Added lock files

module_usb_aud_shared/locks/lock.h

@@ -0,0 +1,25 @@
+/** @file       lock.h
+  * @brief      Functions for using hardware locks
+  * @author     Ross Owen, XMOS Limited
+  */
+
+#ifndef _LOCK_H_
+#define _LOCK_H_ 1
+
+typedef unsigned lock;
+
+/* Allocates and returns a lock resource - returns 0 if out of lock */
+lock GetLockResource() ;
+
+/* Claims the passed lock, this is a blocking call */
+void ClaimLock(lock l);
+
+/* Frees the passed lock */
+void FreeLock(lock l);
+
+/* De-allocated the passed lock resource */
+void FreeLockResource(lock l);
+
+
+
+#endif