[PATCH 6/6] drm/i915/dp: Write panel override luminance values

[Suraj Kandpal]

Write panel override luminance values which helps the TCON decide
if tone mapping needs to be enabled or not.

Signed-off-by: Suraj Kandpal <suraj.kand...@intel.com>
---
 .../drm/i915/display/intel_dp_aux_backlight.c | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c 
b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index e23694257ea5..9e885eb40805 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -374,6 +374,29 @@ static const char *dpcd_vs_pwm_str(bool aux)
        return aux ? "DPCD" : "PWM";
 }
 
+static void
+intel_dp_aux_write_panel_luminance_override(struct intel_connector *connector)
+{
+       struct drm_i915_private *i915 = to_i915(connector->base.dev);
+       struct intel_panel *panel = &connector->panel;
+       struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
+       int ret;
+       u8 buf[4] = {};
+
+       buf[0] = panel->backlight.min & 0xFF;
+       buf[1] = (panel->backlight.min & 0xFF00) >> 8;
+       buf[2] = panel->backlight.max & 0xFF;
+       buf[3] = (panel->backlight.max & 0xFF00) >> 8;
+
+       ret = drm_dp_dpcd_write(&intel_dp->aux,
+                               INTEL_EDP_HDR_PANEL_LUMINANCE_OVERRIDE,
+                               buf, sizeof(buf));
+       if (ret < 0)
+               drm_dbg_kms(&i915->drm,
+                           "Panel Luminance DPCD reg write failed, err:-%d\n",
+                           ret);
+}
+
 static int
 intel_dp_aux_hdr_setup_backlight(struct intel_connector *connector, enum pipe 
pipe)
 {
@@ -405,6 +428,8 @@ intel_dp_aux_hdr_setup_backlight(struct intel_connector 
*connector, enum pipe pi
                panel->backlight.min = 0;
        }
 
+       intel_dp_aux_write_panel_luminance_override(connector);
+
        drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] Using AUX HDR interface for 
backlight control (range %d..%d)\n",
                    connector->base.base.id, connector->base.name,
                    panel->backlight.min, panel->backlight.max);
-- 
2.43.2