nmea_gps: renamed vk2828u7 to nmea_gps

This driver will serve as a generic module for grabbing NMEA data from
various GPS devices via a serial interface.  ublox6 will also be
removed in favor of using this driver going forward.

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

src/nmea_gps/nmea_gps.h

@@ -0,0 +1,126 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.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.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include "upm.h"
+#include "mraa/uart.h"
+#include "mraa/gpio.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+  /**
+   * @brief UPM C API for a generic GPS serial device reporting NMEA data
+   *
+   * This driver was tested with a number of GPS devices that emit
+   * NMEA data via a serial interface of some sort (typically a UART).
+   *
+   * @snippet nmea_gps.c Interesting
+   */
+  
+  /**
+   * Device context
+   */
+  typedef struct _nmea_gps_context {
+    mraa_uart_context        uart;
+    mraa_gpio_context        gpio_en;
+  } *nmea_gps_context;
+  
+  /**
+   * NMEA_GPS Initializer
+   *
+   * @param uart Specify which uart to use.
+   * @param baudrate Specify the baudrate to use.  The device defaults
+   * to 9600 baud.
+   * @param enable_pin Specify the GPIO pin to use for the enable pin,
+   * -1 to not use an enable pin.
+   * @return an initialized device context on success, NULL on error.
+   */
+  nmea_gps_context nmea_gps_init(unsigned int uart, unsigned int baudrate,
+                                 int enable_pin);
+
+  /**
+   * NMEA_GPS sensor close function
+   */
+  void nmea_gps_close(nmea_gps_context dev);
+
+  /**
+   * Read character data from the device.
+   *
+   * @param dev sensor context
+   * @param buffer The character buffer to read data into.
+   * @param len The maximum size of the buffer
+   * @return The number of bytes successfully read, or -1 on error
+   */
+  int nmea_gps_read(const nmea_gps_context dev, char *buffer, size_t len);
+
+  /**
+   * Write character data to the device.
+   *
+   * @param dev sensor context
+   * @param buffer The character buffer containing data to write.
+   * @param len The number of bytes to write.
+   * @return The number of bytes successfully written, or -1 on error.
+   */
+  int nmea_gps_write(const nmea_gps_context dev, char *buffer, size_t len);
+
+  /**
+   * Enable or disable the device.  When disabled, the device enters a
+   * low power mode and does not emit NMEA data.  It will still
+   * maintain location data however.
+   *
+   * @param dev sensor context
+   * @param enable true to enable the device, false otherwise.
+   * @return UPM result
+   */
+  upm_result_t nmea_gps_enable(const nmea_gps_context dev, bool enable);
+
+  /**
+   * Set the baudrate of the device.  By default, nmea_gps_init() will
+   * set the baudrate to 9600.
+   *
+   * @param dev sensor context
+   * @param baudrate The baud rate to set for the device.
+   * @return UPM result
+   */
+  upm_result_t nmea_gps_set_baudrate(const nmea_gps_context dev,
+                                     unsigned int baudrate);
+
+  /**
+   * Determine whether there is data available to be read.
+   *
+   * @param dev sensor context
+   * @param millis The number of milliseconds to wait for data to
+   * become available.
+   * @return true if data is available to be read, false otherwise.
+   */
+  bool nmea_gps_data_available(const nmea_gps_context dev,
+                               unsigned int millis);
+
+#ifdef __cplusplus
+}
+#endif