#include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
+#include <drm/drm_of.h>
 #include <drm/drm_panel.h>
 
 struct lvds_codec {
        struct device_node *bus_node;
        struct drm_panel *panel;
        struct lvds_codec *lvds_codec;
-       const char *mapping;
        int ret;
 
        lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
                        return -ENXIO;
                }
 
-               ret = of_property_read_string(bus_node, "data-mapping",
-                                             &mapping);
+               ret = drm_of_lvds_get_data_mapping(bus_node);
                of_node_put(bus_node);
-               if (ret < 0) {
+               if (ret == -ENODEV) {
                        dev_warn(dev, "missing 'data-mapping' DT property\n");
+               } else if (ret) {
+                       dev_err(dev, "invalid 'data-mapping' DT property\n");
+                       return ret;
                } else {
-                       if (!strcmp(mapping, "jeida-18")) {
-                               lvds_codec->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
-                       } else if (!strcmp(mapping, "jeida-24")) {
-                               lvds_codec->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
-                       } else if (!strcmp(mapping, "vesa-24")) {
-                               lvds_codec->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
-                       } else {
-                               dev_err(dev, "invalid 'data-mapping' DT property\n");
-                               return -EINVAL;
-                       }
+                       lvds_codec->bus_format = ret;
                        lvds_codec->bridge.funcs = &funcs_decoder;
                }
        }
 
                DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
 }
 EXPORT_SYMBOL_GPL(drm_of_lvds_get_dual_link_pixel_order);
+
+/**
+ * drm_of_lvds_get_data_mapping - Get LVDS data mapping
+ * @port: DT port node of the LVDS source or sink
+ *
+ * Convert DT "data-mapping" property string value into media bus format value.
+ *
+ * Return:
+ * * MEDIA_BUS_FMT_RGB666_1X7X3_SPWG - data-mapping is "jeida-18"
+ * * MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA - data-mapping is "jeida-24"
+ * * MEDIA_BUS_FMT_RGB888_1X7X4_SPWG - data-mapping is "vesa-24"
+ * * -EINVAL - the "data-mapping" property is unsupported
+ * * -ENODEV - the "data-mapping" property is missing
+ */
+int drm_of_lvds_get_data_mapping(const struct device_node *port)
+{
+       const char *mapping;
+       int ret;
+
+       ret = of_property_read_string(port, "data-mapping", &mapping);
+       if (ret < 0)
+               return -ENODEV;
+
+       if (!strcmp(mapping, "jeida-18"))
+               return MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
+       if (!strcmp(mapping, "jeida-24"))
+               return MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
+       if (!strcmp(mapping, "vesa-24"))
+               return MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
+
+       return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(drm_of_lvds_get_data_mapping);
 
 #include <video/videomode.h>
 
 #include <drm/drm_crtc.h>
+#include <drm/drm_of.h>
 #include <drm/drm_panel.h>
 
 struct panel_lvds {
 {
        struct device_node *np = lvds->dev->of_node;
        struct display_timing timing;
-       const char *mapping;
        int ret;
 
        ret = of_drm_get_panel_orientation(np, &lvds->orientation);
 
        of_property_read_string(np, "label", &lvds->label);
 
-       ret = of_property_read_string(np, "data-mapping", &mapping);
+       ret = drm_of_lvds_get_data_mapping(np);
        if (ret < 0) {
                dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
                        np, "data-mapping");
-               return -ENODEV;
+               return ret;
        }
 
-       if (!strcmp(mapping, "jeida-18")) {
-               lvds->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
-       } else if (!strcmp(mapping, "jeida-24")) {
-               lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
-       } else if (!strcmp(mapping, "vesa-24")) {
-               lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
-       } else {
-               dev_err(lvds->dev, "%pOF: invalid or missing %s DT property\n",
-                       np, "data-mapping");
-               return -EINVAL;
-       }
+       lvds->bus_format = ret;
 
        lvds->data_mirror = of_property_read_bool(np, "data-mirror");
 
 
                                struct drm_bridge **bridge);
 int drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1,
                                          const struct device_node *port2);
+int drm_of_lvds_get_data_mapping(const struct device_node *port);
 #else
 static inline uint32_t drm_of_crtc_port_mask(struct drm_device *dev,
                                          struct device_node *port)
 {
        return -EINVAL;
 }
+
+static inline int
+drm_of_lvds_get_data_mapping(const struct device_node *port)
+{
+       return -EINVAL;
+}
 #endif
 
 /*