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>

1 files changed, 14 insertions, 0 deletions

diff --git a/include/sound/tlv.h b/include/sound/tlv.h
index d136ea2181ed..9fd5b19ccf5c 100644
--- a/include/sound/tlv.h
+++ b/include/sound/tlv.h
@@ -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), \