grovegprs: Initial implementation

This driver provides support for the Grove GPRS shield, V2:

http://www.seeedstudio.com/wiki/GPRS_Shield_V2.0

It provides a simple interface whereby a user can send and receive
commands and data from the device.  It is controlled by a standardized
set of "AT" commands.  A full description of these commands is
available here:

http://www.seeedstudio.com/wiki/images/7/72/AT_Commands_v1.11.pdf

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

src/grovegprs/grovegprs.cxx

@@ -0,0 +1,74 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2015 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 <iostream>
+
+#include "grovegprs.h"
+
+using namespace upm;
+using namespace std;
+
+static const int defaultDelay = 100;     // max wait time for read
+
+GroveGPRS::GroveGPRS(int uart) :
+  m_uart(uart)
+{
+}
+
+GroveGPRS::~GroveGPRS()
+{
+}
+
+bool GroveGPRS::dataAvailable(unsigned int millis)
+{
+  return m_uart.dataAvailable(millis);
+}
+
+int GroveGPRS::readData(char *buffer, unsigned int len)
+{
+  return m_uart.read(buffer, len);
+}
+
+std::string GroveGPRS::readDataStr(int len)
+{
+  return m_uart.readStr(len);
+}
+
+int GroveGPRS::writeData(char *buffer, unsigned int len)
+{
+  m_uart.flush();
+  return m_uart.write(buffer, len);
+}
+
+int GroveGPRS::writeDataStr(std::string data)
+{
+  m_uart.flush();
+  return m_uart.writeStr(data);
+}
+
+mraa_result_t GroveGPRS::setBaudRate(int baud)
+{
+  return m_uart.setBaudRate(baud);
+}
+