ARM: dts: Correct audio input route & set mic bias for am335x-pepper

Audio-in was incorrectly routed to Line In. It should be Mic3L as per
schematic.

Using mic-bias voltage at 2.0v (<0x1>) does not work for some reason. There
is no voltage seen on micbias (R127). Mic-bias voltage of 2.5v (<0x2>) works.
I see voltage of 2.475v across GND and micbias.

With these changes, I can record audio with a pair of proliferate TRRS earbuds.

Signed-off-by: Adam YH Lee <adam.yh.lee@gmail.com>
Acked-by: Ash Charles <ashcharles@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/arm/boot/dts/am335x-pepper.dts b/arch/arm/boot/dts/am335x-pepper.dts
index 206c042a7c48..7106114c7464 100644
--- a/arch/arm/boot/dts/am335x-pepper.dts
+++ b/arch/arm/boot/dts/am335x-pepper.dts
@@ -74,6 +74,7 @@
         audio_codec: tlv320aic3106@1b {
                 compatible = "ti,tlv320aic3106";
                 reg = <0x1b>;
+                ai3x-micbias-vg = <0x2>;
         };
 
         accel: lis331dlh@1d {
@@ -153,7 +154,7 @@
         ti,audio-routing =
                 "Headphone Jack",       "HPLOUT",
                 "Headphone Jack",       "HPROUT",
-                "LINE1L",               "Line In";
+                "MIC3L",                "Mic3L Switch";
 };
 
 &mcasp0 {