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| author | Derek Basehore <dbasehore@chromium.org> | 2020-08-14 00:56:06 +0300 |
|---|---|---|
| committer | Sam Ravnborg <sam@ravnborg.org> | 2020-08-16 18:12:18 +0300 |
| commit | 5f3e7503b97b3d068304ac8bb74faa10b804b24d (patch) | |
| tree | 5daf87a326d0d20ecc80f2496bf416d21eace9cf /drivers/gpu/drm | |
| parent | 1c243751c095bb95e2795f076ea7a0bcdd60a93a (diff) | |
| download | linux-5f3e7503b97b3d068304ac8bb74faa10b804b24d.tar.xz | |
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 <sam@ravnborg.org>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200813215609.28643-2-digetx@gmail.com
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/drm_panel.c | 43 |
1 files changed, 43 insertions, 0 deletions
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) |