[WATCHDOG] convert AT91RM9200 watchdog to platform driver

Converted to a platform driver.
Added suspend/resume support - the watchdog is disabled during the
sleep states.

Original patch from David Brownell.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@osdl.org>

1 files changed, 71 insertions, 11 deletions

diff --git a/drivers/char/watchdog/at91_wdt.c b/drivers/char/watchdog/at91_wdt.c
index ac83bc4b019a..00080655533d 100644
--- a/drivers/char/watchdog/at91_wdt.c
+++ b/drivers/char/watchdog/at91_wdt.c
@@ -17,14 +17,15 @@
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/platform_device.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
 #include <asm/bitops.h>
 #include <asm/uaccess.h>
 
 
-#define WDT_DEFAULT_TIME        5       /* 5 seconds */
-#define WDT_MAX_TIME            256     /* 256 seconds */
+#define WDT_DEFAULT_TIME        5       /* seconds */
+#define WDT_MAX_TIME            256     /* seconds */
 
 static int wdt_time = WDT_DEFAULT_TIME;
 static int nowayout = WATCHDOG_NOWAYOUT;
@@ -32,8 +33,10 @@ static int nowayout = WATCHDOG_NOWAYOUT;
 module_param(wdt_time, int, 0);
 MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="__MODULE_STRING(WDT_DEFAULT_TIME) ")");
 
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
 module_param(nowayout, int, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+#endif
 
 
 static unsigned long at91wdt_busy;
@@ -138,7 +141,7 @@ static int at91_wdt_ioctl(struct inode *inode, struct file *file,
                 case WDIOC_SETTIMEOUT:
                         if (get_user(new_value, p))
                                 return -EFAULT;
-                                
+
                         if (at91_wdt_settimeout(new_value))
                                 return -EINVAL;
 
@@ -196,27 +199,84 @@ static struct miscdevice at91wdt_miscdev = {
         .fops           = &at91wdt_fops,
 };
 
-static int __init at91_wdt_init(void)
+static int __init at91wdt_probe(struct platform_device *pdev)
 {
         int res;
 
-        /* Check that the heartbeat value is within range; if not reset to the default */
-        if (at91_wdt_settimeout(wdt_time)) {
-                at91_wdt_settimeout(WDT_DEFAULT_TIME);
-                printk(KERN_INFO "at91_wdt: wdt_time value must be 1 <= wdt_time <= 256, using %d\n", wdt_time);
-        }
+        if (at91wdt_miscdev.dev)
+                return -EBUSY;
+        at91wdt_miscdev.dev = &pdev->dev;
 
         res = misc_register(&at91wdt_miscdev);
         if (res)
                 return res;
 
-        printk("AT91 Watchdog Timer enabled (%d seconds, nowayout=%d)\n", wdt_time, nowayout);
+        printk("AT91 Watchdog Timer enabled (%d seconds%s)\n", wdt_time, nowayout ? ", nowayout" : "");
         return 0;
 }
 
+static int __exit at91wdt_remove(struct platform_device *pdev)
+{
+        int res;
+
+        res = misc_deregister(&at91wdt_miscdev);
+        if (!res)
+                at91wdt_miscdev.dev = NULL;
+
+        return res;
+}
+
+static void at91wdt_shutdown(struct platform_device *pdev)
+{
+        at91_wdt_stop();
+}
+
+#ifdef CONFIG_PM
+
+static int at91wdt_suspend(struct platform_device *pdev, pm_message_t message)
+{
+        at91_wdt_stop();
+        return 0;
+}
+
+static int at91wdt_resume(struct platform_device *pdev)
+{
+        if (at91wdt_busy)
+                at91_wdt_start();
+                return 0;
+}
+
+#else
+#define at91wdt_suspend NULL
+#define at91wdt_resume  NULL
+#endif
+
+static struct platform_driver at91wdt_driver = {
+        .probe          = at91wdt_probe,
+        .remove         = __exit_p(at91wdt_remove),
+        .shutdown       = at91wdt_shutdown,
+        .suspend        = at91wdt_suspend,
+        .resume         = at91wdt_resume,
+        .driver         = {
+                .name   = "at91_wdt",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init at91_wdt_init(void)
+{
+        /* Check that the heartbeat value is within range; if not reset to the default */
+        if (at91_wdt_settimeout(wdt_time)) {
+                at91_wdt_settimeout(WDT_DEFAULT_TIME);
+                pr_info("at91_wdt: wdt_time value must be 1 <= wdt_time <= 256, using %d\n", wdt_time);
+        }
+
+        return platform_driver_register(&at91wdt_driver);
+}
+
 static void __exit at91_wdt_exit(void)
 {
-        misc_deregister(&at91wdt_miscdev);
+        platform_driver_unregister(&at91wdt_driver);
 }
 
 module_init(at91_wdt_init);