Re: [PATCH v8 1/2] pwm: meson: Add support for Amlogic S4 PWM

[Jerome Brunet]

On Thu 13 Jun 2024 at 19:46, Kelvin Zhang via B4 Relay <devnull+kelvin.zhang.amlogic.com@xxxxxxxxxx> wrote:

> From: Junyi Zhao <junyi.zhao@xxxxxxxxxxx>
>
> Add support for Amlogic S4 PWM.
>
> Signed-off-by: Junyi Zhao <junyi.zhao@xxxxxxxxxxx>
> Signed-off-by: Kelvin Zhang <kelvin.zhang@xxxxxxxxxxx>
> ---
>  drivers/pwm/pwm-meson.c | 39 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
>
> diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
> index b2f97dfb01bb..98e6c1533312 100644
> --- a/drivers/pwm/pwm-meson.c
> +++ b/drivers/pwm/pwm-meson.c
> @@ -460,6 +460,37 @@ static int meson_pwm_init_channels_meson8b_v2(struct pwm_chip *chip)
>  	return meson_pwm_init_clocks_meson8b(chip, mux_parent_data);
>  }
>  
> +static void meson_pwm_s4_put_clk(void *data)
> +{
> +	struct clk *clk = data;
> +
> +	clk_put(clk);
> +}
> +
> +static int meson_pwm_init_channels_s4(struct pwm_chip *chip)
> +{
> +	struct device *dev = pwmchip_parent(chip);
> +	struct device_node *np = dev->of_node;
> +	struct meson_pwm *meson = to_meson_pwm(chip);
> +	int i, ret;
> +
> +	for (i = 0; i < MESON_NUM_PWMS; i++) {
> +		meson->channels[i].clk = of_clk_get(np, i);
> +		if (IS_ERR(meson->channels[i].clk))
> +			return dev_err_probe(dev,
> +					     PTR_ERR(meson->channels[i].clk),
> +					     "Failed to get clk\n");

here it is ok but ..

> +
> +		ret = devm_add_action_or_reset(dev, meson_pwm_s4_put_clk,
> +					       meson->channels[i].clk);
> +		if (ret)
> +			return dev_err_probe(dev, ret,
> +					     "Failed to add clk_put action\n");

... here, devm_add_action_or_reset cannot defer, so dev_err_probe is not useful.
dev_err() if you must print something. Just "return ret;" would be fine
by me

> +	}
> +
> +	return 0;
> +}
> +
>  static const struct meson_pwm_data pwm_meson8b_data = {
>  	.parent_names = { "xtal", NULL, "fclk_div4", "fclk_div3" },
>  	.channels_init = meson_pwm_init_channels_meson8b_legacy,
> @@ -498,6 +529,10 @@ static const struct meson_pwm_data pwm_meson8_v2_data = {
>  	.channels_init = meson_pwm_init_channels_meson8b_v2,
>  };
>  
> +static const struct meson_pwm_data pwm_s4_data = {
> +	.channels_init = meson_pwm_init_channels_s4,
> +};
> +
>  static const struct of_device_id meson_pwm_matches[] = {
>  	{
>  		.compatible = "amlogic,meson8-pwm-v2",
> @@ -536,6 +571,10 @@ static const struct of_device_id meson_pwm_matches[] = {
>  		.compatible = "amlogic,meson-g12a-ao-pwm-cd",
>  		.data = &pwm_g12a_ao_cd_data
>  	},
> +	{
> +		.compatible = "amlogic,meson-s4-pwm",
> +		.data = &pwm_s4_data
> +	},
>  	{},
>  };
>  MODULE_DEVICE_TABLE(of, meson_pwm_matches);

-- 
Jerome