[Intel-gfx] [PATCH 14/17] drm/i915/dg2: configure TRANS_DP2_CTL for DP 2.0

[Jani Nikula]

Set the DP 2.0 128b/132b channel encoding for UHBR rates.

Bspec: 54128
Reviewed-by: Manasi Navare <manasi.d.navare at intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 203a54f905f6..8b8f5d679b72 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -407,6 +407,20 @@ static u32 bdw_trans_port_sync_master_select(enum transcoder master_transcoder)
 		return master_transcoder + 1;
 }
 
+static void
+intel_ddi_config_transcoder_dp2(struct intel_encoder *encoder,
+				const struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
+	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
+	u32 val = 0;
+
+	if (crtc_state->port_clock > 1000000)
+		val = TRANS_DP2_128B132B_CHANNEL_CODING;
+
+	intel_de_write(i915, TRANS_DP2_CTL(cpu_transcoder), val);
+}
+
 /*
  * Returns the TRANS_DDI_FUNC_CTL value based on CRTC state.
  *
@@ -2375,7 +2389,8 @@ static void dg2_ddi_pre_enable_dp(struct intel_atomic_state *state,
 	 */
 	intel_ddi_enable_pipe_clock(encoder, crtc_state);
 
-	/* 5.b Not relevant to i915 for now */
+	/* 5.b Configure transcoder for DP 2.0 128b/132b */
+	intel_ddi_config_transcoder_dp2(encoder, crtc_state);
 
 	/*
 	 * 5.c Configure TRANS_DDI_FUNC_CTL DDI Select, DDI Mode Select & MST
-- 
2.20.1