linux-kernel - Re: [PATCH] pwm: rockchip: Simplify using devm_pwmchip

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Message-ID: <CAJKOXPfJFgg4ZkfW85mSg8+YaNFJ2G5OyRqJ=Hz-iZTpyNTndA@mail.gmail.com>
Date:   Wed, 1 Sep 2021 10:58:01 +0200
From:   Krzysztof Kozlowski <krzk@...nel.org>
To:     zhaoxiao <zhaoxiao@...ontech.com>
Cc:     thierry.reding@...il.com, lee.jones@...aro.org, heiko@...ech.de,
        u.kleine-koenig@...gutronix.de,
        linux-arm-kernel@...ts.infradead.org,
        linux-rockchip@...ts.infradead.org,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] pwm: rockchip: Simplify using devm_pwmchip_add()

On Tue, 31 Aug 2021 at 14:52, zhaoxiao <zhaoxiao@...ontech.com> wrote:
>
> With devm_pwmchip_add() we can drop pwmchip_remove() from the device
> remove callback. The latter can then go away, too and as this is the
> only user of platform_get_drvdata(), the respective call to
> platform_set_drvdata() can go, too.
>
> Signed-off-by: zhaoxiao <zhaoxiao@...ontech.com>
> ---
>  drivers/pwm/pwm-rockchip.c | 29 +----------------------------
>  1 file changed, 1 insertion(+), 28 deletions(-)
>
> diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
> index cbe900877724..c22856916e63 100644
> --- a/drivers/pwm/pwm-rockchip.c
> +++ b/drivers/pwm/pwm-rockchip.c
> @@ -347,8 +347,6 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
>                 goto err_clk;
>         }
>
> -       platform_set_drvdata(pdev, pc);
> -
>         pc->data = id->data;
>         pc->chip.dev = &pdev->dev;
>         pc->chip.ops = &rockchip_pwm_ops;
> @@ -358,7 +356,7 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
>         ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl);
>         enabled = (ctrl & enable_conf) == enable_conf;
>
> -       ret = pwmchip_add(&pc->chip);
> +       ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
>         if (ret < 0) {
>                 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
>                 goto err_pclk;
> @@ -380,37 +378,12 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
>         return ret;
>  }
>
> -static int rockchip_pwm_remove(struct platform_device *pdev)
> -{
> -       struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);
> -
> -       /*
> -        * Disable the PWM clk before unpreparing it if the PWM device is still
> -        * running. This should only happen when the last PWM user left it
> -        * enabled, or when nobody requested a PWM that was previously enabled
> -        * by the bootloader.
> -        *
> -        * FIXME: Maybe the core should disable all PWM devices in
> -        * pwmchip_remove(). In this case we'd only have to call
> -        * clk_unprepare() after pwmchip_remove().
> -        *
> -        */
> -       if (pwm_is_enabled(pc->chip.pwms))
> -               clk_disable(pc->clk);
> -
> -       clk_unprepare(pc->pclk);
> -       clk_unprepare(pc->clk);

NAK, for the same reason as pwm_samsung.

Please test your patches.

Best regards,
Krzysztof