[PATCH] watchdog: imx2_wdt: Add power management support.

From: Xiubo Li
Date: Mon Sep 22 2014 - 06:01:23 EST


Add power management operations(suspend and resume) as part of
dev_pm_ops for IMX2 watchdog driver.

Signed-off-by: Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx>
---
drivers/watchdog/imx2_wdt.c | 47 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)

diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index 68c3d37..941c36f 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -295,6 +295,52 @@ static void imx2_wdt_shutdown(struct platform_device *pdev)
}
}

+#ifdef CONFIG_PM_SLEEP
+/* Disable watchdog if it is active during suspend */
+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);
+
+ imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
+ imx2_wdt_ping(wdog);
+
+ /* Watchdog has been stopped but IP block is still running */
+ if (!watchdog_active(&wdog) && imx2_wdt_is_running(wdev))
+ 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)) {
+ /* Resumes from deep sleep we need 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)) {
+ imx2_wdt_ping(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 */ }
@@ -307,6 +353,7 @@ 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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