From: Luca Coelho <luciano.coelho@xxxxxxxxx>
Starting from display version 20, we need to read the pin assignment
from the IOM TCSS_DDI_STATUS register instead of reading it from the
FIA.
We use the pin assignment to decide the maximum lane count. So, to
support this change, add a new lnl_tc_port_get_max_lane_count() function
that reads from the TCSS_DDI_STATUS register and decides the maximum
lane count based on that.
BSpec: 69594
Cc: Mika Kahola <mika.kahola@xxxxxxxxx>
Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
Reviewed-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
Reviewed-by: Mika Kahola <mika.kahola@xxxxxxxxx>
Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_tc.c | 28 +++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_reg.h | 1 +
2 files changed, 29 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
index 678693978892..e9ced251c170 100644
--- a/drivers/gpu/drm/i915/display/intel_tc.c
+++ b/drivers/gpu/drm/i915/display/intel_tc.c
@@ -290,6 +290,31 @@ u32 intel_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_port)
DP_PIN_ASSIGNMENT_SHIFT(tc->phy_fia_idx);
}
+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);
@@ -348,6 +373,9 @@ int intel_tc_port_max_lane_count(struct intel_digital_port *dig_port)
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);
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 2f115d339913..efcf1461988f 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6351,6 +6351,7 @@ enum skl_power_gate {
#define TCSS_DDI_STATUS(tc) _MMIO(_PICK_EVEN(tc, \
_TCSS_DDI_STATUS_1, \
_TCSS_DDI_STATUS_2))
+#define TCSS_DDI_STATUS_PIN_ASSIGNMENT_MASK REG_GENMASK(28, 25)
#define TCSS_DDI_STATUS_READY REG_BIT(2)
#define TCSS_DDI_STATUS_HPD_LIVE_STATUS_TBT REG_BIT(1)
#define TCSS_DDI_STATUS_HPD_LIVE_STATUS_ALT REG_BIT(0)
--
2.40.1
