[media] snd_tea575x: Add a cannot_mute flag

Some devices which use the tea575x tuner chip don't allow direct control
over the IO pins, and thus cannot mute the audio output.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
CC: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

include/sound/tea575x-tuner.h

@@ -53,6 +53,7 @@ struct snd_tea575x {
 	int radio_nr;			/* radio_nr */
 	bool tea5759;			/* 5759 chip is present */
 	bool cannot_read_data;		/* Device cannot read the data pin */
+	bool cannot_mute;		/* Device cannot mute */
 	bool mute;			/* Device is muted? */
 	bool stereo;			/* receiving stereo */
 	bool tuned;			/* tuned to a station */

sound/i2c/other/tea575x-tuner.c

@@ -385,7 +385,6 @@ int snd_tea575x_init(struct snd_tea575x *tea, struct module *owner)
 	strlcpy(tea->vd.name, tea->v4l2_dev->name, sizeof(tea->vd.name));
 	tea->vd.lock = &tea->mutex;
 	tea->vd.v4l2_dev = tea->v4l2_dev;
-	tea->vd.ctrl_handler = &tea->ctrl_handler;
 	tea->fops = tea575x_fops;
 	tea->fops.owner = owner;
 	tea->vd.fops = &tea->fops;
@@ -394,8 +393,11 @@ int snd_tea575x_init(struct snd_tea575x *tea, struct module *owner)
 	if (tea->cannot_read_data)
 		v4l2_disable_ioctl(&tea->vd, VIDIOC_S_HW_FREQ_SEEK);
 
+	if (!tea->cannot_mute) {
+		tea->vd.ctrl_handler = &tea->ctrl_handler;
 		v4l2_ctrl_handler_init(&tea->ctrl_handler, 1);
-	v4l2_ctrl_new_std(&tea->ctrl_handler, &tea575x_ctrl_ops, V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
+		v4l2_ctrl_new_std(&tea->ctrl_handler, &tea575x_ctrl_ops,
+				  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
 		retval = tea->ctrl_handler.error;
 		if (retval) {
 			v4l2_err(tea->v4l2_dev, "can't initialize controls\n");
@@ -412,11 +414,12 @@ int snd_tea575x_init(struct snd_tea575x *tea, struct module *owner)
 		}
 
 		v4l2_ctrl_handler_setup(&tea->ctrl_handler);
+	}
 
 	retval = video_register_device(&tea->vd, VFL_TYPE_RADIO, tea->radio_nr);
 	if (retval) {
 		v4l2_err(tea->v4l2_dev, "can't register video device!\n");
-		v4l2_ctrl_handler_free(&tea->ctrl_handler);
+		v4l2_ctrl_handler_free(tea->vd.ctrl_handler);
 		return retval;
 	}
 
@@ -426,7 +429,7 @@ int snd_tea575x_init(struct snd_tea575x *tea, struct module *owner)
 void snd_tea575x_exit(struct snd_tea575x *tea)
 {
 	video_unregister_device(&tea->vd);
-	v4l2_ctrl_handler_free(&tea->ctrl_handler);
+	v4l2_ctrl_handler_free(tea->vd.ctrl_handler);
 }
 
 static int __init alsa_tea575x_module_init(void)