drm/i915/tc: Handle pin assignment NONE on all platforms

For consistency, handle pin assignment NONE on all platforms similarly
to LNL+. On earlier platforms the driver doesn't actually see this pin
assignment - as it's not valid on a connected DP-alt PHY - however it's
a valid HW setting even on those platforms, for instance in legacy mode.
Handle this pin assignment on earlier platforms as well, so that the way
to query the pin assignment can be unified by a follow-up change.

Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://lore.kernel.org/r/20250805073700.642107-12-imre.deak@intel.com
Signed-off-by: Imre Deak <imre.deak@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
index 31663029642a0519f206b48c70462214566169db..d1f17d2f236cc134a4f273c5c6f85371c9678eb9 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_tc.c
+++ b/drivers/gpu/drm/i915/display/intel_tc.c
@@ -334,6 +334,8 @@ static int mtl_tc_port_get_max_lane_count(struct intel_digital_port *dig_port)
        pin_assignment = intel_tc_port_get_pin_assignment(dig_port);
 
        switch (pin_assignment) {
+       case INTEL_TC_PIN_ASSIGNMENT_NONE:
+               return 0;
        default:
                MISSING_CASE(pin_assignment);
                fallthrough;