[WATCHDOG] s3c2410 watchdog power management

Patch from Dimitry Andric <dimitry.andric@tomtom.com>, updated
by Ben Dooks <ben-linux@fluff.org>. Patch is against 2.6.11-mm2

Add power management support to the s3c2410 watchdog, so that
it is shut-down over suspend, and re-initialised on resume.

Also add Dimitry to the list of authors.

Signed-off-by: Dimitry Andric <dimitry.andric@tomtom.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 48 insertions, 3 deletions

diff --git a/drivers/char/watchdog/s3c2410_wdt.c b/drivers/char/watchdog/s3c2410_wdt.c
index f85ac898a49a..522435782e73 100644
--- a/drivers/char/watchdog/s3c2410_wdt.c
+++ b/drivers/char/watchdog/s3c2410_wdt.c
@@ -27,7 +27,9 @@
  *                              Fixed tmr_count / wdt_count confusion
  *                              Added configurable debug
  *
- *      11-Jan-2004     BJD     Fixed divide-by-2 in timeout code
+ *      11-Jan-2005     BJD     Fixed divide-by-2 in timeout code
+ *
+ *      25-Jan-2005     DA      Added suspend/resume support
  *
  *      10-Mar-2005     LCVR    Changed S3C2410_VA to S3C24XX_VA
 */
@@ -479,15 +481,57 @@ static int s3c2410wdt_remove(struct device *dev)
         return 0;
 }
 
+#ifdef CONFIG_PM
+
+static unsigned long wtcon_save;
+static unsigned long wtdat_save;
+
+static int s3c2410wdt_suspend(struct device *dev, u32 state, u32 level)
+{
+        if (level == SUSPEND_POWER_DOWN) {
+                /* Save watchdog state, and turn it off. */
+                wtcon_save = readl(wdt_base + S3C2410_WTCON);
+                wtdat_save = readl(wdt_base + S3C2410_WTDAT);
+
+                /* Note that WTCNT doesn't need to be saved. */
+                s3c2410wdt_stop();
+        }
+
+        return 0;
+}
+
+static int s3c2410wdt_resume(struct device *dev, u32 level)
+{
+        if (level == RESUME_POWER_ON) {
+                /* Restore watchdog state. */
+
+                writel(wtdat_save, wdt_base + S3C2410_WTDAT);
+                writel(wtdat_save, wdt_base + S3C2410_WTCNT); /* Reset count */
+                writel(wtcon_save, wdt_base + S3C2410_WTCON);
+
+                printk(KERN_INFO PFX "watchdog %sabled\n",
+                       (wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");
+        }
+
+        return 0;
+}
+
+#else
+#define s3c2410wdt_suspend NULL
+#define s3c2410wdt_resume  NULL
+#endif /* CONFIG_PM */
+
+
 static struct device_driver s3c2410wdt_driver = {
         .name           = "s3c2410-wdt",
         .bus            = &platform_bus_type,
         .probe          = s3c2410wdt_probe,
         .remove         = s3c2410wdt_remove,
+        .suspend        = s3c2410wdt_suspend,
+        .resume         = s3c2410wdt_resume,
 };
 
 
-
 static char banner[] __initdata = KERN_INFO "S3C2410 Watchdog Timer, (c) 2004 Simtec Electronics\n";
 
 static int __init watchdog_init(void)
@@ -505,7 +549,8 @@ static void __exit watchdog_exit(void)
 module_init(watchdog_init);
 module_exit(watchdog_exit);
 
-MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
+MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, "
+              "Dimitry Andric <dimitry.andric@tomtom.com>");
 MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);