pcm: Make more of the low-level PCM API private

* pcm_play_data
 * pcm_play_stop
 * pcm_play_stop_int
 * pcm_is_playing
 * pcm_set_frequency
 * pcm_get_frequency
 * pcm_apply_settings

Now, the only user of these functions are the mixer and recording layers
that provide a higher-level API to plugins and the main [playback]
application.

Outside of the PCM core, pcm_apply_settings() was only used immediately
following a call to mixer_set_frequency(), so the latter function
now always calls the former.

Change-Id: I61c3144dc156b9de9b7963160b525c6d10c6ad4b

apps/plugin.c

@@ -644,7 +644,6 @@ static const struct plugin_api rockbox_api = {
 #endif
     &audio_master_sampr_list[0],
     &hw_freq_sampr[0],
-    pcm_apply_settings,
     pcm_play_lock,
     pcm_play_unlock,
     pcm_current_sink_caps,

apps/plugin.h

@@ -179,7 +179,7 @@ int plugin_open(const char *plugin, const char *parameter);
  * when this happens please take the opportunity to sort in
  * any new functions "waiting" at the end of the list.
  */
-#define PLUGIN_API_VERSION 279
+#define PLUGIN_API_VERSION 280
 
 /* 239 Marks the removal of ARCHOS HWCODEC and CHARCELL */
 
@@ -743,7 +743,6 @@ struct plugin_api {
 #endif
     const unsigned long *audio_master_sampr_list;
     const unsigned long *hw_freq_sampr;
-    void (*pcm_apply_settings)(void);
     void (*pcm_play_lock)(void);
     void (*pcm_play_unlock)(void);
     const struct pcm_sink_caps* (*pcm_current_sink_caps)(void);

apps/plugins/lua/include_lua/pcm.lua

@@ -24,6 +24,5 @@
 -- [[ conversion to old style pcm_ functions ]]
 if not rb.pcm then rb.splash(rb.HZ, "No Support!") return nil end
 
-rb.pcm_apply_settings = function() rb.pcm("apply_settings") end
 rb.pcm_play_lock = function() rb.pcm("play_lock") end
 rb.pcm_play_unlock = function() rb.pcm("play_unlock") end

apps/plugins/lua/rocklib.c

@@ -549,10 +549,10 @@ RB_WRAP(sound)
 
 RB_WRAP(pcm)
 {
-    enum e_pcm {PCM_APPLYSETTINGS = 0, PCM_PLAYLOCK, PCM_PLAYUNLOCK,
+    enum e_pcm {PCM_PLAYLOCK = 0, PCM_PLAYUNLOCK,
                 PCM_ECOUNT};
 
-    const char *pcm_option[] = {"apply_settings", "play_lock", "play_unlock",
+    const char *pcm_option[] = {"play_lock", "play_unlock",
                                 NULL};
 
     lua_pushnil(L); /*push nil so options w/o return have something to return */
@@ -560,9 +560,6 @@ RB_WRAP(pcm)
     int option = luaL_checkoption (L, 1, NULL, pcm_option);
     switch(option)
     {
-        case PCM_APPLYSETTINGS:
-            rb->pcm_apply_settings();
-            break;
         case PCM_PLAYLOCK:
             rb->pcm_play_lock();
             break;

apps/plugins/pdbox/PDa/src/s_audio_rockbox.c

@@ -64,7 +64,6 @@ void rockbox_open_audio(int rate)
 
     /* Set sample rate of the audio buffer. */
     rb->mixer_set_frequency(rate);
-    rb->pcm_apply_settings();
 
     /* Initialize output buffer. */
     for(i = 0; i < OUTBUFSIZE; i++)
@@ -86,7 +85,6 @@ void rockbox_close_audio(void)
 
     /* Restore default sampling rate. */
     rb->mixer_set_frequency(HW_SAMPR_DEFAULT);
-    rb->pcm_apply_settings();
 }
 
 /* Rockbox audio callback. */

apps/plugins/test_sampr.c

@@ -168,7 +168,6 @@ static void set_frequency(int index)
     update_gen_step();
 
     rb->mixer_set_frequency(hw_sampr);
-    rb->pcm_apply_settings();
 }
 
 #ifndef HAVE_VOLUME_IN_LIST

apps/plugins/xrick/system/syssnd_rockbox.c

@@ -253,7 +253,6 @@ bool syssnd_init(void)
 #endif
 
     rb->mixer_set_frequency(HW_FREQ_44);
-    rb->pcm_apply_settings();
 
     rb->memset(channels, 0, sizeof(channels));
     rb->memset(mixBuffers, 0, sizeof(mixBuffers));
@@ -286,7 +285,6 @@ void syssnd_shutdown(void)
 
     /* Restore default sampling rate. */
     rb->mixer_set_frequency(HW_SAMPR_DEFAULT);
-    rb->pcm_apply_settings();
 
     rb->talk_disable(false);
 

apps/recorder/pcm_record.c

@@ -616,6 +616,10 @@ static void init_state(void)
     record_status = RECORD_STOPPED;
 }
 
+/* To avoid having to pull in all of pcm-internal.h */
+void pcm_set_frequency(unsigned int samplerate);
+void pcm_apply_settings(void);
+
 /* Set hardware samplerate and save it */
 static void update_samplerate_config(unsigned long sampr)
 {
@@ -876,7 +880,7 @@ copy_buffer_mono_lr(void *dst, const void *src, size_t src_size)
     int16_t *d = (int16_t*) dst;
     int16_t const *s = (int16_t const*) src;
     ssize_t copy_size = src_size;
- 
+
      /* mono = (L + R) / 2 */
     while(copy_size > 0) {
         *d++ = ((int32_t)s[0] + (int32_t)s[1] + 1) >> 1;

docs/PLUGIN_API

@@ -1754,10 +1754,6 @@ void pcmbuf_set_low_latency(bool state)
     \param state
     \description
 
-void pcm_apply_settings(void)
-    \group sound
-    \description
-
 void pcm_calculate_rec_peaks(int *left, int *right)
     \group sound
     \conditions (defined(HAVE_RECORDING))

firmware/export/pcm-internal.h

@@ -71,6 +71,20 @@ void pcm_sync_pcm_factors(void);
     ({ (start) = (void *)(((uintptr_t)(start) + 3) & ~3); \
        (size) &= ~3; })
 
+/* Internal PCM API calls for playback */
+void pcm_play_data(pcm_play_callback_type get_more,
+                   pcm_status_callback_type status_cb,
+                   const void *start, size_t size);
+
+void pcm_play_stop(void);
+void pcm_play_stop_int(void); /* requires PCM lock held */
+bool pcm_is_playing(void);
+
+void pcm_set_frequency(unsigned int samplerate);
+unsigned int pcm_get_frequency(void);
+/* apply settings to hardware immediately */
+void pcm_apply_settings(void);
+
 void pcm_do_peak_calculation(struct pcm_peaks *peaks, bool active,
                              const void *addr, int count);
 
@@ -125,7 +139,6 @@ pcm_play_dma_status_callback(enum pcm_dma_status status)
 #if defined(HAVE_SW_VOLUME_CONTROL) && !defined(PCM_SW_VOLUME_UNBUFFERED)
 void pcm_play_dma_start_int(const void *addr, size_t size);
 void pcm_play_dma_stop_int(void);
-void pcm_play_stop_int(void);
 #endif /* HAVE_SW_VOLUME_CONTROL && !PCM_SW_VOLUME_UNBUFFERED */
 
 /* Called by the bottom layer ISR when more data is needed. Returns true

firmware/export/pcm.h

@@ -44,7 +44,7 @@ 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 
+/* set the pcm frequency - use values in hw_sampr_list
  * when CONFIG_SAMPR_TYPES is #defined, or-in SAMPR_TYPE_* fields with
  * frequency value. SAMPR_TYPE_PLAY is 0 and the default if none is
  * specified. */
@@ -54,15 +54,6 @@ unsigned int pcm_sampr_type_rec_to_play(unsigned int samplerate);
 #endif
 #endif /* CONFIG_SAMPR_TYPES */
 
-/* set next frequency to be used */
-void pcm_set_frequency(unsigned int samplerate);
-/* return last-set frequency */
-unsigned int pcm_get_frequency(void);
-/* apply settings to hardware immediately */
-void pcm_apply_settings(void);
-
-/** RAW PCM playback routines **/
-
 /* Reenterable locks for locking and unlocking the playback interrupt */
 void pcm_play_lock(void);
 void pcm_play_unlock(void);
@@ -77,11 +68,6 @@ const struct pcm_sink_caps* pcm_sink_caps(enum pcm_sink_ids sink);
 /* shortcut for plugins */
 const struct pcm_sink_caps* pcm_current_sink_caps(void);
 
-/* This is for playing "raw" PCM data */
-void pcm_play_data(pcm_play_callback_type get_more,
-                   pcm_status_callback_type status_cb,
-                   const void *start, size_t size);
-
 /* Kept internally for global PCM and used by mixer's verion of peak
    calculation */
 struct pcm_peaks
@@ -92,9 +78,6 @@ struct pcm_peaks
     long tick;      /* Last tick called */
 };
 
-void pcm_play_stop(void);
-bool pcm_is_playing(void);
-
 #ifdef HAVE_RECORDING
 
 /** RAW PCM recording routines **/

firmware/pcm.c

@@ -94,8 +94,6 @@ volatile pcm_status_callback_type
 /* PCM playback state */
 volatile bool pcm_playing SHAREDBSS_ATTR = false;
 
-void pcm_play_stop_int(void);
-
 struct pcm_sink* pcm_get_current_sink(void)
 {
     return sinks[cur_sink];

firmware/pcm_mixer.c

@@ -475,6 +475,9 @@ void mixer_set_frequency(unsigned int samplerate)
         mix_frame_size = 1;
 
     mix_frame_size *= MIX_FRAME_SAMPLES * 4;
+
+    if (pcm_is_initialized())
+        pcm_apply_settings();
 }
 
 /* Get output samplerate */

firmware/usbstack/usb_audio.c

@@ -493,7 +493,6 @@ static void set_playback_sampling_frequency(unsigned long f)
         hw_freq_sampr[as_playback_freq_idx], f);
 
     mixer_set_frequency(hw_freq_sampr[as_playback_freq_idx]);
-    pcm_apply_settings();
 }
 
 unsigned long usb_audio_get_playback_sampling_frequency(void)
@@ -706,7 +705,6 @@ static void usb_audio_start_playback(void)
 #endif
     logf("usbaudio: start playback at %lu Hz", hw_freq_sampr[as_playback_freq_idx]);
     mixer_set_frequency(hw_freq_sampr[as_playback_freq_idx]);
-    pcm_apply_settings();
     mixer_channel_set_amplitude(PCM_MIXER_CHAN_USBAUDIO, MIX_AMP_UNITY);
 
     usb_drv_recv_nonblocking(EP_ISO_OUT, rx_buffer, BUFFER_SIZE);
@@ -787,7 +785,7 @@ int usb_audio_get_alt_intf(void)
 {
     return usb_as_playback_intf_alt;
 }
-    
+
 int32_t usb_audio_get_samplesperframe(void)
 {
     return samples_fb;
@@ -1348,7 +1346,7 @@ bool usb_audio_fast_transfer_complete(int ep, int dir, int status, int length)
     {
         retval = false;
     }
-    
+
     // send feedback value every N frames!
     // NOTE: important that we need to queue this up _the frame before_ it's needed - on MacOS especially!
     if ((usb_drv_get_frame_number()+1) % FEEDBACK_UPDATE_RATE_FRAMES == 0 && send_fb)