linux-kernel - Re: [PATCH 1/1] extcon: usb-gpio: add pinctrl operation during system PM

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Message-ID: <ee98009c-0bfe-e19f-e5cc-c2342d08afae@ti.com>
Date:   Tue, 3 Jan 2017 11:57:19 +0200
From:   Roger Quadros <rogerq@...com>
To:     Peter Chen <peter.chen@....com>, <myungjoo.ham@...sung.com>,
        <cw00.choi@...sung.com>
CC:     <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/1] extcon: usb-gpio: add pinctrl operation during system
 PM

Hi Peter,

On 03/01/17 10:17, Peter Chen wrote:
> At some systems, the pinctrl setting will be lost or needs to
> set as "sleep" state to save power consumption. So, we need to
> configure pinctrl as "sleep" state when system enters suspend,
> and as "default" state after system resumes. In this way, the
> pinctrl value can be recovered as "default" state after resuming.
> 
> Signed-off-by: Peter Chen <peter.chen@....com>
> ---
>  drivers/extcon/extcon-usb-gpio.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c
> index d589c5f..f7172ae 100644
> --- a/drivers/extcon/extcon-usb-gpio.c
> +++ b/drivers/extcon/extcon-usb-gpio.c
> @@ -244,6 +244,7 @@ static int usb_extcon_suspend(struct device *dev)
>  		disable_irq(info->id_irq);
>  	if (info->vbus_gpiod)
>  		disable_irq(info->vbus_irq);
> +	pinctrl_pm_select_sleep_state(dev);
>  
>  	return ret;
>  }
> @@ -253,6 +254,7 @@ static int usb_extcon_resume(struct device *dev)
>  	struct usb_extcon_info *info = dev_get_drvdata(dev);
>  	int ret = 0;
>  
> +	pinctrl_pm_select_default_state(dev);
>  	if (device_may_wakeup(dev)) {
>  		if (info->id_gpiod) {
>  			ret = disable_irq_wake(info->id_irq);
> 

How does this work if wake from suspend is desired?
pinctrl sleep state might not support wakeup.

cheers,
-roger