From 5f3e7503b97b3d068304ac8bb74faa10b804b24d Mon Sep 17 00:00:00 2001 From: Derek Basehore Date: Fri, 14 Aug 2020 00:56:06 +0300 Subject: [PATCH] drm/panel: Add helper for reading DT rotation This adds a helper function for reading the rotation (panel orientation) from the device tree. Reviewed-by: Sam Ravnborg Tested-by: Dmitry Osipenko Signed-off-by: Derek Basehore Signed-off-by: Dmitry Osipenko Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200813215609.28643-2-digetx@gmail.com --- drivers/gpu/drm/drm_panel.c | 43 +++++++++++++++++++++++++++++++++++++++++++ include/drm/drm_panel.h | 10 ++++++++++ 2 files changed, 53 insertions(+) diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index ba11c3641bf3..f634371c717a 100644 --- 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) diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 45a1b5a2275d..33605c3f0eba 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 * @@ -188,11 +190,19 @@ 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) || \ -- 2.11.0