[PATCH 0/3] Add runtime PM for SAI digital audio interface

[PATCH 0/3] Add runtime PM for SAI digital audio interface

[Daniel Baluta]

First patch fixes a bug by correctly setting is_slave_mode, then
second patch adds support for runtime PM and finally 3rd patch moves
clock handling from startup/shtudown function to runtime PM handlers.

Changes since v1:
	- added patch 1
	- added fsl_sai_remove in order to call pm_runtime_disable
	- only disable/enable mclk when SAI in master mode.

Daniel Baluta (2):
  ASoC: fsl_sai: Update is_slave_mode with correct value
  ASoC: fsl_sai: Add support for runtime pm

Shengjiu Wang (1):
  ASoC: fsl_sai: Move clock operation to PM runtime

 sound/soc/fsl/fsl_sai.c | 84 +++++++++++++++++++++++++++++++++--------
 1 file changed, 69 insertions(+), 15 deletions(-)

-- 
2.17.1

[PATCH 1/3 v2] ASoC: fsl_sai: Update is_slave_mode with correct value

[Daniel Baluta]

is_slave_mode defaults to false because sai structure
that contains it is kzalloc'ed.

Anyhow, if we decide to set the following configuration
SAI slave -> SAI master, is_slave_mode will remain set on true
although SAI being master it should be set to false.

Fix this by updating is_slave_mode for each call of
fsl_sai_set_dai_fmt.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
 sound/soc/fsl/fsl_sai.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index b563004fb89f..d9df98975cf8 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -268,12 +268,14 @@ static int fsl_sai_set_dai_fmt_tr(struct snd_soc_dai *cpu_dai,
 	case SND_SOC_DAIFMT_CBS_CFS:
 		val_cr2 |= FSL_SAI_CR2_BCD_MSTR;
 		val_cr4 |= FSL_SAI_CR4_FSD_MSTR;
+		sai->is_slave_mode = false;
 		break;
 	case SND_SOC_DAIFMT_CBM_CFM:
 		sai->is_slave_mode = true;
 		break;
 	case SND_SOC_DAIFMT_CBS_CFM:
 		val_cr2 |= FSL_SAI_CR2_BCD_MSTR;
+		sai->is_slave_mode = false;
 		break;
 	case SND_SOC_DAIFMT_CBM_CFS:
 		val_cr4 |= FSL_SAI_CR4_FSD_MSTR;
-- 
2.17.1

Re: [PATCH 1/3 v2] ASoC: fsl_sai: Update is_slave_mode with correct value

[Nicolin Chen]

On Sun, Apr 21, 2019 at 07:39:08PM +0000, Daniel Baluta wrote:
> is_slave_mode defaults to false because sai structure
> that contains it is kzalloc'ed.
> 
> Anyhow, if we decide to set the following configuration
> SAI slave -> SAI master, is_slave_mode will remain set on true
> although SAI being master it should be set to false.
> 
> Fix this by updating is_slave_mode for each call of
> fsl_sai_set_dai_fmt.
> 
> Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>

Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>

Thanks

> ---
>  sound/soc/fsl/fsl_sai.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
> index b563004fb89f..d9df98975cf8 100644
> --- a/sound/soc/fsl/fsl_sai.c
> +++ b/sound/soc/fsl/fsl_sai.c
> @@ -268,12 +268,14 @@ static int fsl_sai_set_dai_fmt_tr(struct snd_soc_dai *cpu_dai,
>  	case SND_SOC_DAIFMT_CBS_CFS:
>  		val_cr2 |= FSL_SAI_CR2_BCD_MSTR;
>  		val_cr4 |= FSL_SAI_CR4_FSD_MSTR;
> +		sai->is_slave_mode = false;
>  		break;
>  	case SND_SOC_DAIFMT_CBM_CFM:
>  		sai->is_slave_mode = true;
>  		break;
>  	case SND_SOC_DAIFMT_CBS_CFM:
>  		val_cr2 |= FSL_SAI_CR2_BCD_MSTR;
> +		sai->is_slave_mode = false;
>  		break;
>  	case SND_SOC_DAIFMT_CBM_CFS:
>  		val_cr4 |= FSL_SAI_CR4_FSD_MSTR;
> -- 
> 2.17.1
> 

[PATCH 2/3 v2] ASoC: fsl_sai: Add support for runtime pm

[Daniel Baluta]

Basically the same actions as for system PM, so make use
of pm_runtime_force_suspend/pm_runtime_force_resume.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
 sound/soc/fsl/fsl_sai.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index d9df98975cf8..8623b7f882b9 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -9,6 +9,7 @@
 #include <linux/dmaengine.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/time.h>
@@ -900,6 +901,8 @@ static int fsl_sai_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, sai);
 
+	pm_runtime_enable(&pdev->dev);
+
 	ret = devm_snd_soc_register_component(&pdev->dev, &fsl_component,
 			&fsl_sai_dai, 1);
 	if (ret)
@@ -911,6 +914,11 @@ static int fsl_sai_probe(struct platform_device *pdev)
 		return devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
 }
 
+static int fsl_sai_remove(struct platform_device *pdev)
+{
+	pm_runtime_disable(&pdev->dev);
+}
+
 static const struct of_device_id fsl_sai_ids[] = {
 	{ .compatible = "fsl,vf610-sai", },
 	{ .compatible = "fsl,imx6sx-sai", },
@@ -919,8 +927,8 @@ static const struct of_device_id fsl_sai_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, fsl_sai_ids);
 
-#ifdef CONFIG_PM_SLEEP
-static int fsl_sai_suspend(struct device *dev)
+#ifdef CONFIG_PM
+static int fsl_sai_runtime_suspend(struct device *dev)
 {
 	struct fsl_sai *sai = dev_get_drvdata(dev);
 
@@ -930,7 +938,7 @@ static int fsl_sai_suspend(struct device *dev)
 	return 0;
 }
 
-static int fsl_sai_resume(struct device *dev)
+static int fsl_sai_runtime_resume(struct device *dev)
 {
 	struct fsl_sai *sai = dev_get_drvdata(dev);
 
@@ -942,14 +950,18 @@ static int fsl_sai_resume(struct device *dev)
 	regmap_write(sai->regmap, FSL_SAI_RCSR, 0);
 	return regcache_sync(sai->regmap);
 }
-#endif /* CONFIG_PM_SLEEP */
+#endif /* CONFIG_PM */
 
 static const struct dev_pm_ops fsl_sai_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(fsl_sai_suspend, fsl_sai_resume)
+	SET_RUNTIME_PM_OPS(fsl_sai_runtime_suspend,
+			   fsl_sai_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
 };
 
 static struct platform_driver fsl_sai_driver = {
 	.probe = fsl_sai_probe,
+	.remove = fsl_sai_remove,
 	.driver = {
 		.name = "fsl-sai",
 		.pm = &fsl_sai_pm_ops,
-- 
2.17.1

Re: [PATCH 2/3 v2] ASoC: fsl_sai: Add support for runtime pm

[Nicolin Chen]

On Sun, Apr 21, 2019 at 07:39:09PM +0000, Daniel Baluta wrote:
> Basically the same actions as for system PM, so make use
> of pm_runtime_force_suspend/pm_runtime_force_resume.
> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>

Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>

Thanks

> ---
>  sound/soc/fsl/fsl_sai.c | 22 +++++++++++++++++-----
>  1 file changed, 17 insertions(+), 5 deletions(-)
> 
> diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
> index d9df98975cf8..8623b7f882b9 100644
> --- a/sound/soc/fsl/fsl_sai.c
> +++ b/sound/soc/fsl/fsl_sai.c
> @@ -9,6 +9,7 @@
>  #include <linux/dmaengine.h>
>  #include <linux/module.h>
>  #include <linux/of_address.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/regmap.h>
>  #include <linux/slab.h>
>  #include <linux/time.h>
> @@ -900,6 +901,8 @@ static int fsl_sai_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, sai);
>  
> +	pm_runtime_enable(&pdev->dev);
> +
>  	ret = devm_snd_soc_register_component(&pdev->dev, &fsl_component,
>  			&fsl_sai_dai, 1);
>  	if (ret)
> @@ -911,6 +914,11 @@ static int fsl_sai_probe(struct platform_device *pdev)
>  		return devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
>  }
>  
> +static int fsl_sai_remove(struct platform_device *pdev)
> +{
> +	pm_runtime_disable(&pdev->dev);
> +}
> +
>  static const struct of_device_id fsl_sai_ids[] = {
>  	{ .compatible = "fsl,vf610-sai", },
>  	{ .compatible = "fsl,imx6sx-sai", },
> @@ -919,8 +927,8 @@ static const struct of_device_id fsl_sai_ids[] = {
>  };
>  MODULE_DEVICE_TABLE(of, fsl_sai_ids);
>  
> -#ifdef CONFIG_PM_SLEEP
> -static int fsl_sai_suspend(struct device *dev)
> +#ifdef CONFIG_PM
> +static int fsl_sai_runtime_suspend(struct device *dev)
>  {
>  	struct fsl_sai *sai = dev_get_drvdata(dev);
>  
> @@ -930,7 +938,7 @@ static int fsl_sai_suspend(struct device *dev)
>  	return 0;
>  }
>  
> -static int fsl_sai_resume(struct device *dev)
> +static int fsl_sai_runtime_resume(struct device *dev)
>  {
>  	struct fsl_sai *sai = dev_get_drvdata(dev);
>  
> @@ -942,14 +950,18 @@ static int fsl_sai_resume(struct device *dev)
>  	regmap_write(sai->regmap, FSL_SAI_RCSR, 0);
>  	return regcache_sync(sai->regmap);
>  }
> -#endif /* CONFIG_PM_SLEEP */
> +#endif /* CONFIG_PM */
>  
>  static const struct dev_pm_ops fsl_sai_pm_ops = {
> -	SET_SYSTEM_SLEEP_PM_OPS(fsl_sai_suspend, fsl_sai_resume)
> +	SET_RUNTIME_PM_OPS(fsl_sai_runtime_suspend,
> +			   fsl_sai_runtime_resume, NULL)
> +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +				pm_runtime_force_resume)
>  };
>  
>  static struct platform_driver fsl_sai_driver = {
>  	.probe = fsl_sai_probe,
> +	.remove = fsl_sai_remove,
>  	.driver = {
>  		.name = "fsl-sai",
>  		.pm = &fsl_sai_pm_ops,
> -- 
> 2.17.1
> 

Re: [PATCH 2/3 v2] ASoC: fsl_sai: Add support for runtime pm

[Mark Brown]

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On Sun, Apr 21, 2019 at 07:39:09PM +0000, Daniel Baluta wrote:
> Basically the same actions as for system PM, so make use
> of pm_runtime_force_suspend/pm_runtime_force_resume.

This doesn't apply against current code, please check and resend.

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Re: [PATCH 2/3 v2] ASoC: fsl_sai: Add support for runtime pm

[Daniel Baluta]

On Fri, Apr 26, 2019 at 1:01 PM Mark Brown <broonie@kernel.org> wrote:
>
> On Sun, Apr 21, 2019 at 07:39:09PM +0000, Daniel Baluta wrote:
> > Basically the same actions as for system PM, so make use
> > of pm_runtime_force_suspend/pm_runtime_force_resume.
>
> This doesn't apply against current code, please check and resend.

Hi Mark,

This patch is already applied:

https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git/commit/?h=for-next&id=812ad463e0894d78e93ab8017e0edbe69038c55c

The only patch left in the series that needs to be applied is this:

https://www.spinics.net/lists/alsa-devel/msg89733.html

I will reply also to that email, to be easier for you to find it.

Re: [PATCH 2/3 v2] ASoC: fsl_sai: Add support for runtime pm

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 295 bytes --]

On Fri, Apr 26, 2019 at 03:10:10PM +0300, Daniel Baluta wrote:

> The only patch left in the series that needs to be applied is this:

> https://www.spinics.net/lists/alsa-devel/msg89733.html

> I will reply also to that email, to be easier for you to find it.

Content free pings don't help...

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[PATCH 3/3 v3] ASoC: fsl_sai: Move clock operation to PM runtime

[Daniel Baluta]

From: Shengjiu Wang <shengjiu.wang@nxp.com>

Turn off/on clocks when device enters suspend/resume. This
can help saving power.

As a further optimization, we turn off/on mclk only when SAI
is in master mode because otherwise mclk is externally provided.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
 sound/soc/fsl/fsl_sai.c | 60 ++++++++++++++++++++++++++++++++++-------
 1 file changed, 50 insertions(+), 10 deletions(-)

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index 8623b7f882b9..13a462360ed3 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -596,15 +596,8 @@ static int fsl_sai_startup(struct snd_pcm_substream *substream,
 {
 	struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
-	struct device *dev = &sai->pdev->dev;
 	int ret;
 
-	ret = clk_prepare_enable(sai->bus_clk);
-	if (ret) {
-		dev_err(dev, "failed to enable bus clock: %d\n", ret);
-		return ret;
-	}
-
 	regmap_update_bits(sai->regmap, FSL_SAI_xCR3(tx), FSL_SAI_CR3_TRCE,
 			   FSL_SAI_CR3_TRCE);
 
@@ -621,8 +614,6 @@ static void fsl_sai_shutdown(struct snd_pcm_substream *substream,
 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 
 	regmap_update_bits(sai->regmap, FSL_SAI_xCR3(tx), FSL_SAI_CR3_TRCE, 0);
-
-	clk_disable_unprepare(sai->bus_clk);
 }
 
 static const struct snd_soc_dai_ops fsl_sai_pcm_dai_ops = {
@@ -932,6 +923,16 @@ static int fsl_sai_runtime_suspend(struct device *dev)
 {
 	struct fsl_sai *sai = dev_get_drvdata(dev);
 
+	if (!sai->is_slave_mode) {
+		if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_CAPTURE))
+			clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[0]]);
+
+		if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_PLAYBACK))
+			clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[1]]);
+	}
+
+	clk_disable_unprepare(sai->bus_clk);
+
 	regcache_cache_only(sai->regmap, true);
 	regcache_mark_dirty(sai->regmap);
 
@@ -941,6 +942,27 @@ static int fsl_sai_runtime_suspend(struct device *dev)
 static int fsl_sai_runtime_resume(struct device *dev)
 {
 	struct fsl_sai *sai = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(sai->bus_clk);
+	if (ret) {
+		dev_err(dev, "failed to enable bus clock: %d\n", ret);
+		return ret;
+	}
+
+	if (!sai->is_slave_mode) {
+		if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_PLAYBACK)) {
+			ret = clk_prepare_enable(sai->mclk_clk[sai->mclk_id[1]]);
+			if (ret)
+				goto disable_bus_clk;
+		}
+
+		if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_CAPTURE)) {
+			ret = clk_prepare_enable(sai->mclk_clk[sai->mclk_id[0]]);
+			if (ret)
+				goto disable_tx_clk;
+		}
+	}
 
 	regcache_cache_only(sai->regmap, false);
 	regmap_write(sai->regmap, FSL_SAI_TCSR, FSL_SAI_CSR_SR);
@@ -948,7 +970,25 @@ static int fsl_sai_runtime_resume(struct device *dev)
 	usleep_range(1000, 2000);
 	regmap_write(sai->regmap, FSL_SAI_TCSR, 0);
 	regmap_write(sai->regmap, FSL_SAI_RCSR, 0);
-	return regcache_sync(sai->regmap);
+
+	ret = regcache_sync(sai->regmap);
+	if (ret)
+		goto disable_rx_clk;
+
+	return 0;
+
+disable_rx_clk:
+	if (!sai->is_slave_mode &&
+	    (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_CAPTURE)))
+		clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[0]]);
+disable_tx_clk:
+	if (!sai->is_slave_mode &&
+	    (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_PLAYBACK)))
+		clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[1]]);
+disable_bus_clk:
+	clk_disable_unprepare(sai->bus_clk);
+
+	return ret;
 }
 #endif /* CONFIG_PM */
 
-- 
2.17.1

Re: [PATCH 3/3 v3] ASoC: fsl_sai: Move clock operation to PM runtime

[Nicolin Chen]

On Sun, Apr 21, 2019 at 07:39:10PM +0000, Daniel Baluta wrote:
> From: Shengjiu Wang <shengjiu.wang@nxp.com>
> 
> Turn off/on clocks when device enters suspend/resume. This
> can help saving power.
> 
> As a further optimization, we turn off/on mclk only when SAI
> is in master mode because otherwise mclk is externally provided.
> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>

Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>

Thanks

Re: [PATCH 3/3 v3] ASoC: fsl_sai: Move clock operation to PM runtime

[Viorel Suman]

Hi Daniel,

On Du, 2019-04-21 at 19:39 +0000, Daniel Baluta wrote:
> From: Shengjiu Wang <shengjiu.wang@nxp.com>
> 
> Turn off/on clocks when device enters suspend/resume. This
> can help saving power.
> 
> As a further optimization, we turn off/on mclk only when SAI
> is in master mode because otherwise mclk is externally provided.
> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
> ---
>  sound/soc/fsl/fsl_sai.c | 60 ++++++++++++++++++++++++++++++++++-------
>  1 file changed, 50 insertions(+), 10 deletions(-)
> 
> diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
> index 8623b7f882b9..13a462360ed3 100644
> --- a/sound/soc/fsl/fsl_sai.c
> +++ b/sound/soc/fsl/fsl_sai.c
> @@ -596,15 +596,8 @@ static int fsl_sai_startup(struct snd_pcm_substream *substream,
>  {
>  	struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
>  	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
> -	struct device *dev = &sai->pdev->dev;
>  	int ret;
>  
> -	ret = clk_prepare_enable(sai->bus_clk);
> -	if (ret) {
> -		dev_err(dev, "failed to enable bus clock: %d\n", ret);
> -		return ret;
> -	}
> -
>  	regmap_update_bits(sai->regmap, FSL_SAI_xCR3(tx), FSL_SAI_CR3_TRCE,
>  			   FSL_SAI_CR3_TRCE);
>  
> @@ -621,8 +614,6 @@ static void fsl_sai_shutdown(struct snd_pcm_substream *substream,
>  	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
>  
>  	regmap_update_bits(sai->regmap, FSL_SAI_xCR3(tx), FSL_SAI_CR3_TRCE, 0);
> -
> -	clk_disable_unprepare(sai->bus_clk);
>  }
>  
>  static const struct snd_soc_dai_ops fsl_sai_pcm_dai_ops = {
> @@ -932,6 +923,16 @@ static int fsl_sai_runtime_suspend(struct device *dev)
>  {
>  	struct fsl_sai *sai = dev_get_drvdata(dev);
>  
> +	if (!sai->is_slave_mode) {
This check is redundant as the bits in sai->mclk_streams are set/unset for master
mode only, please check fsl_sai_hw_params and fsl_sai_hw_free functions.

> +		if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_CAPTURE))
> +			clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[0]]);
> +
> +		if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_PLAYBACK))
> +			clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[1]]);
> +	}
> +
> +	clk_disable_unprepare(sai->bus_clk);
> +
>  	regcache_cache_only(sai->regmap, true);
>  	regcache_mark_dirty(sai->regmap);
>  
> @@ -941,6 +942,27 @@ static int fsl_sai_runtime_suspend(struct device *dev)
>  static int fsl_sai_runtime_resume(struct device *dev)
>  {
>  	struct fsl_sai *sai = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = clk_prepare_enable(sai->bus_clk);
> +	if (ret) {
> +		dev_err(dev, "failed to enable bus clock: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (!sai->is_slave_mode) {
> +		if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_PLAYBACK)) {
> +			ret = clk_prepare_enable(sai->mclk_clk[sai->mclk_id[1]]);
> +			if (ret)
> +				goto disable_bus_clk;
> +		}
> +
> +		if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_CAPTURE)) {
> +			ret = clk_prepare_enable(sai->mclk_clk[sai->mclk_id[0]]);
> +			if (ret)
> +				goto disable_tx_clk;
> +		}
> +	}
>  
>  	regcache_cache_only(sai->regmap, false);
>  	regmap_write(sai->regmap, FSL_SAI_TCSR, FSL_SAI_CSR_SR);
> @@ -948,7 +970,25 @@ static int fsl_sai_runtime_resume(struct device *dev)
>  	usleep_range(1000, 2000);
>  	regmap_write(sai->regmap, FSL_SAI_TCSR, 0);
>  	regmap_write(sai->regmap, FSL_SAI_RCSR, 0);
> -	return regcache_sync(sai->regmap);
> +
> +	ret = regcache_sync(sai->regmap);
> +	if (ret)
> +		goto disable_rx_clk;
> +
> +	return 0;
> +
> +disable_rx_clk:
> +	if (!sai->is_slave_mode &&
> +	    (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_CAPTURE)))
> +		clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[0]]);
> +disable_tx_clk:
> +	if (!sai->is_slave_mode &&
> +	    (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_PLAYBACK)))
> +		clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[1]]);
> +disable_bus_clk:
> +	clk_disable_unprepare(sai->bus_clk);
> +
> +	return ret;
>  }
>  #endif /* CONFIG_PM */
>  
> -- 
> 2.17.1
> 

Re: [alsa-devel] [PATCH 3/3 v3] ASoC: fsl_sai: Move clock operation to PM runtime

[Daniel Baluta]

On Mon, Apr 22, 2019 at 2:07 PM Viorel Suman <viorel.suman@nxp.com> wrote:
>
> Hi Daniel,
>
> On Du, 2019-04-21 at 19:39 +0000, Daniel Baluta wrote:
> > From: Shengjiu Wang <shengjiu.wang@nxp.com>
> >
> > Turn off/on clocks when device enters suspend/resume. This
> > can help saving power.
> >
> > As a further optimization, we turn off/on mclk only when SAI
> > is in master mode because otherwise mclk is externally provided.
> >
> > Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> > Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
> > ---
> >  sound/soc/fsl/fsl_sai.c | 60 ++++++++++++++++++++++++++++++++++-------
> >  1 file changed, 50 insertions(+), 10 deletions(-)
> >
> > diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
> > index 8623b7f882b9..13a462360ed3 100644
> > --- a/sound/soc/fsl/fsl_sai.c
> > +++ b/sound/soc/fsl/fsl_sai.c
> > @@ -596,15 +596,8 @@ static int fsl_sai_startup(struct snd_pcm_substream *substream,
> >  {
> >       struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
> >       bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
> > -     struct device *dev = &sai->pdev->dev;
> >       int ret;
> >
> > -     ret = clk_prepare_enable(sai->bus_clk);
> > -     if (ret) {
> > -             dev_err(dev, "failed to enable bus clock: %d\n", ret);
> > -             return ret;
> > -     }
> > -
> >       regmap_update_bits(sai->regmap, FSL_SAI_xCR3(tx), FSL_SAI_CR3_TRCE,
> >                          FSL_SAI_CR3_TRCE);
> >
> > @@ -621,8 +614,6 @@ static void fsl_sai_shutdown(struct snd_pcm_substream *substream,
> >       bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
> >
> >       regmap_update_bits(sai->regmap, FSL_SAI_xCR3(tx), FSL_SAI_CR3_TRCE, 0);
> > -
> > -     clk_disable_unprepare(sai->bus_clk);
> >  }
> >
> >  static const struct snd_soc_dai_ops fsl_sai_pcm_dai_ops = {
> > @@ -932,6 +923,16 @@ static int fsl_sai_runtime_suspend(struct device *dev)
> >  {
> >       struct fsl_sai *sai = dev_get_drvdata(dev);
> >
> > +     if (!sai->is_slave_mode) {
> This check is redundant as the bits in sai->mclk_streams are set/unset for master
> mode only, please check fsl_sai_hw_params and fsl_sai_hw_free functions.

Hi Viorel,

I think you make a very good point here. Will fix and send v3.

Thanks!