From c74b76bb8a4da44a9f8cf06f4aba9f3334e1a148 Mon Sep 17 00:00:00 2001 From: Derek Basehore Date: Tue, 9 Jul 2019 19:16:56 -0700 Subject: [PATCH 1/4] drm/panel: Add helper for reading DT rotation This adds a helper function for reading the rotation (panel orientation) from the device tree. Signed-off-by: Derek Basehore --- 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 d37b83f40..b2d8fa2c3 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -168,6 +168,49 @@ 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 int drm_panel_notifier_register(struct drm_panel *panel, diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 6aab8fefc..c58c4c19f 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -53,6 +53,8 @@ struct drm_device; struct drm_panel; struct display_timing; +enum drm_panel_orientation; + /** * @loader_protect: protect loader logo panel's power * struct drm_panel_funcs - perform operations on a given panel @@ -240,11 +242,18 @@ int drm_panel_notifier_call_chain(struct drm_panel *panel, #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 #endif -- 2.34.1