ASoC: Intel: bytcr_rt5640: enable differential mic quirk

Some Baytrail-CR devices rely on analog mics connected with
differential pairs and not the single-ended default
Add quirk and enable it for T00TAF
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/boards/bytcr_rt5640.c

@@ -41,6 +41,7 @@ enum {
 #define BYT_RT5640_MAP(quirk)	((quirk) & 0xff)
 #define BYT_RT5640_DMIC_EN	BIT(16)
 #define BYT_RT5640_MONO_SPEAKER BIT(17)
+#define BYT_RT5640_DIFF_MIC     BIT(18) /* defaut is single-ended */
 
 static unsigned long byt_rt5640_quirk = BYT_RT5640_DMIC1_MAP |
 					BYT_RT5640_DMIC_EN;
@@ -148,7 +149,8 @@ static const struct dmi_system_id byt_rt5640_quirk_table[] = {
 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "T100TAF"),
 		},
 		.driver_data = (unsigned long *)(BYT_RT5640_IN1_MAP |
-						 BYT_RT5640_MONO_SPEAKER
+						 BYT_RT5640_MONO_SPEAKER |
+						 BYT_RT5640_DIFF_MIC
 						 ),
 	},
 	{
@@ -223,6 +225,11 @@ static int byt_rt5640_init(struct snd_soc_pcm_runtime *runtime)
 	if (ret)
 		return ret;
 
+	if (byt_rt5640_quirk & BYT_RT5640_DIFF_MIC) {
+		snd_soc_update_bits(codec,  RT5640_IN1_IN2, RT5640_IN_DF1,
+				    RT5640_IN_DF1);
+	}
+
 	if (byt_rt5640_quirk & BYT_RT5640_DMIC_EN) {
 		ret = rt5640_dmic_enable(codec, 0, 0);
 		if (ret)