1 files changed, 24 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c
index 584c14c4cbd0..f61ed82e8867 100644
--- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c
@@ -47,33 +47,42 @@ static u32 dcs_get_backlight(struct intel_connector *connector, enum pipe unused
 {
 	struct intel_encoder *encoder = intel_attached_encoder(connector);
 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
+	struct intel_panel *panel = &connector->panel;
 	struct mipi_dsi_device *dsi_device;
-	u8 data = 0;
+	u8 data[2] = {};
 	enum port port;
+	size_t len = panel->backlight.max > U8_MAX ? 2 : 1;
 
-	/* FIXME: Need to take care of 16 bit brightness level */
 	for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) {
 		dsi_device = intel_dsi->dsi_hosts[port]->device;
 		mipi_dsi_dcs_read(dsi_device, MIPI_DCS_GET_DISPLAY_BRIGHTNESS,
-				  &data, sizeof(data));
+				  &data, len);
 		break;
 	}
 
-	return data;
+	return (data[1] << 8) | data[0];
 }
 
 static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32 level)
 {
 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(to_intel_encoder(conn_state->best_encoder));
+	struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel;
 	struct mipi_dsi_device *dsi_device;
-	u8 data = level;
+	u8 data[2] = {};
 	enum port port;
+	size_t len = panel->backlight.max > U8_MAX ? 2 : 1;
+
+	if (len == 1) {
+		data[0] = level;
+	} else {
+		data[0] = level >> 8;
+		data[1] = level;
+	}
 
-	/* FIXME: Need to take care of 16 bit brightness level */
 	for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) {
 		dsi_device = intel_dsi->dsi_hosts[port]->device;
 		mipi_dsi_dcs_write(dsi_device, MIPI_DCS_SET_DISPLAY_BRIGHTNESS,
-				   &data, sizeof(data));
+				   &data, len);
 	}
 }
 
@@ -147,10 +156,16 @@ static void dcs_enable_backlight(const struct intel_crtc_state *crtc_state,
 static int dcs_setup_backlight(struct intel_connector *connector,
 			       enum pipe unused)
 {
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_panel *panel = &connector->panel;
 
-	panel->backlight.max = PANEL_PWM_MAX_VALUE;
-	panel->backlight.level = PANEL_PWM_MAX_VALUE;
+	if (dev_priv->vbt.backlight.brightness_precision_bits > 8)
+		panel->backlight.max = (1 << dev_priv->vbt.backlight.brightness_precision_bits) - 1;
+	else
+		panel->backlight.max = PANEL_PWM_MAX_VALUE;
+
+	panel->backlight.level = panel->backlight.max;
 
 	return 0;
 }