drm/i915/icl: program MG_DP_MODE

Programming this register is part of the Enable Sequence for
DisplayPort on ICL. Do as the spec says.

v2: Simple rebase.

Cc: Animesh Manna <animesh.manna@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> (v1)
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180725002813.6938-5-paulo.r.zanoni@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -2092,6 +2092,21 @@ enum i915_power_well_id {
 #define   CFG_AMI_CK_DIV_OVERRIDE_VAL_MASK	(0x3 << 25)
 #define   CFG_AMI_CK_DIV_OVERRIDE_EN		(1 << 24)
 
+#define MG_DP_MODE_LN0_ACU_PORT1			0x1683A0
+#define MG_DP_MODE_LN1_ACU_PORT1			0x1687A0
+#define MG_DP_MODE_LN0_ACU_PORT2			0x1693A0
+#define MG_DP_MODE_LN1_ACU_PORT2			0x1697A0
+#define MG_DP_MODE_LN0_ACU_PORT3			0x16A3A0
+#define MG_DP_MODE_LN1_ACU_PORT3			0x16A7A0
+#define MG_DP_MODE_LN0_ACU_PORT4			0x16B3A0
+#define MG_DP_MODE_LN1_ACU_PORT4			0x16B7A0
+#define MG_DP_MODE(port, ln)	\
+	MG_PHY_PORT_LN(port, ln, MG_DP_MODE_LN0_ACU_PORT1, \
+				 MG_DP_MODE_LN0_ACU_PORT2, \
+				 MG_DP_MODE_LN1_ACU_PORT1)
+#define   MG_DP_MODE_CFG_DP_X2_MODE			(1 << 7)
+#define   MG_DP_MODE_CFG_DP_X1_MODE			(1 << 6)
+
 /* The spec defines this only for BXT PHY0, but lets assume that this
  * would exist for PHY1 too if it had a second channel.
  */

drivers/gpu/drm/i915/intel_ddi.c

@@ -2809,6 +2809,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
 
 	intel_display_power_get(dev_priv, dig_port->ddi_io_power_domain);
 
+	icl_program_mg_dp_mode(intel_dp);
+
 	if (IS_ICELAKE(dev_priv))
 		icl_ddi_vswing_sequence(encoder, crtc_state->port_clock,
 					level, encoder->type);

drivers/gpu/drm/i915/intel_dp.c

@@ -229,6 +229,72 @@ intel_dp_link_required(int pixel_clock, int bpp)
 	return DIV_ROUND_UP(pixel_clock * bpp, 8);
 }
 
+void icl_program_mg_dp_mode(struct intel_dp *intel_dp)
+{
+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+	struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));
+	enum port port = intel_dig_port->base.port;
+	enum tc_port tc_port = intel_port_to_tc(dev_priv, port);
+	u32 ln0, ln1, lane_info;
+
+	if (tc_port == PORT_TC_NONE || intel_dig_port->tc_type == TC_PORT_TBT)
+		return;
+
+	ln0 = I915_READ(MG_DP_MODE(port, 0));
+	ln1 = I915_READ(MG_DP_MODE(port, 1));
+
+	switch (intel_dig_port->tc_type) {
+	case TC_PORT_TYPEC:
+		ln0 &= ~(MG_DP_MODE_CFG_DP_X1_MODE | MG_DP_MODE_CFG_DP_X2_MODE);
+		ln1 &= ~(MG_DP_MODE_CFG_DP_X1_MODE | MG_DP_MODE_CFG_DP_X2_MODE);
+
+		lane_info = (I915_READ(PORT_TX_DFLEXDPSP) &
+			     DP_LANE_ASSIGNMENT_MASK(tc_port)) >>
+			    DP_LANE_ASSIGNMENT_SHIFT(tc_port);
+
+		switch (lane_info) {
+		case 0x1:
+		case 0x4:
+			break;
+		case 0x2:
+			ln0 |= MG_DP_MODE_CFG_DP_X1_MODE;
+			break;
+		case 0x3:
+			ln0 |= MG_DP_MODE_CFG_DP_X1_MODE |
+			       MG_DP_MODE_CFG_DP_X2_MODE;
+			break;
+		case 0x8:
+			ln1 |= MG_DP_MODE_CFG_DP_X1_MODE;
+			break;
+		case 0xC:
+			ln1 |= MG_DP_MODE_CFG_DP_X1_MODE |
+			       MG_DP_MODE_CFG_DP_X2_MODE;
+			break;
+		case 0xF:
+			ln0 |= MG_DP_MODE_CFG_DP_X1_MODE |
+			       MG_DP_MODE_CFG_DP_X2_MODE;
+			ln1 |= MG_DP_MODE_CFG_DP_X1_MODE |
+			       MG_DP_MODE_CFG_DP_X2_MODE;
+			break;
+		default:
+			MISSING_CASE(lane_info);
+		}
+		break;
+
+	case TC_PORT_LEGACY:
+		ln0 |= MG_DP_MODE_CFG_DP_X1_MODE | MG_DP_MODE_CFG_DP_X2_MODE;
+		ln1 |= MG_DP_MODE_CFG_DP_X1_MODE | MG_DP_MODE_CFG_DP_X2_MODE;
+		break;
+
+	default:
+		MISSING_CASE(intel_dig_port->tc_type);
+		return;
+	}
+
+	I915_WRITE(MG_DP_MODE(port, 0), ln0);
+	I915_WRITE(MG_DP_MODE(port, 1), ln1);
+}
+
 int
 intel_dp_max_data_rate(int max_link_clock, int max_lanes)
 {

drivers/gpu/drm/i915/intel_drv.h

@@ -1714,6 +1714,7 @@ void intel_edp_drrs_invalidate(struct drm_i915_private *dev_priv,
 			       unsigned int frontbuffer_bits);
 void intel_edp_drrs_flush(struct drm_i915_private *dev_priv,
 			  unsigned int frontbuffer_bits);
+void icl_program_mg_dp_mode(struct intel_dp *intel_dp);
 
 void
 intel_dp_program_link_training_pattern(struct intel_dp *intel_dp,