1 files changed, 86 insertions, 0 deletions
diff --git a/drivers/staging/csr/oska/refcount.h b/drivers/staging/csr/oska/refcount.h
new file mode 100644
index 000000000000..741b00afcdf0
--- /dev/null
+++ b/drivers/staging/csr/oska/refcount.h
@@ -0,0 +1,86 @@
+/*
+ * Operating system kernel abstraction -- reference counting.
+ *
+ * Copyright (C) 2010 Cambridge Silicon Radio Ltd.
+ *
+ * Refer to LICENSE.txt included with this source code for details on
+ * the license terms.
+ */
+#ifndef __OSKA_REFCOUNT_H
+#define __OSKA_REFCOUNT_H
+
+#include "spinlock.h"
+
+/**
+ * @defgroup refcount Reference Counting
+ *
+ * A reference count is an atomic counter.  A callback function is
+ * called whenever the count reaches zero.
+ *
+ * A generic implementation is provided that is suitable for all
+ * platforms that support the spinlock API in <oska/spinlock.h> (see
+ * \ref spinlock).
+ */
+
+typedef void (*os_refcount_callback_f)(void *arg);
+
+struct __os_refcount_impl {
+    unsigned count;
+    os_spinlock_t lock;
+    os_refcount_callback_f func;
+    void *arg;
+};
+
+/**
+ * A reference count object.
+ *
+ * @ingroup refcount
+ */
+typedef struct __os_refcount_impl os_refcount_t;
+
+/**
+ * Initialize a reference count to 1.
+ *
+ * Initialized reference counts must be destroyed by calling
+ * os_refcount_destroy().
+ *
+ * @param refcount the reference count.
+ * @param func     the function which will be called when the
+ *                 reference count reaches 0.
+ * @param arg      an argument to pass to func.
+ *
+ * @ingroup refcount
+ */
+void os_refcount_init(os_refcount_t *refcount, os_refcount_callback_f func, void *arg);
+
+/**
+ * Destroy a reference count object.
+ *
+ * @param refcount the reference count.
+ *
+ * @ingroup refcount
+ */
+void os_refcount_destroy(os_refcount_t *refcount);
+
+/**
+ * Atomically increase the reference count by 1.
+ *
+ * @param refcount the reference count.
+ *
+ * @ingroup refcount
+ */
+void os_refcount_get(os_refcount_t *refcount);
+
+/**
+ * Atomically decrease the reference count by 1.
+ *
+ * The callback function passed to the call to os_refcount_init() is
+ * called if the count was decreased to zero.
+ *
+ * @param refcount the reference count.
+ *
+ * @ingroup refcount
+ */
+void os_refcount_put(os_refcount_t *refcount);
+
+#endif /* #ifndef __OSKA_REFCOUNT_H */