diff --git a/pcm_io.h b/pcm_io.h
index 2271d76..4d9746d 100644
--- a/pcm_io.h
+++ b/pcm_io.h
@@ -31,11 +31,17 @@
 #ifndef __PCM_H__
 #define __PCM_H__
 
+#include <poll.h>
+
 struct pcm_ops {
     int (*open) (unsigned int card, unsigned int device,
                  unsigned int flags, void **data, void *node);
     void (*close) (void *data);
     int (*ioctl) (void *data, unsigned int cmd, ...);
+    void* (*mmap) (void *data, void *addr, size_t length, int prot, int flags,
+                 off_t offset);
+    int (*munmap) (void *data, void *addr, size_t length);
+    int (*poll) (void *data, struct pollfd *pfd, nfds_t nfds, int timeout);
 };
 
 #endif /* end of __PCM_H__ */