spi: Make Spi write() work from SWIG with typemaps

This change also changes the C++ API write(char) call to writeByte(uint8_t) and
the write() call now takes a uint8_t* instead of a char*. This should not alter
any code significantly and does not affect the C API.

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

examples/javascript/spi.js

@@ -0,0 +1,41 @@
+#!/usr/bin/env node
+
+/*
+ * Author: Brendan Le Foll <brendan.le.foll@intel.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.
+ */
+
+var m = require('mraa'); //require mraa
+
+// helper function to go from hex val to dec
+function char(x) { return parseInt(x, 16); }
+
+x = new m.Spi(0)
+buf = new Buffer(4)
+buf[0] = char('0xf4')
+buf[1] = char('0x2e')
+buf[2] = char('0x3e')
+buf[3] = char('0x4e')
+buf2 = x.write(buf)
+console.log("Sent: " + buf.toString('hex') + ". Received: " + buf2.toString('hex'))
+
+