gpio: initial implementation of interupt handling on gpio

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

examples/isr_pin6.c

@@ -0,0 +1,64 @@
+/*
+ * Author: Brendan Le Foll
+ * 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 <unistd.h>
+
+#include "gpio.h"
+
+static volatile int counter = 0;
+static volatile int oldcounter = 0;
+
+void interrupt (void) {
+    ++counter;
+}
+
+int main ()
+{
+    maa_init();
+    maa_gpio_context* x;
+
+    x = maa_gpio_init(6);
+    if (x == NULL) {
+        return 1;
+    }
+
+    maa_gpio_dir(x, MAA_GPIO_IN);
+
+    gpio_edge_t edge = MAA_GPIO_EDGE_BOTH;
+   
+    maa_gpio_isr(x, edge, &interrupt);
+
+    for(;;) {
+        if(counter != oldcounter) {
+          fprintf(stdout, "timeout counter == %d\n", counter);
+          oldcounter = counter;
+        }
+        // got to relieve our poor CPU!
+        sleep(1);
+    }
+
+    maa_gpio_close(x);
+
+    return MAA_SUCCESS;
+}