Add init callback to extplug

- Fix the hw constraints of extplug
- Add init callback to extplug

include/pcm_extplug.h

@@ -55,7 +55,7 @@ typedef struct snd_pcm_extplug_callback snd_pcm_extplug_callback_t;
  */
 #define SND_PCM_EXTPLUG_VERSION_MAJOR	1	/**< Protocol major version */
 #define SND_PCM_EXTPLUG_VERSION_MINOR	0	/**< Protocol minor version */
-#define SND_PCM_EXTPLUG_VERSION_TINY	0	/**< Protocol tiny version */
+#define SND_PCM_EXTPLUG_VERSION_TINY	1	/**< Protocol tiny version */
 /**
  * Filter-plugin protocol version
  */
@@ -147,6 +147,10 @@ struct snd_pcm_extplug_callback {
 	 * dump; optional
 	 */
 	void (*dump)(snd_pcm_extplug_t *ext, snd_output_t *out);
+	/**
+	 * init; optional initialization called at prepare or reset
+	 */
+	int (*init)(snd_pcm_extplug_t *ext);
 };
 
 

src/pcm/pcm_extplug.c

@@ -228,7 +228,19 @@ static int snd_pcm_extplug_hw_refine_sprepare(snd_pcm_t *pcm,
 static unsigned int get_links(struct snd_ext_parm *params)
 {
 	int i;
-	unsigned int links = -1;
+	unsigned int links = (SND_PCM_HW_PARBIT_FORMAT |
+			      SND_PCM_HW_PARBIT_SUBFORMAT |
+			      SND_PCM_HW_PARBIT_SAMPLE_BITS |
+			      SND_PCM_HW_PARBIT_CHANNELS |
+			      SND_PCM_HW_PARBIT_FRAME_BITS |
+			      SND_PCM_HW_PARBIT_RATE |
+			      SND_PCM_HW_PARBIT_PERIODS |
+			      SND_PCM_HW_PARBIT_PERIOD_SIZE |
+			      SND_PCM_HW_PARBIT_PERIOD_TIME |
+			      SND_PCM_HW_PARBIT_BUFFER_SIZE |
+			      SND_PCM_HW_PARBIT_BUFFER_TIME |
+			      SND_PCM_HW_PARBIT_TICK_TIME);
+
 	for (i = 0; i < SND_PCM_EXTPLUG_HW_PARAMS; i++) {
 		if (params[i].active)
 			links &= ~excl_parbits[i];
@@ -242,16 +254,8 @@ static int snd_pcm_extplug_hw_refine_schange(snd_pcm_t *pcm,
 {
 	extplug_priv_t *ext = pcm->private_data;
 	unsigned int links = get_links(ext->sparams);
-	int err, change;
+
-	err = extplug_hw_refine(sparams, ext->sparams);
+	return _snd_pcm_hw_params_refine(sparams, links, params);
-	if (err < 0)
-		return err;
-	change = err;
-	err = _snd_pcm_hw_params_refine(sparams, links, params);
-	if (err < 0)
-		return err;
-	change |= err;
-	return change;
 }
 	
 static int snd_pcm_extplug_hw_refine_cchange(snd_pcm_t *pcm,
@@ -260,26 +264,19 @@ static int snd_pcm_extplug_hw_refine_cchange(snd_pcm_t *pcm,
 {
 	extplug_priv_t *ext = pcm->private_data;
 	unsigned int links = get_links(ext->params);
-	int err, change;
+
-	err = extplug_hw_refine(params, ext->params);
+	return _snd_pcm_hw_params_refine(params, links, sparams);
-	if (err < 0)
-		return err;
-	change = err;
-	err = _snd_pcm_hw_params_refine(params, links, sparams);
-	if (err < 0)
-		return err;
-	change |= err;
-	return change;
 }
 
 static int snd_pcm_extplug_hw_refine(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
 {
-	return snd_pcm_hw_refine_slave(pcm, params,
+	int err = snd_pcm_hw_refine_slave(pcm, params,
 				       snd_pcm_extplug_hw_refine_cprepare,
 				       snd_pcm_extplug_hw_refine_cchange,
 				       snd_pcm_extplug_hw_refine_sprepare,
 				       snd_pcm_extplug_hw_refine_schange,
 				       snd_pcm_generic_hw_refine);
+	return err;
 }
 
 /*
@@ -368,6 +365,15 @@ snd_pcm_extplug_read_areas(snd_pcm_t *pcm,
 	return size;
 }
 
+/*
+ * call init callback
+ */
+static int snd_pcm_extplug_init(snd_pcm_t *pcm)
+{
+	extplug_priv_t *ext = pcm->private_data;
+	return ext->data->callback->init(ext->data);
+}
+
 /*
  * dump setup
  */
@@ -480,6 +486,7 @@ struct myplug_info {
 SND_PCM_PLUGIN_DEFINE_FUNC(myplug)
 {
 	snd_config_iterator_t i, next;
+	snd_config_t *slave = NULL;
 	struct myplug_info *myplug;
 	int err;
 
@@ -490,6 +497,10 @@ SND_PCM_PLUGIN_DEFINE_FUNC(myplug)
 			continue;
 		if (strcmp(id, "comment") == 0 || strcmp(id, "type") == 0)
 			continue;
+		if (strcmp(id, "slave") == 0) {
+			slave = n;
+			continue;
+		}
 		if (strcmp(id, "my_own_parameter") == 0) {
 			....
 			continue;
@@ -498,6 +509,11 @@ SND_PCM_PLUGIN_DEFINE_FUNC(myplug)
 		return -EINVAL;
 	}
 
+	if (! slave) {
+		SNDERR("No slave defined for myplug");
+		return -EINVAL;
+	}
+
 	myplug = calloc(1, sizeof(*myplug));
 	if (myplug == NULL)
 		return -ENOMEM;
@@ -508,7 +524,7 @@ SND_PCM_PLUGIN_DEFINE_FUNC(myplug)
 	myplug->ext.private_data = myplug;
 	....
 
-	err = snd_pcm_extplug_create(&myplug->ext, name, stream, mode);
+	err = snd_pcm_extplug_create(&myplug->ext, name, root, conf, stream, mode);
 	if (err < 0) {
 		myplug_free(myplug);
 		return err;
@@ -562,6 +578,10 @@ again.  The hw_params and hw_free callbacks are called at
 respectively.  The last, dump callback, is called for printing the
 information of the given plugin.
 
+The init callback is called when the PCM is at prepare state or any
+initialization is issued.  Use this callback to reset the PCM instance
+to a sane initial state.
+
 The hw_params constraints can be defined via either
 #snd_pcm_extplug_set_param_minmax() and #snd_pcm_extplug_set_param_list()
 functions after calling #snd_pcm_extplug_create().
@@ -641,6 +661,8 @@ int snd_pcm_extplug_create(snd_pcm_extplug_t *extplug, const char *name,
 	ext->plug.undo_write = snd_pcm_plugin_undo_write_generic;
 	ext->plug.gen.slave = spcm;
 	ext->plug.gen.close_slave = 1;
+	if (extplug->callback->init)
+		ext->plug.init = snd_pcm_extplug_init;
 
 	err = snd_pcm_new(&pcm, SND_PCM_TYPE_EXTPLUG, name, stream, mode);
 	if (err < 0) {