[RFC PATCH 39/40] soundwire: intel: add pm_runtime support

[Pierre-Louis Bossart]

Add basic hooks in DAI .startup and .shutdown callbacks. The SoundWire
IP should be powered between those two calls.

By default the platform_device is in SUSPENDED mode, it is required to
call pm_runtime_set_active() before _enable()

FIXME: do we need to use mark_last_busy()?

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
---
 drivers/soundwire/intel.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index db7bf2912767..1394a2322553 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -707,6 +707,23 @@ static void intel_port_cleanup(struct sdw_cdns_dma_data *dma)
 	}
 }
 
+static int intel_startup(struct snd_pcm_substream *substream,
+			 struct snd_soc_dai *dai)
+{
+	struct sdw_cdns *cdns = snd_soc_dai_get_drvdata(dai);
+	int ret;
+
+	ret = pm_runtime_get_sync(cdns->dev);
+	if (ret < 0) {
+		dev_err_ratelimited(cdns->dev,
+				    "pm_runtime_get_sync failed in %s, ret %d\n",
+				    __func__, ret);
+		pm_runtime_put_noidle(cdns->dev);
+	}
+
+	return ret;
+}
+
 static int intel_hw_params(struct snd_pcm_substream *substream,
 			   struct snd_pcm_hw_params *params,
 			   struct snd_soc_dai *dai)
@@ -829,6 +846,8 @@ void intel_shutdown(struct snd_pcm_substream *substream,
 		    struct snd_soc_dai *dai)
 {
 	struct sdw_cdns_dma_data *dma;
+	struct sdw_cdns *cdns = snd_soc_dai_get_drvdata(dai);
+	int ret;
 
 	dma = snd_soc_dai_get_dma_data(dai, substream);
 	if (!dma)
@@ -836,6 +855,13 @@ void intel_shutdown(struct snd_pcm_substream *substream,
 
 	snd_soc_dai_set_dma_data(dai, substream, NULL);
 	kfree(dma);
+
+	pm_runtime_mark_last_busy(cdns->dev);
+	ret = pm_runtime_put_autosuspend(cdns->dev);
+	if (ret < 0)
+		dev_err_ratelimited(cdns->dev,
+				    "pM_runtime_put_autosuspend failed in %s:, ret %d\n",
+				    __func__, ret);
 }
 
 static int intel_pcm_set_sdw_stream(struct snd_soc_dai *dai,
@@ -851,6 +877,7 @@ static int intel_pdm_set_sdw_stream(struct snd_soc_dai *dai,
 }
 
 static const struct snd_soc_dai_ops intel_pcm_dai_ops = {
+	.startup = intel_startup,
 	.hw_params = intel_hw_params,
 	.hw_free = intel_hw_free,
 	.shutdown = intel_shutdown,
@@ -1124,6 +1151,15 @@ static int intel_probe(struct platform_device *pdev)
 
 	intel_debugfs_init(sdw);
 
+	/* Enable PM */
+	pm_runtime_set_autosuspend_delay(&pdev->dev, 3000);
+	pm_runtime_use_autosuspend(&pdev->dev);
+
+	pm_runtime_mark_last_busy(&pdev->dev); /* FIXME: needed? */
+
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
 	return 0;
 
 err_dai:
@@ -1141,6 +1177,7 @@ static int intel_remove(struct platform_device *pdev)
 	sdw = platform_get_drvdata(pdev);
 
 	if (!sdw->cdns.bus.prop.hw_disabled) {
+		pm_runtime_disable(&pdev->dev);
 		intel_debugfs_exit(sdw);
 		free_irq(sdw->res->irq, sdw);
 		snd_soc_unregister_component(sdw->cdns.dev);
@@ -1212,6 +1249,7 @@ static int intel_resume(struct device *dev)
 
 static const struct dev_pm_ops intel_pm = {
 	SET_SYSTEM_SLEEP_PM_OPS(intel_suspend, intel_resume)
+	SET_RUNTIME_PM_OPS(intel_suspend, intel_resume, NULL)
 };
 
 static struct platform_driver sdw_intel_drv = {
-- 
2.20.1