drm: bridge: adv7511: Support I2S IEC958 encoded PCM format

Support IEC958 encoded PCM format for ADV7511 so that ADV7511 HDMI
audio driver can accept the IEC958 data from the I2S input.
Signed-off-by: Sia Jee Heng <jee.heng.sia@intel.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210422064015.15285-1-jee.heng.sia@intel.com

drivers/gpu/drm/bridge/adv7511/adv7511.h

@@ -191,6 +191,7 @@
 #define ADV7511_I2S_FORMAT_I2S			0
 #define ADV7511_I2S_FORMAT_RIGHT_J		1
 #define ADV7511_I2S_FORMAT_LEFT_J		2
+#define ADV7511_I2S_IEC958_DIRECT		3
 
 #define ADV7511_PACKET(p, x)	    ((p) * 0x20 + (x))
 #define ADV7511_PACKET_SDP(x)	    ADV7511_PACKET(0, x)

drivers/gpu/drm/bridge/adv7511/adv7511_audio.c

@@ -101,6 +101,10 @@ static int adv7511_hdmi_hw_params(struct device *dev, void *data,
 	case 20:
 		len = ADV7511_I2S_SAMPLE_LEN_20;
 		break;
+	case 32:
+		if (fmt->bit_fmt != SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE)
+			return -EINVAL;
+		fallthrough;
 	case 24:
 		len = ADV7511_I2S_SAMPLE_LEN_24;
 		break;
@@ -112,6 +116,8 @@ static int adv7511_hdmi_hw_params(struct device *dev, void *data,
 	case HDMI_I2S:
 		audio_source = ADV7511_AUDIO_SOURCE_I2S;
 		i2s_format = ADV7511_I2S_FORMAT_I2S;
+		if (fmt->bit_fmt == SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE)
+			i2s_format = ADV7511_I2S_IEC958_DIRECT;
 		break;
 	case HDMI_RIGHT_J:
 		audio_source = ADV7511_AUDIO_SOURCE_I2S;