drm/msm/sde: Add backlight class support for sde drm driver

Add backlight class support for sde drm driver which provides
sysfs interface to userspace to control display brightness.

Change-Id: I4f777618e8f2ff61e72beddb7a5bd1fa6e9dd5df
Signed-off-by: Vishnuvardhan Prodduturi <vproddut@codeaurora.org>
diff --git a/drivers/gpu/drm/msm/sde/sde_connector.c b/drivers/gpu/drm/msm/sde/sde_connector.c
index 056cf60..6bc69cb 100644
--- a/drivers/gpu/drm/msm/sde/sde_connector.c
+++ b/drivers/gpu/drm/msm/sde/sde_connector.c
@@ -15,6 +15,7 @@
 
 #include "sde_kms.h"
 #include "sde_connector.h"
+#include "sde_backlight.h"
 
 static const struct drm_prop_enum_list e_topology_name[] = {
 	{SDE_RM_TOPOLOGY_UNKNOWN,	"sde_unknown"},
@@ -536,6 +537,14 @@
 		goto error_unregister_conn;
 	}
 
+	if (c_conn->ops.set_backlight) {
+		rc = sde_backlight_setup(&c_conn->base);
+		if (rc) {
+			pr_err("failed to setup backlight, rc=%d\n", rc);
+			goto error_unregister_conn;
+		}
+	}
+
 	/* create properties */
 	msm_property_init(&c_conn->property_info, &c_conn->base.base, dev,
 			priv->conn_property, c_conn->property_data,