From 637d3847ba0ca2c7780e6521cbe75568d19ff0db Mon Sep 17 00:00:00 2001 From: Peter Ujfalusi Date: Fri, 7 May 2010 14:05:49 +0300 Subject: ASoC: core: Support for limiting the volume Add support for the core to limit the maximum volume on an existing control. The function will modify the soc_mixer_control.max value of the given control. The new value must be lower than the original one (chip maximum) If there is a need for limiting a gain on a given control, than machine drivers can do the following in their snd_soc_dai_link.init function: snd_soc_limit_volume(codec, "TPA6140A2 Headphone Playback Volume", 21); This will modify the original 31 (chip maximum) to 21, so user space will not be able to set the gain higher than this. Signed-off-by: Peter Ujfalusi Acked-by: Liam Girdwood Signed-off-by: Mark Brown --- include/sound/soc.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/sound') diff --git a/include/sound/soc.h b/include/sound/soc.h index 01e9c66ddc6d..9f306f0710df 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -326,6 +326,8 @@ int snd_soc_get_volsw_s8(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol); int snd_soc_put_volsw_s8(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol); +int snd_soc_limit_volume(struct snd_soc_codec *codec, + const char *name, int max); /** * struct snd_soc_jack_pin - Describes a pin to update based on jack detection -- cgit v1.2.3