Import of the watch repository from Pebble

src/fw/drivers/mic.h

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+
+#define MIC_SAMPLE_RATE     (16000) //!< Microphone audio data sample rate
+#define MIC_DEFAULT_VOLUME  (-1)
+
+typedef const struct MicDevice MicDevice;
+
+//! Microphone audio data handler callback. Called when buffer is full
+typedef void (*MicDataHandlerCB)(int16_t *samples, size_t sample_count, void *context);
+
+//! Initialize microphone driver. Should be called on boot
+void mic_init(MicDevice *this);
+
+//! Set the mic volume.  This must be called afer mic_init, and not while the mic is running.
+void mic_set_volume(MicDevice *this, uint16_t volume);
+
+//! Start the microphone. The driver will fill the specified buffer with up to the specified size
+//! each time it calls the audio data handler callback. audio_buffer_len should be specified as the
+//! length of the buffer (number of 16-bit samples it can hold)
+//! @return true if mic was started, false if mic was already running
+bool mic_start(MicDevice *this, MicDataHandlerCB data_handler, void *context,
+               int16_t *audio_buffer, size_t audio_buffer_len);
+
+//! Stop the microphone. If buffer is not full, the remaining samples will be abandoned. No more
+//! callbacks will be executed nor data copied into the buffer after this returns
+void mic_stop(MicDevice *this);
+
+//! Indicates whether the mic is running
+bool mic_is_running(MicDevice *this);