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path: root/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
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Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp_aux_backlight.c')
-rw-r--r--drivers/gpu/drm/i915/intel_dp_aux_backlight.c45
1 files changed, 35 insertions, 10 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
index 6532e226db29..a0995c00fc84 100644
--- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
@@ -28,6 +28,10 @@ static void set_aux_backlight_enable(struct intel_dp *intel_dp, bool enable)
{
uint8_t reg_val = 0;
+ /* Early return when display use other mechanism to enable backlight. */
+ if (!(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP))
+ return;
+
if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER,
&reg_val) < 0) {
DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n",
@@ -97,15 +101,37 @@ static void intel_dp_aux_enable_backlight(struct intel_connector *connector)
{
struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base);
uint8_t dpcd_buf = 0;
+ uint8_t edp_backlight_mode = 0;
- set_aux_backlight_enable(intel_dp, true);
+ if (drm_dp_dpcd_readb(&intel_dp->aux,
+ DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) != 1) {
+ DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n",
+ DP_EDP_BACKLIGHT_MODE_SET_REGISTER);
+ return;
+ }
+
+ edp_backlight_mode = dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK;
+
+ switch (edp_backlight_mode) {
+ case DP_EDP_BACKLIGHT_CONTROL_MODE_PWM:
+ case DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET:
+ case DP_EDP_BACKLIGHT_CONTROL_MODE_PRODUCT:
+ dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK;
+ dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD;
+ if (drm_dp_dpcd_writeb(&intel_dp->aux,
+ DP_EDP_BACKLIGHT_MODE_SET_REGISTER, dpcd_buf) < 0) {
+ DRM_DEBUG_KMS("Failed to write aux backlight mode\n");
+ }
+ break;
+
+ /* Do nothing when it is already DPCD mode */
+ case DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD:
+ default:
+ break;
+ }
- if ((drm_dp_dpcd_readb(&intel_dp->aux,
- DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) == 1) &&
- ((dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK) ==
- DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET))
- drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER,
- (dpcd_buf | DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD));
+ set_aux_backlight_enable(intel_dp, true);
+ intel_dp_aux_set_backlight(connector, connector->panel.backlight.level);
}
static void intel_dp_aux_disable_backlight(struct intel_connector *connector)
@@ -143,9 +169,8 @@ intel_dp_aux_display_control_capable(struct intel_connector *connector)
* the panel can support backlight control over the aux channel
*/
if (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP &&
- (intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) &&
- !((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_PIN_ENABLE_CAP) ||
- (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP))) {
+ (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP) &&
+ !(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP)) {
DRM_DEBUG_KMS("AUX Backlight Control Supported!\n");
return true;
}