[i2s_audio] Move test bus into a shared package and give fixtures unique ids (#16793)

tests/test_build_components/common/README.md

@@ -145,6 +145,15 @@ Same pin allocations as standard I2C, but with 10kHz frequency for components re
 Same UART pins as above, plus:
 - **flow_control_pin**: GPIO4 (all platforms)
 
+### I2S Audio
+Provides a shared `i2s_audio_bus` (clock pins only); ESP32 family only:
+- **ESP32 IDF / ESP32-S3 IDF**: BCLK=GPIO5, LRCLK=GPIO4, MCLK=GPIO15
+
+Each consumer keeps its own `i2s_dout_pin`/`i2s_din_pin` substitution and must use a
+unique data pin, since several speakers/microphones can share one bus when grouped.
+The `i2s_audio` component itself (and the isolated PDM `microphone`) keep defining the
+bus inline and are not grouped.
+
 ### BLE
 - **ESP32**: Shared `esp32_ble_tracker` infrastructure
 - Each component defines unique `ble_client` with different MAC addresses

tests/test_build_components/common/i2s_audio/esp32-idf.yaml

@@ -0,0 +1,14 @@
+# Common I2S audio bus configuration for ESP32 IDF tests
+# Provides a shared i2s_audio bus that speaker/microphone components can use
+# Each consumer must give its speaker/microphone a unique data pin
+
+substitutions:
+  i2s_bclk_pin: GPIO5
+  i2s_lrclk_pin: GPIO4
+  i2s_mclk_pin: GPIO15
+
+i2s_audio:
+  - id: i2s_audio_bus
+    i2s_bclk_pin: ${i2s_bclk_pin}
+    i2s_lrclk_pin: ${i2s_lrclk_pin}
+    i2s_mclk_pin: ${i2s_mclk_pin}

tests/test_build_components/common/i2s_audio/esp32-s3-idf.yaml

@@ -0,0 +1,14 @@
+# Common I2S audio bus configuration for ESP32-S3 IDF tests
+# Provides a shared i2s_audio bus that speaker/microphone components can use
+# Each consumer must give its speaker/microphone a unique data pin
+
+substitutions:
+  i2s_bclk_pin: GPIO5
+  i2s_lrclk_pin: GPIO4
+  i2s_mclk_pin: GPIO15
+
+i2s_audio:
+  - id: i2s_audio_bus
+    i2s_bclk_pin: ${i2s_bclk_pin}
+    i2s_lrclk_pin: ${i2s_lrclk_pin}
+    i2s_mclk_pin: ${i2s_mclk_pin}