imx233: make microphone bias, bias pin and resistor configurable

This clearly fixes recording on targets where the bias pin was wrong. It may
also improve recording on targets where the bias voltage was wrong. I was unable
to find those parameters on the ZEN Mozaic, which fallback to default values.

Change-Id: Ifb5f823c9cbd01f0d9a80fa5d49d93972c8b7cfe

1 files changed, 18 insertions, 4 deletions

diff --git a/firmware/target/arm/imx233/audioin-imx233.c b/firmware/target/arm/imx233/audioin-imx233.c
index e538765244..e221ac07e9 100644
--- a/firmware/target/arm/imx233/audioin-imx233.c
+++ b/firmware/target/arm/imx233/audioin-imx233.c
@@ -26,6 +26,20 @@
 /* some audioout registers impact audioin */
 #include "regs/audioout.h"
 
+#include "audio-target.h"
+
+#ifndef IMX233_AUDIO_MIC_SELECT
+#define IMX233_AUDIO_MIC_SELECT 1 /* lradc1 */
+#endif
+
+#ifndef IMX233_AUDIO_MIC_BIAS
+#define IMX233_AUDIO_MIC_BIAS   0 /* 1.21V */
+#endif
+
+#ifndef IMX233_AUDIO_MIC_RESISTOR
+#define IMX233_AUDIO_MIC_RESISTOR   2KOhm
+#endif
+
 /* values in half-dB, one for each setting */
 static int audioin_vol[2][4]; /* 0=left, 1=right */
 static int audioin_select[2]; /* idem */
@@ -58,7 +72,7 @@ void imx233_audioin_open(void)
 
 void imx233_audioin_close(void)
 {
-    /* Stop ADC (doc says it gate off the module but that's not the case) */
+    /* Stop ADC (doc says it gates off the module but that's not the case) */
     BF_CLR(AUDIOIN_CTRL, RUN);
     /* Disable ADC clock */
     BF_SET(AUDIOIN_ANACLKCTRL, CLKGATE);
@@ -157,9 +171,9 @@ void imx233_audioin_enable_mic(bool enable)
 {
     if(enable)
     {
-        BF_WR(AUDIOIN_MICLINE, MIC_RESISTOR_V(2KOhm));
-        BF_WR(AUDIOIN_MICLINE, MIC_BIAS(4));
-        BF_WR(AUDIOIN_MICLINE, MIC_SELECT(1));
+        BF_WR(AUDIOIN_MICLINE, MIC_RESISTOR_V(IMX233_AUDIO_MIC_RESISTOR));
+        BF_WR(AUDIOIN_MICLINE, MIC_BIAS(IMX233_AUDIO_MIC_BIAS));
+        BF_WR(AUDIOIN_MICLINE, MIC_SELECT(IMX233_AUDIO_MIC_SELECT));
     }
     else
         BF_WR(AUDIOIN_MICLINE, MIC_RESISTOR_V(Off));