[media] tea575x: allow multiple opens

Change locking to allow tea575x-radio device to be opened multiple times.
Signed-off-by: NOndrej Zary <linux@rainbow-software.org>
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

include/sound/tea575x-tuner.h

@@ -49,7 +49,7 @@ struct snd_tea575x {
 	bool tuned;			/* tuned to a station */
 	unsigned int val;		/* hw value */
 	unsigned long freq;		/* frequency */
-	unsigned long in_use;		/* set if the device is in use */
+	struct mutex mutex;
 	struct snd_tea575x_ops *ops;
 	void *private_data;
 	u8 card[32];

sound/i2c/other/tea575x-tuner.c

@@ -282,26 +282,9 @@ static int vidioc_s_input(struct file *filp, void *priv, unsigned int i)
 	return 0;
 }
 
-static int snd_tea575x_exclusive_open(struct file *file)
-{
-	struct snd_tea575x *tea = video_drvdata(file);
-
-	return test_and_set_bit(0, &tea->in_use) ? -EBUSY : 0;
-}
-
-static int snd_tea575x_exclusive_release(struct file *file)
-{
-	struct snd_tea575x *tea = video_drvdata(file);
-
-	clear_bit(0, &tea->in_use);
-	return 0;
-}
-
 static const struct v4l2_file_operations tea575x_fops = {
 	.owner		= THIS_MODULE,
-	.open           = snd_tea575x_exclusive_open,
-	.release        = snd_tea575x_exclusive_release,
-	.ioctl		= video_ioctl2,
+	.unlocked_ioctl	= video_ioctl2,
 };
 
 static const struct v4l2_ioctl_ops tea575x_ioctl_ops = {
@@ -340,13 +323,14 @@ int snd_tea575x_init(struct snd_tea575x *tea)
 	if (snd_tea575x_read(tea) != 0x55AA)
 		return -ENODEV;
 
-	tea->in_use = 0;
 	tea->val = TEA575X_BIT_BAND_FM | TEA575X_BIT_SEARCH_10_40;
 	tea->freq = 90500 * 16;		/* 90.5Mhz default */
 	snd_tea575x_set_freq(tea);
 
 	tea->vd = tea575x_radio;
 	video_set_drvdata(&tea->vd, tea);
+	mutex_init(&tea->mutex);
+	tea->vd.lock = &tea->mutex;
 
 	v4l2_ctrl_handler_init(&tea->ctrl_handler, 1);
 	tea->vd.ctrl_handler = &tea->ctrl_handler;