V4L/DVB (7993): si470x: move global lock to device structure

this patch brings the following changes:
- move the global disconnect lock into the device structure
- code cleanup (spaces to tabs, long line splits, ...)
Signed-off-by: Tobias Lorenz <tobias.lorenz@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/radio/radio-si470x.c

@@ -426,6 +426,7 @@ struct si470x_device {
 	/* driver management */
 	unsigned int users;
 	unsigned char disconnected;
+	struct mutex disconnect_lock;
 
 	/* Silabs internal registers (0..15) */
 	unsigned short registers[RADIO_REGISTER_NUM];
@@ -441,12 +442,6 @@ struct si470x_device {
 };
 
 
-/*
- * Lock to prevent kfree of data before all users have releases the device.
- */
-static DEFINE_MUTEX(open_close_lock);
-
-
 /*
  * The frequency is set in units of 62.5 Hz when using V4L2_TUNER_CAP_LOW,
  * 62.5 kHz otherwise.
@@ -591,7 +586,8 @@ static int si470x_get_rds_registers(struct si470x_device *radio)
 	if (retval >= 0)
 		for (regnr = 0; regnr < RDS_REGISTER_NUM; regnr++)
 			radio->registers[STATUSRSSI + regnr] =
-				get_unaligned_be16(&buf[regnr * RADIO_REGISTER_SIZE + 1]);
+				get_unaligned_be16(
+				&buf[regnr * RADIO_REGISTER_SIZE + 1]);
 
 	return (retval < 0) ? -EINVAL : 0;
 }
@@ -1012,14 +1008,14 @@ static int si470x_fops_release(struct inode *inode, struct file *file)
 	if (!radio)
 		return -ENODEV;
 
-       mutex_lock(&open_close_lock);
+	mutex_lock(&radio->disconnect_lock);
 	radio->users--;
 	if (radio->users == 0) {
 		if (radio->disconnected) {
 			video_unregister_device(radio->videodev);
 			kfree(radio->buffer);
 			kfree(radio);
-		       goto done;
+			goto unlock;
 		}
 
 		/* stop rds reception */
@@ -1032,8 +1028,8 @@ static int si470x_fops_release(struct inode *inode, struct file *file)
 		usb_autopm_put_interface(radio->intf);
 	}
 
-done:
-       mutex_unlock(&open_close_lock);
+unlock:
+	mutex_unlock(&radio->disconnect_lock);
 	return retval;
 }
 
@@ -1436,8 +1432,10 @@ static int si470x_usb_driver_probe(struct usb_interface *intf,
 	memcpy(radio->videodev, &si470x_viddev_template,
 			sizeof(si470x_viddev_template));
 	radio->users = 0;
+	radio->disconnected = 0;
 	radio->usbdev = interface_to_usbdev(intf);
 	radio->intf = intf;
+	mutex_init(&radio->disconnect_lock);
 	mutex_init(&radio->lock);
 	video_set_drvdata(radio->videodev, radio);
 
@@ -1542,7 +1540,7 @@ static void si470x_usb_driver_disconnect(struct usb_interface *intf)
 {
 	struct si470x_device *radio = usb_get_intfdata(intf);
 
-       mutex_lock(&open_close_lock);
+	mutex_lock(&radio->disconnect_lock);
 	radio->disconnected = 1;
 	cancel_delayed_work_sync(&radio->work);
 	usb_set_intfdata(intf, NULL);
@@ -1551,7 +1549,7 @@ static void si470x_usb_driver_disconnect(struct usb_interface *intf)
 		kfree(radio->buffer);
 		kfree(radio);
 	}
-       mutex_unlock(&open_close_lock);
+	mutex_unlock(&radio->disconnect_lock);
 }