From: Ben Dooks <ben-linux@fluff.org>
To: wim@iguana.be, linux-kernel@vger.kernel.org
Subject: [PATCH] s3c2410 watchdog power management
Date: Sat, 12 Mar 2005 11:18:19 +0000 [thread overview]
Message-ID: <20050312111819.GA23857@home.fluff.org> (raw)
[-- Attachment #1: Type: text/plain, Size: 2721 bytes --]
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>
diff -urN -X ../dontdiff linux-2.6.11-mm2/drivers/char/watchdog/s3c2410_wdt.c linux-2.6.11-mm2-bjd1/drivers/char/watchdog/s3c2410_wdt.c
--- linux-2.6.11-mm2/drivers/char/watchdog/s3c2410_wdt.c 2005-03-02 07:38:10.000000000 +0000
+++ linux-2.6.11-mm2-bjd1/drivers/char/watchdog/s3c2410_wdt.c 2005-03-12 11:11:08.000000000 +0000
@@ -26,6 +26,7 @@
* 05-Oct-2004 BJD Added semaphore init to stop crashes on open
* Fixed tmr_count / wdt_count confusion
* Added configurable debug
+ * 25-Jan-2005 DA Added suspend/resume support
*/
#include <linux/module.h>
@@ -484,15 +485,57 @@
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)
@@ -510,7 +553,8 @@
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);
[-- Attachment #2: s3c2410-wdt-pm.patch --]
[-- Type: text/plain, Size: 2322 bytes --]
diff -urN -X ../dontdiff linux-2.6.11-mm2/drivers/char/watchdog/s3c2410_wdt.c linux-2.6.11-mm2-bjd1/drivers/char/watchdog/s3c2410_wdt.c
--- linux-2.6.11-mm2/drivers/char/watchdog/s3c2410_wdt.c 2005-03-02 07:38:10.000000000 +0000
+++ linux-2.6.11-mm2-bjd1/drivers/char/watchdog/s3c2410_wdt.c 2005-03-12 11:11:08.000000000 +0000
@@ -26,6 +26,7 @@
* 05-Oct-2004 BJD Added semaphore init to stop crashes on open
* Fixed tmr_count / wdt_count confusion
* Added configurable debug
+ * 25-Jan-2005 DA Added suspend/resume support
*/
#include <linux/module.h>
@@ -484,15 +485,57 @@
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)
@@ -510,7 +553,8 @@
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);
reply other threads:[~2005-03-12 11:26 UTC|newest]
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