Create separate input module

input.c

@@ -0,0 +1,56 @@
+#include "input.h"
+
+#include <assert.h>
+#include <fcntl.h>
+#include <linux/input.h>
+#include <string.h>
+#include <unistd.h>
+
+enum {
+	RELEASE = 0,
+	PRESS = 1,
+	REPEAT = 2,
+	NCALLBACKS,
+};
+
+static int input_fd;
+static input_callback_t callbacks[NCALLBACKS];
+
+int input_init()
+{
+	input_fd = open("/dev/input/event0", O_RDONLY);
+	assert(input_fd != -1);
+	memset(callbacks, 0, sizeof(callbacks));
+	return input_fd;
+}
+
+void input_cleanup()
+{
+	close(input_fd);
+}
+
+void input_on_press(input_callback_t cb)
+{
+	callbacks[PRESS] = cb;
+}
+
+void input_on_release(input_callback_t cb)
+{
+	callbacks[RELEASE] = cb;
+}
+
+void input_on_repeat(input_callback_t cb)
+{
+	callbacks[REPEAT] = cb;
+}
+
+void input_handle()
+{
+	struct input_event ev;
+	const int len = read(input_fd, &ev, sizeof(ev));
+	assert(len == sizeof(ev));
+	if (ev.type == EV_KEY && 0 <= ev.value && ev.value < NCALLBACKS) {
+		if (callbacks[ev.value] != nullptr)
+			callbacks[ev.value](ev.code);
+	}
+}