[alsa-devel] [PATCH 25/26] ASoC: SOF: PM: Add support for DSP D0i3 state when entering S0ix

[Pierre-Louis Bossart]

From: Keyon Jie <yang.jie at linux.intel.com>

When system is entering into S0ix, the PCI device may transition to the
D0i3 substate instead of D3. In D0i3, some always-on functionality can
be enabled, such as acoustic event detection, voice activity detection
or hotwording. When an event is detected, the DSP firmware can wake-up
the device for a transition to D0 with an interrupt.

Signed-off-by: Keyon Jie <yang.jie at linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
 sound/soc/sof/pm.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/sound/soc/sof/pm.c b/sound/soc/sof/pm.c
index 99e4e6ffff74..560a937e0484 100644
--- a/sound/soc/sof/pm.c
+++ b/sound/soc/sof/pm.c
@@ -430,12 +430,58 @@ EXPORT_SYMBOL(snd_sof_set_d0_substate);
 
 int snd_sof_resume(struct device *dev)
 {
+	struct snd_sof_dev *sdev = dev_get_drvdata(dev);
+	int ret;
+
+	if (sdev->s0_suspend) {
+		/* resume from D0I3 */
+		dev_dbg(sdev->dev, "DSP will exit from D0i3...\n");
+		ret = snd_sof_set_d0_substate(sdev, SOF_DSP_D0I0);
+		if (ret == -ENOTSUPP) {
+			/* fallback to resume from D3 */
+			dev_dbg(sdev->dev, "D0i3 not supported, fall back to resume from D3...\n");
+			goto d3_resume;
+		} else if (ret < 0) {
+			dev_err(sdev->dev, "error: failed to exit from D0I3 %d\n",
+				ret);
+			return ret;
+		}
+
+		/* platform-specific resume from D0i3 */
+		return snd_sof_dsp_resume(sdev);
+	}
+
+d3_resume:
+	/* resume from D3 */
 	return sof_resume(dev, false);
 }
 EXPORT_SYMBOL(snd_sof_resume);
 
 int snd_sof_suspend(struct device *dev)
 {
+	struct snd_sof_dev *sdev = dev_get_drvdata(dev);
+	int ret;
+
+	if (sdev->s0_suspend) {
+		/* suspend to D0i3 */
+		dev_dbg(sdev->dev, "DSP is trying to enter D0i3...\n");
+		ret = snd_sof_set_d0_substate(sdev, SOF_DSP_D0I3);
+		if (ret == -ENOTSUPP) {
+			/* fallback to D3 suspend */
+			dev_dbg(sdev->dev, "D0i3 not supported, fall back to D3...\n");
+			goto d3_suspend;
+		} else if (ret < 0) {
+			dev_err(sdev->dev, "error: failed to enter D0I3, %d\n",
+				ret);
+			return ret;
+		}
+
+		/* platform-specific suspend to D0i3 */
+		return snd_sof_dsp_suspend(sdev);
+	}
+
+d3_suspend:
+	/* suspend to D3 */
 	return sof_suspend(dev, false);
 }
 EXPORT_SYMBOL(snd_sof_suspend);
-- 
2.20.1