7] pwm: rockchip: Enable PWM clock of probed device only if running

[Kever Yang <kever.yang@rock-chips.com>]

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+ David and Steven,

Hi Steven,
    please help to review this patch set.

Thanks
- Kever

Simon South <simon@simonsouth.net> 于2020年12月24日周四 上午12:01写道：

> Currently rockchip_pwm_probe() enables the PWM clock of every device it
> matches, then disables the clock unless the device itself appears to have
> been enabled (by a bootloader, presumably) before the kernel started.
>
> Simplify this by enabling (rather, keeping enabled) the PWM clock of only
> devices that are already running, as enabling the clock for any other
> device during probing is unnecessary.
>
> Signed-off-by: Simon South <simon@simonsouth.net>
> ---
>  drivers/pwm/pwm-rockchip.c | 21 +++++++++++++--------
>  1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
> index 80f5e69d9b8a..02da7370db70 100644
> --- a/drivers/pwm/pwm-rockchip.c
> +++ b/drivers/pwm/pwm-rockchip.c
> @@ -327,12 +327,6 @@ static int rockchip_pwm_probe(struct platform_device
> *pdev)
>                 return ret;
>         }
>
> -       ret = clk_prepare_enable(pc->clk);
> -       if (ret) {
> -               dev_err(&pdev->dev, "Can't prepare enable PWM clk: %d\n",
> ret);
> -               return ret;
> -       }
> -
>         ret = clk_prepare_enable(pc->pclk);
>         if (ret) {
>                 dev_err(&pdev->dev, "Can't enable APB clk: %d\n", ret);
> @@ -357,8 +351,19 @@ static int rockchip_pwm_probe(struct platform_device
> *pdev)
>         enable_conf = pc->data->enable_conf;
>         ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl);
>         enabled = ((ctrl & enable_conf) == enable_conf);
> -       if (!enabled)
> -               clk_disable(pc->clk);
> +       if (enabled) {
> +               ret = clk_prepare_enable(pc->clk);
> +               if (ret) {
> +                       dev_err(&pdev->dev, "Can't enable PWM clk: %d\n",
> ret);
> +                       return ret;
> +               }
> +       } else {
> +               ret = clk_prepare(pc->clk);
> +               if (ret) {
> +                       dev_err(&pdev->dev, "Can't prepare PWM clk: %d\n",
> ret);
> +                       return ret;
> +               }
> +       }
>
>         clk_disable(pc->pclk);
>
> --
> 2.29.2
>
>
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>
>

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