On Thu, Oct 16, 2014 at 11:44:15AM +0800, Xiubo Li wrote:
> Add power management operations(suspend and resume) as part of
> dev_pm_ops for IMX2 watchdog driver.
>
> If PM will be supported, please make sure that the wdev->clk
> could disable the watchdog's counter input clock source or can
> mask watchdog's reset request to the core.
>
> If watchdog is still used by consumers and resumes from deep
> sleep state, we need to restart the watchdog again without
> enabling the timer.
>
> If watchdog been has started --> stopped by the consumers and
> resumes from non-deep sleep state, then start the timer again.
>
> If watchdog has been started --> stopped by the consumers and
> resumes from deep sleep state, will do nothing. The watchdog
> will be restarted by consumers next time to be used.
>
> Signed-off-by: Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx>
Looks ok to me.
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
>
> Change in V3:
> - Uses standard multi-line comments.
>
>
> drivers/watchdog/imx2_wdt.c | 60 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 60 insertions(+)
>
> diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
> index 7e12f88..22ab599 100644
> --- a/drivers/watchdog/imx2_wdt.c
> +++ b/drivers/watchdog/imx2_wdt.c
> @@ -326,6 +326,65 @@ static void imx2_wdt_shutdown(struct platform_device *pdev)
> }
> }
>
> +#ifdef CONFIG_PM_SLEEP
> +/* Disable watchdog if it is active or non-active but still running */
> +static int imx2_wdt_suspend(struct device *dev)
> +{
> + struct watchdog_device *wdog = dev_get_drvdata(dev);
> + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
> +
> + /* The watchdog IP block is running */
> + if (imx2_wdt_is_running(wdev)) {
> + imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
> + imx2_wdt_ping(wdog);
> +
> + /* The watchdog is not active */
> + if (!watchdog_active(wdog))
> + del_timer_sync(&wdev->timer);
> + }
> +
> + clk_disable_unprepare(wdev->clk);
> +
> + return 0;
> +}
> +
> +/* Enable watchdog and configure it if necessary */
> +static int imx2_wdt_resume(struct device *dev)
> +{
> + struct watchdog_device *wdog = dev_get_drvdata(dev);
> + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
> +
> + clk_prepare_enable(wdev->clk);
> +
> + if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) {
> + /*
> + * If the watchdog is still active and resumes
> + * from deep sleep state, need to restart the
> + * watchdog again.
> + */
> + imx2_wdt_setup(wdog);
> + imx2_wdt_set_timeout(wdog, wdog->timeout);
> + imx2_wdt_ping(wdog);
> + } else if (imx2_wdt_is_running(wdev)) {
> + /* Resuming from non-deep sleep state. */
> + imx2_wdt_set_timeout(wdog, wdog->timeout);
> + imx2_wdt_ping(wdog);
> + /*
> + * But the watchdog is not active, then start
> + * the timer again.
> + */
> + if (!watchdog_active(wdog))
> + mod_timer(&wdev->timer,
> + jiffies + wdog->timeout * HZ / 2);
> + }
> +
> + return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend,
> + imx2_wdt_resume);
> +
> static const struct of_device_id imx2_wdt_dt_ids[] = {
> { .compatible = "fsl,imx21-wdt", },
> { /* sentinel */ }
> @@ -338,6 +397,7 @@ static struct platform_driver imx2_wdt_driver = {
> .driver = {
> .name = DRIVER_NAME,
> .owner = THIS_MODULE,
> + .pm = &imx2_wdt_pm_ops,
> .of_match_table = imx2_wdt_dt_ids,
> },
> };
> --
> 2.1.0.27.g96db324
>
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