ipod6g: some fixes for recording

- Fix broken recording from jack microphone.
- Fix recording hardware detection on models that do not support
  the jack microphone.
- Enable monitor mode when recording.

Change-Id: Ib79a2746f2d75f74cf6667d33bc9ed6512bbc8a9

firmware/target/arm/s5l8702/gpio-s5l8702.c

@@ -62,6 +62,7 @@ void INIT_ATTR gpio_init(void)
      *   1    0        120/160slim  dock line-in + jack mic
      */
     GPIOCMD = 0xe0700;
+    udelay(10000);
     rec_hw_ver = (PDAT(14) & (1 << 7)) ? 0 : 1;
     GPIOCMD = 0xe070e;  /* restore default configuration */
 

firmware/target/arm/s5l8702/ipod6g/audio-6g.c

@@ -23,10 +23,55 @@
 #include "audio.h"
 #include "sound.h"
 #include "pmu-target.h"
+#include "i2c-s5l8702.h"
 
 extern int rec_hw_ver;
 
+/* Mikey is the internal controller for jack microphone and/or
+ * remote accessories.
+ * TODO:
+ *  - move to mikey-6g.c
+ *  - detect jack accessory
+ *  - support for remote buttons
+ */
+unsigned char mikey_read(int address)
+{
+    unsigned char val;
+    i2c_read(0, 0x72, address, 1, &val);
+    return val;
+}
+
+int mikey_write(int address, unsigned char val)
+{
+    return i2c_write(0, 0x72, address, 1, &val);
+}
+
+void mikey_reset(void)
+{
+    mikey_write(0, 5);
+    mikey_write(1, 0x80);
+}
+
 #if INPUT_SRC_CAPS != 0
+#ifdef HAVE_RECORDING
+void audio_enable_mic(bool enable)
+{
+    if (rec_hw_ver == 0)
+        return;
+
+    if (enable)
+    {
+        mikey_write(0, 7);  /* raise voltage to polarize microphone */
+        GPIOCMD = 0xe070f;  /* enable preamp */
+    }
+    else
+    {
+        mikey_reset();      /* microphone line voltage = 0 */
+        GPIOCMD = 0xe070e;  /* disable preamp */
+    }
+}
+#endif
+
 void audio_set_output_source(int source)
 {
     if ((unsigned)source >= AUDIO_NUM_SOURCES)
@@ -53,8 +98,7 @@ void audio_input_mux(int source, unsigned flags)
                 /* Vcodec = 1800mV (900mV + value*100mV) */
                 pmu_ldo_set_voltage(3, 0x9);
 
-                if (rec_hw_ver == 1)
+                audio_enable_mic(false);
-                    GPIOCMD = 0xe070e;
             }
 #endif
         break;
@@ -63,13 +107,12 @@ void audio_input_mux(int source, unsigned flags)
         case AUDIO_SRC_MIC:             /* recording only */
             if (source != last_source)
             {
-                if (rec_hw_ver == 1)
+                audio_enable_mic(true);
-                    GPIOCMD = 0xe070f;
 
                 /* Vcodec = 2400mV (900mV + value*100mV) */
                 pmu_ldo_set_voltage(3, 0xf);
 
-                audiohw_set_monitor(false);
+                audiohw_set_monitor(true);
                 audiohw_enable_recording(true);  /* source mic */
             }
         break;
@@ -79,13 +122,12 @@ void audio_input_mux(int source, unsigned flags)
         case AUDIO_SRC_LINEIN:          /* recording only */
             if (source != last_source)
             {
-                if (rec_hw_ver == 1)
+                audio_enable_mic(false);
-                    GPIOCMD = 0xe070e;
 
                 /* Vcodec = 2400mV (900mV + value*100mV) */
                 pmu_ldo_set_voltage(3, 0xf);
 
-                audiohw_set_monitor(false);
+                audiohw_set_monitor(true);
                 audiohw_enable_recording(false); /* source line */
             }
         break;