From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Use the second backlight controller on ICP+ if the VBT asks us to do so. On pre-MTP we also check the chicken bit to make sure the pins have been correctly muxed by the firmware. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8016 Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> --- .../gpu/drm/i915/display/intel_backlight.c | 34 +++++++++++++++++-- 1 file changed, 31 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c index 5b7da72c95b8..a4e4b7f79e4d 100644 --- a/drivers/gpu/drm/i915/display/intel_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_backlight.c @@ -1431,6 +1431,30 @@ bxt_setup_backlight(struct intel_connector *connector, enum pipe unused) return 0; } +static int cnp_num_backlight_controllers(struct drm_i915_private *i915) +{ + if (INTEL_PCH_TYPE(i915) >= PCH_DG1) + return 1; + + if (INTEL_PCH_TYPE(i915) >= PCH_ICP) + return 2; + + return 1; +} + +static bool cnp_backlight_controller_is_valid(struct drm_i915_private *i915, int controller) +{ + if (controller < 0 || controller >= cnp_num_backlight_controllers(i915)) + return false; + + if (controller == 1 && + INTEL_PCH_TYPE(i915) >= PCH_ICP && + INTEL_PCH_TYPE(i915) < PCH_MTP) + return intel_de_read(i915, SOUTH_CHICKEN1) & ICP_SECOND_PPS_IO_SELECT; + + return true; +} + static int cnp_setup_backlight(struct intel_connector *connector, enum pipe unused) { @@ -1440,10 +1464,14 @@ cnp_setup_backlight(struct intel_connector *connector, enum pipe unused) /* * CNP has the BXT implementation of backlight, but with only one - * controller. TODO: ICP has multiple controllers but we only use - * controller 0 for now. + * controller. ICP+ can have two controllers, depending on pin muxing. */ - panel->backlight.controller = 0; + panel->backlight.controller = connector->panel.vbt.backlight.controller; + if (!cnp_backlight_controller_is_valid(i915, panel->backlight.controller)) { + drm_dbg_kms(&i915->drm, "Invalid backlight controller %d, assuming 0\n", + panel->backlight.controller); + panel->backlight.controller = 0; + } pwm_ctl = intel_de_read(i915, BXT_BLC_PWM_CTL(panel->backlight.controller)); -- 2.39.1
