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authorTakashi Iwai <tiwai@suse.de>2009-06-16 13:57:07 +0200
committerTakashi Iwai <tiwai@suse.de>2009-06-17 10:56:53 +0200
commit085f30654175a91c28d2b66b9ea6cceab627fed0 (patch)
tree58bb41875f6169e170647e76c72947050290852a /sound
parent07a2039b8eb0af4ff464efd3dfd95de5c02648c6 (diff)
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ALSA: Add new TLV types for dBwith min/max
Add new types for TLV dB scale specified with min/max values instead of min/step since the resolution can't match always with the one a device provides. For example, usb audio devices give 1/256 dB resolution while ALSA TLV is based on 1/100 dB resolution. The new min/max types have less problems because the possible rounding error happens only at min/max. Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
-rw-r--r--sound/core/vmaster.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/sound/core/vmaster.c b/sound/core/vmaster.c
index 257624bd199..3b9b550109c 100644
--- a/sound/core/vmaster.c
+++ b/sound/core/vmaster.c
@@ -353,7 +353,8 @@ static void master_free(struct snd_kcontrol *kcontrol)
*
* The optional argument @tlv can be used to specify the TLV information
* for dB scale of the master control. It should be a single element
- * with #SNDRV_CTL_TLVT_DB_SCALE type, and should be the max 0dB.
+ * with #SNDRV_CTL_TLVT_DB_SCALE, #SNDRV_CTL_TLV_DB_MINMAX or
+ * #SNDRV_CTL_TLVT_DB_MINMAX_MUTE type, and should be the max 0dB.
*/
struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
const unsigned int *tlv)
@@ -384,7 +385,10 @@ struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
kctl->private_free = master_free;
/* additional (constant) TLV read */
- if (tlv && tlv[0] == SNDRV_CTL_TLVT_DB_SCALE) {
+ if (tlv &&
+ (tlv[0] == SNDRV_CTL_TLVT_DB_SCALE ||
+ tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX ||
+ tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX_MUTE)) {
kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
memcpy(master->tlv, tlv, sizeof(master->tlv));
kctl->tlv.p = master->tlv;