buzzer: C implementation; C++ wraps C

Signed-off-by: Jon Trulson <jtrulson@ics.com>

src/buzzer/buzzer.h

@@ -0,0 +1,115 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * based on original C++ driver by
+ * Author: Yevgeniy Kiveisha <yevgeniy.kiveisha@intel.com>
+ * Copyright (c) 2014 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#pragma once
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <upm.h>
+
+#include <mraa/pwm.h>
+#include <buzzer_tones.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+    /**
+     * @file buzzer.h
+     * @library buzzer
+     * @brief C API for the buzzer driver
+     *
+     * @include buzzer.c
+     */
+
+    /**
+     * Device context
+     */
+    typedef struct _buzzer_context {
+        mraa_pwm_context pwm;
+
+        float volume;
+        bool initialized;
+    } *buzzer_context;
+
+    /**
+     * Initialize a buzzer context.
+     *
+     * @param pin Buzzer pin number (pwm capable)
+     * @return buzzer device context
+     */
+    buzzer_context buzzer_init(int pin);
+
+    /**
+     * Buzzer object destructor.
+     *
+     * @param dev Device context.
+     */
+    void buzzer_close(buzzer_context dev);
+
+    /**
+     * Plays a tone for a certain amount of time or indefinitely. When delay
+     * is not used, the sound can be stopped by calling stopSound().
+     *
+     * @param dev Device context.
+     * @param note Note to play (DO, RE, MI, etc.) or frequency
+     * @param delay Time in microseconds for which to play the sound;
+     * if the value is 0, the sound is played indefinitely
+     * @return UPM result
+     */
+    upm_result_t buzzer_play_sound(const buzzer_context dev, int note,
+                                   int delay);
+
+    /**
+     * Stops the sound currently playing. Should be called when playSound()
+     * does not have a delay value.
+     *
+     * @param dev Device context.
+     * @return UPM result
+     */
+    upm_result_t buzzer_stop_sound(const buzzer_context dev);
+
+    /**
+     * Sets the volume for the buzzer, but may affect the sound timbre.
+     * Works best with halved values; e.g., 1.0, 0.5, 0.25, etc.
+     *
+     * @param dev Device context.
+     * @param vol Value to set the volume to, from 0.0 to 1.0
+     */
+    void buzzer_set_volume(const buzzer_context dev, float vol);
+
+    /**
+     * Gets the buzzer volume.
+     *
+     * @param dev Device context.
+     * @return Value the volume was set to
+     */
+    float buzzer_get_volume(const buzzer_context dev);
+
+#ifdef __cplusplus
+}
+#endif