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()
40 static int ssam_device_uevent(const struct device *dev, struct kobj_uevent_env *env)  in ssam_device_uevent()
45 			      sdev->uid.domain, sdev->uid.category,  in ssam_device_uevent()
46 			      sdev->uid.target, sdev->uid.instance,  in ssam_device_uevent()
47 			      sdev->uid.function);  in ssam_device_uevent()
50 static void ssam_device_release(struct device *dev)  in ssam_device_release()
54 	ssam_controller_put(sdev->ctrl);  in ssam_device_release()
55 	fwnode_handle_put(sdev->dev.fwnode);  in ssam_device_release()
68  * ssam_device_alloc() - Allocate and initialize a SSAM client device.
69  * @ctrl: The controller under which the device should be added.
70  * @uid:  The UID of the device to be added.
72  * Allocates and initializes a new client device. The parent of the device
73  * will be set to the controller device and the name will be set based on the
74  * UID. Note that the device still has to be added via ssam_device_add().
77  * Return: Returns the newly allocated and initialized SSAM client device, or
89 	device_initialize(&sdev->dev);  in ssam_device_alloc()
90 	sdev->dev.bus = &ssam_bus_type;  in ssam_device_alloc()
91 	sdev->dev.type = &ssam_device_type;  in ssam_device_alloc()
92 	sdev->dev.parent = ssam_controller_device(ctrl);  in ssam_device_alloc()
93 	sdev->ctrl = ssam_controller_get(ctrl);  in ssam_device_alloc()
94 	sdev->uid = uid;  in ssam_device_alloc()
96 	dev_set_name(&sdev->dev, "%02x:%02x:%02x:%02x:%02x",  in ssam_device_alloc()
97 		     sdev->uid.domain, sdev->uid.category, sdev->uid.target,  in ssam_device_alloc()
98 		     sdev->uid.instance, sdev->uid.function);  in ssam_device_alloc()
105  * ssam_device_add() - Add a SSAM client device.
106  * @sdev: The SSAM client device to be added.
109  * controller. Thus, this function will fail with %-ENODEV if the controller
110  * of the device has not been initialized yet, has been suspended, or has been
115  * added device is a direct child of the controller device (default), it will
118  * By default, the controller device will become the parent of the newly
119  * created client device. The parent may be changed before ssam_device_add is
121  * is guaranteed and b) the client device does not outlive the controller,
122  * i.e. that the device is removed before the controller is being shut down.
125  * set up device-links for this purpose.
137 	 * controller device, i.e. it ensures that the controller (sdev->ctrl)  in ssam_device_add()
139 	 * device we add here is registered as child under it. This essentially  in ssam_device_add()
145 	 * Note that for this to work, the controller has to be a parent device.  in ssam_device_add()
146 	 * If it is not a direct parent, care has to be taken that the device is  in ssam_device_add()
150 	ssam_controller_statelock(sdev->ctrl);  in ssam_device_add()
152 	if (sdev->ctrl->state != SSAM_CONTROLLER_STARTED) {  in ssam_device_add()
153 		ssam_controller_stateunlock(sdev->ctrl);  in ssam_device_add()
154 		return -ENODEV;  in ssam_device_add()
157 	status = device_add(&sdev->dev);  in ssam_device_add()
159 	ssam_controller_stateunlock(sdev->ctrl);  in ssam_device_add()
165  * ssam_device_remove() - Remove a SSAM client device.
166  * @sdev: The device to remove.
168  * Removes and unregisters the provided SSAM client device.
172 	device_unregister(&sdev->dev);  in ssam_device_remove()
177  * ssam_device_id_compatible() - Check if a device ID matches a UID.
178  * @id:  The device ID as potential match.
179  * @uid: The device UID matching against.
181  * Check if the given ID is a match for the given UID, i.e. if a device with
182  * the provided UID is compatible to the given ID following the match rules
186  * described by the given ID, %false otherwise.
188 static bool ssam_device_id_compatible(const struct ssam_device_id *id,  in ssam_device_id_compatible()  argument
191 	if (id->domain != uid.domain || id->category != uid.category)  in ssam_device_id_compatible()
194 	if ((id->match_flags & SSAM_MATCH_TARGET) && id->target != uid.target)  in ssam_device_id_compatible()
197 	if ((id->match_flags & SSAM_MATCH_INSTANCE) && id->instance != uid.instance)  in ssam_device_id_compatible()
200 	if ((id->match_flags & SSAM_MATCH_FUNCTION) && id->function != uid.function)  in ssam_device_id_compatible()
207  * ssam_device_id_is_null() - Check if a device ID is null.
208  * @id: The device ID to check.
210  * Check if a given device ID is null, i.e. all zeros. Used to check for the
213  * Return: Returns %true if the given ID represents a null ID, %false
216 static bool ssam_device_id_is_null(const struct ssam_device_id *id)  in ssam_device_id_is_null()  argument
218 	return id->match_flags == 0 &&  in ssam_device_id_is_null()
219 		id->domain == 0 &&  in ssam_device_id_is_null()
220 		id->category == 0 &&  in ssam_device_id_is_null()
221 		id->target == 0 &&  in ssam_device_id_is_null()
222 		id->instance == 0 &&  in ssam_device_id_is_null()
223 		id->function == 0 &&  in ssam_device_id_is_null()
224 		id->driver_data == 0;  in ssam_device_id_is_null()
228  * ssam_device_id_match() - Find the matching ID table entry for the given UID.
232  * Find the first match for the provided device UID in the provided ID table
238 	const struct ssam_device_id *id;  in ssam_device_id_match()  local
240 	for (id = table; !ssam_device_id_is_null(id); ++id)  in ssam_device_id_match()
241 		if (ssam_device_id_compatible(id, uid))  in ssam_device_id_match()
242 			return id;  in ssam_device_id_match()
249  * ssam_device_get_match() - Find and return the ID matching the device in the
250  * ID table of the bound driver.
251  * @dev: The device for which to get the matching ID table entry.
253  * Find the fist match for the UID of the device in the ID table of the
254  * currently bound driver and return it. Returns %NULL if the device does not
258  * This function essentially calls ssam_device_id_match() with the ID table of
259  * the bound device driver and the UID of the device.
261  * Return: Returns the first match for the UID of the device in the device
268 	sdrv = to_ssam_device_driver(dev->dev.driver);  in ssam_device_get_match()
272 	if (!sdrv->match_table)  in ssam_device_get_match()
275 	return ssam_device_id_match(sdrv->match_table, dev->uid);  in ssam_device_get_match()
280  * ssam_device_get_match_data() - Find the ID matching the device in the
281  * ID table of the bound driver and return its ``driver_data`` member.
282  * @dev: The device for which to get the match data.
284  * Find the fist match for the UID of the device in the ID table of the
286  * device does not have a driver bound to it, the driver does not have
294  * of the device in the device driver's match table, or %NULL if no such match
299 	const struct ssam_device_id *id;  in ssam_device_get_match_data()  local
301 	id = ssam_device_get_match(dev);  in ssam_device_get_match_data()
302 	if (!id)  in ssam_device_get_match_data()
305 	return (const void *)id->driver_data;  in ssam_device_get_match_data()
309 static int ssam_bus_match(struct device *dev, struct device_driver *drv)  in ssam_bus_match()
317 	return !!ssam_device_id_match(sdrv->match_table, sdev->uid);  in ssam_bus_match()
320 static int ssam_bus_probe(struct device *dev)  in ssam_bus_probe()
322 	return to_ssam_device_driver(dev->driver)  in ssam_bus_probe()
323 		->probe(to_ssam_device(dev));  in ssam_bus_probe()
326 static void ssam_bus_remove(struct device *dev)  in ssam_bus_remove()
328 	struct ssam_device_driver *sdrv = to_ssam_device_driver(dev->driver);  in ssam_bus_remove()
330 	if (sdrv->remove)  in ssam_bus_remove()
331 		sdrv->remove(to_ssam_device(dev));  in ssam_bus_remove()
342  * __ssam_device_driver_register() - Register a SSAM client device driver.
352 	sdrv->driver.owner = owner;  in __ssam_device_driver_register()
353 	sdrv->driver.bus = &ssam_bus_type;  in __ssam_device_driver_register()
356 	sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;  in __ssam_device_driver_register()
358 	return driver_register(&sdrv->driver);  in __ssam_device_driver_register()
363  * ssam_device_driver_unregister - Unregister a SSAM device driver.
368 	driver_unregister(&sdrv->driver);  in ssam_device_driver_unregister()
373 /* -- Bus registration. ----------------------------------------------------- */
376  * ssam_bus_register() - Register and set-up the SSAM client device bus.
384  * ssam_bus_unregister() - Unregister the SSAM client device bus.
392 /* -- Helpers for controller and hub devices. ------------------------------- */
401 		return -EINVAL;  in ssam_device_uid_from_string()
403 	uid->domain = d;  in ssam_device_uid_from_string()
404 	uid->category = tc;  in ssam_device_uid_from_string()
405 	uid->target = tid;  in ssam_device_uid_from_string()
406 	uid->instance = iid;  in ssam_device_uid_from_string()
407 	uid->function = fn;  in ssam_device_uid_from_string()
417 	 * To simplify definitions of firmware nodes, we set the device name  in ssam_get_uid_for_node()
418 	 * based on the UID of the device, prefixed with "ssam:".  in ssam_get_uid_for_node()
421 		return -ENODEV;  in ssam_get_uid_for_node()
427 static int ssam_add_client_device(struct device *parent, struct ssam_controller *ctrl,  in ssam_add_client_device()
440 		return -ENOMEM;  in ssam_add_client_device()
442 	sdev->dev.parent = parent;  in ssam_add_client_device()
443 	sdev->dev.fwnode = fwnode_handle_get(node);  in ssam_add_client_device()
453  * __ssam_register_clients() - Register client devices defined under the
454  * given firmware node as children of the given device.
455  * @parent: The parent device under which clients should be registered.
460  * firmware node as children of the given parent device. The respective child
469  * firmware node and/or controller associated with the given device. This
470  * function is only intended for use when different device specifications (e.g.
472  * of the device registry).
476 int __ssam_register_clients(struct device *parent, struct ssam_controller *ctrl,  in __ssam_register_clients()
484 		 * Try to add the device specified in the firmware node. If  in __ssam_register_clients()
485 		 * this fails with -ENODEV, the node does not specify any SSAM  in __ssam_register_clients()
486 		 * device, so ignore it and continue with the next one.  in __ssam_register_clients()
489 		if (status && status != -ENODEV) {  in __ssam_register_clients()
502 static int ssam_remove_device(struct device *dev, void *_data)  in ssam_remove_device()
513  * ssam_remove_clients() - Remove SSAM client devices registered as direct
514  * children under the given parent device.
515  * @dev: The (parent) device to remove all direct clients for.
518  * device. Note that this only accounts for direct children of the device.
521 void ssam_remove_clients(struct device *dev)  in ssam_remove_clients()