- Added AudioHwConfig_Mute() and AudioHwConfig_UnMute()

- Added default (empty) implementations of AudioHW.. functions

lib_xua/api/xua_audiohub.h

@@ -63,16 +63,32 @@ void XUA_AudioHub(chanend ?c_aud,
 
 void SpdifTxWrapper(chanend c_spdif_tx);
 
-/* These functions must be implemented for the CODEC/ADC/DAC arrangement of a specific design */
+/* The 4 functions below should implemented for the external audio haardware arrangement of a specific design.
+ * Note, default (empty) implementations of these are provided in audiohub_user.c
+ */
 
-/* Any required clocking and CODEC initialisation - run once at start up */
-/* TODO Provide default implementation of this */
-void AudioHwInit();
+/** User code for any required audio hardwarte initialisation - run once at start up */
+void AudioHwInit(void);
 
-/* Configure audio hardware (clocking, CODECs etc) for a specific mClk/Sample frquency - run on every sample frequency change */
-/* TODO Provide default implementation of this */
-void AudioHwConfig(unsigned samFreq, unsigned mClk, unsigned dsdMode,
-        unsigned sampRes_DAC, unsigned sampRes_ADC);
+/** User code to mute audio hardware before a sample rate change - run every sample frequency change */
+void AudioHwConfig_Mute(void);
+
+/** User code to un-mute audio hardware after a sample rate change - run every sample frequency change */
+void AudioHwConfig_UnMute(void);
+
+/** User code Configure audio hardware (clocking, CODECs etc) for a specific mClk/Sample frquency - run on every sample frequency change
+ *
+ * \param samFreq       The new sample frequency (in Hz)
+ *
+ * \param mclk          The new master clock frequency (in Hz)
+ *
+ * \param dsdMode       DSD mode, DSD_MODE_NATIVE, DSD_MODE_DOP or DSD_MODE_OFF
+ *
+ * \param sampReq_DAC   Playback sample resolution (in bits)
+ *
+ * \param sampReq_ADC   Record sample resolution (in bits)
+ */
+void AudioHwConfig(unsigned samFreq, unsigned mClk, unsigned dsdMode, unsigned sampRes_DAC, unsigned sampRes_ADC);
 
 #endif // __XC__
 

lib_xua/src/core/audiohub/audiohub_user.c

@@ -0,0 +1,29 @@
+// Copyright 2023 XMOS LIMITED.
+// This Software is subject to the terms of the XMOS Public Licence: Version 1.
+
+/* Default implementations of AudioHwInit(), AudioHwConfig(), AudioHwConfig_Mute() and AudioHwConfig_UnMute() */
+
+void AudioHwInit() __attribute__ ((weak));
+void AudioHwInit()
+{
+    return;
+}
+
+void AudioHwConfig(unsigned samFreq, unsigned mClk, unsigned dsdMode, unsigned sampRes_DAC, unsigned sampRes_ADC) __attribute__ ((weak));
+void AudioHwConfig(unsigned samFreq, unsigned mClk, unsigned dsdMode, unsigned sampRes_DAC, unsigned sampRes_ADC)
+{
+    return;
+}
+
+void AudioHwConfig_Mute() __attribute__ ((weak));
+void AudioHwConfig_Mute()
+{
+    return;
+}
+
+void AudioHwConfig_UnMute() __attribute__ ((weak));
+void AudioHwConfig_UnMute()
+{
+    return;
+}
+

lib_xua/src/core/audiohub/xua_audiohub.xc

@@ -86,7 +86,7 @@ static inline int HandleSampleClock(int frameCount, buffered _XUA_CLK_DIR port:3
     unsigned syncError = 0;
     unsigned lrval = 0;
     const unsigned lrval_mask = (0xffffffff << (32 - XUA_I2S_N_BITS));
-    
+
     if(XUA_I2S_N_BITS != 32)
     {
         asm volatile("in %0, res[%1]":"=r"(lrval):"r"(p_lrclk):"memory");
@@ -306,7 +306,7 @@ unsigned static AudioHub_MainLoop(chanend ?c_out, chanend ?c_spd_out
                     // Manual IN instruction since compiler generates an extra setc per IN (bug #15256)
                     unsigned sample;
                     asm volatile("in %0, res[%1]" : "=r"(sample)  : "r"(p_i2s_adc[index]));
-                    
+
                     sample = bitrev(sample);
                     if(XUA_I2S_N_BITS != 32)
                     {
@@ -805,12 +805,18 @@ void XUA_AudioHub(chanend ?c_aud, clock ?clk_audio_mclk, clock ?clk_audio_bclk,
             }
 #endif
 
+            /* User should mute audio hardware */
+            AudioHwConfig_Mute();
+
 #if (XUA_USE_APP_PLL)
             AppPllEnable(tile[AUDIO_IO_TILE], mClk);
 #endif
 
-            /* Configure Clocking/CODEC/DAC/ADC for SampleFreq/MClk */
+            /* User code should configure audio harware for SampleFreq/MClk etc */
             AudioHwConfig(curFreq, mClk, dsdMode, curSamRes_DAC, curSamRes_ADC);
+
+            /* User should unmute audio hardware */
+            AudioHwConfig_UnMute();
         }
 
         if(!firstRun)