Audio System + Drivers (#562)

Drivers/dummy-i2s-amp-module/include/bindings/dummy_i2s_amp.h

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/bindings/bindings.h>
+#include <drivers/dummy_i2s_amp.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// One DEFINE_DEVICETREE per compatible string -- the devicetree compiler derives the
+// expected config typedef name from the compatible string's suffix (e.g. "maxim,max98357a"
+// -> max98357a_config_dt), not from a name we choose, so each supported chip needs its own
+// typedef even though they all share the same underlying config layout.
+DEFINE_DEVICETREE(max98357a, struct DummyI2sAmpConfig)
+DEFINE_DEVICETREE(ns4168, struct DummyI2sAmpConfig)
+
+#ifdef __cplusplus
+}
+#endif

Drivers/dummy-i2s-amp-module/include/drivers/dummy_i2s_amp.h

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <tactility/error.h>
+#include <tactility/drivers/audio_codec.h>
+#include <tactility/drivers/gpio.h>
+
+struct Device;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Dummy class-D amplifier configuration.
+ *
+ * Covers any speaker amp with no I2C/register interface -- just I2S data in plus an
+ * optional GPIO enable (SD) pin -- e.g. MAX98357A, NS4168. There is no I2C parent; the
+ * device sits standalone in the devicetree and only references the I2S controller by name.
+ */
+struct DummyI2sAmpConfig {
+    /** I2S controller device that carries audio data */
+    struct Device* i2s_device;
+    /** Optional amplifier enable pin (SD pin). GPIO_PIN_SPEC_NONE if not wired. */
+    struct GpioPinSpec enable_pin;
+};
+
+#ifdef __cplusplus
+}
+#endif

Drivers/dummy-i2s-amp-module/include/dummy_i2s_amp_module.h

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern struct Module dummy_i2s_amp_module;
+
+#ifdef __cplusplus
+}
+#endif