add runtime pm for watchdog

add runtime pm for watchdog

Signed-off-by: Ziv.Xu <Ziv.Xu@starfivetech.com>

diff --git a/drivers/watchdog/starfive-wdt.c b/drivers/watchdog/starfive-wdt.c
index 70588a5..22d5dfc 100755 (executable)
--- a/drivers/watchdog/starfive-wdt.c
+++ b/drivers/watchdog/starfive-wdt.c
@@ -31,6 +31,7 @@
 #include <linux/watchdog.h>
 #include <linux/reset.h>
 #include <linux/reset-controller.h>
+#include <linux/pm_runtime.h>
 
 #define WDT_INT_DIS    BIT(0)
 #define DELAY_US       0
@@ -500,6 +501,8 @@ static int starfive_wdt_stop(struct watchdog_device *wdd)
 
        spin_unlock(&wdt->lock);
 
+       pm_runtime_put(wdt->dev);
+
        return 0;
 }
 
@@ -507,6 +510,8 @@ static int starfive_wdt_start(struct watchdog_device *wdd)
 {
        struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
 
+       pm_runtime_get_sync(wdt->dev);
+
        spin_lock(&wdt->lock);
 
        starfive_wdt_unlock(wdt);
@@ -642,6 +647,8 @@ static int starfive_wdt_probe(struct platform_device *pdev)
        int started = 0;
        int ret;
 
+       pm_runtime_enable(dev);
+
        wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
        if (!wdt)
                return -ENOMEM;
@@ -728,9 +735,13 @@ static int starfive_wdt_probe(struct platform_device *pdev)
                 * disabled if it has been left running from the bootloader
                 * or other source.
                 */
+               pm_runtime_get_noresume(dev);
                starfive_wdt_stop(&wdt->wdt_device);
        }
 
+       clk_disable_unprepare(wdt->core_clk);
+       clk_disable_unprepare(wdt->apb_clk);
+
        platform_set_drvdata(pdev, wdt);
 
        return 0;
@@ -754,6 +765,7 @@ static int starfive_wdt_remove(struct platform_device *dev)
        watchdog_unregister_device(&wdt->wdt_device);
 
        clk_disable_unprepare(wdt->core_clk);
+       pm_runtime_disable(wdt->dev);
 
        return 0;
 }
@@ -765,7 +777,6 @@ static void starfive_wdt_shutdown(struct platform_device *dev)
        starfive_wdt_mask_and_disable_reset(wdt, true);
 
        starfive_wdt_stop(&wdt->wdt_device);
-
 }
 
 #ifdef CONFIG_PM_SLEEP
@@ -815,8 +826,33 @@ static int starfive_wdt_resume(struct device *dev)
 }
 #endif /* CONFIG_PM_SLEEP */
 
-static SIMPLE_DEV_PM_OPS(starfive_wdt_pm_ops, starfive_wdt_suspend,
-                       starfive_wdt_resume);
+#ifdef CONFIG_PM
+
+static int starfive_wdt_runtime_suspend(struct device *dev)
+{
+       struct starfive_wdt *wdt = dev_get_drvdata(dev);
+
+       clk_disable_unprepare(wdt->apb_clk);
+       clk_disable_unprepare(wdt->core_clk);
+
+       return 0;
+}
+
+static int starfive_wdt_runtime_resume(struct device *dev)
+{
+       struct starfive_wdt *wdt = dev_get_drvdata(dev);
+
+       clk_prepare_enable(wdt->apb_clk);
+       clk_prepare_enable(wdt->core_clk);
+
+       return 0;
+}
+
+#endif /*CONFIG_PM*/
+
+static const struct dev_pm_ops starfive_wdt_pm_ops = {
+       SET_RUNTIME_PM_OPS(starfive_wdt_runtime_suspend, starfive_wdt_runtime_resume, NULL)
+};
 
 static struct platform_driver starfive_starfive_wdt_driver = {
        .probe          = starfive_wdt_probe,
@@ -825,6 +861,11 @@ static struct platform_driver starfive_starfive_wdt_driver = {
        .id_table       = starfive_wdt_ids,
        .driver         = {
                .name   = "starfive-wdt",
+#if 1
+               /* Currently wdt suspend & resume will cause system reboot.
+                * Comment the pm operation for now, will add it back once
+                * the feature is ready.
+                */
                .pm     = &starfive_wdt_pm_ops,
                .of_match_table = of_match_ptr(starfive_wdt_match),
        },