1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index aa18b1d7d3e4..fa9baacc863b 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -932,6 +932,13 @@ DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list)
  *        is no longer protected and userspace should take appropriate action
  *        (whatever that might be).
  *
+ * max bpc:
+ *      This range property is used by userspace to limit the bit depth. When
+ *      used the driver would limit the bpc in accordance with the valid range
+ *      supported by the hardware and sink. Drivers to use the function
+ *      drm_connector_attach_max_bpc_property() to create and attach the
+ *      property to the connector during initialization.
+ *
  * Connectors also have one standardized atomic property:
  *
  * CRTC_ID:
@@ -1600,6 +1607,40 @@ void drm_connector_set_link_status_property(struct drm_connector *connector,
 EXPORT_SYMBOL(drm_connector_set_link_status_property);
 
 /**
+ * drm_connector_attach_max_bpc_property - attach "max bpc" property
+ * @connector: connector to attach max bpc property on.
+ * @min: The minimum bit depth supported by the connector.
+ * @max: The maximum bit depth supported by the connector.
+ *
+ * This is used to add support for limiting the bit depth on a connector.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_connector_attach_max_bpc_property(struct drm_connector *connector,
+                                          int min, int max)
+{
+        struct drm_device *dev = connector->dev;
+        struct drm_property *prop;
+
+        prop = connector->max_bpc_property;
+        if (!prop) {
+                prop = drm_property_create_range(dev, 0, "max bpc", min, max);
+                if (!prop)
+                        return -ENOMEM;
+
+                connector->max_bpc_property = prop;
+        }
+
+        drm_object_attach_property(&connector->base, prop, max);
+        connector->state->max_requested_bpc = max;
+        connector->state->max_bpc = max;
+
+        return 0;
+}
+EXPORT_SYMBOL(drm_connector_attach_max_bpc_property);
+
+/**
  * drm_connector_init_panel_orientation_property -
  *      initialize the connecters panel_orientation property
  * @connector: connector for which to init the panel-orientation property.