[PATCH v2 0/2] ASoC: img-i2s-in: Add power management

[PATCH v2 0/2] ASoC: img-i2s-in: Add power management

[Ed Blake]

This patch set adds power managment to the img-i2s-in driver. The first
patch adds system PM suspend / resume handling and the second patch
adds runtime PM.

Changes in v2:
 - Changed from ASoC specific pm callbacks to device ones
 - Errors returned from pm_runtime_get_sync are now handled

Ed Blake (2):
  ASoC: img-i2s-in: Add suspend / resume handling
  ASoC: img-i2s-in: Add runtime PM

 sound/soc/img/img-i2s-in.c | 130 ++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 118 insertions(+), 12 deletions(-)

-- 
2.11.0

[PATCH v2 1/2] ASoC: img-i2s-in: Add suspend / resume handling

[Ed Blake]

Implement suspend and resume callbacks to save and restore register
state, to support platforms where the power is disabled during suspend.

In future the driver could be converted to use regmap which would
simplify the suspend and resume code.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
---
Changes in v2:
 - Changed from ASoC specific pm callbacks to device ones
---
 sound/soc/img/img-i2s-in.c | 54 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 1 deletion(-)

diff --git a/sound/soc/img/img-i2s-in.c b/sound/soc/img/img-i2s-in.c
index 567f9767fb73..3d151ddda937 100644
--- a/sound/soc/img/img-i2s-in.c
+++ b/sound/soc/img/img-i2s-in.c
@@ -60,6 +60,8 @@ struct img_i2s_in {
 	void __iomem *channel_base;
 	unsigned int active_channels;
 	struct snd_soc_dai_driver dai_driver;
+	u32 suspend_ctl;
+	u32 *suspend_ch_ctl;
 };
 
 static inline void img_i2s_in_writel(struct img_i2s_in *i2s, u32 val, u32 reg)
@@ -469,6 +471,13 @@ static int img_i2s_in_probe(struct platform_device *pdev)
 			IMG_I2S_IN_CH_CTL_JUST_MASK |
 			IMG_I2S_IN_CH_CTL_FW_MASK, IMG_I2S_IN_CH_CTL);
 
+	i2s->suspend_ch_ctl = devm_kzalloc(dev,
+		sizeof(*i2s->suspend_ch_ctl) * i2s->max_i2s_chan, GFP_KERNEL);
+	if (!i2s->suspend_ch_ctl) {
+		ret = -ENOMEM;
+		goto err_clk_disable;
+	}
+
 	ret = devm_snd_soc_register_component(dev, &img_i2s_in_component,
 						&i2s->dai_driver, 1);
 	if (ret)
@@ -495,16 +504,59 @@ static int img_i2s_in_dev_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int img_i2s_in_suspend(struct device *dev)
+{
+	struct img_i2s_in *i2s = dev_get_drvdata(dev);
+	int i;
+	u32 reg;
+
+	for (i = 0; i < i2s->max_i2s_chan; i++) {
+		reg = img_i2s_in_ch_readl(i2s, i, IMG_I2S_IN_CH_CTL);
+		i2s->suspend_ch_ctl[i] = reg;
+	}
+
+	i2s->suspend_ctl = img_i2s_in_readl(i2s, IMG_I2S_IN_CTL);
+
+	clk_disable_unprepare(i2s->clk_sys);
+
+	return 0;
+}
+
+static int img_i2s_in_resume(struct device *dev)
+{
+	struct img_i2s_in *i2s = dev_get_drvdata(dev);
+	int i;
+	u32 reg;
+
+	clk_prepare_enable(i2s->clk_sys);
+
+	for (i = 0; i < i2s->max_i2s_chan; i++) {
+		reg = i2s->suspend_ch_ctl[i];
+		img_i2s_in_ch_writel(i2s, i, reg, IMG_I2S_IN_CH_CTL);
+	}
+
+	img_i2s_in_writel(i2s, i2s->suspend_ctl, IMG_I2S_IN_CTL);
+
+	return 0;
+}
+#endif
+
 static const struct of_device_id img_i2s_in_of_match[] = {
 	{ .compatible = "img,i2s-in" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, img_i2s_in_of_match);
 
+static const struct dev_pm_ops img_i2s_in_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(img_i2s_in_suspend, img_i2s_in_resume)
+};
+
 static struct platform_driver img_i2s_in_driver = {
 	.driver = {
 		.name = "img-i2s-in",
-		.of_match_table = img_i2s_in_of_match
+		.of_match_table = img_i2s_in_of_match,
+		.pm = &img_i2s_in_pm_ops
 	},
 	.probe = img_i2s_in_probe,
 	.remove = img_i2s_in_dev_remove
-- 
2.11.0

[PATCH v2 2/2] ASoC: img-i2s-in: Add runtime PM

[Ed Blake]

Add runtime PM to disable the clock when the device is not in use.
The ASoC core takes care of the pm_runtime_get_sync / put calls so we
just need to provide runtime_suspend / runtime_resume functions and
enable runtime PM.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
---
Changes in v2:
 - Errors returned from pm_runtime_get_sync are now handled
---
 sound/soc/img/img-i2s-in.c | 88 +++++++++++++++++++++++++++++++++++++---------
 1 file changed, 71 insertions(+), 17 deletions(-)

diff --git a/sound/soc/img/img-i2s-in.c b/sound/soc/img/img-i2s-in.c
index 3d151ddda937..d7fbb0a0a28b 100644
--- a/sound/soc/img/img-i2s-in.c
+++ b/sound/soc/img/img-i2s-in.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/reset.h>
 
 #include <sound/core.h>
@@ -64,6 +65,29 @@ struct img_i2s_in {
 	u32 *suspend_ch_ctl;
 };
 
+static int img_i2s_in_runtime_suspend(struct device *dev)
+{
+	struct img_i2s_in *i2s = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(i2s->clk_sys);
+
+	return 0;
+}
+
+static int img_i2s_in_runtime_resume(struct device *dev)
+{
+	struct img_i2s_in *i2s = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(i2s->clk_sys);
+	if (ret) {
+		dev_err(dev, "Unable to enable sys clock\n");
+		return ret;
+	}
+
+	return 0;
+}
+
 static inline void img_i2s_in_writel(struct img_i2s_in *i2s, u32 val, u32 reg)
 {
 	writel(val, i2s->base + reg);
@@ -281,7 +305,7 @@ static int img_i2s_in_hw_params(struct snd_pcm_substream *substream,
 static int img_i2s_in_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 {
 	struct img_i2s_in *i2s = snd_soc_dai_get_drvdata(dai);
-	int i;
+	int i, ret;
 	u32 chan_control_mask, lrd_set = 0, blkp_set = 0, chan_control_set = 0;
 	u32 reg;
 
@@ -321,6 +345,10 @@ static int img_i2s_in_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 
 	chan_control_mask = IMG_I2S_IN_CH_CTL_CLK_TRANS_MASK;
 
+	ret = pm_runtime_get_sync(i2s->dev);
+	if (ret < 0)
+		return ret;
+
 	for (i = 0; i < i2s->active_channels; i++)
 		img_i2s_in_ch_disable(i2s, i);
 
@@ -340,6 +368,8 @@ static int img_i2s_in_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 	for (i = 0; i < i2s->active_channels; i++)
 		img_i2s_in_ch_enable(i2s, i);
 
+	pm_runtime_put(i2s->dev);
+
 	return 0;
 }
 
@@ -429,9 +459,15 @@ static int img_i2s_in_probe(struct platform_device *pdev)
 		return PTR_ERR(i2s->clk_sys);
 	}
 
-	ret = clk_prepare_enable(i2s->clk_sys);
-	if (ret)
-		return ret;
+	pm_runtime_enable(&pdev->dev);
+	if (!pm_runtime_enabled(&pdev->dev)) {
+		ret = img_i2s_in_runtime_resume(&pdev->dev);
+		if (ret)
+			goto err_pm_disable;
+	}
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0)
+		goto err_suspend;
 
 	i2s->active_channels = 1;
 	i2s->dma_data.addr = res->start + IMG_I2S_IN_RX_FIFO;
@@ -449,7 +485,7 @@ static int img_i2s_in_probe(struct platform_device *pdev)
 	if (IS_ERR(rst)) {
 		if (PTR_ERR(rst) == -EPROBE_DEFER) {
 			ret = -EPROBE_DEFER;
-			goto err_clk_disable;
+			goto err_suspend;
 		}
 
 		dev_dbg(dev, "No top level reset found\n");
@@ -471,35 +507,40 @@ static int img_i2s_in_probe(struct platform_device *pdev)
 			IMG_I2S_IN_CH_CTL_JUST_MASK |
 			IMG_I2S_IN_CH_CTL_FW_MASK, IMG_I2S_IN_CH_CTL);
 
+	pm_runtime_put(&pdev->dev);
+
 	i2s->suspend_ch_ctl = devm_kzalloc(dev,
 		sizeof(*i2s->suspend_ch_ctl) * i2s->max_i2s_chan, GFP_KERNEL);
 	if (!i2s->suspend_ch_ctl) {
 		ret = -ENOMEM;
-		goto err_clk_disable;
+		goto err_suspend;
 	}
 
 	ret = devm_snd_soc_register_component(dev, &img_i2s_in_component,
 						&i2s->dai_driver, 1);
 	if (ret)
-		goto err_clk_disable;
+		goto err_suspend;
 
 	ret = devm_snd_dmaengine_pcm_register(dev, &img_i2s_in_dma_config, 0);
 	if (ret)
-		goto err_clk_disable;
+		goto err_suspend;
 
 	return 0;
 
-err_clk_disable:
-	clk_disable_unprepare(i2s->clk_sys);
+err_suspend:
+	if (!pm_runtime_enabled(&pdev->dev))
+		img_i2s_in_runtime_suspend(&pdev->dev);
+err_pm_disable:
+	pm_runtime_disable(&pdev->dev);
 
 	return ret;
 }
 
 static int img_i2s_in_dev_remove(struct platform_device *pdev)
 {
-	struct img_i2s_in *i2s = platform_get_drvdata(pdev);
-
-	clk_disable_unprepare(i2s->clk_sys);
+	pm_runtime_disable(&pdev->dev);
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		img_i2s_in_runtime_suspend(&pdev->dev);
 
 	return 0;
 }
@@ -508,9 +549,15 @@ static int img_i2s_in_dev_remove(struct platform_device *pdev)
 static int img_i2s_in_suspend(struct device *dev)
 {
 	struct img_i2s_in *i2s = dev_get_drvdata(dev);
-	int i;
+	int i, ret;
 	u32 reg;
 
+	if (pm_runtime_status_suspended(dev)) {
+		ret = img_i2s_in_runtime_resume(dev);
+		if (ret)
+			return ret;
+	}
+
 	for (i = 0; i < i2s->max_i2s_chan; i++) {
 		reg = img_i2s_in_ch_readl(i2s, i, IMG_I2S_IN_CH_CTL);
 		i2s->suspend_ch_ctl[i] = reg;
@@ -518,7 +565,7 @@ static int img_i2s_in_suspend(struct device *dev)
 
 	i2s->suspend_ctl = img_i2s_in_readl(i2s, IMG_I2S_IN_CTL);
 
-	clk_disable_unprepare(i2s->clk_sys);
+	img_i2s_in_runtime_suspend(dev);
 
 	return 0;
 }
@@ -526,10 +573,12 @@ static int img_i2s_in_suspend(struct device *dev)
 static int img_i2s_in_resume(struct device *dev)
 {
 	struct img_i2s_in *i2s = dev_get_drvdata(dev);
-	int i;
+	int i, ret;
 	u32 reg;
 
-	clk_prepare_enable(i2s->clk_sys);
+	ret = img_i2s_in_runtime_resume(dev);
+	if (ret)
+		return ret;
 
 	for (i = 0; i < i2s->max_i2s_chan; i++) {
 		reg = i2s->suspend_ch_ctl[i];
@@ -538,6 +587,9 @@ static int img_i2s_in_resume(struct device *dev)
 
 	img_i2s_in_writel(i2s, i2s->suspend_ctl, IMG_I2S_IN_CTL);
 
+	if (pm_runtime_status_suspended(dev))
+		img_i2s_in_runtime_suspend(dev);
+
 	return 0;
 }
 #endif
@@ -549,6 +601,8 @@ static const struct of_device_id img_i2s_in_of_match[] = {
 MODULE_DEVICE_TABLE(of, img_i2s_in_of_match);
 
 static const struct dev_pm_ops img_i2s_in_pm_ops = {
+	SET_RUNTIME_PM_OPS(img_i2s_in_runtime_suspend,
+			   img_i2s_in_runtime_resume, NULL)
 	SET_SYSTEM_SLEEP_PM_OPS(img_i2s_in_suspend, img_i2s_in_resume)
 };
 
-- 
2.11.0

Applied "ASoC: img-i2s-in: Add runtime PM" to the asoc tree

[Mark Brown]

The patch

   ASoC: img-i2s-in: Add runtime PM

has been applied to the asoc tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From f65bb92ca12e72c6ebed20dacaa75ee1f2f0735a Mon Sep 17 00:00:00 2001
From: Ed Blake <ed.blake@sondrel.com>
Date: Fri, 6 Oct 2017 15:50:40 +0100
Subject: [PATCH] ASoC: img-i2s-in: Add runtime PM

Add runtime PM to disable the clock when the device is not in use.
The ASoC core takes care of the pm_runtime_get_sync / put calls so we
just need to provide runtime_suspend / runtime_resume functions and
enable runtime PM.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/img/img-i2s-in.c | 88 +++++++++++++++++++++++++++++++++++++---------
 1 file changed, 71 insertions(+), 17 deletions(-)

diff --git a/sound/soc/img/img-i2s-in.c b/sound/soc/img/img-i2s-in.c
index 3d151ddda937..d7fbb0a0a28b 100644
--- a/sound/soc/img/img-i2s-in.c
+++ b/sound/soc/img/img-i2s-in.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/reset.h>
 
 #include <sound/core.h>
@@ -64,6 +65,29 @@ struct img_i2s_in {
 	u32 *suspend_ch_ctl;
 };
 
+static int img_i2s_in_runtime_suspend(struct device *dev)
+{
+	struct img_i2s_in *i2s = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(i2s->clk_sys);
+
+	return 0;
+}
+
+static int img_i2s_in_runtime_resume(struct device *dev)
+{
+	struct img_i2s_in *i2s = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(i2s->clk_sys);
+	if (ret) {
+		dev_err(dev, "Unable to enable sys clock\n");
+		return ret;
+	}
+
+	return 0;
+}
+
 static inline void img_i2s_in_writel(struct img_i2s_in *i2s, u32 val, u32 reg)
 {
 	writel(val, i2s->base + reg);
@@ -281,7 +305,7 @@ static int img_i2s_in_hw_params(struct snd_pcm_substream *substream,
 static int img_i2s_in_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 {
 	struct img_i2s_in *i2s = snd_soc_dai_get_drvdata(dai);
-	int i;
+	int i, ret;
 	u32 chan_control_mask, lrd_set = 0, blkp_set = 0, chan_control_set = 0;
 	u32 reg;
 
@@ -321,6 +345,10 @@ static int img_i2s_in_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 
 	chan_control_mask = IMG_I2S_IN_CH_CTL_CLK_TRANS_MASK;
 
+	ret = pm_runtime_get_sync(i2s->dev);
+	if (ret < 0)
+		return ret;
+
 	for (i = 0; i < i2s->active_channels; i++)
 		img_i2s_in_ch_disable(i2s, i);
 
@@ -340,6 +368,8 @@ static int img_i2s_in_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 	for (i = 0; i < i2s->active_channels; i++)
 		img_i2s_in_ch_enable(i2s, i);
 
+	pm_runtime_put(i2s->dev);
+
 	return 0;
 }
 
@@ -429,9 +459,15 @@ static int img_i2s_in_probe(struct platform_device *pdev)
 		return PTR_ERR(i2s->clk_sys);
 	}
 
-	ret = clk_prepare_enable(i2s->clk_sys);
-	if (ret)
-		return ret;
+	pm_runtime_enable(&pdev->dev);
+	if (!pm_runtime_enabled(&pdev->dev)) {
+		ret = img_i2s_in_runtime_resume(&pdev->dev);
+		if (ret)
+			goto err_pm_disable;
+	}
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0)
+		goto err_suspend;
 
 	i2s->active_channels = 1;
 	i2s->dma_data.addr = res->start + IMG_I2S_IN_RX_FIFO;
@@ -449,7 +485,7 @@ static int img_i2s_in_probe(struct platform_device *pdev)
 	if (IS_ERR(rst)) {
 		if (PTR_ERR(rst) == -EPROBE_DEFER) {
 			ret = -EPROBE_DEFER;
-			goto err_clk_disable;
+			goto err_suspend;
 		}
 
 		dev_dbg(dev, "No top level reset found\n");
@@ -471,35 +507,40 @@ static int img_i2s_in_probe(struct platform_device *pdev)
 			IMG_I2S_IN_CH_CTL_JUST_MASK |
 			IMG_I2S_IN_CH_CTL_FW_MASK, IMG_I2S_IN_CH_CTL);
 
+	pm_runtime_put(&pdev->dev);
+
 	i2s->suspend_ch_ctl = devm_kzalloc(dev,
 		sizeof(*i2s->suspend_ch_ctl) * i2s->max_i2s_chan, GFP_KERNEL);
 	if (!i2s->suspend_ch_ctl) {
 		ret = -ENOMEM;
-		goto err_clk_disable;
+		goto err_suspend;
 	}
 
 	ret = devm_snd_soc_register_component(dev, &img_i2s_in_component,
 						&i2s->dai_driver, 1);
 	if (ret)
-		goto err_clk_disable;
+		goto err_suspend;
 
 	ret = devm_snd_dmaengine_pcm_register(dev, &img_i2s_in_dma_config, 0);
 	if (ret)
-		goto err_clk_disable;
+		goto err_suspend;
 
 	return 0;
 
-err_clk_disable:
-	clk_disable_unprepare(i2s->clk_sys);
+err_suspend:
+	if (!pm_runtime_enabled(&pdev->dev))
+		img_i2s_in_runtime_suspend(&pdev->dev);
+err_pm_disable:
+	pm_runtime_disable(&pdev->dev);
 
 	return ret;
 }
 
 static int img_i2s_in_dev_remove(struct platform_device *pdev)
 {
-	struct img_i2s_in *i2s = platform_get_drvdata(pdev);
-
-	clk_disable_unprepare(i2s->clk_sys);
+	pm_runtime_disable(&pdev->dev);
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		img_i2s_in_runtime_suspend(&pdev->dev);
 
 	return 0;
 }
@@ -508,9 +549,15 @@ static int img_i2s_in_dev_remove(struct platform_device *pdev)
 static int img_i2s_in_suspend(struct device *dev)
 {
 	struct img_i2s_in *i2s = dev_get_drvdata(dev);
-	int i;
+	int i, ret;
 	u32 reg;
 
+	if (pm_runtime_status_suspended(dev)) {
+		ret = img_i2s_in_runtime_resume(dev);
+		if (ret)
+			return ret;
+	}
+
 	for (i = 0; i < i2s->max_i2s_chan; i++) {
 		reg = img_i2s_in_ch_readl(i2s, i, IMG_I2S_IN_CH_CTL);
 		i2s->suspend_ch_ctl[i] = reg;
@@ -518,7 +565,7 @@ static int img_i2s_in_suspend(struct device *dev)
 
 	i2s->suspend_ctl = img_i2s_in_readl(i2s, IMG_I2S_IN_CTL);
 
-	clk_disable_unprepare(i2s->clk_sys);
+	img_i2s_in_runtime_suspend(dev);
 
 	return 0;
 }
@@ -526,10 +573,12 @@ static int img_i2s_in_suspend(struct device *dev)
 static int img_i2s_in_resume(struct device *dev)
 {
 	struct img_i2s_in *i2s = dev_get_drvdata(dev);
-	int i;
+	int i, ret;
 	u32 reg;
 
-	clk_prepare_enable(i2s->clk_sys);
+	ret = img_i2s_in_runtime_resume(dev);
+	if (ret)
+		return ret;
 
 	for (i = 0; i < i2s->max_i2s_chan; i++) {
 		reg = i2s->suspend_ch_ctl[i];
@@ -538,6 +587,9 @@ static int img_i2s_in_resume(struct device *dev)
 
 	img_i2s_in_writel(i2s, i2s->suspend_ctl, IMG_I2S_IN_CTL);
 
+	if (pm_runtime_status_suspended(dev))
+		img_i2s_in_runtime_suspend(dev);
+
 	return 0;
 }
 #endif
@@ -549,6 +601,8 @@ static const struct of_device_id img_i2s_in_of_match[] = {
 MODULE_DEVICE_TABLE(of, img_i2s_in_of_match);
 
 static const struct dev_pm_ops img_i2s_in_pm_ops = {
+	SET_RUNTIME_PM_OPS(img_i2s_in_runtime_suspend,
+			   img_i2s_in_runtime_resume, NULL)
 	SET_SYSTEM_SLEEP_PM_OPS(img_i2s_in_suspend, img_i2s_in_resume)
 };
 
-- 
2.14.1

Applied "ASoC: img-i2s-in: Add suspend / resume handling" to the asoc tree

[Mark Brown]

The patch

   ASoC: img-i2s-in: Add suspend / resume handling

has been applied to the asoc tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 8ab7f885da23719aef1ba03f563589e44ca6ab66 Mon Sep 17 00:00:00 2001
From: Ed Blake <ed.blake@sondrel.com>
Date: Fri, 6 Oct 2017 15:50:39 +0100
Subject: [PATCH] ASoC: img-i2s-in: Add suspend / resume handling

Implement suspend and resume callbacks to save and restore register
state, to support platforms where the power is disabled during suspend.

In future the driver could be converted to use regmap which would
simplify the suspend and resume code.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/img/img-i2s-in.c | 54 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 1 deletion(-)

diff --git a/sound/soc/img/img-i2s-in.c b/sound/soc/img/img-i2s-in.c
index 567f9767fb73..3d151ddda937 100644
--- a/sound/soc/img/img-i2s-in.c
+++ b/sound/soc/img/img-i2s-in.c
@@ -60,6 +60,8 @@ struct img_i2s_in {
 	void __iomem *channel_base;
 	unsigned int active_channels;
 	struct snd_soc_dai_driver dai_driver;
+	u32 suspend_ctl;
+	u32 *suspend_ch_ctl;
 };
 
 static inline void img_i2s_in_writel(struct img_i2s_in *i2s, u32 val, u32 reg)
@@ -469,6 +471,13 @@ static int img_i2s_in_probe(struct platform_device *pdev)
 			IMG_I2S_IN_CH_CTL_JUST_MASK |
 			IMG_I2S_IN_CH_CTL_FW_MASK, IMG_I2S_IN_CH_CTL);
 
+	i2s->suspend_ch_ctl = devm_kzalloc(dev,
+		sizeof(*i2s->suspend_ch_ctl) * i2s->max_i2s_chan, GFP_KERNEL);
+	if (!i2s->suspend_ch_ctl) {
+		ret = -ENOMEM;
+		goto err_clk_disable;
+	}
+
 	ret = devm_snd_soc_register_component(dev, &img_i2s_in_component,
 						&i2s->dai_driver, 1);
 	if (ret)
@@ -495,16 +504,59 @@ static int img_i2s_in_dev_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int img_i2s_in_suspend(struct device *dev)
+{
+	struct img_i2s_in *i2s = dev_get_drvdata(dev);
+	int i;
+	u32 reg;
+
+	for (i = 0; i < i2s->max_i2s_chan; i++) {
+		reg = img_i2s_in_ch_readl(i2s, i, IMG_I2S_IN_CH_CTL);
+		i2s->suspend_ch_ctl[i] = reg;
+	}
+
+	i2s->suspend_ctl = img_i2s_in_readl(i2s, IMG_I2S_IN_CTL);
+
+	clk_disable_unprepare(i2s->clk_sys);
+
+	return 0;
+}
+
+static int img_i2s_in_resume(struct device *dev)
+{
+	struct img_i2s_in *i2s = dev_get_drvdata(dev);
+	int i;
+	u32 reg;
+
+	clk_prepare_enable(i2s->clk_sys);
+
+	for (i = 0; i < i2s->max_i2s_chan; i++) {
+		reg = i2s->suspend_ch_ctl[i];
+		img_i2s_in_ch_writel(i2s, i, reg, IMG_I2S_IN_CH_CTL);
+	}
+
+	img_i2s_in_writel(i2s, i2s->suspend_ctl, IMG_I2S_IN_CTL);
+
+	return 0;
+}
+#endif
+
 static const struct of_device_id img_i2s_in_of_match[] = {
 	{ .compatible = "img,i2s-in" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, img_i2s_in_of_match);
 
+static const struct dev_pm_ops img_i2s_in_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(img_i2s_in_suspend, img_i2s_in_resume)
+};
+
 static struct platform_driver img_i2s_in_driver = {
 	.driver = {
 		.name = "img-i2s-in",
-		.of_match_table = img_i2s_in_of_match
+		.of_match_table = img_i2s_in_of_match,
+		.pm = &img_i2s_in_pm_ops
 	},
 	.probe = img_i2s_in_probe,
 	.remove = img_i2s_in_dev_remove
-- 
2.14.1