[7/8] ASoC: mchp-spdifrx: add runtime pm support

diff --git a/sound/soc/atmel/mchp-spdifrx.c b/sound/soc/atmel/mchp-spdifrx.c
index 46fff31321f3..796d4ec2b2b1 100644
--- a/sound/soc/atmel/mchp-spdifrx.c
+++ b/sound/soc/atmel/mchp-spdifrx.c
@@ -9,6 +9,7 @@ 
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/module.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/spinlock.h>
 
@@ -192,6 +193,43 @@  static bool mchp_spdifrx_precious_reg(struct device *dev, unsigned int reg)
 	}
 }
 
+static bool mchp_spdifrx_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case SPDIFRX_IMR:
+	case SPDIFRX_ISR:
+	case SPDIFRX_RSR:
+	case SPDIFRX_CHSR(0, 0):
+	case SPDIFRX_CHSR(0, 1):
+	case SPDIFRX_CHSR(0, 2):
+	case SPDIFRX_CHSR(0, 3):
+	case SPDIFRX_CHSR(0, 4):
+	case SPDIFRX_CHSR(0, 5):
+	case SPDIFRX_CHUD(0, 0):
+	case SPDIFRX_CHUD(0, 1):
+	case SPDIFRX_CHUD(0, 2):
+	case SPDIFRX_CHUD(0, 3):
+	case SPDIFRX_CHUD(0, 4):
+	case SPDIFRX_CHUD(0, 5):
+	case SPDIFRX_CHSR(1, 0):
+	case SPDIFRX_CHSR(1, 1):
+	case SPDIFRX_CHSR(1, 2):
+	case SPDIFRX_CHSR(1, 3):
+	case SPDIFRX_CHSR(1, 4):
+	case SPDIFRX_CHSR(1, 5):
+	case SPDIFRX_CHUD(1, 0):
+	case SPDIFRX_CHUD(1, 1):
+	case SPDIFRX_CHUD(1, 2):
+	case SPDIFRX_CHUD(1, 3):
+	case SPDIFRX_CHUD(1, 4):
+	case SPDIFRX_CHUD(1, 5):
+	case SPDIFRX_VERSION:
+		return true;
+	default:
+		return false;
+	}
+}
+
 static const struct regmap_config mchp_spdifrx_regmap_config = {
 	.reg_bits = 32,
 	.reg_stride = 4,
@@ -200,6 +238,8 @@  static const struct regmap_config mchp_spdifrx_regmap_config = {
 	.readable_reg = mchp_spdifrx_readable_reg,
 	.writeable_reg = mchp_spdifrx_writeable_reg,
 	.precious_reg = mchp_spdifrx_precious_reg,
+	.volatile_reg = mchp_spdifrx_volatile_reg,
+	.cache_type = REGCACHE_FLAT,
 };
 
 #define SPDIFRX_GCLK_RATIO_MIN	(12 * 64)
@@ -236,7 +276,6 @@  struct mchp_spdifrx_dev {
 	struct clk				*pclk;
 	struct clk				*gclk;
 	unsigned int				trigger_enabled;
-	unsigned int				gclk_enabled:1;
 };
 
 static void mchp_spdifrx_channel_status_read(struct mchp_spdifrx_dev *dev,
@@ -405,16 +444,17 @@  static int mchp_spdifrx_hw_params(struct snd_pcm_substream *substream,
 		goto unlock;
 	}
 
-	if (dev->gclk_enabled) {
-		clk_disable_unprepare(dev->gclk);
-		dev->gclk_enabled = 0;
-	}
+	/* GCLK is enabled by runtime PM. */
+	clk_disable_unprepare(dev->gclk);
+
 	ret = clk_set_min_rate(dev->gclk, params_rate(params) *
 					  SPDIFRX_GCLK_RATIO_MIN + 1);
 	if (ret) {
 		dev_err(dev->dev,
 			"unable to set gclk min rate: rate %u * ratio %u + 1\n",
 			params_rate(params), SPDIFRX_GCLK_RATIO_MIN);
+		/* Restore runtime PM state. */
+		clk_prepare_enable(dev->gclk);
 		goto unlock;
 	}
 	ret = clk_prepare_enable(dev->gclk);
@@ -422,7 +462,6 @@  static int mchp_spdifrx_hw_params(struct snd_pcm_substream *substream,
 		dev_err(dev->dev, "unable to enable gclk: %d\n", ret);
 		goto unlock;
 	}
-	dev->gclk_enabled = 1;
 
 	dev_dbg(dev->dev, "GCLK range min set to %d\n",
 		params_rate(params) * SPDIFRX_GCLK_RATIO_MIN + 1);
@@ -435,24 +474,9 @@  static int mchp_spdifrx_hw_params(struct snd_pcm_substream *substream,
 	return ret;
 }
 
-static int mchp_spdifrx_hw_free(struct snd_pcm_substream *substream,
-				struct snd_soc_dai *dai)
-{
-	struct mchp_spdifrx_dev *dev = snd_soc_dai_get_drvdata(dai);
-
-	mutex_lock(&dev->mlock);
-	if (dev->gclk_enabled) {
-		clk_disable_unprepare(dev->gclk);
-		dev->gclk_enabled = 0;
-	}
-	mutex_unlock(&dev->mlock);
-	return 0;
-}
-
 static const struct snd_soc_dai_ops mchp_spdifrx_dai_ops = {
 	.trigger	= mchp_spdifrx_trigger,
 	.hw_params	= mchp_spdifrx_hw_params,
-	.hw_free	= mchp_spdifrx_hw_free,
 };
 
 #define MCHP_SPDIF_RATES	SNDRV_PCM_RATE_8000_192000
@@ -486,6 +510,10 @@  static int mchp_spdifrx_cs_get(struct mchp_spdifrx_dev *dev,
 
 	mutex_lock(&dev->mlock);
 
+	ret = pm_runtime_resume_and_get(dev->dev);
+	if (ret < 0)
+		goto unlock;
+
 	/*
 	 * We may reach this point with both clocks enabled but the receiver
 	 * still disabled. To void waiting for completion and return with
@@ -512,7 +540,7 @@  static int mchp_spdifrx_cs_get(struct mchp_spdifrx_dev *dev,
 				channel);
 			regmap_write(dev->regmap, SPDIFRX_IDR, SPDIFRX_IR_CSC(channel));
 			ret = ret ? : -ETIMEDOUT;
-			goto unlock;
+			goto pm_runtime_put;
 		} else {
 			ret = 0;
 		}
@@ -524,6 +552,9 @@  static int mchp_spdifrx_cs_get(struct mchp_spdifrx_dev *dev,
 	memcpy(uvalue->value.iec958.status, ch_stat->data,
 	       sizeof(ch_stat->data));
 
+pm_runtime_put:
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
 unlock:
 	mutex_unlock(&dev->mlock);
 	return ret;
@@ -566,6 +597,10 @@  static int mchp_spdifrx_subcode_ch_get(struct mchp_spdifrx_dev *dev,
 
 	mutex_lock(&dev->mlock);
 
+	ret = pm_runtime_resume_and_get(dev->dev);
+	if (ret < 0)
+		goto unlock;
+
 	/*
 	 * We may reach this point with both clocks enabled but the receiver
 	 * still disabled. To void waiting for completion to just timeout we
@@ -588,7 +623,7 @@  static int mchp_spdifrx_subcode_ch_get(struct mchp_spdifrx_dev *dev,
 				channel);
 			regmap_write(dev->regmap, SPDIFRX_IDR, SPDIFRX_IR_BLOCKEND);
 			ret = ret ? : -ETIMEDOUT;
-			goto unlock;
+			goto pm_runtime_put;
 		} else {
 			ret = 0;
 		}
@@ -600,6 +635,9 @@  static int mchp_spdifrx_subcode_ch_get(struct mchp_spdifrx_dev *dev,
 	memcpy(uvalue->value.iec958.subcode, user_data->data,
 	       sizeof(user_data->data));
 
+pm_runtime_put:
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
 unlock:
 	mutex_unlock(&dev->mlock);
 	return ret;
@@ -641,10 +679,15 @@  static int mchp_spdifrx_ulock_get(struct snd_kcontrol *kcontrol,
 	struct mchp_spdifrx_dev *dev = snd_soc_dai_get_drvdata(dai);
 	struct mchp_spdifrx_mixer_control *ctrl = &dev->control;
 	u32 val;
+	int ret;
 	bool ulock_old = ctrl->ulock;
 
 	mutex_lock(&dev->mlock);
 
+	ret = pm_runtime_resume_and_get(dev->dev);
+	if (ret < 0)
+		goto unlock;
+
 	/*
 	 * The RSR.ULOCK has wrong value if both pclk and gclk are enabled
 	 * and the receiver is disabled. Thus we take into account the
@@ -659,6 +702,9 @@  static int mchp_spdifrx_ulock_get(struct snd_kcontrol *kcontrol,
 
 	uvalue->value.integer.value[0] = ctrl->ulock;
 
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
+unlock:
 	mutex_unlock(&dev->mlock);
 
 	return ulock_old != ctrl->ulock;
@@ -671,10 +717,15 @@  static int mchp_spdifrx_badf_get(struct snd_kcontrol *kcontrol,
 	struct mchp_spdifrx_dev *dev = snd_soc_dai_get_drvdata(dai);
 	struct mchp_spdifrx_mixer_control *ctrl = &dev->control;
 	u32 val;
+	int ret;
 	bool badf_old = ctrl->badf;
 
 	mutex_lock(&dev->mlock);
 
+	ret = pm_runtime_resume_and_get(dev->dev);
+	if (ret < 0)
+		goto unlock;
+
 	/*
 	 * The RSR.ULOCK has wrong value if both pclk and gclk are enabled
 	 * and the receiver is disabled. Thus we take into account the
@@ -687,6 +738,9 @@  static int mchp_spdifrx_badf_get(struct snd_kcontrol *kcontrol,
 		ctrl->badf = 0;
 	}
 
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
+unlock:
 	mutex_unlock(&dev->mlock);
 
 	uvalue->value.integer.value[0] = ctrl->badf;
@@ -706,16 +760,16 @@  static int mchp_spdifrx_signal_get(struct snd_kcontrol *kcontrol,
 
 	mutex_lock(&dev->mlock);
 
+	ret = pm_runtime_resume_and_get(dev->dev);
+	if (ret < 0)
+		goto unlock;
+
 	/*
 	 * To get the signal we need to have receiver enabled. This
 	 * could be enabled also from trigger() function thus we need to
 	 * take care of not disabling the receiver when it runs.
 	 */
 	if (!dev->trigger_enabled) {
-		ret = clk_prepare_enable(dev->gclk);
-		if (ret)
-			goto unlock;
-
 		regmap_update_bits(dev->regmap, SPDIFRX_MR, SPDIFRX_MR_RXEN_MASK,
 				   SPDIFRX_MR_RXEN_ENABLE);
 
@@ -729,12 +783,13 @@  static int mchp_spdifrx_signal_get(struct snd_kcontrol *kcontrol,
 
 		regmap_update_bits(dev->regmap, SPDIFRX_MR, SPDIFRX_MR_RXEN_MASK,
 				   SPDIFRX_MR_RXEN_DISABLE);
-
-		clk_disable_unprepare(dev->gclk);
 	} else {
 		regmap_read(dev->regmap, SPDIFRX_RSR, &val);
 	}
 
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
+
 unlock:
 	mutex_unlock(&dev->mlock);
 
@@ -765,9 +820,14 @@  static int mchp_spdifrx_rate_get(struct snd_kcontrol *kcontrol,
 	struct mchp_spdifrx_dev *dev = snd_soc_dai_get_drvdata(dai);
 	unsigned long rate;
 	u32 val;
+	int ret;
 
 	mutex_lock(&dev->mlock);
 
+	ret = pm_runtime_resume_and_get(dev->dev);
+	if (ret < 0)
+		goto unlock;
+
 	/*
 	 * The RSR.ULOCK has wrong value if both pclk and gclk are enabled
 	 * and the receiver is disabled. Thus we take into account the
@@ -778,21 +838,24 @@  static int mchp_spdifrx_rate_get(struct snd_kcontrol *kcontrol,
 		/* If the receiver is not locked, ISF data is invalid. */
 		if (val & SPDIFRX_RSR_ULOCK || !(val & SPDIFRX_RSR_IFS_MASK)) {
 			ucontrol->value.integer.value[0] = 0;
-			goto unlock;
+			goto pm_runtime_put;
 		}
 	} else {
 		/* Reveicer is not locked, IFS data is invalid. */
 		ucontrol->value.integer.value[0] = 0;
-		goto unlock;
+		goto pm_runtime_put;
 	}
 
 	rate = clk_get_rate(dev->gclk);
 
 	ucontrol->value.integer.value[0] = rate / (32 * SPDIFRX_RSR_IFS(val));
 
+pm_runtime_put:
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
 unlock:
 	mutex_unlock(&dev->mlock);
-	return 0;
+	return ret;
 }
 
 static struct snd_kcontrol_new mchp_spdifrx_ctrls[] = {
@@ -882,14 +945,6 @@  static int mchp_spdifrx_dai_probe(struct snd_soc_dai *dai)
 	struct mchp_spdifrx_dev *dev = snd_soc_dai_get_drvdata(dai);
 	struct mchp_spdifrx_mixer_control *ctrl = &dev->control;
 	int ch;
-	int err;
-
-	err = clk_prepare_enable(dev->pclk);
-	if (err) {
-		dev_err(dev->dev,
-			"failed to enable the peripheral clock: %d\n", err);
-		return err;
-	}
 
 	snd_soc_dai_init_dma_data(dai, NULL, &dev->capture);
 
@@ -922,8 +977,6 @@  static int mchp_spdifrx_dai_remove(struct snd_soc_dai *dai)
 	/* Disable interrupts */
 	regmap_write(dev->regmap, SPDIFRX_IDR, GENMASK(14, 0));
 
-	clk_disable_unprepare(dev->pclk);
-
 	return 0;
 }
 
@@ -954,6 +1007,48 @@  static const struct of_device_id mchp_spdifrx_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, mchp_spdifrx_dt_ids);
 
+static int mchp_spdifrx_runtime_suspend(struct device *dev)
+{
+	struct mchp_spdifrx_dev *spdifrx = dev_get_drvdata(dev);
+
+	regcache_cache_only(spdifrx->regmap, true);
+	clk_disable_unprepare(spdifrx->gclk);
+	clk_disable_unprepare(spdifrx->pclk);
+
+	return 0;
+}
+
+static int mchp_spdifrx_runtime_resume(struct device *dev)
+{
+	struct mchp_spdifrx_dev *spdifrx = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(spdifrx->pclk);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(spdifrx->gclk);
+	if (ret)
+		goto disable_pclk;
+
+	regcache_cache_only(spdifrx->regmap, false);
+	regcache_mark_dirty(spdifrx->regmap);
+	ret = regcache_sync(spdifrx->regmap);
+	if (ret) {
+		regcache_cache_only(spdifrx->regmap, true);
+		clk_disable_unprepare(spdifrx->gclk);
+disable_pclk:
+		clk_disable_unprepare(spdifrx->pclk);
+	}
+
+	return ret;
+}
+
+static const struct dev_pm_ops mchp_spdifrx_pm_ops = {
+	RUNTIME_PM_OPS(mchp_spdifrx_runtime_suspend, mchp_spdifrx_runtime_resume,
+		       NULL)
+};
+
 static int mchp_spdifrx_probe(struct platform_device *pdev)
 {
 	struct mchp_spdifrx_dev *dev;
@@ -1022,13 +1117,20 @@  static int mchp_spdifrx_probe(struct platform_device *pdev)
 	dev->regmap = regmap;
 	platform_set_drvdata(pdev, dev);
 
+	pm_runtime_enable(dev->dev);
+	if (!pm_runtime_enabled(dev->dev)) {
+		err = mchp_spdifrx_runtime_resume(dev->dev);
+		if (err)
+			goto pm_runtime_disable;
+	}
+
 	dev->capture.addr	= (dma_addr_t)mem->start + SPDIFRX_RHR;
 	dev->capture.maxburst	= 1;
 
 	err = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
 	if (err) {
 		dev_err(&pdev->dev, "failed to register PCM: %d\n", err);
-		return err;
+		goto pm_runtime_suspend;
 	}
 
 	err = devm_snd_soc_register_component(&pdev->dev,
@@ -1036,20 +1138,40 @@  static int mchp_spdifrx_probe(struct platform_device *pdev)
 					      &mchp_spdifrx_dai, 1);
 	if (err) {
 		dev_err(&pdev->dev, "fail to register dai\n");
-		return err;
+		goto pm_runtime_suspend;
 	}
 
 	regmap_read(regmap, SPDIFRX_VERSION, &vers);
 	dev_info(&pdev->dev, "hw version: %#lx\n", vers & SPDIFRX_VERSION_MASK);
 
 	return 0;
+
+pm_runtime_suspend:
+	if (!pm_runtime_status_suspended(dev->dev))
+		mchp_spdifrx_runtime_suspend(dev->dev);
+pm_runtime_disable:
+	pm_runtime_disable(dev->dev);
+	return err;
+}
+
+static int mchp_spdifrx_remove(struct platform_device *pdev)
+{
+	struct mchp_spdifrx_dev *dev = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(dev->dev);
+	if (!pm_runtime_status_suspended(dev->dev))
+		mchp_spdifrx_runtime_suspend(dev->dev);
+
+	return 0;
 }
 
 static struct platform_driver mchp_spdifrx_driver = {
 	.probe	= mchp_spdifrx_probe,
+	.remove = mchp_spdifrx_remove,
 	.driver	= {
 		.name	= "mchp_spdifrx",
 		.of_match_table = of_match_ptr(mchp_spdifrx_dt_ids),
+		.pm	= pm_ptr(&mchp_spdifrx_pm_ops),
 	},
 };