1 // SPDX-License-Identifier: GPL-2.0
5  * The DP AUX bus is used for devices that are connected over a DisplayPort
6  * AUX bus. The devices on the far side of the bus are referred to as
9  * Commonly there is only one device connected to the DP AUX bus: a panel.
11  * platform devices, putting them under the DP AUX bus allows the panel driver
12  * to perform transactions on that bus.
26  * dp_aux_ep_match() - The match function for the dp_aux_bus.
36 	return !!of_match_device(drv->of_match_table, dev);  in dp_aux_ep_match()
40  * dp_aux_ep_probe() - The probe function for the dp_aux_bus.
49 	struct dp_aux_ep_driver *aux_ep_drv = to_dp_aux_ep_drv(dev->driver);  in dp_aux_ep_probe()
57 	ret = aux_ep_drv->probe(aux_ep);  in dp_aux_ep_probe()
65  * dp_aux_ep_remove() - The remove function for the dp_aux_bus.
73 	struct dp_aux_ep_driver *aux_ep_drv = to_dp_aux_ep_drv(dev->driver);  in dp_aux_ep_remove()
76 	if (aux_ep_drv->remove)  in dp_aux_ep_remove()
77 		aux_ep_drv->remove(aux_ep);  in dp_aux_ep_remove()
82  * dp_aux_ep_shutdown() - The shutdown function for the dp_aux_bus.
91 	if (!dev->driver)  in dp_aux_ep_shutdown()
94 	aux_ep_drv = to_dp_aux_ep_drv(dev->driver);  in dp_aux_ep_shutdown()
95 	if (aux_ep_drv->shutdown)  in dp_aux_ep_shutdown()
96 		aux_ep_drv->shutdown(to_dp_aux_ep_dev(dev));  in dp_aux_ep_shutdown()
100 	.name		= "dp-aux",
121  * dp_aux_ep_dev_release() - Free memory for the dp_aux_ep device
138  * of_dp_aux_ep_destroy() - Destroy an DP AUX endpoint device
143  * is called for _all_ of the child devices of the device providing the AUX bus.
153 	struct device_node *np = dev->of_node;  in of_dp_aux_ep_destroy()
155 	if (dev->bus != &dp_aux_bus_type)  in of_dp_aux_ep_destroy()
170  * of_dp_aux_depopulate_ep_devices() - Undo of_dp_aux_populate_ep_devices
178 	device_for_each_child_reverse(aux->dev, NULL, of_dp_aux_ep_destroy);  in of_dp_aux_depopulate_ep_devices()
183  * of_dp_aux_populate_ep_devices() - Populate the endpoint devices on the DP AUX
187  * This will populate all the devices under the "aux-bus" node of the device
188  * providing the AUX channel (AKA aux->dev).
191  * our sub-devices will have finished probing. It should be noted that if our
192  * sub-devices return -EPROBE_DEFER that we will not return any error codes
193  * ourselves but our sub-devices will _not_ have actually probed successfully
194  * yet. There may be other cases (maybe added in the future?) where sub-devices
206 	struct device_node *bus, *np;  in of_dp_aux_populate_ep_devices()  local
211 	WARN_ON_ONCE(!aux->ddc.algo);  in of_dp_aux_populate_ep_devices()
213 	if (!aux->dev->of_node)  in of_dp_aux_populate_ep_devices()
216 	bus = of_get_child_by_name(aux->dev->of_node, "aux-bus");  in of_dp_aux_populate_ep_devices()
217 	if (!bus)  in of_dp_aux_populate_ep_devices()
220 	for_each_available_child_of_node(bus, np) {  in of_dp_aux_populate_ep_devices()
227 		aux_ep->aux = aux;  in of_dp_aux_populate_ep_devices()
229 		aux_ep->dev.parent = aux->dev;  in of_dp_aux_populate_ep_devices()
230 		aux_ep->dev.bus = &dp_aux_bus_type;  in of_dp_aux_populate_ep_devices()
231 		aux_ep->dev.type = &dp_aux_device_type_type;  in of_dp_aux_populate_ep_devices()
232 		aux_ep->dev.of_node = of_node_get(np);  in of_dp_aux_populate_ep_devices()
233 		dev_set_name(&aux_ep->dev, "aux-%s", dev_name(aux->dev));  in of_dp_aux_populate_ep_devices()
235 		ret = device_register(&aux_ep->dev);  in of_dp_aux_populate_ep_devices()
237 			dev_err(aux->dev, "Failed to create AUX EP for %pOF: %d\n", np, ret);  in of_dp_aux_populate_ep_devices()
245 			put_device(&aux_ep->dev);  in of_dp_aux_populate_ep_devices()
249 			 * we won't fail the whole function here--we'll just  in of_dp_aux_populate_ep_devices()
255 	of_node_put(bus);  in of_dp_aux_populate_ep_devices()
266  * devm_of_dp_aux_populate_ep_devices() - devm wrapper for of_dp_aux_populate_ep_devices()
269  * Handles freeing w/ devm on the device "aux->dev".
281 	return devm_add_action_or_reset(aux->dev,  in devm_of_dp_aux_populate_ep_devices()
289 	drv->driver.owner = owner;  in __dp_aux_dp_driver_register()
290 	drv->driver.bus = &dp_aux_bus_type;  in __dp_aux_dp_driver_register()
292 	return driver_register(&drv->driver);  in __dp_aux_dp_driver_register()
298 	driver_unregister(&drv->driver);  in dp_aux_dp_driver_unregister()
322 MODULE_DESCRIPTION("DRM DisplayPort AUX bus");