1 // SPDX-License-Identifier: GPL-2.0+
3  * Surface System Aggregator Module bus and device integration.
5  * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
8 #include <linux/device.h>
13 #include <linux/surface_aggregator/device.h>
19 /* -- Device and bus functions. --------------------------------------------- */
21 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,  in modalias_show()
27 			sdev->uid.domain, sdev->uid.category, sdev->uid.target,  in modalias_show()
28 			sdev->uid.instance, sdev->uid.function);  in modalias_show()
38 static int ssam_device_uevent(struct device *dev, struct kobj_uevent_env *env)  in ssam_device_uevent()
43 			      sdev->uid.domain, sdev->uid.category,  in ssam_device_uevent()
44 			      sdev->uid.target, sdev->uid.instance,  in ssam_device_uevent()
45 			      sdev->uid.function);  in ssam_device_uevent()
48 static void ssam_device_release(struct device *dev)  in ssam_device_release()
52 	ssam_controller_put(sdev->ctrl);  in ssam_device_release()
53 	fwnode_handle_put(sdev->dev.fwnode);  in ssam_device_release()
66  * ssam_device_alloc() - Allocate and initialize a SSAM client device.
67  * @ctrl: The controller under which the device should be added.
68  * @uid:  The UID of the device to be added.
70  * Allocates and initializes a new client device. The parent of the device
71  * will be set to the controller device and the name will be set based on the
72  * UID. Note that the device still has to be added via ssam_device_add().
75  * Return: Returns the newly allocated and initialized SSAM client device, or
87 	device_initialize(&sdev->dev);  in ssam_device_alloc()
88 	sdev->dev.bus = &ssam_bus_type;  in ssam_device_alloc()
89 	sdev->dev.type = &ssam_device_type;  in ssam_device_alloc()
90 	sdev->dev.parent = ssam_controller_device(ctrl);  in ssam_device_alloc()
91 	sdev->ctrl = ssam_controller_get(ctrl);  in ssam_device_alloc()
92 	sdev->uid = uid;  in ssam_device_alloc()
94 	dev_set_name(&sdev->dev, "%02x:%02x:%02x:%02x:%02x",  in ssam_device_alloc()
95 		     sdev->uid.domain, sdev->uid.category, sdev->uid.target,  in ssam_device_alloc()
96 		     sdev->uid.instance, sdev->uid.function);  in ssam_device_alloc()
103  * ssam_device_add() - Add a SSAM client device.
104  * @sdev: The SSAM client device to be added.
107  * controller. Thus, this function will fail with %-ENODEV if the controller
108  * of the device has not been initialized yet, has been suspended, or has been
113  * added device is a direct child of the controller device (default), it will
116  * By default, the controller device will become the parent of the newly
117  * created client device. The parent may be changed before ssam_device_add is
119  * is guaranteed and b) the client device does not outlive the controller,
120  * i.e. that the device is removed before the controller is being shut down.
123  * set up device-links for this purpose.
135 	 * controller device, i.e. it ensures that the controller (sdev->ctrl)  in ssam_device_add()
137 	 * device we add here is registered as child under it. This essentially  in ssam_device_add()
143 	 * Note that for this to work, the controller has to be a parent device.  in ssam_device_add()
144 	 * If it is not a direct parent, care has to be taken that the device is  in ssam_device_add()
148 	ssam_controller_statelock(sdev->ctrl);  in ssam_device_add()
150 	if (sdev->ctrl->state != SSAM_CONTROLLER_STARTED) {  in ssam_device_add()
151 		ssam_controller_stateunlock(sdev->ctrl);  in ssam_device_add()
152 		return -ENODEV;  in ssam_device_add()
155 	status = device_add(&sdev->dev);  in ssam_device_add()
157 	ssam_controller_stateunlock(sdev->ctrl);  in ssam_device_add()
163  * ssam_device_remove() - Remove a SSAM client device.
164  * @sdev: The device to remove.
166  * Removes and unregisters the provided SSAM client device.
170 	device_unregister(&sdev->dev);  in ssam_device_remove()
175  * ssam_device_id_compatible() - Check if a device ID matches a UID.
176  * @id:  The device ID as potential match.
177  * @uid: The device UID matching against.
179  * Check if the given ID is a match for the given UID, i.e. if a device with
180  * the provided UID is compatible to the given ID following the match rules
184  * described by the given ID, %false otherwise.
186 static bool ssam_device_id_compatible(const struct ssam_device_id *id,  in ssam_device_id_compatible()  argument
189 	if (id->domain != uid.domain || id->category != uid.category)  in ssam_device_id_compatible()
192 	if ((id->match_flags & SSAM_MATCH_TARGET) && id->target != uid.target)  in ssam_device_id_compatible()
195 	if ((id->match_flags & SSAM_MATCH_INSTANCE) && id->instance != uid.instance)  in ssam_device_id_compatible()
198 	if ((id->match_flags & SSAM_MATCH_FUNCTION) && id->function != uid.function)  in ssam_device_id_compatible()
205  * ssam_device_id_is_null() - Check if a device ID is null.
206  * @id: The device ID to check.
208  * Check if a given device ID is null, i.e. all zeros. Used to check for the
211  * Return: Returns %true if the given ID represents a null ID, %false
214 static bool ssam_device_id_is_null(const struct ssam_device_id *id)  in ssam_device_id_is_null()  argument
216 	return id->match_flags == 0 &&  in ssam_device_id_is_null()
217 		id->domain == 0 &&  in ssam_device_id_is_null()
218 		id->category == 0 &&  in ssam_device_id_is_null()
219 		id->target == 0 &&  in ssam_device_id_is_null()
220 		id->instance == 0 &&  in ssam_device_id_is_null()
221 		id->function == 0 &&  in ssam_device_id_is_null()
222 		id->driver_data == 0;  in ssam_device_id_is_null()
226  * ssam_device_id_match() - Find the matching ID table entry for the given UID.
230  * Find the first match for the provided device UID in the provided ID table
236 	const struct ssam_device_id *id;  in ssam_device_id_match()  local
238 	for (id = table; !ssam_device_id_is_null(id); ++id)  in ssam_device_id_match()
239 		if (ssam_device_id_compatible(id, uid))  in ssam_device_id_match()
240 			return id;  in ssam_device_id_match()
247  * ssam_device_get_match() - Find and return the ID matching the device in the
248  * ID table of the bound driver.
249  * @dev: The device for which to get the matching ID table entry.
251  * Find the fist match for the UID of the device in the ID table of the
252  * currently bound driver and return it. Returns %NULL if the device does not
256  * This function essentially calls ssam_device_id_match() with the ID table of
257  * the bound device driver and the UID of the device.
259  * Return: Returns the first match for the UID of the device in the device
266 	sdrv = to_ssam_device_driver(dev->dev.driver);  in ssam_device_get_match()
270 	if (!sdrv->match_table)  in ssam_device_get_match()
273 	return ssam_device_id_match(sdrv->match_table, dev->uid);  in ssam_device_get_match()
278  * ssam_device_get_match_data() - Find the ID matching the device in the
279  * ID table of the bound driver and return its ``driver_data`` member.
280  * @dev: The device for which to get the match data.
282  * Find the fist match for the UID of the device in the ID table of the
284  * device does not have a driver bound to it, the driver does not have
292  * of the device in the device driver's match table, or %NULL if no such match
297 	const struct ssam_device_id *id;  in ssam_device_get_match_data()  local
299 	id = ssam_device_get_match(dev);  in ssam_device_get_match_data()
300 	if (!id)  in ssam_device_get_match_data()
303 	return (const void *)id->driver_data;  in ssam_device_get_match_data()
307 static int ssam_bus_match(struct device *dev, struct device_driver *drv)  in ssam_bus_match()
315 	return !!ssam_device_id_match(sdrv->match_table, sdev->uid);  in ssam_bus_match()
318 static int ssam_bus_probe(struct device *dev)  in ssam_bus_probe()
320 	return to_ssam_device_driver(dev->driver)  in ssam_bus_probe()
321 		->probe(to_ssam_device(dev));  in ssam_bus_probe()
324 static void ssam_bus_remove(struct device *dev)  in ssam_bus_remove()
326 	struct ssam_device_driver *sdrv = to_ssam_device_driver(dev->driver);  in ssam_bus_remove()
328 	if (sdrv->remove)  in ssam_bus_remove()
329 		sdrv->remove(to_ssam_device(dev));  in ssam_bus_remove()
341  * __ssam_device_driver_register() - Register a SSAM client device driver.
351 	sdrv->driver.owner = owner;  in __ssam_device_driver_register()
352 	sdrv->driver.bus = &ssam_bus_type;  in __ssam_device_driver_register()
355 	sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;  in __ssam_device_driver_register()
357 	return driver_register(&sdrv->driver);  in __ssam_device_driver_register()
362  * ssam_device_driver_unregister - Unregister a SSAM device driver.
367 	driver_unregister(&sdrv->driver);  in ssam_device_driver_unregister()
372 /* -- Bus registration. ----------------------------------------------------- */
375  * ssam_bus_register() - Register and set-up the SSAM client device bus.
383  * ssam_bus_unregister() - Unregister the SSAM client device bus.
391 /* -- Helpers for controller and hub devices. ------------------------------- */
400 		return -EINVAL;  in ssam_device_uid_from_string()
402 	uid->domain = d;  in ssam_device_uid_from_string()
403 	uid->category = tc;  in ssam_device_uid_from_string()
404 	uid->target = tid;  in ssam_device_uid_from_string()
405 	uid->instance = iid;  in ssam_device_uid_from_string()
406 	uid->function = fn;  in ssam_device_uid_from_string()
416 	 * To simplify definitions of firmware nodes, we set the device name  in ssam_get_uid_for_node()
417 	 * based on the UID of the device, prefixed with "ssam:".  in ssam_get_uid_for_node()
420 		return -ENODEV;  in ssam_get_uid_for_node()
426 static int ssam_add_client_device(struct device *parent, struct ssam_controller *ctrl,  in ssam_add_client_device()
439 		return -ENOMEM;  in ssam_add_client_device()
441 	sdev->dev.parent = parent;  in ssam_add_client_device()
442 	sdev->dev.fwnode = fwnode_handle_get(node);  in ssam_add_client_device()
452  * __ssam_register_clients() - Register client devices defined under the
453  * given firmware node as children of the given device.
454  * @parent: The parent device under which clients should be registered.
459  * firmware node as children of the given parent device. The respective child
468  * firmware node and/or controller associated with the given device. This
469  * function is only intended for use when different device specifications (e.g.
471  * of the device registry).
475 int __ssam_register_clients(struct device *parent, struct ssam_controller *ctrl,  in __ssam_register_clients()
483 		 * Try to add the device specified in the firmware node. If  in __ssam_register_clients()
484 		 * this fails with -ENODEV, the node does not specify any SSAM  in __ssam_register_clients()
485 		 * device, so ignore it and continue with the next one.  in __ssam_register_clients()
488 		if (status && status != -ENODEV)  in __ssam_register_clients()
499 static int ssam_remove_device(struct device *dev, void *_data)  in ssam_remove_device()
510  * ssam_remove_clients() - Remove SSAM client devices registered as direct
511  * children under the given parent device.
512  * @dev: The (parent) device to remove all direct clients for.
515  * device. Note that this only accounts for direct children of the device.
518 void ssam_remove_clients(struct device *dev)  in ssam_remove_clients()