Commit 5f3e7503 authored by Derek Basehore's avatar Derek Basehore Committed by Sam Ravnborg

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: default avatarSam Ravnborg <sam@ravnborg.org>
Tested-by: default avatarDmitry Osipenko <digetx@gmail.com>
Signed-off-by: default avatarDerek Basehore <dbasehore@chromium.org>
Signed-off-by: default avatarDmitry Osipenko <digetx@gmail.com>
Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200813215609.28643-2-digetx@gmail.com
parent 1c243751
......@@ -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)
......
......@@ -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) || \
......
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