Re: watchdog's pm support preffered implementation

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Small fix below in the second implementation.

best regards
Janusz

W dniu 2014-09-18 23:40, Janusz Użycki pisze:
Hi again,

This is the second implementation. Which do you prefer?

Subject: [PATCH] stmp3xxx_rtc_wdt: Add suspend/resume PM support


Signed-off-by: Janusz Uzycki <j.uzycki@xxxxxxxxxxxxxx>
---
 drivers/watchdog/stmp3xxx_rtc_wdt.c | 39 +++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/watchdog/stmp3xxx_rtc_wdt.c b/drivers/watchdog/stmp3xxx_rtc_wdt.c
index 3546f03..1946277 100644
--- a/drivers/watchdog/stmp3xxx_rtc_wdt.c
+++ b/drivers/watchdog/stmp3xxx_rtc_wdt.c
@@ -95,9 +95,48 @@ static int stmp3xxx_wdt_remove(struct platform_device *pdev)
        return 0;
 }

+#ifdef CONFIG_PM_SLEEP
+/* There is no conflict with rtc/rtc-stmp3xxx.c parent
+ * because modified registers in PM functions are different */
+static int __maybe_unused stmp3xxx_wdt_suspend(struct device *dev)
+{
+       struct watchdog_device *wdd = dev_get_drvdata(dev);

drvdata is NULL, too fast,
+       struct watchdog_device *wdd = &stmp3xxx_wdd;

+
+       /* Is keep-on/ping timer suspended before?
+        * or additional driver-specific flag must be added
+        *  to block watchdog ping in the timer?
+        * or disable WATCHDOG_KEEP_ON before wdt_stop
+        *  and restore it in resume? */
+       if (watchdog_active(wdd)) {
+               dev_info(wdd->dev, "%s: wdt was active\n", __func__);
+               return wdt_stop(wdd);
+       }
+       /* should we use pm_runtime like omap_wdt.c does? */
+
+       return 0;
+}
+
+static int __maybe_unused stmp3xxx_wdt_resume(struct device *dev)
+{
+       struct watchdog_device *wdd = dev_get_drvdata(dev);
+       struct watchdog_device *wdd = &stmp3xxx_wdd;

+
+       if (watchdog_active(wdd)) {
+               dev_info(wdd->dev, "%s: wdt was active\n", __func__);
+               return wdt_start(wdd);
+       }
+
+       return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static SIMPLE_DEV_PM_OPS(stmp3xxx_wdt_pm_ops,
+               stmp3xxx_wdt_suspend, stmp3xxx_wdt_resume);
+
 static struct platform_driver stmp3xxx_wdt_driver = {
        .driver = {
                .name = "stmp3xxx_rtc_wdt",
+               .owner = THIS_MODULE,
+               .pm = &stmp3xxx_wdt_pm_ops,
        },
        .probe = stmp3xxx_wdt_probe,
        .remove = stmp3xxx_wdt_remove,
--
1.7.11.3


W dniu 2014-09-18 13:07, Janusz Użycki pisze:

I work under suspend/resume PM support for stmp3xxx driver.

Most of them use suspend() with struct platform_device and CONFIG_PM.
Only sp805, sirfsoc, s3c2410, dw drivers use suspend() with struct device
and SIMPLE_DEV_PM_OPS.
Which implementation is preffered today?

best regards
Janusz

P.S. Patch on the moment:
Signed-off-by: Janusz Uzycki <j.uzycki@xxxxxxxxxxxxxx>
---
 drivers/watchdog/stmp3xxx_rtc_wdt.c | 41 +++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/drivers/watchdog/stmp3xxx_rtc_wdt.c b/drivers/watchdog/stmp3xxx_rtc_wdt.c
index 3546f03..12060ab 100644
--- a/drivers/watchdog/stmp3xxx_rtc_wdt.c
+++ b/drivers/watchdog/stmp3xxx_rtc_wdt.c
@@ -74,6 +74,7 @@ static int stmp3xxx_wdt_probe(struct platform_device *pdev)
 {
        int ret;

+       platform_set_drvdata(pdev, &stmp3xxx_wdd);
        watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev);

stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT); @@ -95,12 +96,52 @@ static int stmp3xxx_wdt_remove(struct platform_device *pdev)
        return 0;
 }

+#ifdef CONFIG_PM
+/* There is no conflict with rtc/rtc-stmp3xxx.c parent
+ * because modified registers in PM functions are different */
+static int stmp3xxx_wdt_suspend(struct platform_device *pdev,
+                                       pm_message_t state)
+{
+       struct watchdog_device *wdd = platform_get_drvdata(pdev);
+
+       /* Is keep-on/ping timer suspended before?
+        * or additional driver-specific flag must be added
+        *  to block watchdog ping in the timer?
+        * or disable WATCHDOG_KEEP_ON before wdt_stop
+        *  and restore it in resume? */
+       if (watchdog_active(wdd)) {
+               dev_info(wdd->dev, "%s: wdt was active\n", __func__);
+               return wdt_stop(wdd);
+       }
+       /* should we use pm_runtime like omap_wdt.c does? */
+
+       return 0;
+}
+
+static int stmp3xxx_wdt_resume(struct platform_device *pdev)
+{
+       struct watchdog_device *wdd = platform_get_drvdata(pdev);
+
+       if (watchdog_active(wdd)) {
+               dev_info(wdd->dev, "%s: wdt was active\n", __func__);
+               return wdt_start(wdd);
+       }
+
+       return 0;
+}
+#else
+#define stmp3xxx_wdt_suspend   NULL
+#define stmp3xxx_wdt_resume    NULL
+#endif
+
 static struct platform_driver stmp3xxx_wdt_driver = {
        .driver = {
                .name = "stmp3xxx_rtc_wdt",
        },
        .probe = stmp3xxx_wdt_probe,
        .remove = stmp3xxx_wdt_remove,
+       .suspend = stmp3xxx_wdt_suspend,
+       .resume = stmp3xxx_wdt_resume,
 };
 module_platform_driver(stmp3xxx_wdt_driver);



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