17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
48  * drm_panel_init - initialize a panel
50  * @dev: parent device of the panel
58 void drm_panel_init(struct drm_panel *panel, struct device *dev,  in drm_panel_init()
61 	INIT_LIST_HEAD(&panel->list);  in drm_panel_init()
62 	INIT_LIST_HEAD(&panel->followers);  in drm_panel_init()
63 	mutex_init(&panel->follower_lock);  in drm_panel_init()
64 	panel->dev = dev;  in drm_panel_init()
65 	panel->funcs = funcs;  in drm_panel_init()
66 	panel->connector_type = connector_type;  in drm_panel_init()
71  * drm_panel_add - add a panel to the global registry
80 	list_add_tail(&panel->list, &panel_list);  in drm_panel_add()
86  * drm_panel_remove - remove a panel from the global registry
94 	list_del_init(&panel->list);  in drm_panel_remove()
100  * drm_panel_prepare - power on a panel
115 		return -EINVAL;  in drm_panel_prepare()
117 	if (panel->prepared) {  in drm_panel_prepare()
118 		dev_warn(panel->dev, "Skipping prepare of already prepared panel\n");  in drm_panel_prepare()
122 	mutex_lock(&panel->follower_lock);  in drm_panel_prepare()
124 	if (panel->funcs && panel->funcs->prepare) {  in drm_panel_prepare()
125 		ret = panel->funcs->prepare(panel);  in drm_panel_prepare()
129 	panel->prepared = true;  in drm_panel_prepare()
131 	list_for_each_entry(follower, &panel->followers, list) {  in drm_panel_prepare()
132 		ret = follower->funcs->panel_prepared(follower);  in drm_panel_prepare()
134 			dev_info(panel->dev, "%ps failed: %d\n",  in drm_panel_prepare()
135 				 follower->funcs->panel_prepared, ret);  in drm_panel_prepare()
140 	mutex_unlock(&panel->follower_lock);  in drm_panel_prepare()
147  * drm_panel_unprepare - power off a panel
163 		return -EINVAL;  in drm_panel_unprepare()
167 	 * - Your panel driver incorrectly calls drm_panel_unprepare() in its  in drm_panel_unprepare()
169 	 * - You are using panel-edp or panel-simple and your DRM modeset  in drm_panel_unprepare()
174 	if (!panel->prepared) {  in drm_panel_unprepare()
175 		dev_warn(panel->dev, "Skipping unprepare of already unprepared panel\n");  in drm_panel_unprepare()
179 	mutex_lock(&panel->follower_lock);  in drm_panel_unprepare()
181 	list_for_each_entry(follower, &panel->followers, list) {  in drm_panel_unprepare()
182 		ret = follower->funcs->panel_unpreparing(follower);  in drm_panel_unprepare()
184 			dev_info(panel->dev, "%ps failed: %d\n",  in drm_panel_unprepare()
185 				 follower->funcs->panel_unpreparing, ret);  in drm_panel_unprepare()
188 	if (panel->funcs && panel->funcs->unprepare) {  in drm_panel_unprepare()
189 		ret = panel->funcs->unprepare(panel);  in drm_panel_unprepare()
193 	panel->prepared = false;  in drm_panel_unprepare()
197 	mutex_unlock(&panel->follower_lock);  in drm_panel_unprepare()
204  * drm_panel_enable - enable a panel
218 		return -EINVAL;  in drm_panel_enable()
220 	if (panel->enabled) {  in drm_panel_enable()
221 		dev_warn(panel->dev, "Skipping enable of already enabled panel\n");  in drm_panel_enable()
225 	if (panel->funcs && panel->funcs->enable) {  in drm_panel_enable()
226 		ret = panel->funcs->enable(panel);  in drm_panel_enable()
230 	panel->enabled = true;  in drm_panel_enable()
232 	ret = backlight_enable(panel->backlight);  in drm_panel_enable()
234 		DRM_DEV_INFO(panel->dev, "failed to enable backlight: %d\n",  in drm_panel_enable()
242  * drm_panel_disable - disable a panel
256 		return -EINVAL;  in drm_panel_disable()
260 	 * - Your panel driver incorrectly calls drm_panel_disable() in its  in drm_panel_disable()
262 	 * - You are using panel-edp or panel-simple and your DRM modeset  in drm_panel_disable()
267 	if (!panel->enabled) {  in drm_panel_disable()
268 		dev_warn(panel->dev, "Skipping disable of already disabled panel\n");  in drm_panel_disable()
272 	ret = backlight_disable(panel->backlight);  in drm_panel_disable()
274 		DRM_DEV_INFO(panel->dev, "failed to disable backlight: %d\n",  in drm_panel_disable()
277 	if (panel->funcs && panel->funcs->disable) {  in drm_panel_disable()
278 		ret = panel->funcs->disable(panel);  in drm_panel_disable()
282 	panel->enabled = false;  in drm_panel_disable()
289  * drm_panel_get_modes - probe the available display modes of a panel
305 	if (panel->funcs && panel->funcs->get_modes) {  in drm_panel_get_modes()
308 		num = panel->funcs->get_modes(panel, connector);  in drm_panel_get_modes()
319  * of_drm_find_panel - look up a panel using a device tree node
320  * @np: device tree node of the panel
322  * Searches the set of registered panels for one that matches the given device
323  * tree node. If a matching panel is found, return a pointer to it.
325  * Return: A pointer to the panel registered for the specified device tree
326  * node or an ERR_PTR() if no panel matching the device tree node can be found.
330  * - EPROBE_DEFER: the panel device has not been probed yet, and the caller
332  * - ENODEV: the device is not available (status != "okay" or "ok")
339 		return ERR_PTR(-ENODEV);  in of_drm_find_panel()
344 		if (panel->dev->of_node == np) {  in of_drm_find_panel()
351 	return ERR_PTR(-EPROBE_DEFER);  in of_drm_find_panel()
356  * of_drm_get_panel_orientation - look up the orientation of the panel through
357  * the "rotation" binding from a device tree node
358  * @np: device tree node of the panel
361  * Looks up the rotation of a panel in the device tree. The orientation of the
362  * panel is expressed as a property name "rotation" in the device tree. The
363  * rotation in the device tree is counter clockwise.
374 	if (ret == -EINVAL) {  in of_drm_get_panel_orientation()
392 		return -EINVAL;  in of_drm_get_panel_orientation()
400  * drm_is_panel_follower() - Check if the device is a panel follower
401  * @dev: The 'struct device' to check
403  * This checks to see if a device needs to be power sequenced together with
405  * At the moment panels can only be followed on device tree enabled systems.
410 bool drm_is_panel_follower(struct device *dev)  in drm_is_panel_follower()
417 	return of_property_present(dev->of_node, "panel");  in drm_is_panel_follower()
422  * drm_panel_add_follower() - Register something to follow panel state.
423  * @follower_dev: The 'struct device' for the follower.
434  * At the moment panels can only be followed on device tree enabled systems.
437  * Return: 0 or an error code. Note that -ENODEV means that we detected that
441 int drm_panel_add_follower(struct device *follower_dev,  in drm_panel_add_follower()
448 	panel_np = of_parse_phandle(follower_dev->of_node, "panel", 0);  in drm_panel_add_follower()
450 		return -ENODEV;  in drm_panel_add_follower()
457 	get_device(panel->dev);  in drm_panel_add_follower()
458 	follower->panel = panel;  in drm_panel_add_follower()
460 	mutex_lock(&panel->follower_lock);  in drm_panel_add_follower()
462 	list_add_tail(&follower->list, &panel->followers);  in drm_panel_add_follower()
463 	if (panel->prepared) {  in drm_panel_add_follower()
464 		ret = follower->funcs->panel_prepared(follower);  in drm_panel_add_follower()
466 			dev_info(panel->dev, "%ps failed: %d\n",  in drm_panel_add_follower()
467 				 follower->funcs->panel_prepared, ret);  in drm_panel_add_follower()
470 	mutex_unlock(&panel->follower_lock);  in drm_panel_add_follower()
477  * drm_panel_remove_follower() - Reverse drm_panel_add_follower().
487 	struct drm_panel *panel = follower->panel;  in drm_panel_remove_follower()
490 	mutex_lock(&panel->follower_lock);  in drm_panel_remove_follower()
492 	if (panel->prepared) {  in drm_panel_remove_follower()
493 		ret = follower->funcs->panel_unpreparing(follower);  in drm_panel_remove_follower()
495 			dev_info(panel->dev, "%ps failed: %d\n",  in drm_panel_remove_follower()
496 				 follower->funcs->panel_unpreparing, ret);  in drm_panel_remove_follower()
498 	list_del_init(&follower->list);  in drm_panel_remove_follower()
500 	mutex_unlock(&panel->follower_lock);  in drm_panel_remove_follower()
502 	put_device(panel->dev);  in drm_panel_remove_follower()
512  * devm_drm_panel_add_follower() - devm version of drm_panel_add_follower()
513  * @follower_dev: The 'struct device' for the follower.
520 int devm_drm_panel_add_follower(struct device *follower_dev,  in devm_drm_panel_add_follower()
536  * drm_panel_of_backlight - use backlight device node for backlight
540  * uses device tree and has a backlight phandle.
548  * A typical implementation for a panel driver supporting device tree
559 	if (!panel || !panel->dev)  in drm_panel_of_backlight()
560 		return -EINVAL;  in drm_panel_of_backlight()
562 	backlight = devm_of_find_backlight(panel->dev);  in drm_panel_of_backlight()
567 	panel->backlight = backlight;  in drm_panel_of_backlight()