buzzer: C implementation; C++ wraps C

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

src/buzzer/buzzer.c

@@ -0,0 +1,142 @@
+/*
+ * 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.
+ */
+
+#include <assert.h>
+#include <unistd.h>
+#include <upm_utilities.h>
+#include "buzzer.h"
+
+buzzer_context buzzer_init(int pin)
+{
+    buzzer_context dev =
+        (buzzer_context)malloc(sizeof(struct _buzzer_context));
+
+    if (!dev)
+        return NULL;
+
+    dev->pwm = NULL;
+    dev->volume = 0.0;
+    dev->initialized = false;
+
+    // make sure MRAA is initialized
+    int mraa_rv;
+    if ((mraa_rv = mraa_init()) != MRAA_SUCCESS)
+    {
+        printf("%s: mraa_init() failed (%d).\n", __FUNCTION__, mraa_rv);
+        buzzer_close(dev);
+        return NULL;
+    }
+
+    // MRAA contexts...
+    if ( !(dev->pwm = mraa_pwm_init(pin)) )
+    {
+        printf("%s: mraa_pwm_init() failed\n",
+               __FUNCTION__);
+        buzzer_close(dev);
+        return NULL;
+    }
+
+    mraa_pwm_enable(dev->pwm, 1);
+
+    buzzer_set_volume(dev, 1.0);
+
+    dev->initialized = true;
+    return dev;
+}
+
+void buzzer_close(buzzer_context dev)
+{
+    assert(dev != NULL);
+
+    if (dev->initialized)
+        buzzer_stop_sound(dev);
+
+    if (dev->pwm)
+    {
+        mraa_pwm_enable(dev->pwm, 0);
+        mraa_pwm_close(dev->pwm);
+    }
+
+    free(dev);
+}
+
+void buzzer_set_volume(const buzzer_context dev, float vol)
+{
+    assert(dev != NULL);
+
+    dev->volume = vol;
+}
+
+float buzzer_get_volume(const buzzer_context dev)
+{
+    assert(dev != NULL);
+
+    return dev->volume;
+}
+
+upm_result_t buzzer_play_sound(const buzzer_context dev, int note, int delay)
+{
+    assert(dev != NULL);
+
+    if (mraa_pwm_period_us(dev->pwm, note))
+    {
+        printf("%s: mraa_pwm_period_us() failed\n", __FUNCTION__);
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    if (mraa_pwm_write(dev->pwm, dev->volume * 0.5))
+    {
+        printf("%s: mraa_pwm_write() failed\n", __FUNCTION__);
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    if (delay >= 0)
+    {
+        upm_delay_us(delay);
+        return buzzer_stop_sound(dev);
+    }
+
+    return UPM_SUCCESS;
+}
+
+upm_result_t buzzer_stop_sound(const buzzer_context dev)
+{
+    assert(dev != NULL);
+
+    mraa_result_t rv = MRAA_SUCCESS;
+
+    rv = mraa_pwm_period_us(dev->pwm, 1);
+    rv = mraa_pwm_write(dev->pwm, 0);
+
+    if (rv)
+    {
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    return UPM_SUCCESS;
+}