V4L/DVB (5809): Use mutex instead of semaphore in Philips webcam driver

The Philips webcam driver uses a semaphore as mutex. Use the mutex API
instead of the (binary) semaphore.
--
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/pwc/pwc-if.c

@@ -1099,7 +1099,7 @@ static int pwc_video_open(struct inode *inode, struct file *file)
 		return -EBUSY;
 	}
 
-	down(&pdev->modlock);
+	mutex_lock(&pdev->modlock);
 	if (!pdev->usb_init) {
 		PWC_DEBUG_OPEN("Doing first time initialization.\n");
 		pdev->usb_init = 1;
@@ -1131,7 +1131,7 @@ static int pwc_video_open(struct inode *inode, struct file *file)
 	if (i < 0) {
 		PWC_DEBUG_OPEN("Failed to allocate buffers memory.\n");
 		pwc_free_buffers(pdev);
-		up(&pdev->modlock);
+		mutex_unlock(&pdev->modlock);
 		return i;
 	}
 
@@ -1172,7 +1172,7 @@ static int pwc_video_open(struct inode *inode, struct file *file)
 	if (i) {
 		PWC_DEBUG_OPEN("Second attempt at set_video_mode failed.\n");
 		pwc_free_buffers(pdev);
-		up(&pdev->modlock);
+		mutex_unlock(&pdev->modlock);
 		return i;
 	}
 
@@ -1181,7 +1181,7 @@ static int pwc_video_open(struct inode *inode, struct file *file)
 		PWC_DEBUG_OPEN("Failed to init ISOC stuff = %d.\n", i);
 		pwc_isoc_cleanup(pdev);
 		pwc_free_buffers(pdev);
-		up(&pdev->modlock);
+		mutex_unlock(&pdev->modlock);
 		return i;
 	}
 
@@ -1191,7 +1191,7 @@ static int pwc_video_open(struct inode *inode, struct file *file)
 
 	pdev->vopen++;
 	file->private_data = vdev;
-	up(&pdev->modlock);
+	mutex_unlock(&pdev->modlock);
 	PWC_DEBUG_OPEN("<< video_open() returns 0.\n");
 	return 0;
 }
@@ -1685,7 +1685,7 @@ static int usb_pwc_probe(struct usb_interface *intf, const struct usb_device_id
 		pdev->angle_range.tilt_max =  2500;
 	}
 
-	init_MUTEX(&pdev->modlock);
+	mutex_init(&pdev->modlock);
 	spin_lock_init(&pdev->ptrlock);
 
 	pdev->udev = udev;

drivers/media/video/pwc/pwc.h

@@ -31,7 +31,7 @@
 #include <linux/wait.h>
 #include <linux/smp_lock.h>
 #include <linux/version.h>
-#include <asm/semaphore.h>
+#include <linux/mutex.h>
 #include <asm/errno.h>
 #include <linux/videodev.h>
 #include <media/v4l2-common.h>
@@ -244,7 +244,7 @@ struct pwc_device
    int image_read_pos;			/* In case we read data in pieces, keep track of were we are in the imagebuffer */
    int image_used[MAX_IMAGES];		/* For MCAPTURE and SYNC */
 
-   struct semaphore modlock;		/* to prevent races in video_open(), etc */
+   struct mutex modlock;		/* to prevent races in video_open(), etc */
    spinlock_t ptrlock;			/* for manipulating the buffer pointers */
 
    /*** motorized pan/tilt feature */