Alcohol Sensor: Add C Source

Signed-off-by: Abhishek Malik <abhishek.malik@intel.com>

src/mq303a/mq303a.c

@@ -0,0 +1,69 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ *         Abhishek Malik <abhishek.malik@intel.com>
+ * Copyright (c) 2016 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 "mq303a.h"
+
+mq303a_context mq303a_init(int pin, int heater_pin){
+    mq303a_context dev =
+      (mq303a_context)malloc(sizeof(struct _mq303a_context));
+
+    if (!dev)
+      return NULL;
+
+    dev->aio_pin = pin;
+    dev->gpio_pin = heater_pin;
+    dev->aio = mraa_aio_init(dev->aio_pin);
+    dev->gpio = mraa_gpio_init(dev->gpio_pin);
+
+    if(mraa_gpio_dir(dev->gpio, MRAA_GPIO_OUT) != MRAA_SUCCESS)
+      {
+        free(dev);
+        return NULL;
+      }
+
+    return dev;
+}
+
+void mq303a_close(mq303a_context dev){
+    free(dev);
+}
+
+upm_result_t mq303a_heater_enable(mq303a_context dev, bool enable){
+    if(enable)
+        mraa_gpio_write(dev->gpio, 0);
+    else
+        mraa_gpio_write(dev->gpio, 1);
+
+    return UPM_SUCCESS;
+}
+
+upm_result_t mq303a_get_value(mq303a_context dev, int* val){
+    *val = mraa_aio_read(dev->aio);
+
+    if (*val < 0)
+        return UPM_ERROR_OPERATION_FAILED;
+
+    return UPM_SUCCESS;
+}