watchdog: max77620: add sysfs to enable/disable WDT on normal

Add support to enable/disable watchdog on normal state although it
is enabled on boottime.

This will help to dynamically change the property of watchdog.

Sysfs path: /sys/devices/platform/7000d000.i2c/i2c-4/4-003c/max77620-wdt.5
Sysfs file: watchdog_normal_state
$ cat watchdog_normal_state
disable
$ echo enable > watchdog_normal_state
$ cat watchdog_normal_state
enable
$ echo disable > watchdog_normal_state
$ cat watchdog_normal_state
disable

bug 200120580

Change-Id: I876adff05103fef5ea5cb5591bfd333ec6d2e34e
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
(cherry picked from commit 4ae5caf94b6f94194b60860ead405e5ad575c5f3)
Reviewed-on: http://git-master/r/767158

diff --git a/drivers/watchdog/max77620_wdt.c b/drivers/watchdog/max77620_wdt.c
index 843d7ca865d5c85e7a24ea7e74161646de37b7a0..d649223227b9aea94f99eafbe82c06aee1e5e452 100644 (file)
--- a/drivers/watchdog/max77620_wdt.c
+++ b/drivers/watchdog/max77620_wdt.c
@@ -45,6 +45,7 @@ struct max77620_wdt {
        struct rtc_device               *rtc;
 
        int                             boot_timeout;
+       int                             org_boot_timeout;
        int                             clear_time;
        bool                            otp_wdtt;
        bool                            otp_wdten;
@@ -300,6 +301,63 @@ static ssize_t set_wdt_suspend_state(struct device *dev,
 static DEVICE_ATTR(watchdog_suspend_state, 0644, show_wdt_suspend_state,
                        set_wdt_suspend_state);
 
+static ssize_t show_wdt_normal_state(struct device *dev,
+                struct device_attribute *attr, char *buf)
+{
+       struct max77620_wdt *wdt = dev_get_drvdata(dev);
+
+        return sprintf(buf, "%s",
+                       (wdt->boot_timeout) ? "enable\n" : "disable\n");
+}
+
+static ssize_t set_wdt_normal_state(struct device *dev,
+                struct device_attribute *attr, const char *buf, size_t count)
+{
+       struct max77620_wdt *wdt = dev_get_drvdata(dev);
+       int enable;
+        char *p = (char *)buf;
+       char ch = *p;
+       int ret;
+
+       if ((ch == 'e') || (ch == 'E'))
+               enable = 1;
+       else if ((ch == 'd') || (ch == 'D'))
+               enable = 0;
+       else
+               return -EINVAL;
+
+       if (enable && wdt->boot_timeout)
+               return count;
+       if (!enable && !wdt->boot_timeout)
+               return count;
+
+       if (enable)
+               wdt->boot_timeout = wdt->org_boot_timeout;
+       else
+               wdt->boot_timeout = 0;
+
+       if (wdt->org_boot_timeout) {
+               if (wdt->boot_timeout) {
+                       ret = max77620_wdt_restart(&wdt->wdt_dev,
+                                       wdt->boot_timeout);
+                       if (ret < 0)
+                               dev_err(wdt->dev,
+                                       "Watchdog not restarted %d\n", ret);
+
+                       schedule_delayed_work(&wdt->clear_wdt_wq,
+                               msecs_to_jiffies(wdt->clear_time * HZ));
+               } else {
+                       ret = max77620_wdt_stop(&wdt->wdt_dev);
+                       if (ret < 0)
+                               dev_err(wdt->dev, "wdt stop failed: %d\n", ret);
+                       cancel_delayed_work(&wdt->clear_wdt_wq);
+               }
+       }
+        return count;
+}
+static DEVICE_ATTR(watchdog_normal_state, 0644, show_wdt_normal_state,
+                       set_wdt_normal_state);
+
 static int max77620_wdt_probe(struct platform_device *pdev)
 {
        struct max77620_wdt *wdt;
@@ -362,6 +420,7 @@ static int max77620_wdt_probe(struct platform_device *pdev)
        wdt_dev->max_timeout = 128;
 
        wdt->org_suspend_timeout = wdt->suspend_timeout;
+       wdt->org_boot_timeout = wdt->boot_timeout;
 
        watchdog_set_nowayout(wdt_dev, nowayout);
        watchdog_set_drvdata(wdt_dev, wdt);
@@ -385,7 +444,13 @@ static int max77620_wdt_probe(struct platform_device *pdev)
 
        ret = device_create_file(&pdev->dev, &dev_attr_watchdog_suspend_state);
        if (ret < 0)
-               dev_warn(&pdev->dev, "sysfs creation failed: %d\n", ret);
+               dev_warn(&pdev->dev,
+                       "wdt suspend sysfs creation failed: %d\n", ret);
+
+       ret = device_create_file(&pdev->dev, &dev_attr_watchdog_normal_state);
+       if (ret < 0)
+               dev_warn(&pdev->dev,
+                       "wdt normal sysfs creation failed: %d\n", ret);
 
        /*Enable WD_RST_WK - WDT expire results in a restart*/
        ret = max77620_reg_update(wdt->chip->dev, MAX77620_PWR_SLAVE,