[ALSA] snd-emu10k1: Implement dB gain infomation.

Signed-off-by: James Courtier-Dutton <James@superbug.co.uk>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

sound/pci/emu10k1/emufx.c

@@ -35,6 +35,7 @@
 #include <linux/mutex.h>
 
 #include <sound/core.h>
+#include <sound/tlv.h>
 #include <sound/emu10k1.h>
 
 #if 0		/* for testing purposes - digital out -> capture */
@@ -290,6 +291,9 @@ static const u32 db_table[101] = {
 	0x7fffffff,
 };
 
+/* EMU10k1/EMU10k2 DSP control db gain */
+static DECLARE_TLV_DB_SCALE(snd_emu10k1_db_scale1, -4000, 40, 1);
+
 static const u32 onoff_table[2] = {
 	0x00000000, 0x00000001
 };
@@ -755,6 +759,11 @@ static int snd_emu10k1_add_controls(struct snd_emu10k1 *emu,
 		knew.device = gctl->id.device;
 		knew.subdevice = gctl->id.subdevice;
 		knew.info = snd_emu10k1_gpr_ctl_info;
+		if (gctl->tlv.p) {
+			knew.tlv.p = gctl->tlv.p;
+			knew.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+				SNDRV_CTL_ELEM_ACCESS_TLV_READ;
+		} 
 		knew.get = snd_emu10k1_gpr_ctl_get;
 		knew.put = snd_emu10k1_gpr_ctl_put;
 		memset(nctl, 0, sizeof(*nctl));
@@ -1013,6 +1022,7 @@ snd_emu10k1_init_mono_control(struct snd_emu10k1_fx8010_control_gpr *ctl,
 	ctl->gpr[0] = gpr + 0; ctl->value[0] = defval;
 	ctl->min = 0;
 	ctl->max = 100;
+	ctl->tlv.p = snd_emu10k1_db_scale1;
 	ctl->translation = EMU10K1_GPR_TRANSLATION_TABLE100;	
 }
 
@@ -1027,6 +1037,7 @@ snd_emu10k1_init_stereo_control(struct snd_emu10k1_fx8010_control_gpr *ctl,
 	ctl->gpr[1] = gpr + 1; ctl->value[1] = defval;
 	ctl->min = 0;
 	ctl->max = 100;
+	ctl->tlv.p = snd_emu10k1_db_scale1;
 	ctl->translation = EMU10K1_GPR_TRANSLATION_TABLE100;
 }