[ALSA] Add definition of TLV dB range compound

Added the definition of TLV dB range compound.  It contains one or
more dB-range or linear-volume TLV entries with min/max ranges.
Used for volume controls with non-linear curves.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

include/sound/tlv.h

@@ -34,19 +34,26 @@
 #define SNDRV_CTL_TLVT_CONTAINER 0	/* one level down - group of TLVs */
 #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 TLV_DB_SCALE_ITEM(min, step, mute)			\
+	SNDRV_CTL_TLVT_DB_SCALE, 2 * sizeof(unsigned int),	\
+	(min), ((step) & 0xffff) | ((mute) ? 0x10000 : 0)
 #define DECLARE_TLV_DB_SCALE(name, min, step, mute) \
-unsigned int name[] = { \
-        SNDRV_CTL_TLVT_DB_SCALE, 2 * sizeof(unsigned int), \
-        (min), ((step) & 0xffff) | ((mute) ? 0x10000 : 0) \
-}
+	unsigned int name[] = { TLV_DB_SCALE_ITEM(min, step, mute) }
 
 /* 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), \
+	(min_dB), (max_dB)
 #define DECLARE_TLV_DB_LINEAR(name, min_dB, max_dB)	\
-unsigned int name[] = { \
-        SNDRV_CTL_TLVT_DB_LINEAR, 2 * sizeof(unsigned int), \
-        (min_dB), (max_dB)				\
-}
+	unsigned int name[] = { TLV_DB_LINEAR_ITEM(min_dB, max_dB) }
+
+/* dB range container */
+/* Each item is: <min> <max> <TLV> */
+/* The below assumes that each item TLV is 4 words like DB_SCALE or LINEAR */
+#define TLV_DB_RANGE_HEAD(num)			\
+	SNDRV_CTL_TLVT_DB_RANGE, 6 * (num) * sizeof(unsigned int)
 
 #define TLV_DB_GAIN_MUTE	-9999999