1 files changed, 47 insertions, 7 deletions

diff --git a/sound/soc/tegra/tegra20_i2s.c b/sound/soc/tegra/tegra20_i2s.c
index 9427f36..b598ebd 100644
--- a/sound/soc/tegra/tegra20_i2s.c
+++ b/sound/soc/tegra/tegra20_i2s.c
@@ -35,6 +35,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <sound/core.h>
@@ -56,6 +57,29 @@ static inline u32 tegra20_i2s_read(struct tegra20_i2s *i2s, u32 reg)
 	return __raw_readl(i2s->regs + reg);
 }
 
+static int tegra20_i2s_runtime_suspend(struct device *dev)
+{
+	struct tegra20_i2s *i2s = dev_get_drvdata(dev);
+
+	clk_disable(i2s->clk_i2s);
+
+	return 0;
+}
+
+static int tegra20_i2s_runtime_resume(struct device *dev)
+{
+	struct tegra20_i2s *i2s = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_enable(i2s->clk_i2s);
+	if (ret) {
+		dev_err(dev, "clk_enable failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 #ifdef CONFIG_DEBUG_FS
 static int tegra20_i2s_show(struct seq_file *s, void *unused)
 {
@@ -219,16 +243,12 @@ static int tegra20_i2s_hw_params(struct snd_pcm_substream *substream,
 	if (i2sclock % (2 * srate))
 		reg |= TEGRA20_I2S_TIMING_NON_SYM_ENABLE;
 
-	clk_enable(i2s->clk_i2s);
-
 	tegra20_i2s_write(i2s, TEGRA20_I2S_TIMING, reg);
 
 	tegra20_i2s_write(i2s, TEGRA20_I2S_FIFO_SCR,
 		TEGRA20_I2S_FIFO_SCR_FIFO2_ATN_LVL_FOUR_SLOTS |
 		TEGRA20_I2S_FIFO_SCR_FIFO1_ATN_LVL_FOUR_SLOTS);
 
-	clk_disable(i2s->clk_i2s);
-
 	return 0;
 }
 
@@ -265,7 +285,6 @@ static int tegra20_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 	case SNDRV_PCM_TRIGGER_RESUME:
-		clk_enable(i2s->clk_i2s);
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			tegra20_i2s_start_playback(i2s);
 		else
@@ -278,7 +297,6 @@ static int tegra20_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
 			tegra20_i2s_stop_playback(i2s);
 		else
 			tegra20_i2s_stop_capture(i2s);
-		clk_disable(i2s->clk_i2s);
 		break;
 	default:
 		return -EINVAL;
@@ -395,11 +413,18 @@ static __devinit int tegra20_i2s_platform_probe(struct platform_device *pdev)
 
 	i2s->reg_ctrl = TEGRA20_I2S_CTRL_FIFO_FORMAT_PACKED;
 
+	pm_runtime_enable(&pdev->dev);
+	if (!pm_runtime_enabled(&pdev->dev)) {
+		ret = tegra20_i2s_runtime_resume(&pdev->dev);
+		if (ret)
+			goto err_pm_disable;
+	}
+
 	ret = snd_soc_register_dai(&pdev->dev, &i2s->dai);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not register DAI: %d\n", ret);
 		ret = -ENOMEM;
-		goto err_clk_put;
+		goto err_suspend;
 	}
 
 	ret = tegra_pcm_platform_register(&pdev->dev);
@@ -414,6 +439,11 @@ static __devinit int tegra20_i2s_platform_probe(struct platform_device *pdev)
 
 err_unregister_dai:
 	snd_soc_unregister_dai(&pdev->dev);
+err_suspend:
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		tegra20_i2s_runtime_suspend(&pdev->dev);
+err_pm_disable:
+	pm_runtime_disable(&pdev->dev);
 err_clk_put:
 	clk_put(i2s->clk_i2s);
 err:
@@ -424,6 +454,10 @@ static int __devexit tegra20_i2s_platform_remove(struct platform_device *pdev)
 {
 	struct tegra20_i2s *i2s = dev_get_drvdata(&pdev->dev);
 
+	pm_runtime_disable(&pdev->dev);
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		tegra20_i2s_runtime_suspend(&pdev->dev);
+
 	tegra_pcm_platform_unregister(&pdev->dev);
 	snd_soc_unregister_dai(&pdev->dev);
 
@@ -439,11 +473,17 @@ static const struct of_device_id tegra20_i2s_of_match[] __devinitconst = {
 	{},
 };
 
+static const struct dev_pm_ops tegra20_i2s_pm_ops __devinitconst = {
+	SET_RUNTIME_PM_OPS(tegra20_i2s_runtime_suspend,
+			   tegra20_i2s_runtime_resume, NULL)
+};
+
 static struct platform_driver tegra20_i2s_driver = {
 	.driver = {
 		.name = DRV_NAME,
 		.owner = THIS_MODULE,
 		.of_match_table = tegra20_i2s_of_match,
+		.pm = &tegra20_i2s_pm_ops,
 	},
 	.probe = tegra20_i2s_platform_probe,
 	.remove = __devexit_p(tegra20_i2s_platform_remove),