wm8751: document and fix audiohw settings

Document 3D depth range. Fix mismatch in recording volume: the displayed volume
is completely off the chart

Change-Id: I4c363f369e5d72f332391a6f96457b4e450404f9

2 files changed, 11 insertions, 6 deletions

diff --git a/firmware/drivers/audio/wm8751.c b/firmware/drivers/audio/wm8751.c
index 7b6a2712e5..1b4af3eca8 100644
--- a/firmware/drivers/audio/wm8751.c
+++ b/firmware/drivers/audio/wm8751.c
@@ -385,7 +385,8 @@ void audiohw_set_frequency(int fsel)
 
 #ifdef HAVE_WM8750
 #ifdef AUDIOHW_HAVE_DEPTH_3D
-/* Set the depth of the 3D effect */
+/* Set the depth of the 3D effect
+ * value in 0 .. 15, corresponds to 0% .. 100% in 6.66% steps */
 void audiohw_set_depth_3d(int val)
 {
     if (val > 0)
@@ -631,6 +632,7 @@ static int pga_gain2hw(int value)
     return ((4 * value) / 300) + 23;
 }
 
+/* volume in hundredth of dB in -1725 .. 6000 */
 void audiohw_set_recvol(int vol_l, int vol_r, int type)
 {
     int d_vol_l = 0;
diff --git a/firmware/export/wm8751.h b/firmware/export/wm8751.h
index 214643c64d..9b66981129 100644
--- a/firmware/export/wm8751.h
+++ b/firmware/export/wm8751.h
@@ -25,18 +25,21 @@
 #define AUDIOHW_CAPS (BASS_CAP | TREBLE_CAP | PRESCALER_CAP | \
                       BASS_CUTOFF_CAP | TREBLE_CUTOFF_CAP | \
                       DEPTH_3D_CAP | LIN_GAIN_CAP | MIC_GAIN_CAP)
-
+/* Percentage from 0% to 100% in steps of 6.66%:
+ * Values: 0, 1, 2, ... 14, 15
+ *      => 0%, 6%, 14%, ..., 93%, 100%
+ */
 AUDIOHW_SETTING(DEPTH_3D,        "%", 0,  1,    0,   15,    0, (100 * val + 8) / 15)
 #ifdef HAVE_RECORDING
     /* PGA -17.25dB to 30.0dB in 0.75dB increments 64 steps
      * digital gain 0dB to 30.0dB in 0.5dB increments
      * we use 0.75dB fake steps through whole range
      *
-     * This combined gives -17.25 to 60.0dB 
+     * This combined gives -17.25 to 60.0dB
      */
-AUDIOHW_SETTING(LEFT_GAIN,      "dB", 2, 75,-1725, 6000,    0, val * 5)
-AUDIOHW_SETTING(RIGHT_GAIN,     "dB", 2, 75,-1725, 6000,    0, val * 5)
-AUDIOHW_SETTING(MIC_GAIN,       "dB", 2, 75,-1725, 6000, 3000, val * 5)
+AUDIOHW_SETTING(LEFT_GAIN,      "dB", 2, 75,-1725, 6000,    0)
+AUDIOHW_SETTING(RIGHT_GAIN,     "dB", 2, 75,-1725, 6000,    0)
+AUDIOHW_SETTING(MIC_GAIN,       "dB", 2, 75,-1725, 6000, 3000)
 
 void audiohw_set_recsrc(int source, bool recording);
 #endif /* HAVE_RECORDING */