2 * Intel Management Engine Interface (Intel MEI) Linux driver
3 * Copyright (c) 2012-2013, Intel Corporation.
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 #include <linux/module.h>
17 #include <linux/device.h>
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/init.h>
21 #include <linux/errno.h>
22 #include <linux/slab.h>
23 #include <linux/mutex.h>
24 #include <linux/interrupt.h>
25 #include <linux/mei_cl_bus.h>
30 #define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
31 #define to_mei_cl_device(d) container_of(d, struct mei_cl_device, dev)
34 * __mei_cl_send - internal client send (write)
37 * @buf: buffer to send
38 * @length: buffer length
39 * @blocking: wait for write completion
41 * Return: written size bytes or < 0 on error
43 ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
46 struct mei_device *bus;
47 struct mei_cl_cb *cb = NULL;
50 if (WARN_ON(!cl || !cl->dev))
55 mutex_lock(&bus->device_lock);
56 if (!mei_cl_is_connected(cl)) {
61 /* Check if we have an ME client device */
62 if (!mei_me_cl_is_active(cl->me_cl)) {
67 if (length > mei_cl_mtu(cl)) {
72 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
78 memcpy(cb->buf.data, buf, length);
80 rets = mei_cl_write(cl, cb, blocking);
83 mutex_unlock(&bus->device_lock);
91 * __mei_cl_recv - internal client receive (read)
94 * @buf: buffer to send
95 * @length: buffer length
97 * Return: read size in bytes of < 0 on error
99 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
101 struct mei_device *bus;
102 struct mei_cl_cb *cb;
106 if (WARN_ON(!cl || !cl->dev))
111 mutex_lock(&bus->device_lock);
113 cb = mei_cl_read_cb(cl, NULL);
117 rets = mei_cl_read_start(cl, length, NULL);
118 if (rets && rets != -EBUSY)
121 /* wait on event only if there is no other waiter */
122 if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) {
124 mutex_unlock(&bus->device_lock);
126 if (wait_event_interruptible(cl->rx_wait,
127 (!list_empty(&cl->rd_completed)) ||
128 (!mei_cl_is_connected(cl)))) {
130 if (signal_pending(current))
135 mutex_lock(&bus->device_lock);
137 if (!mei_cl_is_connected(cl)) {
143 cb = mei_cl_read_cb(cl, NULL);
155 r_length = min_t(size_t, length, cb->buf_idx);
156 memcpy(buf, cb->buf.data, r_length);
162 mutex_unlock(&bus->device_lock);
168 * mei_cl_send - me device send (write)
170 * @cldev: me client device
171 * @buf: buffer to send
172 * @length: buffer length
174 * Return: written size in bytes or < 0 on error
176 ssize_t mei_cl_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
178 struct mei_cl *cl = cldev->cl;
183 return __mei_cl_send(cl, buf, length, 1);
185 EXPORT_SYMBOL_GPL(mei_cl_send);
188 * mei_cl_recv - client receive (read)
190 * @cldev: me client device
191 * @buf: buffer to send
192 * @length: buffer length
194 * Return: read size in bytes of < 0 on error
196 ssize_t mei_cl_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
198 struct mei_cl *cl = cldev->cl;
203 return __mei_cl_recv(cl, buf, length);
205 EXPORT_SYMBOL_GPL(mei_cl_recv);
208 * mei_bus_event_work - dispatch rx event for a bus device
209 * and schedule new work
213 static void mei_bus_event_work(struct work_struct *work)
215 struct mei_cl_device *cldev;
217 cldev = container_of(work, struct mei_cl_device, event_work);
220 cldev->event_cb(cldev, cldev->events, cldev->event_context);
224 /* Prepare for the next read */
225 if (cldev->events_mask & BIT(MEI_CL_EVENT_RX))
226 mei_cl_read_start(cldev->cl, 0, NULL);
230 * mei_cl_bus_notify_event - schedule notify cb on bus client
234 void mei_cl_bus_notify_event(struct mei_cl *cl)
236 struct mei_cl_device *cldev = cl->cldev;
238 if (!cldev || !cldev->event_cb)
241 if (!(cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)))
247 set_bit(MEI_CL_EVENT_NOTIF, &cldev->events);
249 schedule_work(&cldev->event_work);
251 cl->notify_ev = false;
255 * mei_cl_bus_rx_event - schedule rx evenet
259 void mei_cl_bus_rx_event(struct mei_cl *cl)
261 struct mei_cl_device *cldev = cl->cldev;
263 if (!cldev || !cldev->event_cb)
266 if (!(cldev->events_mask & BIT(MEI_CL_EVENT_RX)))
269 set_bit(MEI_CL_EVENT_RX, &cldev->events);
271 schedule_work(&cldev->event_work);
275 * mei_cl_register_event_cb - register event callback
277 * @cldev: me client devices
278 * @event_cb: callback function
279 * @events_mask: requested events bitmask
280 * @context: driver context data
282 * Return: 0 on success
283 * -EALREADY if an callback is already registered
286 int mei_cl_register_event_cb(struct mei_cl_device *cldev,
287 unsigned long events_mask,
288 mei_cl_event_cb_t event_cb, void *context)
296 cldev->events_mask = events_mask;
297 cldev->event_cb = event_cb;
298 cldev->event_context = context;
299 INIT_WORK(&cldev->event_work, mei_bus_event_work);
301 if (cldev->events_mask & BIT(MEI_CL_EVENT_RX)) {
302 ret = mei_cl_read_start(cldev->cl, 0, NULL);
303 if (ret && ret != -EBUSY)
307 if (cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)) {
308 mutex_lock(&cldev->cl->dev->device_lock);
309 ret = mei_cl_notify_request(cldev->cl, NULL, event_cb ? 1 : 0);
310 mutex_unlock(&cldev->cl->dev->device_lock);
317 EXPORT_SYMBOL_GPL(mei_cl_register_event_cb);
320 * mei_cl_get_drvdata - driver data getter
322 * @cldev: mei client device
324 * Return: driver private data
326 void *mei_cl_get_drvdata(const struct mei_cl_device *cldev)
328 return dev_get_drvdata(&cldev->dev);
330 EXPORT_SYMBOL_GPL(mei_cl_get_drvdata);
333 * mei_cl_set_drvdata - driver data setter
335 * @cldev: mei client device
336 * @data: data to store
338 void mei_cl_set_drvdata(struct mei_cl_device *cldev, void *data)
340 dev_set_drvdata(&cldev->dev, data);
342 EXPORT_SYMBOL_GPL(mei_cl_set_drvdata);
345 * mei_cl_enable_device - enable me client device
346 * create connection with me client
348 * @cldev: me client device
350 * Return: 0 on success and < 0 on error
352 int mei_cl_enable_device(struct mei_cl_device *cldev)
354 struct mei_device *bus = cldev->bus;
361 mutex_lock(&bus->device_lock);
362 cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
363 mutex_unlock(&bus->device_lock);
366 /* update pointers */
371 mutex_lock(&bus->device_lock);
372 if (mei_cl_is_connected(cl)) {
377 if (!mei_me_cl_is_active(cldev->me_cl)) {
378 dev_err(&cldev->dev, "me client is not active\n");
383 ret = mei_cl_connect(cl, cldev->me_cl, NULL);
385 dev_err(&cldev->dev, "cannot connect\n");
388 mutex_unlock(&bus->device_lock);
392 EXPORT_SYMBOL_GPL(mei_cl_enable_device);
395 * mei_cl_disable_device - disable me client device
396 * disconnect form the me client
398 * @cldev: me client device
400 * Return: 0 on success and < 0 on error
402 int mei_cl_disable_device(struct mei_cl_device *cldev)
404 struct mei_device *bus;
408 if (!cldev || !cldev->cl)
415 cldev->event_cb = NULL;
417 mutex_lock(&bus->device_lock);
419 if (!mei_cl_is_connected(cl)) {
420 dev_err(bus->dev, "Already disconnected");
425 err = mei_cl_disconnect(cl);
427 dev_err(bus->dev, "Could not disconnect from the ME client");
430 /* Flush queues and remove any pending read */
431 mei_cl_flush_queues(cl, NULL);
437 mutex_unlock(&bus->device_lock);
440 EXPORT_SYMBOL_GPL(mei_cl_disable_device);
443 * mei_cl_device_find - find matching entry in the driver id table
445 * @cldev: me client device
446 * @cldrv: me client driver
448 * Return: id on success; NULL if no id is matching
451 struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
452 struct mei_cl_driver *cldrv)
454 const struct mei_cl_device_id *id;
457 uuid = mei_me_cl_uuid(cldev->me_cl);
459 id = cldrv->id_table;
460 while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
461 if (!uuid_le_cmp(*uuid, id->uuid)) {
466 if (!strncmp(cldev->name, id->name, sizeof(id->name)))
477 * mei_cl_device_match - device match function
482 * Return: 1 if matching device was found 0 otherwise
484 static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
486 struct mei_cl_device *cldev = to_mei_cl_device(dev);
487 struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
488 const struct mei_cl_device_id *found_id;
493 if (!cldev->do_match)
496 if (!cldrv || !cldrv->id_table)
499 found_id = mei_cl_device_find(cldev, cldrv);
507 * mei_cl_device_probe - bus probe function
511 * Return: 0 on success; < 0 otherwise
513 static int mei_cl_device_probe(struct device *dev)
515 struct mei_cl_device *cldev;
516 struct mei_cl_driver *cldrv;
517 const struct mei_cl_device_id *id;
519 cldev = to_mei_cl_device(dev);
520 cldrv = to_mei_cl_driver(dev->driver);
525 if (!cldrv || !cldrv->probe)
528 id = mei_cl_device_find(cldev, cldrv);
532 __module_get(THIS_MODULE);
534 return cldrv->probe(cldev, id);
538 * mei_cl_device_remove - remove device from the bus
542 * Return: 0 on success; < 0 otherwise
544 static int mei_cl_device_remove(struct device *dev)
546 struct mei_cl_device *cldev = to_mei_cl_device(dev);
547 struct mei_cl_driver *cldrv;
550 if (!cldev || !dev->driver)
553 if (cldev->event_cb) {
554 cldev->event_cb = NULL;
555 cancel_work_sync(&cldev->event_work);
558 cldrv = to_mei_cl_driver(dev->driver);
560 ret = cldrv->remove(cldev);
562 module_put(THIS_MODULE);
568 static ssize_t name_show(struct device *dev, struct device_attribute *a,
571 struct mei_cl_device *cldev = to_mei_cl_device(dev);
574 len = snprintf(buf, PAGE_SIZE, "%s", cldev->name);
576 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
578 static DEVICE_ATTR_RO(name);
580 static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
583 struct mei_cl_device *cldev = to_mei_cl_device(dev);
584 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
587 len = snprintf(buf, PAGE_SIZE, "%pUl", uuid);
589 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
591 static DEVICE_ATTR_RO(uuid);
593 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
596 struct mei_cl_device *cldev = to_mei_cl_device(dev);
597 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
600 len = snprintf(buf, PAGE_SIZE, "mei:%s:" MEI_CL_UUID_FMT ":",
601 cldev->name, MEI_CL_UUID_ARGS(uuid->b));
603 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
605 static DEVICE_ATTR_RO(modalias);
607 static struct attribute *mei_cl_dev_attrs[] = {
610 &dev_attr_modalias.attr,
613 ATTRIBUTE_GROUPS(mei_cl_dev);
616 * mei_cl_device_uevent - me client bus uevent handler
619 * @env: uevent kobject
621 * Return: 0 on success -ENOMEM on when add_uevent_var fails
623 static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
625 struct mei_cl_device *cldev = to_mei_cl_device(dev);
626 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
628 if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
631 if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
634 if (add_uevent_var(env, "MODALIAS=mei:%s:" MEI_CL_UUID_FMT ":",
635 cldev->name, MEI_CL_UUID_ARGS(uuid->b)))
641 static struct bus_type mei_cl_bus_type = {
643 .dev_groups = mei_cl_dev_groups,
644 .match = mei_cl_device_match,
645 .probe = mei_cl_device_probe,
646 .remove = mei_cl_device_remove,
647 .uevent = mei_cl_device_uevent,
650 static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
653 get_device(bus->dev);
658 static void mei_dev_bus_put(struct mei_device *bus)
661 put_device(bus->dev);
664 static void mei_cl_dev_release(struct device *dev)
666 struct mei_cl_device *cldev = to_mei_cl_device(dev);
671 mei_me_cl_put(cldev->me_cl);
672 mei_dev_bus_put(cldev->bus);
676 static struct device_type mei_cl_device_type = {
677 .release = mei_cl_dev_release,
681 * mei_cl_dev_alloc - initialize and allocate mei client device
686 * Return: allocated device structur or NULL on allocation failure
688 static struct mei_cl_device *mei_cl_dev_alloc(struct mei_device *bus,
689 struct mei_me_client *me_cl)
691 struct mei_cl_device *cldev;
693 cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
697 device_initialize(&cldev->dev);
698 cldev->dev.parent = bus->dev;
699 cldev->dev.bus = &mei_cl_bus_type;
700 cldev->dev.type = &mei_cl_device_type;
701 cldev->bus = mei_dev_bus_get(bus);
702 cldev->me_cl = mei_me_cl_get(me_cl);
704 INIT_LIST_HEAD(&cldev->bus_list);
710 * mei_cl_dev_setup - setup me client device
711 * run fix up routines and set the device name
714 * @cldev: me client device
716 * Return: true if the device is eligible for enumeration
718 static bool mei_cl_dev_setup(struct mei_device *bus,
719 struct mei_cl_device *cldev)
722 mei_cl_dev_fixup(cldev);
725 dev_set_name(&cldev->dev, "mei:%s:%pUl",
726 cldev->name, mei_me_cl_uuid(cldev->me_cl));
728 return cldev->do_match == 1;
732 * mei_cl_bus_dev_add - add me client devices
734 * @cldev: me client device
736 * Return: 0 on success; < 0 on failre
738 static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
742 dev_dbg(cldev->bus->dev, "adding %pUL\n", mei_me_cl_uuid(cldev->me_cl));
743 ret = device_add(&cldev->dev);
751 * mei_cl_bus_dev_stop - stop the driver
753 * @cldev: me client device
755 static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
758 device_release_driver(&cldev->dev);
762 * mei_cl_bus_dev_destroy - destroy me client devices object
764 * @cldev: me client device
766 static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
768 if (!cldev->is_added)
771 device_del(&cldev->dev);
773 mutex_lock(&cldev->bus->cl_bus_lock);
774 list_del_init(&cldev->bus_list);
775 mutex_unlock(&cldev->bus->cl_bus_lock);
778 put_device(&cldev->dev);
782 * mei_cl_bus_remove_device - remove a devices form the bus
784 * @cldev: me client device
786 static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
788 mei_cl_bus_dev_stop(cldev);
789 mei_cl_bus_dev_destroy(cldev);
793 * mei_cl_bus_remove_devices - remove all devices form the bus
797 void mei_cl_bus_remove_devices(struct mei_device *bus)
799 struct mei_cl_device *cldev, *next;
801 list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
802 mei_cl_bus_remove_device(cldev);
807 * mei_cl_dev_init - allocate and initializes an mei client devices
813 static void mei_cl_dev_init(struct mei_device *bus, struct mei_me_client *me_cl)
815 struct mei_cl_device *cldev;
817 dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
819 if (me_cl->bus_added)
822 cldev = mei_cl_dev_alloc(bus, me_cl);
826 mutex_lock(&cldev->bus->cl_bus_lock);
827 me_cl->bus_added = true;
828 list_add_tail(&cldev->bus_list, &bus->device_list);
829 mutex_unlock(&cldev->bus->cl_bus_lock);
834 * mei_cl_bus_rescan - scan me clients list and add create
835 * devices for eligible clients
839 void mei_cl_bus_rescan(struct mei_device *bus)
841 struct mei_cl_device *cldev, *n;
842 struct mei_me_client *me_cl;
844 down_read(&bus->me_clients_rwsem);
845 list_for_each_entry(me_cl, &bus->me_clients, list)
846 mei_cl_dev_init(bus, me_cl);
847 up_read(&bus->me_clients_rwsem);
849 mutex_lock(&bus->cl_bus_lock);
850 list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
852 if (!mei_me_cl_is_active(cldev->me_cl)) {
853 mei_cl_bus_remove_device(cldev);
860 if (mei_cl_dev_setup(bus, cldev))
861 mei_cl_bus_dev_add(cldev);
863 list_del_init(&cldev->bus_list);
864 put_device(&cldev->dev);
867 mutex_unlock(&bus->cl_bus_lock);
869 dev_dbg(bus->dev, "rescan end");
872 int __mei_cl_driver_register(struct mei_cl_driver *cldrv, struct module *owner)
876 cldrv->driver.name = cldrv->name;
877 cldrv->driver.owner = owner;
878 cldrv->driver.bus = &mei_cl_bus_type;
880 err = driver_register(&cldrv->driver);
884 pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
888 EXPORT_SYMBOL_GPL(__mei_cl_driver_register);
890 void mei_cl_driver_unregister(struct mei_cl_driver *cldrv)
892 driver_unregister(&cldrv->driver);
894 pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
896 EXPORT_SYMBOL_GPL(mei_cl_driver_unregister);
899 int __init mei_cl_bus_init(void)
901 return bus_register(&mei_cl_bus_type);
904 void __exit mei_cl_bus_exit(void)
906 bus_unregister(&mei_cl_bus_type);