V4L/DVB (6187): cx88-alsa: Add TLV support
Lets mixer apps display a dB range for the volume control.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/cx88/cx88-alsa.c b/drivers/media/video/cx88/cx88-alsa.c
index 6cf8609..40ffd7a 100644
--- a/drivers/media/video/cx88/cx88-alsa.c
+++ b/drivers/media/video/cx88/cx88-alsa.c
@@ -39,6 +39,7 @@
#include <sound/pcm_params.h>
#include <sound/control.h>
#include <sound/initval.h>
+#include <sound/tlv.h>
#include "cx88.h"
#include "cx88-reg.h"
@@ -605,12 +606,17 @@
return changed;
}
+static const DECLARE_TLV_DB_SCALE(snd_cx88_db_scale, -6300, 100, 0);
+
static struct snd_kcontrol_new snd_cx88_volume = {
.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+ .access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+ SNDRV_CTL_ELEM_ACCESS_TLV_READ,
.name = "Playback Volume",
.info = snd_cx88_volume_info,
.get = snd_cx88_volume_get,
.put = snd_cx88_volume_put,
+ .tlv.p = snd_cx88_db_scale,
};
static int snd_cx88_switch_get(struct snd_kcontrol *kcontrol,