Added route(..), fixed dap_enable(..)

Adding route() made me review dap_enable() more closely and it wasn't
doing what I intended to do before, it was ignoring I2S coming back from
Teensy, DAP was sourced from ADC as was I2S_DOUT and DAC was sourced
from DAP; Teensy received valid data from ADC but data from Teensy was
just discarded if user selected it.

control_sgtl5000.cpp

@@ -568,6 +568,16 @@ unsigned int AudioControlSGTL5000::modify(unsigned int reg, unsigned int val, un
 	return val1;
 }
 
+unsigned short AudioControlSGTL5000::route(uint8_t i2s_out, uint8_t dac, uint8_t dap, uint8_t dap_mix)
+{
+	i2s_out&=3;
+	dac&=3;
+	dap&=3;
+	dap_mix&=3;
+	if((i2s_out==SGTL_AUDIO_PROCESSOR)||(dac==SGTL_AUDIO_PROCESSOR)) modify(DAP_CONTROL,1,1); // enable DAP
+	return modify(CHIP_SSS_CTRL,(dap_mix<<8)|(dap<<6)|(dac<<4)|i2s_out,(3<<8)|(3<<6)|(3<<4)|3);
+}
+
 bool AudioControlSGTL5000::volumeInteger(unsigned int n)
 {
 	if (n == 0) {
@@ -641,9 +651,9 @@ unsigned short AudioControlSGTL5000::dap_mix_enable(uint8_t n)
 unsigned short AudioControlSGTL5000::dap_enable(uint8_t n)
 {
 	if(n) n=1;
-	unsigned char DAC=1+(2*n); // I2S_IN if n==0 else DAP
+	unsigned char i2s_sel=3*n; // ADC if n==0 else DAP
 	modify(DAP_CONTROL,n,1);
-	return modify(CHIP_SSS_CTRL,(0<<6)|(DAC<<4),(3<<6)|(3<<4));
+	return route(i2s_sel,SGTL_I2S_TEENSY,SGTL_ADC);
 }
 
 unsigned short AudioControlSGTL5000::dap_enable(void)

control_sgtl5000.h

@@ -29,6 +29,10 @@
 
 #include "AudioControl.h"
 
+#define SGTL_ADC 0
+#define SGTL_I2S_TEENSY 1
+#define SGTL_AUDIO_PROCESSOR 3
+
 class AudioControlSGTL5000 : public AudioControl
 {
 public:
@@ -53,6 +57,8 @@ public:
 	//bool inputLinein(void) { return write(0x0024, ana_ctrl | (1<<2)); }
 	//bool inputMic(void) { return write(0x002A, 0x0172) && write(0x0024, ana_ctrl & ~(1<<2)); }
 
+	unsigned short route(uint8_t i2s_out, uint8_t dac, uint8_t dap, uint8_t dap_mix);
+	unsigned short route(uint8_t i2s_out, uint8_t dac, uint8_t dap) { route(i2s_out,dac,dap,0); }
 	bool volume(float left, float right);
 	unsigned short micGain(unsigned int n) { return modify(0x002A, n&3, 3); }
 	unsigned short lo_lvl(uint8_t n);