STM32 i2s pin support

Author: pschatzmann

src/AudioI2S/I2SConfigStd.h

@@ -51,12 +51,13 @@ class I2SConfigStd : public AudioInfo {
     int buffer_count = I2S_BUFFER_COUNT;
     int buffer_size = I2S_BUFFER_SIZE;
 
-#ifndef STM32
     int pin_ws = PIN_I2S_WS;
     int pin_bck = PIN_I2S_BCK;
-    int pin_data; // rx or tx pin dependent on mode: tx pin for RXTX_MODE
-    int pin_data_rx; // rx pin for RXTX_MODE
+    int pin_data = -1; // rx or tx pin dependent on mode: tx pin for RXTX_MODE
+    int pin_data_rx = -1; // rx pin for RXTX_MODE
     int pin_mck = PIN_I2S_MCK;
+#ifdef STM32
+    int pin_alt_function = -1;
 #endif
 
 #if defined(RP2040_HOWER)

src/AudioI2S/I2SSTM32.h

@@ -55,6 +55,7 @@ class I2SDriverSTM32 {
     }
 
     setupDefaultI2SParameters();
+    setupPins();
     result = use_dma ? startI2SDMA() : startI2S();
     this->active = result;
     return result;
@@ -323,6 +324,48 @@ class I2SDriverSTM32 {
     i2s_stm32.ref = this;
   }
 
+  void setupPins(){
+    if (cfg.pin_bck != -1 || cfg.pin_ws != -1 || cfg.pin_data != -1) {
+      LOGW("pins ignored: used from stm32-i2s");
+    } else {
+      LOGI("setting up pins for stm32-i2s");
+      i2s_stm32.hardware_config.pins[0].function = stm32_i2s::mclk;
+      i2s_stm32.hardware_config.pins[0].pin = digitalPinToPinName(cfg.pin_mck);
+      i2s_stm32.hardware_config.pins[0].altFunction = cfg.pin_alt_function;
+
+      i2s_stm32.hardware_config.pins[1].function = stm32_i2s::bck;
+      i2s_stm32.hardware_config.pins[1].pin = digitalPinToPinName(cfg.pin_bck);
+      i2s_stm32.hardware_config.pins[1].altFunction = cfg.pin_alt_function;
+
+      i2s_stm32.hardware_config.pins[2].function = stm32_i2s::ws;
+      i2s_stm32.hardware_config.pins[2].pin = digitalPinToPinName(cfg.pin_ws);
+      i2s_stm32.hardware_config.pins[2].altFunction = cfg.pin_alt_function;
+
+      switch (cfg.rx_tx_mode) {
+        case TX_MODE:
+          i2s_stm32.hardware_config.pins[3].function = stm32_i2s::data_out;
+          i2s_stm32.hardware_config.pins[3].pin = digitalPinToPinName(cfg.pin_data);
+          i2s_stm32.hardware_config.pins[3].altFunction = cfg.pin_alt_function;
+          break;
+        case RX_MODE:
+          i2s_stm32.hardware_config.pins[4].function = stm32_i2s::data_in;
+          i2s_stm32.hardware_config.pins[4].pin = digitalPinToPinName(cfg.pin_data);
+          i2s_stm32.hardware_config.pins[4].altFunction = cfg.pin_alt_function;
+          break;
+        case RXTX_MODE:
+          i2s_stm32.hardware_config.pins[3].function = stm32_i2s::data_out;
+          i2s_stm32.hardware_config.pins[3].pin = digitalPinToPinName(cfg.pin_data);
+          i2s_stm32.hardware_config.pins[3].altFunction = cfg.pin_alt_function;
+
+          i2s_stm32.hardware_config.pins[4].function = stm32_i2s::data_in;
+          i2s_stm32.hardware_config.pins[4].pin = digitalPinToPinName(cfg.pin_data);
+          i2s_stm32.hardware_config.pins[4].altFunction = cfg.pin_alt_function;
+          break;
+      };
+
+    }
+  }
+
   uint32_t getMode(I2SConfigStd &cfg) {
     if (cfg.is_master) {
       switch (cfg.rx_tx_mode) {