Merge tag 'mtd/for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux

[linux-2.6-microblaze.git] / drivers / gpu / drm / drm_panel.c

diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index ba11c36..f634371 100644 (file)
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -260,6 +260,49 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np)
        return ERR_PTR(-EPROBE_DEFER);
 }
 EXPORT_SYMBOL(of_drm_find_panel);
+
+/**
+ * of_drm_get_panel_orientation - look up the orientation of the panel through
+ * the "rotation" binding from a device tree node
+ * @np: device tree node of the panel
+ * @orientation: orientation enum to be filled in
+ *
+ * Looks up the rotation of a panel in the device tree. The orientation of the
+ * panel is expressed as a property name "rotation" in the device tree. The
+ * rotation in the device tree is counter clockwise.
+ *
+ * Return: 0 when a valid rotation value (0, 90, 180, or 270) is read or the
+ * rotation property doesn't exist. Return a negative error code on failure.
+ */
+int of_drm_get_panel_orientation(const struct device_node *np,
+                                enum drm_panel_orientation *orientation)
+{
+       int rotation, ret;
+
+       ret = of_property_read_u32(np, "rotation", &rotation);
+       if (ret == -EINVAL) {
+               /* Don't return an error if there's no rotation property. */
+               *orientation = DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
+               return 0;
+       }
+
+       if (ret < 0)
+               return ret;
+
+       if (rotation == 0)
+               *orientation = DRM_MODE_PANEL_ORIENTATION_NORMAL;
+       else if (rotation == 90)
+               *orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP;
+       else if (rotation == 180)
+               *orientation = DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP;
+       else if (rotation == 270)
+               *orientation = DRM_MODE_PANEL_ORIENTATION_LEFT_UP;
+       else
+               return -EINVAL;
+
+       return 0;
+}
+EXPORT_SYMBOL(of_drm_get_panel_orientation);
 #endif
 
 #if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE)