linux-kernel - Re: [PATCH V3 4/4] pwm: tegra: Add support to configure pin state in suspends/resume

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Message-ID: <afc48437-a35c-7074-1f86-b6c29d3dc257@nvidia.com>
Date:   Fri, 7 Apr 2017 11:27:03 +0100
From:   Jon Hunter <jonathanh@...dia.com>
To:     Laxman Dewangan <ldewangan@...dia.com>, <thierry.reding@...il.com>,
        <robh+dt@...nel.org>
CC:     <mark.rutland@....com>, <linux-pwm@...r.kernel.org>,
        <devicetree@...r.kernel.org>, <linux-tegra@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH V3 4/4] pwm: tegra: Add support to configure pin state in
 suspends/resume


On 07/04/17 10:34, Laxman Dewangan wrote:
> In some of NVIDIA Tegra's platform, PWM controller is used to
> control the PWM controlled regulators. PWM signal is connected to
> the VID pin of the regulator where duty cycle of PWM signal decide
> the voltage level of the regulator output.
> 
> When system enters suspend, some PWM client/slave regulator devices
> require the PWM output to be tristated.
> 
> Add support to configure the pin state via pinctrl frameworks in
> suspend and active state of the system.
> 
> Signed-off-by: Laxman Dewangan <ldewangan@...dia.com>
> 
> ---
> Changes from v1:
> - Use standard pinctrl names for sleep and active state.
> - Use API pinctrl_pm_select_*()
> 
> Changes from V2:
> - Use returns of pinctrl_pm_select_*()
> - Rephrase commit message.
> ---
>  drivers/pwm/pwm-tegra.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c
> index 21518be..9c7f180 100644
> --- a/drivers/pwm/pwm-tegra.c
> +++ b/drivers/pwm/pwm-tegra.c
> @@ -29,6 +29,7 @@
>  #include <linux/of_device.h>
>  #include <linux/pwm.h>
>  #include <linux/platform_device.h>
> +#include <linux/pinctrl/consumer.h>
>  #include <linux/slab.h>
>  #include <linux/reset.h>
>  
> @@ -255,6 +256,18 @@ static int tegra_pwm_remove(struct platform_device *pdev)
>  	return pwmchip_remove(&pc->chip);
>  }
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int tegra_pwm_suspend(struct device *dev)
> +{
> +	return pinctrl_pm_select_sleep_state(dev);
> +}
> +
> +static int tegra_pwm_resume(struct device *dev)
> +{
> +	return pinctrl_pm_select_default_state(dev);
> +}
> +#endif
> +
>  static const struct tegra_pwm_soc tegra20_pwm_soc = {
>  	.num_channels = 4,
>  };
> @@ -271,10 +284,15 @@ static const struct of_device_id tegra_pwm_of_match[] = {
>  
>  MODULE_DEVICE_TABLE(of, tegra_pwm_of_match);
>  
> +static const struct dev_pm_ops tegra_pwm_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(tegra_pwm_suspend, tegra_pwm_resume)
> +};
> +
>  static struct platform_driver tegra_pwm_driver = {
>  	.driver = {
>  		.name = "tegra-pwm",
>  		.of_match_table = tegra_pwm_of_match,
> +		.pm = &tegra_pwm_pm_ops,
>  	},
>  	.probe = tegra_pwm_probe,
>  	.remove = tegra_pwm_remove,

Acked-by: Jon Hunter <jonathanh@...dia.com>

Cheers
Jon

-- 
nvpublic