ASoC: SOF: Intel: hda: set L1SEN on S0ix suspend

Set L1SEN to make sure the system can enter S0ix, and restore it on
resume.
Signed-off-by: Keyon Jie <yang.jie@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191101170916.26517-3-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/intel/hda-dsp.c

@@ -478,9 +478,16 @@ static int hda_resume(struct snd_sof_dev *sdev, bool runtime_resume)
 
 int hda_dsp_resume(struct snd_sof_dev *sdev)
 {
+	struct sof_intel_hda_dev *hda = sdev->pdata->hw_pdata;
 	struct pci_dev *pci = to_pci_dev(sdev->dev);
 
 	if (sdev->s0_suspend) {
+		/* restore L1SEN bit */
+		if (hda->l1_support_changed)
+			snd_sof_dsp_update_bits(sdev, HDA_DSP_HDA_BAR,
+						HDA_VS_INTEL_EM2,
+						HDA_VS_INTEL_EM2_L1SEN, 0);
+
 		/* restore and disable the system wakeup */
 		pci_restore_state(pci);
 		disable_irq_wake(pci->irq);
@@ -518,11 +525,19 @@ int hda_dsp_runtime_suspend(struct snd_sof_dev *sdev)
 
 int hda_dsp_suspend(struct snd_sof_dev *sdev)
 {
+	struct sof_intel_hda_dev *hda = sdev->pdata->hw_pdata;
 	struct hdac_bus *bus = sof_to_bus(sdev);
 	struct pci_dev *pci = to_pci_dev(sdev->dev);
 	int ret;
 
 	if (sdev->s0_suspend) {
+		/* enable L1SEN to make sure the system can enter S0Ix */
+		hda->l1_support_changed =
+			snd_sof_dsp_update_bits(sdev, HDA_DSP_HDA_BAR,
+						HDA_VS_INTEL_EM2,
+						HDA_VS_INTEL_EM2_L1SEN,
+						HDA_VS_INTEL_EM2_L1SEN);
+
 		/* enable the system waking up via IPC IRQ */
 		enable_irq_wake(pci->irq);
 		pci_save_state(pci);

sound/soc/sof/intel/hda.h

@@ -408,6 +408,9 @@ struct sof_intel_hda_dev {
 
 	int irq;
 
+	/* PM related */
+	bool l1_support_changed;/* during suspend, is L1SEN changed or not */
+
 	/* DMIC device */
 	struct platform_device *dmic_dev;
 };