Add cmpxchg_local to m86k

[linux-2.6-omap-h63xx.git] / drivers / rtc / rtc-dev.c

diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 814583bd2fe709c1da0710808ed6f4cffbe8b50f..90dfa0df747acb9314b4ed115c2eec0dee1eae0d 100644 (file)
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -26,10 +26,7 @@ static int rtc_dev_open(struct inode *inode, struct file *file)
                                        struct rtc_device, char_dev);
        const struct rtc_class_ops *ops = rtc->ops;
 
-       /* We keep the lock as long as the device is in use
-        * and return immediately if busy
-        */
-       if (!(mutex_trylock(&rtc->char_lock)))
+       if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
                return -EBUSY;
 
        file->private_data = rtc;
@@ -43,8 +40,8 @@ static int rtc_dev_open(struct inode *inode, struct file *file)
                return 0;
        }
 
-       /* something has gone wrong, release the lock */
-       mutex_unlock(&rtc->char_lock);
+       /* something has gone wrong */
+       clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
        return err;
 }
 
@@ -249,6 +246,15 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file,
        /* if the driver does not provide the ioctl interface
         * or if that particular ioctl was not implemented
         * (-ENOIOCTLCMD), we will try to emulate here.
+        *
+        * Drivers *SHOULD NOT* provide ioctl implementations
+        * for these requests.  Instead, provide methods to
+        * support the following code, so that the RTC's main
+        * features are accessible without using ioctls.
+        *
+        * RTC and alarm times will be in UTC, by preference,
+        * but dual-booting with MS-Windows implies RTCs must
+        * use the local wall clock time.
         */
 
        switch (cmd) {
@@ -405,7 +411,7 @@ static int rtc_dev_release(struct inode *inode, struct file *file)
        if (rtc->ops->release)
                rtc->ops->release(rtc->dev.parent);
 
-       mutex_unlock(&rtc->char_lock);
+       clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
        return 0;
 }
 
@@ -440,7 +446,6 @@ void rtc_dev_prepare(struct rtc_device *rtc)
 
        rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
 
-       mutex_init(&rtc->char_lock);
 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
        INIT_WORK(&rtc->uie_task, rtc_uie_task);
        setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);