ASoC: Intel: Skylake: Add support for active suspend

Some of the usecases can be marked as 'ignore_suspend' by
machine. For these on suspend we should keep audio controller
ON by saving the state and not suspending the device

For this we need to maintain a counter for these streams and be
active on suspend when such a stream is opened.
Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/skylake/skl-pcm.c

@@ -109,6 +109,31 @@ static enum hdac_ext_stream_type skl_get_host_stream_type(struct hdac_ext_bus *e
 		return HDAC_EXT_STREAM_TYPE_COUPLED;
 }
 
+/*
+ * check if the stream opened is marked as ignore_suspend by machine, if so
+ * then enable suspend_active refcount
+ *
+ * The count supend_active does not need lock as it is used in open/close
+ * and suspend context
+ */
+static void skl_set_suspend_active(struct snd_pcm_substream *substream,
+					 struct snd_soc_dai *dai, bool enable)
+{
+	struct hdac_ext_bus *ebus = dev_get_drvdata(dai->dev);
+	struct snd_soc_dapm_widget *w;
+	struct skl *skl = ebus_to_skl(ebus);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		w = dai->playback_widget;
+	else
+		w = dai->capture_widget;
+
+	if (w->ignore_suspend && enable)
+		skl->supend_active++;
+	else if (w->ignore_suspend && !enable)
+		skl->supend_active--;
+}
+
 static int skl_pcm_open(struct snd_pcm_substream *substream,
 		struct snd_soc_dai *dai)
 {
@@ -146,6 +171,7 @@ static int skl_pcm_open(struct snd_pcm_substream *substream,
 
 	dev_dbg(dai->dev, "stream tag set in dma params=%d\n",
 				 dma_params->stream_tag);
+	skl_set_suspend_active(substream, dai, true);
 	snd_pcm_set_sync(substream);
 
 	return 0;
@@ -257,6 +283,7 @@ static void skl_pcm_close(struct snd_pcm_substream *substream,
 	 * dma_params
 	 */
 	snd_soc_dai_set_dma_data(dai, substream, NULL);
+	skl_set_suspend_active(substream, dai, false);
 
 	kfree(dma_params);
 }

sound/soc/intel/skylake/skl.c

@@ -169,16 +169,40 @@ static int skl_suspend(struct device *dev)
 {
 	struct pci_dev *pci = to_pci_dev(dev);
 	struct hdac_ext_bus *ebus = pci_get_drvdata(pci);
+	struct skl *skl  = ebus_to_skl(ebus);
 
-	return _skl_suspend(ebus);
+	/*
+	 * Do not suspend if streams which are marked ignore suspend are
+	 * running, we need to save the state for these and continue
+	 */
+	if (skl->supend_active) {
+		pci_save_state(pci);
+		pci_disable_device(pci);
+		return 0;
+	} else {
+		return _skl_suspend(ebus);
+	}
 }
 
 static int skl_resume(struct device *dev)
 {
 	struct pci_dev *pci = to_pci_dev(dev);
 	struct hdac_ext_bus *ebus = pci_get_drvdata(pci);
+	struct skl *skl  = ebus_to_skl(ebus);
+	int ret;
 
-	return _skl_resume(ebus);
+	/*
+	 * resume only when we are not in suspend active, otherwise need to
+	 * restore the device
+	 */
+	if (skl->supend_active) {
+		pci_restore_state(pci);
+		ret = pci_enable_device(pci);
+	} else {
+		ret = _skl_resume(ebus);
+	}
+
+	return ret;
 }
 #endif /* CONFIG_PM_SLEEP */
 

sound/soc/intel/skylake/skl.h

@@ -70,6 +70,8 @@ struct skl {
 	struct list_head ppl_list;
 
 	const char *fw_name;
+
+	int supend_active;
 };
 
 #define skl_to_ebus(s)	(&(s)->ebus)