linux-kernel - Re: [PATCH V3 RESEND] pwm: meson: add pwm support for S4

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Message-ID: <20231016223749.GA7647@ofsar>
Date:   Mon, 16 Oct 2023 22:37:49 +0000
From:   Yixun Lan <dlan@...too.org>
To:     JunYi Zhao <junyi.zhao@...ogic.com>
Cc:     thierry.reding@...il.com, u.kleine-koenig@...gutronix.de,
        neil.armstrong@...aro.org, khilman@...libre.com,
        jbrunet@...libre.com, martin.blumenstingl@...glemail.com,
        linux-pwm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-amlogic@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH V3 RESEND] pwm: meson: add pwm support for S4

Hi JunYi

On 13:24 Mon 16 Oct     , JunYi Zhao wrote:
> From: "junyi.zhao" <junyi.zhao@...ogic.com>
> 
> Support PWM for S4 soc.
> Now the PWM clock input is done in independent CLKCTRL registers.
> And no more in the PWM registers.
> PWM needs to obtain an external clock source.
> 
> Signed-off-by: junyi.zhao <junyi.zhao@...ogic.com>
> ---
> V2 -> V3: 
> Rebase and Review the latest upstream code again.
> After reconstruction, stick to the previous code as much as possible.
>  drivers/pwm/pwm-meson.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
> index 25519cddc2a9..fe9fd75747c4 100644
> --- a/drivers/pwm/pwm-meson.c
> +++ b/drivers/pwm/pwm-meson.c
> @@ -99,6 +99,7 @@ struct meson_pwm_channel {
>  struct meson_pwm_data {
>  	const char * const *parent_names;
>  	unsigned int num_parents;
> +	unsigned int extern_clk;
>  };
>  
>  struct meson_pwm {
> @@ -396,6 +397,10 @@ static const struct meson_pwm_data pwm_g12a_ao_cd_data = {
>  	.num_parents = ARRAY_SIZE(pwm_g12a_ao_cd_parent_names),
>  };
>  
> +static const struct meson_pwm_data pwm_s4_data = {
> +	.extern_clk = true,
> +};
> +
>  static const struct of_device_id meson_pwm_matches[] = {
>  	{
>  		.compatible = "amlogic,meson8b-pwm",
> @@ -429,6 +434,10 @@ static const struct of_device_id meson_pwm_matches[] = {
>  		.compatible = "amlogic,meson-g12a-ao-pwm-cd",
>  		.data = &pwm_g12a_ao_cd_data
>  	},
> +	{
> +		.compatible = "amlogic,s4-pwm",
> +		.data = &pwm_s4_data,
> +	},
>  	{},
>  };
>  MODULE_DEVICE_TABLE(of, meson_pwm_matches);
> @@ -451,6 +460,16 @@ static int meson_pwm_init_channels(struct meson_pwm *meson)
>  		struct clk_parent_data div_parent = {}, gate_parent = {};
>  		struct clk_init_data init = {};
>  
> +		if (meson->data->extern_clk) {
> +			snprintf(name, sizeof(name), "clkin%u", i);
> +			channel->clk = devm_clk_get(dev, name);
use devm_clk_get_optional() which would save you from introducing
the 'extern_clk' variable

> +			if (IS_ERR(channel->clk)) {
> +				dev_err(meson->chip.dev, "can't get device clock\n");
> +				return PTR_ERR(channel->clk);
> +			}
> +			continue;
> +		}
> +
>  		snprintf(name, sizeof(name), "%s#mux%u", dev_name(dev), i);
>  
>  		init.name = name;
> 
> base-commit: 4d2c646ac07cf4a35ef1c4a935a1a4fd6c6b1a36
> -- 
> 2.41.0
> 
> 
> _______________________________________________
> linux-amlogic mailing list
> linux-amlogic@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-amlogic

-- 
Yixun Lan (dlan)
Gentoo Linux Developer
GPG Key ID AABEFD55

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