lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ALSA: Add new TLV types for dBwith min/max

Browse Source 
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>
This commit is contained in:
Takashi Iwai
2009-06-16 13:57:07 +02:00
parent 07a2039b8e
commit 085f306541
2 changed files with 20 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
include/sound/tlv.h
View File

@@ -35,6 +35,8 @@
#define SNDRV_CTL_TLVT_DB_SCALE 1 /* dB scale */
#define SNDRV_CTL_TLVT_DB_LINEAR 2 /* linear volume */
#define SNDRV_CTL_TLVT_DB_RANGE 3 /* dB range container */
#define SNDRV_CTL_TLVT_DB_MINMAX 4 /* dB scale with min/max */
#define SNDRV_CTL_TLVT_DB_MINMAX_MUTE 5 /* dB scale with min/max with mute */
#define TLV_DB_SCALE_ITEM(min, step, mute) \
SNDRV_CTL_TLVT_DB_SCALE, 2 * sizeof(unsigned int), \
@@ -42,6 +44,18 @@
#define DECLARE_TLV_DB_SCALE(name, min, step, mute) \
unsigned int name[] = { TLV_DB_SCALE_ITEM(min, step, mute) }
/* dB scale specified with min/max values instead of step */
#define TLV_DB_MINMAX_ITEM(min_dB, max_dB) \
SNDRV_CTL_TLVT_DB_MINMAX, 2 * sizeof(unsigned int), \
(min_dB), (max_dB)
#define TLV_DB_MINMAX_MUTE_ITEM(min_dB, max_dB) \
SNDRV_CTL_TLVT_DB_MINMAX_MUTE, 2 * sizeof(unsigned int), \
(min_dB), (max_dB)
#define DECLARE_TLV_DB_MINMAX(name, min_dB, max_dB) \
unsigned int name[] = { TLV_DB_MINMAX_ITEM(min_dB, max_dB) }
#define DECLARE_TLV_DB_MINMAX_MUTE(name, min_dB, max_dB) \
unsigned int name[] = { TLV_DB_MINMAX_MUTE_ITEM(min_dB, max_dB) }
/* linear volume between min_dB and max_dB (.01dB unit) */
#define TLV_DB_LINEAR_ITEM(min_dB, max_dB) \
SNDRV_CTL_TLVT_DB_LINEAR, 2 * sizeof(unsigned int), \