Rework routing system

- Add 'route' to snd_avirt_stream, remove from audio path
- Add route checking - ensure that source ap and ink ap have
compatible hw params
- Add private data support for both source and sink Audio
Paths, to ensure that the PCM can hold multiple private data(s).
- Add ability to use copy_kernel and exttriggers from AVIRT instead of from Audio Paths
- Reintroduce pcm_trigger and pcm_prepare, so that 
they may be called appropriately from AVIRT, rather
than child Audio Paths.

Signed-off-by: Mark Farrugia <mark.farrugia@fiberdyne.com.au>

1 files changed, 87 insertions, 16 deletions

diff --git a/pcm.c b/pcm.c
index fc01953..32456cd 100644
--- a/pcm.c
+++ b/pcm.c
@@ -15,20 +15,57 @@
 #define D_PRINTK(fmt, args...) DDEBUG(D_LOGNAME, fmt, ##args)
 #define D_ERRORK(fmt, args...) DERROR(D_LOGNAME, fmt, ##args)
 
+#define AUDIOPATH_PCM_CB(ap, cb, ops, substream, ...)                          \
+	(((ap)->ops->cb) ? (ap)->ops->cb((substream), ##__VA_ARGS__) : 0)
+
+#define DO_AUDIOPATH_PCM_ROUTE_CBS(ap, cb, ops, substream, ...)                \
+	({                                                                     \
+		int __err = 0, __endpoint = substream->stream;                 \
+		struct snd_avirt_stream *__stream =                            \
+			snd_avirt_stream_find_by_device(                       \
+				substream->pcm->device);                       \
+		if (!IS_ERR_VALUE(__stream) && __stream) {                     \
+			struct snd_avirt_audiopath *__endpoint_ap;             \
+			if (__stream->route) {                                 \
+				__endpoint_ap =                                \
+					__stream->route                        \
+						->endpoint_ap[__endpoint];     \
+				if ((__endpoint_ap)) {                         \
+					__err = AUDIOPATH_PCM_CB(              \
+						__endpoint_ap, cb, ops,        \
+						(substream), ##__VA_ARGS__);   \
+				}                                              \
+			}                                                      \
+		}                                                              \
+		(__err);                                                       \
+	})
 /**
- * DO_AUDIOPATH_CB - Used to call into an Audio Path's ALSA PCM callback from
- * AVIRT, where AVIRT's own callback must be attended to first.
+ * DO_AUDIOPATH_PCM_CBS - Call an Audio Path's ALSA PCM callbacks from AVIRT.
+ * If the Audio Path has routing enabled, then we call the appropriate
+ * from/to Audio Path's ALSA PCM callbacks
  */
-#define DO_AUDIOPATH_CB(ap, callback, substream, ...)                          \
-	((!substream->stream) ?                                                \
-		 (((ap)->pcm_playback_ops->callback) ?                         \
-			  (ap)->pcm_playback_ops->callback((substream),        \
-							   ##__VA_ARGS__) :    \
-			  0) :                                                 \
-		 (((ap)->pcm_capture_ops->callback) ?                          \
-			  (ap)->pcm_capture_ops->callback((substream),         \
-							  ##__VA_ARGS__) :     \
-			  0))
+#define DO_AUDIOPATH_PCM_CBS(ap, cb, substream, ...)                           \
+	({                                                                     \
+		int __err = 0;                                                 \
+		if (substream->stream) {                                       \
+			__err = AUDIOPATH_PCM_CB((ap), cb, pcm_capture_ops,    \
+						 (substream), ##__VA_ARGS__);  \
+			if (__err >= 0) {                                      \
+				__err = DO_AUDIOPATH_PCM_ROUTE_CBS(            \
+					(ap), cb, pcm_playback_ops,            \
+					(substream), ##__VA_ARGS__);           \
+			}                                                      \
+		} else {                                                       \
+			__err = AUDIOPATH_PCM_CB((ap), cb, pcm_playback_ops,   \
+						 (substream), ##__VA_ARGS__);  \
+			if (__err >= 0) {                                      \
+				__err = DO_AUDIOPATH_PCM_ROUTE_CBS(            \
+					(ap), cb, pcm_capture_ops,             \
+					(substream), ##__VA_ARGS__);           \
+			}                                                      \
+		}                                                              \
+		(__err);                                                       \
+	})
 
 #define PRIVATE_DATA(substream)                                                \
 	((struct snd_avirt_private_data *)substream->private_data)
@@ -82,8 +119,8 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	hw->channels_min = chans;
 	hw->channels_max = chans;
 
-	// Do additional Audio Path 'open' callback
-	return DO_AUDIOPATH_CB(audiopath, open, substream);
+	// Do additional Audio Path 'open' callbacks
+	return DO_AUDIOPATH_PCM_CBS(audiopath, open, substream);
 }
 
 /**
@@ -97,12 +134,44 @@ static int pcm_open(struct snd_pcm_substream *substream)
 static int pcm_close(struct snd_pcm_substream *substream)
 {
 	// Do additional Audio Path 'close' callback
-	return DO_AUDIOPATH_CB(
+	return DO_AUDIOPATH_PCM_CBS(
 		(struct snd_avirt_audiopath *)PRIVATE_DATA(substream)->audiopath,
 		close, substream);
 }
 
 /**
+ * pcm_close - Implements 'close' callback for PCM middle layer
+ * @substream: pointer to ALSA PCM substream
+ *
+ * This is called when a PCM substream is closed.
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	// Do additional Audio Path 'trigger' callback
+	return DO_AUDIOPATH_PCM_CBS(
+		(struct snd_avirt_audiopath *)PRIVATE_DATA(substream)->audiopath,
+		trigger, substream, cmd);
+}
+
+/**
+ * pcm_close - Implements 'close' callback for PCM middle layer
+ * @substream: pointer to ALSA PCM substream
+ *
+ * This is called when a PCM substream is closed.
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int pcm_prepare(struct snd_pcm_substream *substream)
+{
+	// Do additional Audio Path 'prepare' callback
+	return DO_AUDIOPATH_PCM_CBS(
+		(struct snd_avirt_audiopath *)PRIVATE_DATA(substream)->audiopath,
+		prepare, substream);
+}
+
+/**
  * pcm_hw_params - Implements 'hw_params' callback for PCM middle layer
  * @substream: pointer to ALSA PCM substream
  * @hw_params: contains the hardware parameters for the PCM
@@ -149,7 +218,7 @@ static int pcm_hw_free(struct snd_pcm_substream *substream)
 	int err;
 
 	// Do additional Audio Path 'hw_free' callback
-	err = DO_AUDIOPATH_CB(
+	err = DO_AUDIOPATH_PCM_CBS(
 		(struct snd_avirt_audiopath *)PRIVATE_DATA(substream)->audiopath,
 		hw_free, substream);
 	if (err < 0)
@@ -165,6 +234,8 @@ static int pcm_hw_free(struct snd_pcm_substream *substream)
 struct snd_pcm_ops pcm_ops_avirt = {
 	.open = pcm_open,
 	.close = pcm_close,
+	.prepare = pcm_prepare,
+	.trigger = pcm_trigger,
 	.ioctl = snd_pcm_lib_ioctl,
 	.hw_params = pcm_hw_params,
 	.hw_free = pcm_hw_free,