drm/i915: Factor out common parts from TypeC port handling functions

Factor out helpers reading/parsing the TypeC specific registers, making
current users of them clearer and letting us use them later.

While at it also:
- Simplify icl_tc_phy_connect() with an early return in legacy mode.
- Simplify the live status check using one bitmask for all HPD bits.
- Remove a micro-optimisation of the repeated safe-mode clearing.
- Make sure we fix the legacy port flag in all cases.

Except for the last two, no functional changes.

v2:
- Don't do reg reads at variable declarations. (Jani)
- Prevent constant truncated compiler warning when assigning the
  valid_hpd_mask. (Nick)
- s/intel_tc_port_get_lane_info/intel_tc_port_get_lane_mask/ (Ville)
v3:
- Make valid_hpd_mask init clear. (Ville)

Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190628143635.22066-10-imre.deak@intel.com

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_tc.h b/drivers/gpu/drm/i915/display/intel_tc.h
index ca1735303252..8c338c45796d 100644
--- a/drivers/gpu/drm/i915/display/intel_tc.h
+++ b/drivers/gpu/drm/i915/display/intel_tc.h
@@ -13,6 +13,7 @@ struct intel_digital_port;
 void icl_tc_phy_disconnect(struct intel_digital_port *dig_port);
 
 bool intel_tc_port_connected(struct intel_digital_port *dig_port);
+u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port);
 int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port);
 
 void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy);