ALSA: hda: Allow SST driver on SKL and KBL platforms with DMIC

Update intel-dspcfg with FLAG_SST_ONLY_IF_DMIC option and use it for
Skylake and Kabylake platforms when DMIC is present.
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200506203951.6369-1-cezary.rojewski@intel.comSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/hda/intel-dsp-config.c

@@ -19,6 +19,7 @@ MODULE_PARM_DESC(dsp_driver, "Force the DSP driver for Intel DSP (0=auto, 1=lega
 
 #define FLAG_SST			BIT(0)
 #define FLAG_SOF			BIT(1)
+#define FLAG_SST_ONLY_IF_DMIC		BIT(15)
 #define FLAG_SOF_ONLY_IF_DMIC		BIT(16)
 #define FLAG_SOF_ONLY_IF_SOUNDWIRE	BIT(17)
 
@@ -107,6 +108,10 @@ static const struct config_entry config_table[] = {
 			{}
 		}
 	},
+	{
+		.flags = FLAG_SST | FLAG_SST_ONLY_IF_DMIC,
+		.device = 0x9d70,
+	},
 #endif
 /* Kabylake-LP */
 #if IS_ENABLED(CONFIG_SND_SOC_INTEL_KBL)
@@ -123,6 +128,10 @@ static const struct config_entry config_table[] = {
 			{}
 		}
 	},
+	{
+		.flags = FLAG_SST | FLAG_SST_ONLY_IF_DMIC,
+		.device = 0x9d71,
+	},
 #endif
 
 /*
@@ -410,8 +419,17 @@ int snd_intel_dsp_driver_probe(struct pci_dev *pci)
 			return SND_INTEL_DSP_DRIVER_SOF;
 	}
 
-	if (cfg->flags & FLAG_SST)
-		return SND_INTEL_DSP_DRIVER_SST;
+
+	if (cfg->flags & FLAG_SST) {
+		if (cfg->flags & FLAG_SST_ONLY_IF_DMIC) {
+			if (snd_intel_dsp_check_dmic(pci)) {
+				dev_info(&pci->dev, "Digital mics found on Skylake+ platform, using SST driver\n");
+				return SND_INTEL_DSP_DRIVER_SST;
+			}
+		} else {
+			return SND_INTEL_DSP_DRIVER_SST;
+		}
+	}
 
 	return SND_INTEL_DSP_DRIVER_LEGACY;
 }