drm/i915/ddi: enable 128b/132b TRANS_DDI_FUNC_CTL mode for UHBR SST

128b/132b SST needs 128b/132b mode enabled in the TRANS_DDI_FUNC_CTL
register.

This is preparation for enabling 128b/132b SST. This path is not
reachable yet.

v2: Use the MST path instead of SST to also set transport select (Imre)

Reviewed-by: Imre Deak <[email protected]>
Signed-off-by: Jani Nikula <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/122ebeadf4bf0870fc26b7d12abdff88f4be8799.1735912293.git.jani.nikula@intel.com

Author: jnikula

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -561,7 +561,8 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder,
 	} else if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_ANALOG)) {
 		temp |= TRANS_DDI_MODE_SELECT_FDI_OR_128B132B;
 		temp |= (crtc_state->fdi_lanes - 1) << 1;
-	} else if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST)) {
+	} else if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST) ||
+		   intel_dp_is_uhbr(crtc_state)) {
 		if (intel_dp_is_uhbr(crtc_state))
 			temp |= TRANS_DDI_MODE_SELECT_FDI_OR_128B132B;
 		else