drm/i915/display/mtl: Fill port width in DDI_BUF_/TRANS_DDI_FUNC_/PORT_BUF_CTL for HDMI

MTL requires the PORT_CTL_WIDTH, TRANS_DDI_FUNC_CTL and DDI_BUF_CTL
to be filled with 4 lanes for TMDS mode.
This patch enables D2D link and fills PORT_WIDTH in appropriate
registers.

v2:
  - Added fixes from Clint's Add HDMI implementation changes.
  - Modified commit message.
v3:
  - Use TRANS_DDI_PORT_WIDTH() instead of DDI_PORT_WIDTH() for the value
    of TRANS_DDI_FUNC_CTL_*. (Gustavo)

Cc: Taylor, Clinton A <clinton.a.taylor@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230413212443.1504245-9-radhakrishna.sripada@intel.com

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

@@ -541,6 +541,8 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder,
 			temp |= TRANS_DDI_HDMI_SCRAMBLING;
 		if (crtc_state->hdmi_high_tmds_clock_ratio)
 			temp |= TRANS_DDI_HIGH_TMDS_CHAR_RATE;
+		if (DISPLAY_VER(dev_priv) >= 14)
+			temp |= TRANS_DDI_PORT_WIDTH(crtc_state->lane_count);
 	} 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;
@@ -3157,6 +3159,10 @@ static void intel_enable_ddi_hdmi(struct intel_atomic_state *state,
 	if (has_buf_trans_select(dev_priv))
 		hsw_prepare_hdmi_ddi_buffers(encoder, crtc_state);
 
+	/* e. Enable D2D Link for C10/C20 Phy */
+	if (DISPLAY_VER(dev_priv) >= 14)
+		mtl_ddi_enable_d2d(encoder);
+
 	encoder->set_signal_levels(encoder, crtc_state);
 
 	/* Display WA #1143: skl,kbl,cfl */
@@ -3202,12 +3208,30 @@ static void intel_enable_ddi_hdmi(struct intel_atomic_state *state,
 	 *
 	 * On ADL_P the PHY link rate and lane count must be programmed but
 	 * these are both 0 for HDMI.
+	 *
+	 * But MTL onwards HDMI2.1 is supported and in TMDS mode this
+	 * is filled with lane count, already set in the crtc_state.
+	 * The same is required to be filled in PORT_BUF_CTL for C10/20 Phy.
 	 */
 	buf_ctl = dig_port->saved_port_bits | DDI_BUF_CTL_ENABLE;
-	if (IS_ALDERLAKE_P(dev_priv) && intel_phy_is_tc(dev_priv, phy)) {
+	if (DISPLAY_VER(dev_priv) >= 14) {
+		u8  lane_count = mtl_get_port_width(crtc_state->lane_count);
+		u32 port_buf = 0;
+
+		port_buf |= XELPDP_PORT_WIDTH(lane_count);
+
+		if (dig_port->saved_port_bits & DDI_BUF_PORT_REVERSAL)
+			port_buf |= XELPDP_PORT_REVERSAL;
+
+		intel_de_rmw(dev_priv, XELPDP_PORT_BUF_CTL1(port),
+			     XELPDP_PORT_WIDTH_MASK | XELPDP_PORT_REVERSAL, port_buf);
+
+		buf_ctl |= DDI_PORT_WIDTH(lane_count);
+	} else if (IS_ALDERLAKE_P(dev_priv) && intel_phy_is_tc(dev_priv, phy)) {
 		drm_WARN_ON(&dev_priv->drm, !intel_tc_port_in_legacy_mode(dig_port));
 		buf_ctl |= DDI_BUF_CTL_TC_PHY_OWNERSHIP;
 	}
+
 	intel_de_write(dev_priv, DDI_BUF_CTL(port), buf_ctl);
 
 	intel_wait_ddi_buf_active(dev_priv, port);
@@ -3668,7 +3692,11 @@ static void intel_ddi_read_func_ctl(struct intel_encoder *encoder,
 		fallthrough;
 	case TRANS_DDI_MODE_SELECT_DVI:
 		pipe_config->output_types |= BIT(INTEL_OUTPUT_HDMI);
-		pipe_config->lane_count = 4;
+		if (DISPLAY_VER(dev_priv) >= 14)
+			pipe_config->lane_count =
+				((temp & DDI_PORT_WIDTH_MASK) >> DDI_PORT_WIDTH_SHIFT) + 1;
+		else
+			pipe_config->lane_count = 4;
 		break;
 	case TRANS_DDI_MODE_SELECT_DP_SST:
 		if (encoder->type == INTEL_OUTPUT_EDP)

drivers/gpu/drm/i915/i915_reg.h

@@ -5586,6 +5586,8 @@ enum skl_power_gate {
 #define  TRANS_DDI_HDCP_SELECT		REG_BIT(5)
 #define  TRANS_DDI_BFI_ENABLE		(1 << 4)
 #define  TRANS_DDI_HIGH_TMDS_CHAR_RATE	(1 << 4)
+#define  TRANS_DDI_PORT_WIDTH_MASK	REG_GENMASK(3, 1)
+#define  TRANS_DDI_PORT_WIDTH(width)	REG_FIELD_PREP(TRANS_DDI_PORT_WIDTH_MASK, (width) - 1)
 #define  TRANS_DDI_HDMI_SCRAMBLING	(1 << 0)
 #define  TRANS_DDI_HDMI_SCRAMBLING_MASK (TRANS_DDI_HDMI_SCRAMBLER_CTS_ENABLE \
 					| TRANS_DDI_HDMI_SCRAMBLER_RESET_FREQ \