ASoC: add new trigger ordering method

Current ASoC is assuming that trigger starting order is
Link -> Component -> DAI as default, and its reverse order for stopping.
But some Driver / Card want to reorder it for some reasons.
We have such flags, but is unbalance like below.

	struct snd_soc_component_driver	:: start_dma_last
	struct snd_soc_dai_link		:: stop_dma_first

We want to have more flexible, and more generic method.
This patch adds new snd_soc_trigger_order for start/stop at
component / DAI-link.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87r0qmfnzx.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc-component.h

@@ -158,6 +158,15 @@ struct snd_soc_component_driver {
 	int probe_order;
 	int remove_order;
 
+	/*
+	 * soc_pcm_trigger() start/stop sequence.
+	 * see also
+	 *	snd_soc_dai_link
+	 *	soc_pcm_trigger()
+	 */
+	enum snd_soc_trigger_order trigger_start;
+	enum snd_soc_trigger_order trigger_stop;
+
 	/*
 	 * signal if the module handling the component should not be removed
 	 * if a pcm is open. Setting this would prevent the module

include/sound/soc.h

@@ -607,6 +607,14 @@ int snd_soc_get_strobe(struct snd_kcontrol *kcontrol,
 int snd_soc_put_strobe(struct snd_kcontrol *kcontrol,
 	struct snd_ctl_elem_value *ucontrol);
 
+enum snd_soc_trigger_order {
+						/* start			stop		     */
+	SND_SOC_TRIGGER_ORDER_DEFAULT	= 0,	/* Link->Component->DAI		DAI->Component->Link */
+	SND_SOC_TRIGGER_ORDER_LDC,		/* Link->DAI->Component		Component->DAI->Link */
+
+	SND_SOC_TRIGGER_ORDER_MAX,
+};
+
 /* SoC PCM stream information */
 struct snd_soc_pcm_stream {
 	const char *stream_name;
@@ -707,6 +715,15 @@ struct snd_soc_dai_link {
 	const struct snd_soc_ops *ops;
 	const struct snd_soc_compr_ops *compr_ops;
 
+	/*
+	 * soc_pcm_trigger() start/stop sequence.
+	 * see also
+	 *	snd_soc_component_driver
+	 *	soc_pcm_trigger()
+	 */
+	enum snd_soc_trigger_order trigger_start;
+	enum snd_soc_trigger_order trigger_stop;
+
 	/* Mark this pcm with non atomic ops */
 	unsigned int nonatomic:1;
 

sound/soc/soc-pcm.c

@@ -1071,49 +1071,77 @@ static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
 	return ret;
 }
 
+#define TRIGGER_MAX 3
+static int (* const trigger[][TRIGGER_MAX])(struct snd_pcm_substream *substream, int cmd, int rollback) = {
+	[SND_SOC_TRIGGER_ORDER_DEFAULT] = {
+		snd_soc_link_trigger,
+		snd_soc_pcm_component_trigger,
+		snd_soc_pcm_dai_trigger,
+	},
+	[SND_SOC_TRIGGER_ORDER_LDC] = {
+		snd_soc_link_trigger,
+		snd_soc_pcm_dai_trigger,
+		snd_soc_pcm_component_trigger,
+	},
+};
+
 static int soc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct snd_soc_component *component;
-	int ret = -EINVAL, _ret = 0, start_dma_last = 0, i;
+	int ret = 0, r = 0, i;
 	int rollback = 0;
+	int start = 0, stop = 0;
 
+	/*
+	 * select START/STOP sequence
+	 */
+	for_each_rtd_components(rtd, i, component) {
+		if (component->driver->trigger_start)
+			start = component->driver->trigger_start;
+		if (component->driver->trigger_stop)
+			stop = component->driver->trigger_stop;
+	}
+	if (rtd->dai_link->trigger_start)
+		start = rtd->dai_link->trigger_start;
+	if (rtd->dai_link->trigger_stop)
+		stop  = rtd->dai_link->trigger_stop;
+
+	if (start < 0 || start >= SND_SOC_TRIGGER_ORDER_MAX ||
+	    stop  < 0 || stop  >= SND_SOC_TRIGGER_ORDER_MAX)
+		return -EINVAL;
+
+	/* REMOVE ME */
+	for_each_rtd_components(rtd, i, component) {
+		if (component->driver->start_dma_last) {
+			start = SND_SOC_TRIGGER_ORDER_LDC;
+			break;
+		}
+	}
+	if (rtd->dai_link->stop_dma_first)
+		stop = SND_SOC_TRIGGER_ORDER_LDC;
+
+	/*
+	 * START
+	 */
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
-		/* Do we need to start dma last? */
+		for (i = 0; i < TRIGGER_MAX; i++) {
-		for_each_rtd_components(rtd, i, component) {
+			r = trigger[start][i](substream, cmd, 0);
-			if (component->driver->start_dma_last) {
+			if (r < 0)
-				start_dma_last = 1;
 				break;
-			}
 		}
-
-		ret = snd_soc_link_trigger(substream, cmd, 0);
-		if (ret < 0)
-			goto start_err;
-
-		if (start_dma_last) {
-			ret = snd_soc_pcm_dai_trigger(substream, cmd, 0);
-			if (ret < 0)
-				goto start_err;
-
-			ret = snd_soc_pcm_component_trigger(substream, cmd, 0);
-		} else {
-			ret = snd_soc_pcm_component_trigger(substream, cmd, 0);
-			if (ret < 0)
-				goto start_err;
-
-			ret = snd_soc_pcm_dai_trigger(substream, cmd, 0);
-		}
-start_err:
-		if (ret < 0)
-			rollback = 1;
 	}
 
-	if (rollback) {
+	/*
-		_ret = ret;
+	 * Rollback if START failed
+	 * find correspond STOP command
+	 */
+	if (r < 0) {
+		rollback = 1;
+		ret = r;
 		switch (cmd) {
 		case SNDRV_PCM_TRIGGER_START:
 			cmd = SNDRV_PCM_TRIGGER_STOP;
@@ -1127,34 +1155,20 @@ start_err:
 		}
 	}
 
+	/*
+	 * STOP
+	 */
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
-		if (rtd->dai_link->stop_dma_first) {
+		for (i = TRIGGER_MAX; i > 0; i--) {
-			ret = snd_soc_pcm_component_trigger(substream, cmd, rollback);
+			r = trigger[stop][i - 1](substream, cmd, rollback);
-			if (ret < 0)
+			if (r < 0)
-				break;
+				ret = r;
-
-			ret = snd_soc_pcm_dai_trigger(substream, cmd, rollback);
-			if (ret < 0)
-				break;
-		} else {
-			ret = snd_soc_pcm_dai_trigger(substream, cmd, rollback);
-			if (ret < 0)
-				break;
-
-			ret = snd_soc_pcm_component_trigger(substream, cmd, rollback);
-			if (ret < 0)
-				break;
 		}
-		ret = snd_soc_link_trigger(substream, cmd, rollback);
-		break;
 	}
 
-	if (_ret)
-		ret = _ret;
-
 	return ret;
 }