[PATCH 01/13] drm/dp: Introduce new member in drm_backlight_info

[Suraj Kandpal]

Introduce luminance_set flag which indicates if we can manipulate
backlight using luminance value or not which is only possible
after eDP v1.5.

Signed-off-by: Suraj Kandpal <suraj.kand...@intel.com>
---
 drivers/gpu/drm/display/drm_dp_helper.c | 8 ++++++--
 include/drm/display/drm_dp_helper.h     | 1 +
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_dp_helper.c 
b/drivers/gpu/drm/display/drm_dp_helper.c
index 57828f2b7b5a..41de7a92d76d 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -4253,11 +4253,15 @@ drm_edp_backlight_init(struct drm_dp_aux *aux, struct 
drm_edp_backlight_info *bl
                bl->aux_set = true;
        if (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT)
                bl->lsb_reg_used = true;
+       if ((edp_dpcd[0] & DP_EDP_15) && edp_dpcd[3] &
+           (DP_EDP_PANEL_LUMINANCE_CONTROL_CAPABLE))
+               bl->luminance_set = true;
 
        /* Sanity check caps */
-       if (!bl->aux_set && !(edp_dpcd[2] & 
DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP)) {
+       if (!bl->aux_set && !(edp_dpcd[2] & 
DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP) &&
+           !bl->luminance_set) {
                drm_dbg_kms(aux->drm_dev,
-                           "%s: Panel supports neither AUX or PWM brightness 
control? Aborting\n",
+                           "%s: Panel does not support AUX, PWM or 
luminance-based brightness control. Aborting\n",
                            aux->name);
                return -EINVAL;
        }
diff --git a/include/drm/display/drm_dp_helper.h 
b/include/drm/display/drm_dp_helper.h
index d9614e2c8939..b8fdc09737fc 100644
--- a/include/drm/display/drm_dp_helper.h
+++ b/include/drm/display/drm_dp_helper.h
@@ -844,6 +844,7 @@ struct drm_edp_backlight_info {
        bool lsb_reg_used : 1;
        bool aux_enable : 1;
        bool aux_set : 1;
+       bool luminance_set : 1;
 };
 
 int
-- 
2.34.1