This adds a helper function for reading the rotation (panel orientation) from the device tree.
Signed-off-by: Derek Basehore dbasehore@chromium.org Reviewed-by: Sam Ravnborg sam@ravnborg.org --- drivers/gpu/drm/drm_panel.c | 43 +++++++++++++++++++++++++++++++++++++ include/drm/drm_panel.h | 9 ++++++++ 2 files changed, 52 insertions(+)
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index 8c7bac85a793..5557c75301f1 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -300,6 +300,49 @@ 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. -EERROR otherwise. + */ +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) diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 6193cb555acc..781c735f0f9b 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -35,6 +35,8 @@ struct drm_device; struct drm_panel; struct display_timing;
+enum drm_panel_orientation; + /** * struct drm_panel_funcs - perform operations on a given panel * @@ -191,11 +193,18 @@ int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector
#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL) struct drm_panel *of_drm_find_panel(const struct device_node *np); +int of_drm_get_panel_orientation(const struct device_node *np, + enum drm_panel_orientation *orientation); #else static inline struct drm_panel *of_drm_find_panel(const struct device_node *np) { return ERR_PTR(-ENODEV); } +static inline int of_drm_get_panel_orientation(const struct device_node *np, + enum drm_panel_orientation *orientation) +{ + return -ENODEV; +} #endif
#if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \