examples: cleanup examples directory

Following changes are done as a part of cleanup:

1. Moved the platform specific `C` examples from top level examples/
directory to platform/ subdirectory and renamed helloedison.c to
gpio_edison.c

2. C specific examples are moved to a new c/ subdirectory. As a part
of this process, examples are modified to follow same standards
and few new examples are also added.

3. Include the newly added C examples to relevant API documentation

4. Ran clang-format for all source files in c/, c++/, platform/
subdirectories

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

examples/c/uart_ow.c

@@ -0,0 +1,105 @@
+/*
+ * 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.
+ *
+ * Example usage: Search and print the found OW device ID recursively.
+ *
+ */
+
+/* standard headers */
+#include "stdio.h"
+
+/* mraa header */
+#include "mraa.h"
+
+int
+main(void)
+{
+    mraa_uart_ow_context uart_ow;
+    mraa_result_t status;
+    uint8_t id[MRAA_UART_OW_ROMCODE_SIZE];
+    uint8_t count = 0;
+
+    //! [Interesting]
+    uart_ow = mraa_uart_ow_init(0);
+    if (uart_ow == NULL) {
+        fprintf(stderr, "Failed to initialize UART OW\n");
+        mraa_deinit();
+        return EXIT_FAILURE;
+    }
+
+    // Reset the ow bus and see if anything is present
+    status = mraa_uart_ow_reset(uart_ow);
+    if (status == MRAA_SUCCESS) {
+        fprintf(stdout, "Reset succeeded, device(s) detected!\n");
+    } else {
+        goto err_exit;
+    }
+
+    fprintf(stdout, "Looking for devices...\n");
+
+    /*
+     * we are essentially doing a binary tree search through the 64
+     * bit address space.  id is modified during this search, and will
+     * be set to the valid rom code for each device found.
+     *
+     * start the search from scratch
+     */
+    status = mraa_uart_ow_rom_search(uart_ow, 1, id);
+    if (status != MRAA_SUCCESS) {
+        goto err_exit;
+    }
+
+    while (status == MRAA_SUCCESS) {
+        /* The first byte (id[0]]) is the device type (family) code.
+         * The last byte (id[7]) is the rom code CRC value.  The
+         * intervening bytes (id[1]-id[6]) are the unique 48 bit
+         * device ID.
+         */
+        fprintf(stdout, "Device %02d Type 0x%02x ID %02x%02x%02x%02x%02x%02x CRC 0x%02x\n", count,
+                id[0], id[6], id[5], id[4], id[3], id[2], id[1], id[7]);
+        count++;
+
+        // continue the search with start argument set to 0
+        status = mraa_uart_ow_rom_search(uart_ow, 0, id);
+    }
+
+    /* stop uart_ow */
+    mraa_uart_ow_stop(uart_ow);
+
+    //! [Interesting]
+    /* deinitialize mraa for the platform (not needed most of the time) */
+    mraa_deinit();
+
+    return EXIT_SUCCESS;
+
+err_exit:
+    mraa_result_print(status);
+
+    /* stop uart_ow */
+    mraa_uart_ow_stop(uart_ow);
+
+    /* deinitialize mraa for the platform (not needed most of the times) */
+    mraa_deinit();
+
+    return EXIT_FAILURE;
+}