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| author |   Takashi Iwai <tiwai@suse.de> | 2009-06-16 13:57:07 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2009-06-17 10:56:53 +0200 |
| commit | 085f30654175a91c28d2b66b9ea6cceab627fed0 (patch) | |
| tree | 58bb41875f6169e170647e76c72947050290852a /sound/core | |
| parent | Linux 2.6.30 (diff) | |
| download | linux-dev-085f30654175a91c28d2b66b9ea6cceab627fed0.tar.xz linux-dev-085f30654175a91c28d2b66b9ea6cceab627fed0.zip | |
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/core')
| -rw-r--r-- | sound/core/vmaster.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/sound/core/vmaster.c b/sound/core/vmaster.c index 257624bd1997..3b9b550109cb 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; |