uart: barebones uart module added.

* Only defined call is the init. Will then expose the uart from
* the multiplexors.

Signed-off-by: Thomas Ingleby <thomas.c.ingleby@intel.com>

src/CMakeLists.txt

@@ -12,6 +12,7 @@ set (mraa_LIB_SRCS
   ${PROJECT_SOURCE_DIR}/src/pwm/pwm.c
   ${PROJECT_SOURCE_DIR}/src/spi/spi.c
   ${PROJECT_SOURCE_DIR}/src/aio/aio.c
+  ${PROJECT_SOURCE_DIR}/src/uart/uart.c
   ${PROJECT_SOURCE_DIR}/src/intel_galileo_rev_d.c
   ${PROJECT_SOURCE_DIR}/src/intel_galileo_rev_g.c
 # autogenerated version file

src/mraa.c

@@ -453,3 +453,32 @@ mraa_adc_supported_bits()
 
     return plat->adc_supported;
 }
+
+mraa_result_t
+mraa_setup_uart(int index)
+{
+    if (plat == NULL)
+        return MRAA_ERROR_PLATFORM_NOT_INITIALISED;
+
+    if (plat->uart_dev_count == 0)
+        return MRAA_ERROR_FEATURE_NOT_SUPPORTED;
+
+    if (plat->uart_dev_count <= index)
+        return MRAA_ERROR_NO_RESOURCES;
+
+    int pos = plat->uart_dev[index].rx;
+    if (pos >= 0) {
+        if (plat->pins[pos].uart.mux_total > 0)
+            if (mraa_setup_mux_mapped(plat->pins[pos].uart) != MRAA_SUCCESS)
+                return MRAA_ERROR_INVALID_RESOURCE;
+    }
+
+    if (pos >= 0) {
+        pos = plat->uart_dev[index].tx;
+        if (plat->pins[pos].uart.mux_total > 0)
+            if (mraa_setup_mux_mapped(plat->pins[pos].uart) != MRAA_SUCCESS)
+                return MRAA_ERROR_INVALID_RESOURCE;
+    }
+
+    return MRAA_SUCCESS;
+}

src/uart/uart.c

@@ -0,0 +1,54 @@
+/*
+ * Author: Thomas Ingleby <thomas.c.ingleby@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 <stdlib.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "uart.h"
+#include "mraa_internal.h"
+
+/**
+ * A structure representing a UART device
+ */
+struct _uart {
+    /*@{*/
+    int index; /**< the uart index, as known to the os. */
+    /*@}*/
+};
+
+mraa_uart_context
+mraa_uart_init(int index)
+{
+    if ( mraa_setup_uart(index) != MRAA_SUCCESS)
+        return NULL;
+
+    mraa_uart_context dev = (mraa_uart_context) malloc(sizeof(struct _uart));
+    memset(dev, 0, sizeof(struct _uart));
+
+    dev->index = index;
+
+    return dev;
+}