Revise the PCM callback system after adding multichannel audio.

Additional status callback is added to pcm_play/rec_data instead of
using a special function to set it. Status includes DMA error
reporting to the status callback. Playback and recording callback
become more alike except playback uses "const void **addr" (because
the data should not be altered) and recording  uses "void **addr".
"const" is put in place throughout where appropriate.

Most changes are fairly trivial. One that should be checked in
particular because it isn't so much is telechips, if anyone cares to
bother. PP5002 is not so trivial either but that tested as working.

Change-Id: I4928d69b3b3be7fb93e259f81635232df9bd1df2
Reviewed-on: http://gerrit.rockbox.org/166
Reviewed-by: Michael Sevakis <jethead71@rockbox.org>
Tested-by: Michael Sevakis <jethead71@rockbox.org>

1 files changed, 18 insertions, 13 deletions

diff --git a/firmware/export/pcm.h b/firmware/export/pcm.h
index 4a7a5b3193..df82c6092d 100644
--- a/firmware/export/pcm.h
+++ b/firmware/export/pcm.h
@@ -24,17 +24,23 @@
 #include <string.h> /* size_t */
 #include "config.h"
 
-#define DMA_REC_ERROR_DMA       (-1)
+enum pcm_dma_status
+{
 #ifdef HAVE_SPDIF_REC
-#define DMA_REC_ERROR_SPDIF     (-2)
+    PCM_DMAST_ERR_SPDIF = -2,
 #endif
+    PCM_DMAST_ERR_DMA   = -1,
+    PCM_DMAST_OK        =  0,
+    PCM_DMAST_STARTED   =  1,
+};
 
 /** RAW PCM routines used with playback and recording **/
 
-/* Typedef for registered callbacks */
-typedef void (*pcm_play_callback_type)(unsigned char **start,
-                                       size_t *size);
-typedef void (*pcm_rec_callback_type)(int status, void **start, size_t *size);
+/* Typedef for registered data callback */
+typedef void (*pcm_play_callback_type)(const void **start, size_t *size);
+
+/* Typedef for registered status callback */
+typedef enum pcm_dma_status (*pcm_status_callback_type)(enum pcm_dma_status status);
 
 /* set the pcm frequency - use values in hw_sampr_list 
  * when CONFIG_SAMPR_TYPES is #defined, or-in SAMPR_TYPE_* fields with
@@ -62,7 +68,8 @@ bool pcm_is_initialized(void);
 
 /* This is for playing "raw" PCM data */
 void pcm_play_data(pcm_play_callback_type get_more,
-                   unsigned char* start, size_t size);
+                   pcm_status_callback_type status_cb,
+                   const void *start, size_t size);
 
 void pcm_calculate_peaks(int *left, int *right);
 const void* pcm_get_peak_buffer(int* count);
@@ -73,12 +80,13 @@ void pcm_play_pause(bool play);
 bool pcm_is_paused(void);
 bool pcm_is_playing(void);
 
-void pcm_play_set_dma_started_callback(void (* callback)(void));
-
 #ifdef HAVE_RECORDING
 
 /** RAW PCM recording routines **/
 
+/* Typedef for registered data callback */
+typedef void (*pcm_rec_callback_type)(void **start, size_t *size);
+
 /* Reenterable locks for locking and unlocking the recording interrupt */
 void pcm_rec_lock(void);
 void pcm_rec_unlock(void);
@@ -90,6 +98,7 @@ void pcm_close_recording(void);
 
 /* Start recording "raw" PCM data */
 void pcm_record_data(pcm_rec_callback_type more_ready,
+                     pcm_status_callback_type status_cb,
                      void *start, size_t size);
 
 /* Stop tranferring data into supplied buffer */
@@ -98,10 +107,6 @@ void pcm_stop_recording(void);
 /* Is pcm currently recording? */
 bool pcm_is_recording(void);
 
-/* Called by bottom layer ISR when transfer is complete. Returns non-zero
- * size if successful. Setting start to NULL forces stop. */
-void pcm_rec_more_ready_callback(int status, void **start, size_t *size);
-
 void pcm_calculate_rec_peaks(int *left, int *right);
 
 #endif /* HAVE_RECORDING */