1 // SPDX-License-Identifier: GPL-2.0
3  * System Control and Management Interface (SCMI) Message Protocol bus layer
5  * Copyright (C) 2018-2021 ARM Ltd.
31 	struct list_head node;  member
38  * scmi_protocol_device_request  - Helper to request a device
40  * @id_table: A protocol/name pair descriptor for the device to be created.
45  * The requested device name MUST NOT be already existent for this protocol;
58 	pr_debug("Requesting SCMI device (%s) for protocol %x\n",  in scmi_protocol_device_request()
59 		 id_table->name, id_table->protocol_id);  in scmi_protocol_device_request()
64 			id_table->name, id_table->protocol_id);  in scmi_protocol_device_request()
65 		return -EINVAL;  in scmi_protocol_device_request()
69 	 * Find the matching protocol rdev list and then search of any  in scmi_protocol_device_request()
73 	phead = idr_find(&scmi_requested_devices, id_table->protocol_id);  in scmi_protocol_device_request()
76 		list_for_each_entry(rdev, head, node) {  in scmi_protocol_device_request()
77 			if (!strcmp(rdev->id_table->name, id_table->name)) {  in scmi_protocol_device_request()
79 				       rdev->id_table->protocol_id,  in scmi_protocol_device_request()
80 				       rdev->id_table->name);  in scmi_protocol_device_request()
81 				ret = -EINVAL;  in scmi_protocol_device_request()
93 		ret = -ENOMEM;  in scmi_protocol_device_request()
96 	rdev->id_table = id_table;  in scmi_protocol_device_request()
100 	 * related protocol list, eventually creating such head if not already  in scmi_protocol_device_request()
107 			ret = -ENOMEM;  in scmi_protocol_device_request()
113 				id_table->protocol_id,  in scmi_protocol_device_request()
114 				id_table->protocol_id + 1, GFP_KERNEL);  in scmi_protocol_device_request()
115 		if (ret != id_table->protocol_id) {  in scmi_protocol_device_request()
116 			pr_err("Failed to save SCMI device - ret:%d\n", ret);  in scmi_protocol_device_request()
119 			ret = -EINVAL;  in scmi_protocol_device_request()
124 	list_add(&rdev->node, phead);  in scmi_protocol_device_request()
132 					     (void *)rdev->id_table);  in scmi_protocol_device_request()
138  * scmi_protocol_device_unrequest  - Helper to unrequest a device
140  * @id_table: A protocol/name pair descriptor for the device to be unrequested.
151 	pr_debug("Unrequesting SCMI device (%s) for protocol %x\n",  in scmi_protocol_device_unrequest()
152 		 id_table->name, id_table->protocol_id);  in scmi_protocol_device_unrequest()
155 	phead = idr_find(&scmi_requested_devices, id_table->protocol_id);  in scmi_protocol_device_unrequest()
159 		list_for_each_entry_safe(victim, tmp, phead, node) {  in scmi_protocol_device_unrequest()
160 			if (!strcmp(victim->id_table->name, id_table->name)) {  in scmi_protocol_device_unrequest()
161 				list_del(&victim->node);  in scmi_protocol_device_unrequest()
166 							     (void *)victim->id_table);  in scmi_protocol_device_unrequest()
175 				   id_table->protocol_id);  in scmi_protocol_device_unrequest()
185 	const struct scmi_device_id *id = scmi_drv->id_table;  in scmi_dev_match_id()
190 	for (; id->protocol_id; id++)  in scmi_dev_match_id()
191 		if (id->protocol_id == scmi_dev->protocol_id) {  in scmi_dev_match_id()
192 			if (!id->name)  in scmi_dev_match_id()
194 			else if (!strcmp(id->name, scmi_dev->name))  in scmi_dev_match_id()
219 	return sdev->protocol_id == id_table->protocol_id &&  in scmi_match_by_id_table()
220 		(id_table->name && !strcmp(sdev->name, id_table->name));  in scmi_match_by_id_table()
244 	struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);  in scmi_dev_probe()
247 	if (!scmi_dev->handle)  in scmi_dev_probe()
248 		return -EPROBE_DEFER;  in scmi_dev_probe()
250 	return scmi_drv->probe(scmi_dev);  in scmi_dev_probe()
255 	struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);  in scmi_dev_remove()
258 	if (scmi_drv->remove)  in scmi_dev_remove()
259 		scmi_drv->remove(scmi_dev);  in scmi_dev_remove()
275 	if (!driver->probe)  in scmi_driver_register()
276 		return -EINVAL;  in scmi_driver_register()
278 	retval = scmi_protocol_device_request(driver->id_table);  in scmi_driver_register()
282 	driver->driver.bus = &scmi_bus_type;  in scmi_driver_register()
283 	driver->driver.name = driver->name;  in scmi_driver_register()
284 	driver->driver.owner = owner;  in scmi_driver_register()
285 	driver->driver.mod_name = mod_name;  in scmi_driver_register()
287 	retval = driver_register(&driver->driver);  in scmi_driver_register()
289 		pr_debug("Registered new scmi driver %s\n", driver->name);  in scmi_driver_register()
297 	driver_unregister(&driver->driver);  in scmi_driver_unregister()
298 	scmi_protocol_device_unrequest(driver->id_table);  in scmi_driver_unregister()
306 	kfree_const(scmi_dev->name);  in scmi_device_release()
312 	pr_debug("(%s) Destroying SCMI device '%s' for protocol 0x%x (%s)\n",  in __scmi_device_destroy()
313 		 of_node_full_name(scmi_dev->dev.parent->of_node),  in __scmi_device_destroy()
314 		 dev_name(&scmi_dev->dev), scmi_dev->protocol_id,  in __scmi_device_destroy()
315 		 scmi_dev->name);  in __scmi_device_destroy()
317 	if (scmi_dev->protocol_id == SCMI_PROTOCOL_SYSTEM)  in __scmi_device_destroy()
320 	ida_free(&scmi_bus_id, scmi_dev->id);  in __scmi_device_destroy()
321 	device_unregister(&scmi_dev->dev);  in __scmi_device_destroy()
326 		     int protocol, const char *name)  in __scmi_device_create()  argument
332 	 * If the same protocol/name device already exist under the same parent  in __scmi_device_create()
335 	 * each DT defined protocol at probe time, and the concurrent  in __scmi_device_create()
338 	scmi_dev = scmi_child_dev_find(parent, protocol, name);  in __scmi_device_create()
349 	if (protocol == SCMI_PROTOCOL_SYSTEM &&  in __scmi_device_create()
352 			 "SCMI SystemPower protocol device must be unique !\n");  in __scmi_device_create()
360 	scmi_dev->name = kstrdup_const(name ?: "unknown", GFP_KERNEL);  in __scmi_device_create()
361 	if (!scmi_dev->name) {  in __scmi_device_create()
368 		kfree_const(scmi_dev->name);  in __scmi_device_create()
373 	scmi_dev->id = id;  in __scmi_device_create()
374 	scmi_dev->protocol_id = protocol;  in __scmi_device_create()
375 	scmi_dev->dev.parent = parent;  in __scmi_device_create()
376 	device_set_node(&scmi_dev->dev, of_fwnode_handle(np));  in __scmi_device_create()
377 	scmi_dev->dev.bus = &scmi_bus_type;  in __scmi_device_create()
378 	scmi_dev->dev.release = scmi_device_release;  in __scmi_device_create()
379 	dev_set_name(&scmi_dev->dev, "scmi_dev.%d", id);  in __scmi_device_create()
381 	retval = device_register(&scmi_dev->dev);  in __scmi_device_create()
385 	pr_debug("(%s) Created SCMI device '%s' for protocol 0x%x (%s)\n",  in __scmi_device_create()
386 		 of_node_full_name(parent->of_node),  in __scmi_device_create()
387 		 dev_name(&scmi_dev->dev), protocol, name);  in __scmi_device_create()
391 	put_device(&scmi_dev->dev);  in __scmi_device_create()
397  * scmi_device_create  - A method to create one or more SCMI devices
399  * @np: A reference to the device node to use for the new device(s)
401  * @protocol: The SCMI protocol to be associated with this device
402  * @name: The requested-name of the device to be created; this is optional
404  *	  be requested on the SCMI bus for @protocol will be created.
406  * This method can be invoked to create a single well-defined device (like
410  * protocol (typically during SCMI core protocol enumeration at probe time).
416  *	   could have been potentially created for a whole protocol, unless no
417  *	   device was found to have been requested for that specific protocol.
420 				       struct device *parent, int protocol,  in scmi_device_create()  argument
428 		return __scmi_device_create(np, parent, protocol, name);  in scmi_device_create()
431 	phead = idr_find(&scmi_requested_devices, protocol);  in scmi_device_create()
438 	/* Walk the list of requested devices for protocol and create them */  in scmi_device_create()
439 	list_for_each_entry(rdev, phead, node) {  in scmi_device_create()
443 					    rdev->id_table->protocol_id,  in scmi_device_create()
444 					    rdev->id_table->name);  in scmi_device_create()
449 			pr_err("(%s) Failed to create device for protocol 0x%x (%s)\n",  in scmi_device_create()
450 			       of_node_full_name(parent->of_node),  in scmi_device_create()
451 			       rdev->id_table->protocol_id,  in scmi_device_create()
452 			       rdev->id_table->name);  in scmi_device_create()
460 void scmi_device_destroy(struct device *parent, int protocol, const char *name)  in scmi_device_destroy()  argument
464 	scmi_dev = scmi_child_dev_find(parent, protocol, name);  in scmi_device_destroy()
489 		pr_err("SCMI protocol bus register failed (%d)\n", retval);  in scmi_bus_init()
491 	pr_info("SCMI protocol bus registered\n");  in scmi_bus_init()
509 MODULE_ALIAS("scmi-core");
511 MODULE_DESCRIPTION("ARM SCMI protocol bus");