Added lock files

module_usb_aud_shared/locks/lock.S

@@ -0,0 +1,55 @@
+/** lock.S
+  * @brief     Functions for using hardware locks
+  * @author    Ross Owen, XMOS Limited
+  */
+
+#include <xs1_user.h>
+
+/////////////////////////////////////////////////////////////////////////
+// void GetLockResource()
+.extern GetLockResource
+.globl GetLockResource.nstackwords
+.linkset GetLockResource.nstackwords, 0
+.globl GetLockResource
+.text 
+GetLockResource:
+  getr		r0, XS1_RES_TYPE_LOCK
+  retsp 	0
+
+
+/////////////////////////////////////////////////////////////////////////
+// void ClaimLock(lock l)
+.extern ClaimLock
+.globl ClaimLock.nstackwords
+.linkset ClaimLock.nstackwords, 0
+.globl ClaimLock
+.text 
+ClaimLock:
+  in		r0, res[r0]
+  retsp 	0
+
+
+/////////////////////////////////////////////////////////////////////////
+// void FreeLock(lock l)
+.extern FreeLock
+.globl FreeLock.nstackwords
+.linkset FreeLock.nstackwords, 0
+.globl FreeLock
+.text 
+FreeLock:
+  out		res[r0], r0
+  retsp 	0
+
+
+/////////////////////////////////////////////////////////////////////////
+// void FreeLockResource(lock l)
+.extern FreeLockResource
+.globl FreeLockResource.nstackwords
+.linkset FreeLockResource.nstackwords, 0
+.globl FreeLockResource
+.text 
+FreeLockResource:
+  freer		res[r0]
+  retsp 	0
+
+

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