1 files changed, 50 insertions, 16 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
index 3ebf41859043..37b0f8529b4f 100644
--- a/drivers/gpu/drm/i915/display/intel_tc.c
+++ b/drivers/gpu/drm/i915/display/intel_tc.c
@@ -260,7 +260,7 @@ assert_tc_port_power_enabled(struct intel_tc_port *tc)
 		    !intel_display_power_is_enabled(i915, tc_port_power_domain(tc)));
 }
 
-u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port)
+static u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port)
 {
 	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
 	struct intel_tc_port *tc = to_tc_port(dig_port);
@@ -290,7 +290,32 @@ u32 intel_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_port)
 	       DP_PIN_ASSIGNMENT_SHIFT(tc->phy_fia_idx);
 }
 
-static int mtl_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_port)
+static int lnl_tc_port_get_max_lane_count(struct intel_digital_port *dig_port)
+{
+	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
+	enum tc_port tc_port = intel_port_to_tc(i915, dig_port->base.port);
+	intel_wakeref_t wakeref;
+	u32 val, pin_assignment;
+
+	with_intel_display_power(i915, POWER_DOMAIN_DISPLAY_CORE, wakeref)
+		val = intel_de_read(i915, TCSS_DDI_STATUS(tc_port));
+
+	pin_assignment =
+		REG_FIELD_GET(TCSS_DDI_STATUS_PIN_ASSIGNMENT_MASK, val);
+
+	switch (pin_assignment) {
+	default:
+		MISSING_CASE(pin_assignment);
+		fallthrough;
+	case DP_PIN_ASSIGNMENT_D:
+		return 2;
+	case DP_PIN_ASSIGNMENT_C:
+	case DP_PIN_ASSIGNMENT_E:
+		return 4;
+	}
+}
+
+static int mtl_tc_port_get_max_lane_count(struct intel_digital_port *dig_port)
 {
 	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
 	intel_wakeref_t wakeref;
@@ -311,23 +336,12 @@ static int mtl_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_po
 	}
 }
 
-int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port)
+static int intel_tc_port_get_max_lane_count(struct intel_digital_port *dig_port)
 {
 	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
-	struct intel_tc_port *tc = to_tc_port(dig_port);
-	enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
 	intel_wakeref_t wakeref;
-	u32 lane_mask;
-
-	if (!intel_phy_is_tc(i915, phy) || tc->mode != TC_PORT_DP_ALT)
-		return 4;
-
-	assert_tc_cold_blocked(tc);
-
-	if (DISPLAY_VER(i915) >= 14)
-		return mtl_tc_port_get_pin_assignment_mask(dig_port);
+	u32 lane_mask = 0;
 
-	lane_mask = 0;
 	with_intel_display_power(i915, POWER_DOMAIN_DISPLAY_CORE, wakeref)
 		lane_mask = intel_tc_port_get_lane_mask(dig_port);
 
@@ -348,6 +362,26 @@ int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port)
 	}
 }
 
+int intel_tc_port_max_lane_count(struct intel_digital_port *dig_port)
+{
+	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
+	struct intel_tc_port *tc = to_tc_port(dig_port);
+	enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
+
+	if (!intel_phy_is_tc(i915, phy) || tc->mode != TC_PORT_DP_ALT)
+		return 4;
+
+	assert_tc_cold_blocked(tc);
+
+	if (DISPLAY_VER(i915) >= 20)
+		return lnl_tc_port_get_max_lane_count(dig_port);
+
+	if (DISPLAY_VER(i915) >= 14)
+		return mtl_tc_port_get_max_lane_count(dig_port);
+
+	return intel_tc_port_get_max_lane_count(dig_port);
+}
+
 void intel_tc_port_set_fia_lane_count(struct intel_digital_port *dig_port,
 				      int required_lanes)
 {
@@ -583,7 +617,7 @@ static bool tc_phy_verify_legacy_or_dp_alt_mode(struct intel_tc_port *tc,
 	struct intel_digital_port *dig_port = tc->dig_port;
 	int max_lanes;
 
-	max_lanes = intel_tc_port_fia_max_lane_count(dig_port);
+	max_lanes = intel_tc_port_max_lane_count(dig_port);
 	if (tc->mode == TC_PORT_LEGACY) {
 		drm_WARN_ON(&i915->drm, max_lanes != 4);
 		return true;