Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / drivers / watchdog / booke_wdt.c

diff --git a/drivers/watchdog/booke_wdt.c b/drivers/watchdog/booke_wdt.c
index d11ffb091b0dfc0fa67edb4422145ce959091182..7e7ec9c35b6a442e1569f4c25d5711ea6668e586 100644 (file)
--- a/drivers/watchdog/booke_wdt.c
+++ b/drivers/watchdog/booke_wdt.c
@@ -85,6 +85,22 @@ static unsigned int sec_to_period(unsigned int secs)
        return 0;
 }
 
+static void __booke_wdt_set(void *data)
+{
+       u32 val;
+
+       val = mfspr(SPRN_TCR);
+       val &= ~WDTP_MASK;
+       val |= WDTP(booke_wdt_period);
+
+       mtspr(SPRN_TCR, val);
+}
+
+static void booke_wdt_set(void)
+{
+       on_each_cpu(__booke_wdt_set, NULL, 0);
+}
+
 static void __booke_wdt_ping(void *data)
 {
        mtspr(SPRN_TSR, TSR_ENW|TSR_WIS);
@@ -181,8 +197,7 @@ static long booke_wdt_ioctl(struct file *file,
 #else
                booke_wdt_period = tmp;
 #endif
-               mtspr(SPRN_TCR, (mfspr(SPRN_TCR) & ~WDTP_MASK) |
-                                               WDTP(booke_wdt_period));
+               booke_wdt_set();
                return 0;
        case WDIOC_GETTIMEOUT:
                return put_user(booke_wdt_period, p);
@@ -193,8 +208,15 @@ static long booke_wdt_ioctl(struct file *file,
        return 0;
 }
 
+/* wdt_is_active stores wether or not the /dev/watchdog device is opened */
+static unsigned long wdt_is_active;
+
 static int booke_wdt_open(struct inode *inode, struct file *file)
 {
+       /* /dev/watchdog can only be opened once */
+       if (test_and_set_bit(0, &wdt_is_active))
+               return -EBUSY;
+
        spin_lock(&booke_wdt_lock);
        if (booke_wdt_enabled == 0) {
                booke_wdt_enabled = 1;
@@ -210,8 +232,17 @@ static int booke_wdt_open(struct inode *inode, struct file *file)
 
 static int booke_wdt_release(struct inode *inode, struct file *file)
 {
+#ifndef CONFIG_WATCHDOG_NOWAYOUT
+       /* Normally, the watchdog is disabled when /dev/watchdog is closed, but
+        * if CONFIG_WATCHDOG_NOWAYOUT is defined, then it means that the
+        * watchdog should remain enabled.  So we disable it only if
+        * CONFIG_WATCHDOG_NOWAYOUT is not defined.
+        */
        on_each_cpu(__booke_wdt_disable, NULL, 0);
        booke_wdt_enabled = 0;
+#endif
+
+       clear_bit(0, &wdt_is_active);
 
        return 0;
 }