ASoC: SOF: Intel: implement runtime idle for CNL

Implement runtime idle for CNL devices using similar runtime
PM idle logic as the Intel AZX HDA driver. If any HDA codecs are
powered when runtime suspend request comes, return -EBUSY. By doing
this, strict ordering is enforced between HDA codec and the HDA
controller.

Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

Author: kv2019i

sound/soc/sof/intel/cnl.c

@@ -249,6 +249,7 @@ const struct snd_sof_dsp_ops sof_cnl_ops = {
 	.resume			= hda_dsp_resume,
 	.runtime_suspend	= hda_dsp_runtime_suspend,
 	.runtime_resume		= hda_dsp_runtime_resume,
+	.runtime_idle		= hda_dsp_runtime_idle,
 	.set_hw_params_upon_resume = hda_dsp_set_hw_params_upon_resume,
 };
 EXPORT_SYMBOL(sof_cnl_ops);

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

@@ -433,6 +433,19 @@ int hda_dsp_runtime_resume(struct snd_sof_dev *sdev)
 	return hda_resume(sdev);
 }
 
+int hda_dsp_runtime_idle(struct snd_sof_dev *sdev)
+{
+	struct hdac_bus *hbus = sof_to_bus(sdev);
+
+	if (hbus->codec_powered) {
+		dev_dbg(sdev->dev, "some codecs still powered (%08X), not idle\n",
+			(unsigned int)hbus->codec_powered);
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
 int hda_dsp_runtime_suspend(struct snd_sof_dev *sdev, int state)
 {
 	/* stop hda controller and power dsp off */