Merge changes I61375a73,Iffe85dd8 into mnc-dr-dev

* changes:
  Add pcm_get_poll_fd
  Export pcm_mmap_avail

include/tinyalsa/asoundlib.h

@@ -235,6 +235,7 @@ int pcm_mmap_read(struct pcm *pcm, void *data, unsigned int count);
 int pcm_mmap_begin(struct pcm *pcm, void **areas, unsigned int *offset,
                    unsigned int *frames);
 int pcm_mmap_commit(struct pcm *pcm, unsigned int offset, unsigned int frames);
+int pcm_mmap_avail(struct pcm *pcm);
 
 /* Prepare the PCM substream to be triggerable */
 int pcm_prepare(struct pcm *pcm);
@@ -247,6 +248,7 @@ int pcm_ioctl(struct pcm *pcm, int request, ...);
 
 /* Interrupt driven API */
 int pcm_wait(struct pcm *pcm, int timeout);
+int pcm_get_poll_fd(struct pcm *pcm);
 
 /* Change avail_min after the stream has been opened with no need to stop the stream.
  * Only accepted if opened with PCM_MMAP and PCM_NOIRQ flags

pcm.c

@@ -1059,7 +1059,7 @@ static inline int pcm_mmap_capture_avail(struct pcm *pcm)
     return avail;
 }
 
-static inline int pcm_mmap_avail(struct pcm *pcm)
+int pcm_mmap_avail(struct pcm *pcm)
 {
     pcm_sync_ptr(pcm, SNDRV_PCM_SYNC_PTR_HWSYNC);
     if (pcm->flags & PCM_IN)
@@ -1180,6 +1180,11 @@ int pcm_wait(struct pcm *pcm, int timeout)
     return 1;
 }
 
+int pcm_get_poll_fd(struct pcm *pcm)
+{
+    return pcm->fd;
+}
+
 int pcm_mmap_transfer(struct pcm *pcm, const void *buffer, unsigned int bytes)
 {
     int err = 0, frames, avail;