drm/i915: Parse panel backlight controller from VBT
Currently the backlight controller is taken as 0. It needs to derive
value from the VBT. Adding the necessary changes.
v2 by Jani:
- drop obsolete comments, drop redundant initialization (Bob)
- merge debug logging into one
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
Reviewed-by: Bob Paauwe <bob.j.paauwe@intel.com>
Tested-by: Bob Paauwe <bob.j.paauwe@intel.com>
Tested-by: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1481189178-426-1-git-send-email-jani.nikula@intel.com
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 3578b40..b01edce 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -1039,10 +1039,7 @@ static void bxt_enable_backlight(struct intel_connector *connector)
enum pipe pipe = intel_get_pipe_from_connector(connector);
u32 pwm_ctl, val;
- /* To use 2nd set of backlight registers, utility pin has to be
- * enabled with PWM mode.
- * The field should only be changed when the utility pin is disabled
- */
+ /* Controller 1 uses the utility pin. */
if (panel->backlight.controller == 1) {
val = I915_READ(UTIL_PIN_CTL);
if (val & UTIL_PIN_ENABLE) {
@@ -1608,19 +1605,11 @@ bxt_setup_backlight(struct intel_connector *connector, enum pipe unused)
struct intel_panel *panel = &connector->panel;
u32 pwm_ctl, val;
- /*
- * For BXT hard coding the Backlight controller to 0.
- * TODO : Read the controller value from VBT and generalize
- */
- panel->backlight.controller = 0;
+ panel->backlight.controller = dev_priv->vbt.backlight.controller;
pwm_ctl = I915_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
- /* Keeping the check if controller 1 is to be programmed.
- * This will come into affect once the VBT parsing
- * is fixed for controller selection, and controller 1 is used
- * for a prticular display configuration.
- */
+ /* Controller 1 uses the utility pin. */
if (panel->backlight.controller == 1) {
val = I915_READ(UTIL_PIN_CTL);
panel->backlight.util_pin_active_low =