mock: added mraa mock platform infra and GPIO implementation

Mock platform allows one to use mraa without having any real HW.

This commit makes necessary foundational changes and implements
GPIO functionality as well as adds respective tests.

Signed-off-by: Alex Tereschenko <alext.mkrs@gmail.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

tests/mock/gpio_checks_dir.py

@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+
+# Author: Alex Tereschenko <alext.mkrs@gmail.com>
+# Copyright (c) 2016 Alex Tereschenko <alext.mkrs@gmail.com>
+#
+# 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.
+
+import mraa as m
+import unittest as u
+
+MRAA_TEST_PIN = 0
+
+class GpioChecksDir(u.TestCase):
+  def setUp(self):
+    self.pin = m.Gpio(MRAA_TEST_PIN)
+
+  def tearDown(self):
+    del self.pin
+
+  def test_set_dir_output(self):
+    direction = m.DIR_OUT
+    res = self.pin.dir(direction)
+    self.assertEqual(res, m.SUCCESS, "Setting GPIO to output failed")
+    self.assertEqual(self.pin.readDir(), direction, "GPIO has incorrect direction after dir(DIR_OUT)")
+
+  def test_set_dir_output_HIGH(self):
+    res = self.pin.dir(m.DIR_OUT_HIGH)
+    self.assertEqual(res, m.SUCCESS, "Setting GPIO to output HIGH failed")
+    self.assertEqual(self.pin.readDir(), m.DIR_OUT, "GPIO has incorrect direction after dir(DIR_OUT_HIGH)")
+    self.assertEqual(self.pin.read(), 1, "GPIO has incorrect state after dir(DIR_OUT_HIGH)")
+
+  def test_set_dir_output_LOW(self):
+    res = self.pin.dir(m.DIR_OUT_LOW)
+    self.assertEqual(res, m.SUCCESS, "Setting GPIO to output LOW failed")
+    self.assertEqual(self.pin.readDir(), m.DIR_OUT, "GPIO has incorrect direction after dir(DIR_OUT_LOW)")
+    self.assertEqual(self.pin.read(), 0, "GPIO has incorrect state after dir(DIR_OUT_LOW)")
+
+  def test_set_dir_input(self):
+    direction = m.DIR_IN
+    res = self.pin.dir(direction)
+    self.assertEqual(res, m.SUCCESS, "Setting GPIO to input failed")
+    self.assertEqual(self.pin.readDir(), direction, "GPIO has incorrect direction after dir(DIR_IN)")
+
+  def test_set_dir_invalid(self):
+    direction = 99
+    res = self.pin.dir(direction)
+    self.assertNotEqual(res, m.SUCCESS, "Setting direction to " + str(direction) + " should have failed")
+
+if __name__ == '__main__':
+  u.main()