ASoC: cs35l56: Use DAPM widget for firmware PLAY/PAUSE

If we use a DAPM widget instead of mute_stream() to send the
PLAY command we can issue the plays to multiple amps in parallel.
With mute_stream each codec driver instance is called one at a
time so we get N * PS0 delay time.

DAPM does each stage on every widget in a card before moving to
the next stage. So all amps will do the PRE_PMU then all will do
the POST_PMU. The PLAY is sent in the PRE_PMU so that they all
power-up in parallel. After the PS0 wait in the first POST_PMU
all the other amps will also be ready so there won't be any extra
delay, or it will be negligible.

There's also no point waiting for the MBOX ack in the PRE_PMU.
We won't see a PS0 state in POST_PMU if it didn't ack the PLAY
command. So we can save a little extra time.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230411152528.329803-3-rf@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/cs35l56.c

@@ -32,6 +32,23 @@
 static int cs35l56_dsp_event(struct snd_soc_dapm_widget *w,
 			     struct snd_kcontrol *kcontrol, int event);
 
+static int cs35l56_mbox_send(struct cs35l56_private *cs35l56, unsigned int command)
+{
+	unsigned int val;
+	int ret;
+
+	regmap_write(cs35l56->regmap, CS35L56_DSP_VIRTUAL1_MBOX_1, command);
+	ret = regmap_read_poll_timeout(cs35l56->regmap, CS35L56_DSP_VIRTUAL1_MBOX_1,
+				       val, (val == 0),
+				       CS35L56_MBOX_POLL_US, CS35L56_MBOX_TIMEOUT_US);
+	if (ret) {
+		dev_warn(cs35l56->dev, "MBOX command %#x failed: %d\n", command, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 static int cs35l56_wait_dsp_ready(struct cs35l56_private *cs35l56)
 {
 	int ret;
@@ -182,10 +199,45 @@ static SOC_VALUE_ENUM_SINGLE_DECL(cs35l56_sdw1tx6_enum,
 static const struct snd_kcontrol_new sdw1_tx6_mux =
 	SOC_DAPM_ENUM("SDW1TX6 SRC", cs35l56_sdw1tx6_enum);
 
+static int cs35l56_play_event(struct snd_soc_dapm_widget *w,
+			      struct snd_kcontrol *kcontrol, int event)
+{
+	struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
+	struct cs35l56_private *cs35l56 = snd_soc_component_get_drvdata(component);
+	unsigned int val;
+	int ret;
+
+	dev_dbg(cs35l56->dev, "play: %d\n", event);
+
+	switch (event) {
+	case SND_SOC_DAPM_PRE_PMU:
+		/* Don't wait for ACK, we check in POST_PMU that it completed */
+		return regmap_write(cs35l56->regmap, CS35L56_DSP_VIRTUAL1_MBOX_1,
+				    CS35L56_MBOX_CMD_AUDIO_PLAY);
+	case SND_SOC_DAPM_POST_PMU:
+		/* Wait for firmware to enter PS0 power state */
+		ret = regmap_read_poll_timeout(cs35l56->regmap,
+					       CS35L56_TRANSDUCER_ACTUAL_PS,
+					       val, (val == CS35L56_PS0),
+					       CS35L56_PS0_POLL_US,
+					       CS35L56_PS0_TIMEOUT_US);
+		if (ret)
+			dev_err(cs35l56->dev, "PS0 wait failed: %d\n", ret);
+		return ret;
+	case SND_SOC_DAPM_POST_PMD:
+		return cs35l56_mbox_send(cs35l56, CS35L56_MBOX_CMD_AUDIO_PAUSE);
+	default:
+		return 0;
+	}
+}
+
 static const struct snd_soc_dapm_widget cs35l56_dapm_widgets[] = {
 	SND_SOC_DAPM_REGULATOR_SUPPLY("VDD_B", 0, 0),
 	SND_SOC_DAPM_REGULATOR_SUPPLY("VDD_AMP", 0, 0),
 
+	SND_SOC_DAPM_SUPPLY("PLAY", SND_SOC_NOPM, 0, 0, cs35l56_play_event,
+			    SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
+
 	SND_SOC_DAPM_OUT_DRV("AMP", SND_SOC_NOPM, 0, 0, NULL, 0),
 	SND_SOC_DAPM_OUTPUT("SPK"),
 
@@ -252,6 +304,9 @@ static const struct snd_soc_dapm_route cs35l56_audio_map[] = {
 	{ "AMP", NULL, "VDD_B" },
 	{ "AMP", NULL, "VDD_AMP" },
 
+	{ "ASP1 Playback", NULL, "PLAY" },
+	{ "SDW1 Playback", NULL, "PLAY" },
+
 	{ "ASP1RX1", NULL, "ASP1 Playback" },
 	{ "ASP1RX2", NULL, "ASP1 Playback" },
 	{ "DSP1", NULL, "ASP1RX1" },
@@ -288,23 +343,6 @@ static const struct snd_soc_dapm_route cs35l56_audio_map[] = {
 	{ "SDW1 Capture", NULL, "SDW1 TX6 Source" },
 };
 
-static int cs35l56_mbox_send(struct cs35l56_private *cs35l56, unsigned int command)
-{
-	unsigned int val;
-	int ret;
-
-	regmap_write(cs35l56->regmap, CS35L56_DSP_VIRTUAL1_MBOX_1, command);
-	ret = regmap_read_poll_timeout(cs35l56->regmap, CS35L56_DSP_VIRTUAL1_MBOX_1,
-				       val, (val == 0),
-				       CS35L56_MBOX_POLL_US, CS35L56_MBOX_TIMEOUT_US);
-	if (ret) {
-		dev_warn(cs35l56->dev, "MBOX command %#x failed: %d\n", command, ret);
-		return ret;
-	}
-
-	return 0;
-}
-
 static int cs35l56_dsp_event(struct snd_soc_dapm_widget *w,
 			     struct snd_kcontrol *kcontrol, int event)
 {
@@ -611,43 +649,11 @@ static int cs35l56_asp_dai_set_sysclk(struct snd_soc_dai *dai,
 	return 0;
 }
 
-static int cs35l56_mute_stream(struct snd_soc_dai *dai, int mute, int stream)
-{
-	struct cs35l56_private *cs35l56 = snd_soc_component_get_drvdata(dai->component);
-	unsigned int val;
-	int ret;
-
-	dev_dbg(cs35l56->dev, "%s: %d %s\n", __func__, stream, mute ? "mute" : "unmute");
-
-	if (stream != SNDRV_PCM_STREAM_PLAYBACK)
-		return 0;
-
-	if (mute) {
-		ret = cs35l56_mbox_send(cs35l56, CS35L56_MBOX_CMD_AUDIO_PAUSE);
-	} else {
-		ret = cs35l56_mbox_send(cs35l56, CS35L56_MBOX_CMD_AUDIO_PLAY);
-		if (ret == 0) {
-			/* Wait for firmware to enter PS0 power state */
-			ret = regmap_read_poll_timeout(cs35l56->regmap,
-						       CS35L56_TRANSDUCER_ACTUAL_PS,
-						       val, (val == CS35L56_PS0),
-						       CS35L56_PS0_POLL_US,
-						       CS35L56_PS0_TIMEOUT_US);
-			if (ret)
-				dev_err(cs35l56->dev, "PS0 wait failed: %d\n", ret);
-			ret = 0;
-		}
-	}
-
-	return ret;
-}
-
 static const struct snd_soc_dai_ops cs35l56_ops = {
 	.set_fmt = cs35l56_asp_dai_set_fmt,
 	.set_tdm_slot = cs35l56_asp_dai_set_tdm_slot,
 	.hw_params = cs35l56_asp_dai_hw_params,
 	.set_sysclk = cs35l56_asp_dai_set_sysclk,
-	.mute_stream = cs35l56_mute_stream,
 };
 
 static void cs35l56_sdw_dai_shutdown(struct snd_pcm_substream *substream,
@@ -749,7 +755,6 @@ static const struct snd_soc_dai_ops cs35l56_sdw_dai_ops = {
 	.shutdown = cs35l56_sdw_dai_shutdown,
 	.hw_params = cs35l56_sdw_dai_hw_params,
 	.hw_free = cs35l56_sdw_dai_hw_free,
-	.mute_stream = cs35l56_mute_stream,
 	.set_stream = cs35l56_sdw_dai_set_stream,
 };