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path: root/drivers/gpu/drm/i915/display/intel_backlight.c
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Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_backlight.c')
-rw-r--r--drivers/gpu/drm/i915/display/intel_backlight.c34
1 files 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));