drm/radeon: add DisplayPort MST support (v2)

This adds initial DP 1.2 MST support to radeon, on CAYMAN
and up in theory.

This is off by default.

v2: agd5f:
- add UNIPHY3 offsets
- move atom cmd table code into atombios_encoders.c
- whitespace cleanup
- replace some magic numbers with proper defines

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 980cbcc..f57c1ab 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -671,7 +671,15 @@
 	struct drm_connector *connector;
 	struct radeon_connector *radeon_connector;
 	struct radeon_connector_atom_dig *dig_connector;
+	struct radeon_encoder_atom_dig *dig_enc;
 
+	if (radeon_encoder_is_digital(encoder)) {
+		dig_enc = radeon_encoder->enc_priv;
+		if (dig_enc->active_mst_links)
+			return ATOM_ENCODER_MODE_DP_MST;
+	}
+	if (radeon_encoder->is_mst_encoder || radeon_encoder->offset)
+		return ATOM_ENCODER_MODE_DP_MST;
 	/* dp bridges are always DP */
 	if (radeon_encoder_get_dp_bridge_encoder_id(encoder) != ENCODER_OBJECT_ID_NONE)
 		return ATOM_ENCODER_MODE_DP;
@@ -1706,6 +1714,11 @@
 	case DRM_MODE_DPMS_STANDBY:
 	case DRM_MODE_DPMS_SUSPEND:
 	case DRM_MODE_DPMS_OFF:
+
+		/* don't power off encoders with active MST links */
+		if (dig->active_mst_links)
+			return;
+
 		if (ASIC_IS_DCE4(rdev)) {
 			if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector)
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_OFF, 0);
@@ -1974,6 +1987,53 @@
 	radeon_atombios_encoder_crtc_scratch_regs(encoder, radeon_crtc->crtc_id);
 }
 
+void
+atombios_set_mst_encoder_crtc_source(struct drm_encoder *encoder, int fe)
+{
+	struct drm_device *dev = encoder->dev;
+	struct radeon_device *rdev = dev->dev_private;
+	struct radeon_crtc *radeon_crtc = to_radeon_crtc(encoder->crtc);
+	int index = GetIndexIntoMasterTable(COMMAND, SelectCRTC_Source);
+	uint8_t frev, crev;
+	union crtc_source_param args;
+
+	memset(&args, 0, sizeof(args));
+
+	if (!atom_parse_cmd_header(rdev->mode_info.atom_context, index, &frev, &crev))
+		return;
+
+	if (frev != 1 && crev != 2)
+		DRM_ERROR("Unknown table for MST %d, %d\n", frev, crev);
+
+	args.v2.ucCRTC = radeon_crtc->crtc_id;
+	args.v2.ucEncodeMode = ATOM_ENCODER_MODE_DP_MST;
+
+	switch (fe) {
+	case 0:
+		args.v2.ucEncoderID = ASIC_INT_DIG1_ENCODER_ID;
+		break;
+	case 1:
+		args.v2.ucEncoderID = ASIC_INT_DIG2_ENCODER_ID;
+		break;
+	case 2:
+		args.v2.ucEncoderID = ASIC_INT_DIG3_ENCODER_ID;
+		break;
+	case 3:
+		args.v2.ucEncoderID = ASIC_INT_DIG4_ENCODER_ID;
+		break;
+	case 4:
+		args.v2.ucEncoderID = ASIC_INT_DIG5_ENCODER_ID;
+		break;
+	case 5:
+		args.v2.ucEncoderID = ASIC_INT_DIG6_ENCODER_ID;
+		break;
+	case 6:
+		args.v2.ucEncoderID = ASIC_INT_DIG7_ENCODER_ID;
+		break;
+	}
+	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
+}
+
 static void
 atombios_apply_encoder_quirks(struct drm_encoder *encoder,
 			      struct drm_display_mode *mode)