Unverified Commit c8a4556d authored by Srinivasa Rao Mandadapu's avatar Srinivasa Rao Mandadapu Committed by Mark Brown
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ASoC: qcom: lpass-cpu: Fix pop noise during audio capture begin 

This patch fixes PoP noise of around 15ms observed during audio
capture begin.
Enables BCLK and LRCLK in snd_soc_dai_ops prepare call for
introducing some delay before capture start.

(am from https://patchwork.kernel.org/patch/12276369/)
(also found at https://lore.kernel.org/r/20210524142114.18676-1-srivasam@codeaurora.org

)

Co-developed-by: default avatarJudy Hsiao <judyhsiao@chromium.org>
Signed-off-by: default avatarJudy Hsiao <judyhsiao@chromium.org>
Signed-off-by: default avatarSrinivasa Rao Mandadapu <srivasam@codeaurora.org>
Reviewed-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210604154545.1198337-1-judyhsiao@chromium.org


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 49783c6f

sound/soc/qcom/lpass-cpu.c

+79 −0
Original line number Diff line number Diff line
@@ -93,8 +93,30 @@ static void lpass_cpu_daiops_shutdown(struct snd_pcm_substream *substream, 
		struct snd_soc_dai *dai)

{

	struct lpass_data *drvdata = snd_soc_dai_get_drvdata(dai);

	struct lpaif_i2sctl *i2sctl = drvdata->i2sctl;

	unsigned int id = dai->driver->id;



	clk_disable_unprepare(drvdata->mi2s_osr_clk[dai->driver->id]);

	/*

	 * Ensure LRCLK is disabled even in device node validation.

	 * Will not impact if disabled in lpass_cpu_daiops_trigger()

	 * suspend.

	 */

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)

		regmap_fields_write(i2sctl->spken, id, LPAIF_I2SCTL_SPKEN_DISABLE);

	else

		regmap_fields_write(i2sctl->micen, id, LPAIF_I2SCTL_MICEN_DISABLE);



	/*

	 * BCLK may not be enabled if lpass_cpu_daiops_prepare is called before

	 * lpass_cpu_daiops_shutdown. It's paired with the clk_enable in

	 * lpass_cpu_daiops_prepare.

	 */

	if (drvdata->mi2s_was_prepared[dai->driver->id]) {

		drvdata->mi2s_was_prepared[dai->driver->id] = false;

		clk_disable(drvdata->mi2s_bit_clk[dai->driver->id]);

	}



	clk_unprepare(drvdata->mi2s_bit_clk[dai->driver->id]);

}
@@ -275,6 +297,18 @@ static int lpass_cpu_daiops_trigger(struct snd_pcm_substream *substream, 
	case SNDRV_PCM_TRIGGER_START:

	case SNDRV_PCM_TRIGGER_RESUME:

	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:

		/*

		 * Ensure lpass BCLK/LRCLK is enabled during

		 * device resume as lpass_cpu_daiops_prepare() is not called

		 * after the device resumes. We don't check mi2s_was_prepared before

		 * enable/disable BCLK in trigger events because:

		 *  1. These trigger events are paired, so the BCLK

		 *     enable_count is balanced.

		 *  2. the BCLK can be shared (ex: headset and headset mic),

		 *     we need to increase the enable_count so that we don't

		 *     turn off the shared BCLK while other devices are using

		 *     it.

		 */

		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {

			ret = regmap_fields_write(i2sctl->spken, id,

						 LPAIF_I2SCTL_SPKEN_ENABLE);
@@ -296,6 +330,10 @@ static int lpass_cpu_daiops_trigger(struct snd_pcm_substream *substream, 
	case SNDRV_PCM_TRIGGER_STOP:

	case SNDRV_PCM_TRIGGER_SUSPEND:

	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:

		/*

		 * To ensure lpass BCLK/LRCLK is disabled during

		 * device suspend.

		 */

		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {

			ret = regmap_fields_write(i2sctl->spken, id,

						 LPAIF_I2SCTL_SPKEN_DISABLE);
@@ -315,12 +353,53 @@ static int lpass_cpu_daiops_trigger(struct snd_pcm_substream *substream, 
	return ret;

}



static int lpass_cpu_daiops_prepare(struct snd_pcm_substream *substream,

		struct snd_soc_dai *dai)

{

	struct lpass_data *drvdata = snd_soc_dai_get_drvdata(dai);

	struct lpaif_i2sctl *i2sctl = drvdata->i2sctl;

	unsigned int id = dai->driver->id;

	int ret;



	/*

	 * Ensure lpass BCLK/LRCLK is enabled bit before playback/capture

	 * data flow starts. This allows other codec to have some delay before

	 * the data flow.

	 * (ex: to drop start up pop noise before capture starts).

	 */

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)

		ret = regmap_fields_write(i2sctl->spken, id, LPAIF_I2SCTL_SPKEN_ENABLE);

	else

		ret = regmap_fields_write(i2sctl->micen, id, LPAIF_I2SCTL_MICEN_ENABLE);



	if (ret) {

		dev_err(dai->dev, "error writing to i2sctl reg: %d\n", ret);

		return ret;

	}



	/*

	 * Check mi2s_was_prepared before enabling BCLK as lpass_cpu_daiops_prepare can

	 * be called multiple times. It's paired with the clk_disable in

	 * lpass_cpu_daiops_shutdown.

	 */

	if (!drvdata->mi2s_was_prepared[dai->driver->id]) {

		ret = clk_enable(drvdata->mi2s_bit_clk[id]);

		if (ret) {

			dev_err(dai->dev, "error in enabling mi2s bit clk: %d\n", ret);

			return ret;

		}

		drvdata->mi2s_was_prepared[dai->driver->id] = true;

	}

	return 0;

}



const struct snd_soc_dai_ops asoc_qcom_lpass_cpu_dai_ops = {

	.set_sysclk	= lpass_cpu_daiops_set_sysclk,

	.startup	= lpass_cpu_daiops_startup,

	.shutdown	= lpass_cpu_daiops_shutdown,

	.hw_params	= lpass_cpu_daiops_hw_params,

	.trigger	= lpass_cpu_daiops_trigger,

	.prepare	= lpass_cpu_daiops_prepare,

};

EXPORT_SYMBOL_GPL(asoc_qcom_lpass_cpu_dai_ops);

sound/soc/qcom/lpass.h

+4 −0
Original line number Diff line number Diff line
@@ -67,6 +67,10 @@ struct lpass_data { 
	/* MI2S SD lines to use for playback/capture */

	unsigned int mi2s_playback_sd_mode[LPASS_MAX_MI2S_PORTS];

	unsigned int mi2s_capture_sd_mode[LPASS_MAX_MI2S_PORTS];



	/* The state of MI2S prepare dai_ops was called */

	bool mi2s_was_prepared[LPASS_MAX_MI2S_PORTS];



	int hdmi_port_enable;



	/* low-power audio interface (LPAIF) registers */