Re: [PATCHv2] watchdog: qcom: Add suspend/resume support

[Guenter Roeck <linux@roeck-us.net>]

On Thu, Jan 17, 2019 at 08:49:42PM +0530, Sai Prakash Ranjan wrote:
> This adds the support for qcom watchdog suspend and resume
> when entering and exiting deep sleep states. Otherwise
> having watchdog active after suspend would result in unwanted
> crashes/resets if resume happens after a long time.
> 
> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> 
> ---
> 
> v2:
>  * Use __maybe_unused instead of #ifdef as suggested by
>    Brian and Guenter
> ---
>  drivers/watchdog/qcom-wdt.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c
> index 780971318810..5dfd604477a4 100644
> --- a/drivers/watchdog/qcom-wdt.c
> +++ b/drivers/watchdog/qcom-wdt.c
> @@ -245,6 +245,28 @@ static int qcom_wdt_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static int __maybe_unused qcom_wdt_suspend(struct device *dev)
> +{
> +	struct qcom_wdt *wdt = dev_get_drvdata(dev);
> +
> +	if (watchdog_active(&wdt->wdd))
> +		qcom_wdt_stop(&wdt->wdd);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused qcom_wdt_resume(struct device *dev)
> +{
> +	struct qcom_wdt *wdt = dev_get_drvdata(dev);
> +
> +	if (watchdog_active(&wdt->wdd))
> +		qcom_wdt_start(&wdt->wdd);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(qcom_wdt_pm_ops, qcom_wdt_suspend, qcom_wdt_resume);
> +
>  static const struct of_device_id qcom_wdt_of_table[] = {
>  	{ .compatible = "qcom,kpss-timer", .data = reg_offset_data_apcs_tmr },
>  	{ .compatible = "qcom,scss-timer", .data = reg_offset_data_apcs_tmr },
> @@ -259,6 +281,7 @@ static struct platform_driver qcom_watchdog_driver = {
>  	.driver	= {
>  		.name		= KBUILD_MODNAME,
>  		.of_match_table	= qcom_wdt_of_table,
> +		.pm		= &qcom_wdt_pm_ops,
>  	},
>  };
>  module_platform_driver(qcom_watchdog_driver);
> -- 
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> of Code Aurora Forum, hosted by The Linux Foundation
>