[PATCH] ASoC: qcom: sdm845: Disable the quaternary MI2S bit clock on shutdown

[yoxcu]

From: Michael Auer <mick@xxxxxxxx>

sdm845_snd_startup() enables the quaternary MI2S bit clock in the ADSP,
but sdm845_snd_shutdown() never disables it. After the first stream on
this port the clock stays on.

On the OnePlus 6 the speaker amplifier is on this port. After the first
playback the ADSP no longer power collapses: it slept under 9 s in 5
hours. With this change it sleeps again when audio is idle (about 40 s
of 45 s).

Refcount the clock like the other MI2S and TDM ports and disable it
when the last user is gone.

Fixes: 5caf64c633a3 ("ASoC: qcom: sdm845: add support to DB845c and Lenovo Yoga")
Assisted-by: LLM
Signed-off-by: Michael Auer <mick@xxxxxxxx>
---
Tested on a OnePlus 6 with an sdm845-mainline 7.1-rc1 based kernel:
the bit clock is set at stream start and set to 0 when the stream is
closed, and the ADSP power collapses again. On sound/for-next it was
only build tested (W=1). Not tested on the other boards that use QUAT
MI2S (DB845c HDMI, Xiaomi beryllium and polaris).

 sound/soc/qcom/sdm845.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/sound/soc/qcom/sdm845.c b/sound/soc/qcom/sdm845.c
index f0fbec9c8df2..85951397cb2b 100644
--- a/sound/soc/qcom/sdm845.c
+++ b/sound/soc/qcom/sdm845.c
@@ -43,6 +43,7 @@ struct sdm845_snd_data {
 	bool stream_prepared[AFE_PORT_MAX];
 	uint32_t pri_mi2s_clk_count;
 	uint32_t sec_mi2s_clk_count;
+	uint32_t quat_mi2s_clk_count;
 	uint32_t quat_tdm_clk_count;
 };
 
@@ -372,9 +373,11 @@ static int sdm845_snd_startup(struct snd_pcm_substream *substream)
 		break;
 	case QUATERNARY_MI2S_RX:
 		codec_dai_fmt |= SND_SOC_DAIFMT_NB_NF | SND_SOC_DAIFMT_I2S;
-		snd_soc_dai_set_sysclk(cpu_dai,
-			Q6AFE_LPASS_CLK_ID_QUAD_MI2S_IBIT,
-			MI2S_BCLK_RATE, SNDRV_PCM_STREAM_PLAYBACK);
+		if (++(data->quat_mi2s_clk_count) == 1) {
+			snd_soc_dai_set_sysclk(cpu_dai,
+				Q6AFE_LPASS_CLK_ID_QUAD_MI2S_IBIT,
+				MI2S_BCLK_RATE, SNDRV_PCM_STREAM_PLAYBACK);
+		}
 		snd_soc_dai_set_fmt(cpu_dai, fmt);
 		snd_soc_dai_set_fmt(codec_dai, codec_dai_fmt);
 		break;
@@ -483,8 +486,16 @@ static void  sdm845_snd_shutdown(struct snd_pcm_substream *substream)
 				0, SNDRV_PCM_STREAM_PLAYBACK);
 		}
 		break;
-	case SLIMBUS_0_RX...SLIMBUS_6_TX:
+
 	case QUATERNARY_MI2S_RX:
+		if (--(data->quat_mi2s_clk_count) == 0) {
+			snd_soc_dai_set_sysclk(cpu_dai,
+				Q6AFE_LPASS_CLK_ID_QUAD_MI2S_IBIT,
+				0, SNDRV_PCM_STREAM_PLAYBACK);
+		}
+		break;
+
+	case SLIMBUS_0_RX...SLIMBUS_6_TX:
 		break;
 
 	default:

base-commit: 631a161db2c5168dd836242571724baba3561a1f
-- 
2.43.0