ASoC: SOF: Intel: byt: Add PM callbacks

Add the PM callbacks for BYT/CHT platforms.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20200526203640.25980-2-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/intel/byt.c

@@ -428,6 +428,34 @@ static void byt_set_mach_params(const struct snd_soc_acpi_mach *mach,
 	mach_params->platform = dev_name(dev);
 }
 
+static void byt_reset_dsp_disable_int(struct snd_sof_dev *sdev)
+{
+	/* Disable Interrupt from both sides */
+	snd_sof_dsp_update_bits64(sdev, BYT_DSP_BAR, SHIM_IMRX, 0x3, 0x3);
+	snd_sof_dsp_update_bits64(sdev, BYT_DSP_BAR, SHIM_IMRD, 0x3, 0x3);
+
+	/* Put DSP into reset, set reset vector */
+	snd_sof_dsp_update_bits64(sdev, BYT_DSP_BAR, SHIM_CSR,
+				  SHIM_BYT_CSR_RST | SHIM_BYT_CSR_VECTOR_SEL,
+				  SHIM_BYT_CSR_RST | SHIM_BYT_CSR_VECTOR_SEL);
+}
+
+static int byt_suspend(struct snd_sof_dev *sdev, u32 target_state)
+{
+	byt_reset_dsp_disable_int(sdev);
+
+	return 0;
+}
+
+static int byt_resume(struct snd_sof_dev *sdev)
+{
+	/* Enable Interrupt from both sides */
+	snd_sof_dsp_update_bits64(sdev, BYT_DSP_BAR, SHIM_IMRX, 0x3, 0x0);
+	snd_sof_dsp_update_bits64(sdev, BYT_DSP_BAR, SHIM_IMRD, 0x3, 0x0);
+
+	return 0;
+}
+
 /* Baytrail DAIs */
 static struct snd_soc_dai_driver byt_dai[] = {
 {
@@ -832,6 +860,10 @@ const struct snd_sof_dsp_ops sof_byt_ops = {
 	/*Firmware loading */
 	.load_firmware	= snd_sof_load_firmware_memcpy,
 
+	/* PM */
+	.suspend = byt_suspend,
+	.resume = byt_resume,
+
 	/* DAI drivers */
 	.drv = byt_dai,
 	.num_drv = 3, /* we have only 3 SSPs on byt*/
@@ -906,6 +938,10 @@ const struct snd_sof_dsp_ops sof_cht_ops = {
 	/*Firmware loading */
 	.load_firmware	= snd_sof_load_firmware_memcpy,
 
+	/* PM */
+	.suspend = byt_suspend,
+	.resume = byt_resume,
+
 	/* DAI drivers */
 	.drv = byt_dai,
 	/* all 6 SSPs may be available for cherrytrail */