4 * Copyright (c) 2012-2016, Intel Corporation.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/kernel.h>
19 #include <linux/device.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
23 #include "ishtp-dev.h"
27 static int ishtp_use_dma;
28 module_param_named(ishtp_use_dma, ishtp_use_dma, int, 0600);
29 MODULE_PARM_DESC(ishtp_use_dma, "Use DMA to send messages");
31 #define to_ishtp_cl_driver(d) container_of(d, struct ishtp_cl_driver, driver)
32 #define to_ishtp_cl_device(d) container_of(d, struct ishtp_cl_device, dev)
33 static bool ishtp_device_ready;
36 * ishtp_recv() - process ishtp message
39 * If a message with valid header and size is received, then
40 * this function calls appropriate handler. The host or firmware
41 * address is zero, then they are host bus management message,
42 * otherwise they are message fo clients.
44 void ishtp_recv(struct ishtp_device *dev)
47 struct ishtp_msg_hdr *ishtp_hdr;
49 /* Read ISHTP header dword */
50 msg_hdr = dev->ops->ishtp_read_hdr(dev);
54 dev->ops->sync_fw_clock(dev);
56 ishtp_hdr = (struct ishtp_msg_hdr *)&msg_hdr;
57 dev->ishtp_msg_hdr = msg_hdr;
59 /* Sanity check: ISHTP frag. length in header */
60 if (ishtp_hdr->length > dev->mtu) {
62 "ISHTP hdr - bad length: %u; dropped [%08X]\n",
63 (unsigned int)ishtp_hdr->length, msg_hdr);
67 /* ISHTP bus message */
68 if (!ishtp_hdr->host_addr && !ishtp_hdr->fw_addr)
69 recv_hbm(dev, ishtp_hdr);
70 /* ISHTP fixed-client message */
71 else if (!ishtp_hdr->host_addr)
72 recv_fixed_cl_msg(dev, ishtp_hdr);
74 /* ISHTP client message */
75 recv_ishtp_cl_msg(dev, ishtp_hdr);
77 EXPORT_SYMBOL(ishtp_recv);
80 * ishtp_send_msg() - Send ishtp message
82 * @hdr: Message header
83 * @msg: Message contents
84 * @ipc_send_compl: completion callback
85 * @ipc_send_compl_prm: completion callback parameter
87 * Send a multi fragment message via IPC. After sending the first fragment
88 * the completion callback is called to schedule transmit of next fragment.
90 * Return: This returns IPC send message status.
92 int ishtp_send_msg(struct ishtp_device *dev, struct ishtp_msg_hdr *hdr,
93 void *msg, void(*ipc_send_compl)(void *),
94 void *ipc_send_compl_prm)
96 unsigned char ipc_msg[IPC_FULL_MSG_SIZE];
99 drbl_val = dev->ops->ipc_get_header(dev, hdr->length +
100 sizeof(struct ishtp_msg_hdr),
103 memcpy(ipc_msg, &drbl_val, sizeof(uint32_t));
104 memcpy(ipc_msg + sizeof(uint32_t), hdr, sizeof(uint32_t));
105 memcpy(ipc_msg + 2 * sizeof(uint32_t), msg, hdr->length);
106 return dev->ops->write(dev, ipc_send_compl, ipc_send_compl_prm,
107 ipc_msg, 2 * sizeof(uint32_t) + hdr->length);
111 * ishtp_write_message() - Send ishtp single fragment message
113 * @hdr: Message header
116 * Send a single fragment message via IPC. This returns IPC send message
119 * Return: This returns IPC send message status.
121 int ishtp_write_message(struct ishtp_device *dev, struct ishtp_msg_hdr *hdr,
124 return ishtp_send_msg(dev, hdr, buf, NULL, NULL);
128 * ishtp_fw_cl_by_uuid() - locate index of fw client
130 * @uuid: uuid of the client to search
132 * Search firmware client using UUID.
134 * Return: fw client index or -ENOENT if not found
136 int ishtp_fw_cl_by_uuid(struct ishtp_device *dev, const guid_t *uuid)
140 for (i = 0; i < dev->fw_clients_num; ++i) {
141 if (guid_equal(uuid, &dev->fw_clients[i].props.protocol_name))
146 EXPORT_SYMBOL(ishtp_fw_cl_by_uuid);
149 * ishtp_fw_cl_get_client() - return client information to client
150 * @dev: the ishtp device structure
151 * @uuid: uuid of the client to search
153 * Search firmware client using UUID and reture related client information.
155 * Return: pointer of client information on success, NULL on failure.
157 struct ishtp_fw_client *ishtp_fw_cl_get_client(struct ishtp_device *dev,
163 spin_lock_irqsave(&dev->fw_clients_lock, flags);
164 i = ishtp_fw_cl_by_uuid(dev, uuid);
165 spin_unlock_irqrestore(&dev->fw_clients_lock, flags);
166 if (i < 0 || dev->fw_clients[i].props.fixed_address)
169 return &dev->fw_clients[i];
171 EXPORT_SYMBOL(ishtp_fw_cl_get_client);
174 * ishtp_get_fw_client_id() - Get fw client id
176 * This interface is used to reset HW get FW client id.
178 * Return: firmware client id.
180 int ishtp_get_fw_client_id(struct ishtp_fw_client *fw_client)
182 return fw_client->client_id;
184 EXPORT_SYMBOL(ishtp_get_fw_client_id);
187 * ishtp_fw_cl_by_id() - return index to fw_clients for client_id
188 * @dev: the ishtp device structure
189 * @client_id: fw client id to search
191 * Search firmware client using client id.
193 * Return: index on success, -ENOENT on failure.
195 int ishtp_fw_cl_by_id(struct ishtp_device *dev, uint8_t client_id)
197 int i, res = -ENOENT;
200 spin_lock_irqsave(&dev->fw_clients_lock, flags);
201 for (i = 0; i < dev->fw_clients_num; i++) {
202 if (dev->fw_clients[i].client_id == client_id) {
207 spin_unlock_irqrestore(&dev->fw_clients_lock, flags);
213 * ishtp_cl_device_probe() - Bus probe() callback
214 * @dev: the device structure
216 * This is a bus probe callback and calls the drive probe function.
218 * Return: Return value from driver probe() call.
220 static int ishtp_cl_device_probe(struct device *dev)
222 struct ishtp_cl_device *device = to_ishtp_cl_device(dev);
223 struct ishtp_cl_driver *driver;
228 driver = to_ishtp_cl_driver(dev->driver);
229 if (!driver || !driver->probe)
232 return driver->probe(device);
236 * ishtp_cl_bus_match() - Bus match() callback
237 * @dev: the device structure
238 * @drv: the driver structure
240 * This is a bus match callback, called when a new ishtp_cl_device is
241 * registered during ishtp bus client enumeration. Use the guid_t in
242 * drv and dev to decide whether they match or not.
244 * Return: 1 if dev & drv matches, 0 otherwise.
246 static int ishtp_cl_bus_match(struct device *dev, struct device_driver *drv)
248 struct ishtp_cl_device *device = to_ishtp_cl_device(dev);
249 struct ishtp_cl_driver *driver = to_ishtp_cl_driver(drv);
251 return guid_equal(driver->guid,
252 &device->fw_client->props.protocol_name);
256 * ishtp_cl_device_remove() - Bus remove() callback
257 * @dev: the device structure
259 * This is a bus remove callback and calls the drive remove function.
260 * Since the ISH driver model supports only built in, this is
261 * primarily can be called during pci driver init failure.
263 * Return: Return value from driver remove() call.
265 static int ishtp_cl_device_remove(struct device *dev)
267 struct ishtp_cl_device *device = to_ishtp_cl_device(dev);
268 struct ishtp_cl_driver *driver;
270 if (!device || !dev->driver)
273 if (device->event_cb) {
274 device->event_cb = NULL;
275 cancel_work_sync(&device->event_work);
278 driver = to_ishtp_cl_driver(dev->driver);
279 if (!driver->remove) {
285 return driver->remove(device);
289 * ishtp_cl_device_suspend() - Bus suspend callback
292 * Called during device suspend process.
294 * Return: Return value from driver suspend() call.
296 static int ishtp_cl_device_suspend(struct device *dev)
298 struct ishtp_cl_device *device = to_ishtp_cl_device(dev);
299 struct ishtp_cl_driver *driver;
305 driver = to_ishtp_cl_driver(dev->driver);
306 if (driver && driver->driver.pm) {
307 if (driver->driver.pm->suspend)
308 ret = driver->driver.pm->suspend(dev);
315 * ishtp_cl_device_resume() - Bus resume callback
318 * Called during device resume process.
320 * Return: Return value from driver resume() call.
322 static int ishtp_cl_device_resume(struct device *dev)
324 struct ishtp_cl_device *device = to_ishtp_cl_device(dev);
325 struct ishtp_cl_driver *driver;
332 * When ISH needs hard reset, it is done asynchrnously, hence bus
333 * resume will be called before full ISH resume
335 if (device->ishtp_dev->resume_flag)
338 driver = to_ishtp_cl_driver(dev->driver);
339 if (driver && driver->driver.pm) {
340 if (driver->driver.pm->resume)
341 ret = driver->driver.pm->resume(dev);
348 * ishtp_cl_device_reset() - Reset callback
349 * @device: ishtp client device instance
351 * This is a callback when HW reset is done and the device need
354 * Return: Return value from driver reset() call.
356 static int ishtp_cl_device_reset(struct ishtp_cl_device *device)
358 struct ishtp_cl_driver *driver;
361 device->event_cb = NULL;
362 cancel_work_sync(&device->event_work);
364 driver = to_ishtp_cl_driver(device->dev.driver);
365 if (driver && driver->reset)
366 ret = driver->reset(device);
371 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
376 len = snprintf(buf, PAGE_SIZE, "ishtp:%s\n", dev_name(dev));
377 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
379 static DEVICE_ATTR_RO(modalias);
381 static struct attribute *ishtp_cl_dev_attrs[] = {
382 &dev_attr_modalias.attr,
385 ATTRIBUTE_GROUPS(ishtp_cl_dev);
387 static int ishtp_cl_uevent(struct device *dev, struct kobj_uevent_env *env)
389 if (add_uevent_var(env, "MODALIAS=ishtp:%s", dev_name(dev)))
394 static const struct dev_pm_ops ishtp_cl_bus_dev_pm_ops = {
395 /* Suspend callbacks */
396 .suspend = ishtp_cl_device_suspend,
397 .resume = ishtp_cl_device_resume,
398 /* Hibernate callbacks */
399 .freeze = ishtp_cl_device_suspend,
400 .thaw = ishtp_cl_device_resume,
401 .restore = ishtp_cl_device_resume,
404 static struct bus_type ishtp_cl_bus_type = {
406 .dev_groups = ishtp_cl_dev_groups,
407 .probe = ishtp_cl_device_probe,
408 .match = ishtp_cl_bus_match,
409 .remove = ishtp_cl_device_remove,
410 .pm = &ishtp_cl_bus_dev_pm_ops,
411 .uevent = ishtp_cl_uevent,
414 static void ishtp_cl_dev_release(struct device *dev)
416 kfree(to_ishtp_cl_device(dev));
419 static const struct device_type ishtp_cl_device_type = {
420 .release = ishtp_cl_dev_release,
424 * ishtp_bus_add_device() - Function to create device on bus
426 * @uuid: uuid of the client
427 * @name: Name of the client
429 * Allocate ISHTP bus client device, attach it to uuid
430 * and register with ISHTP bus.
432 * Return: ishtp_cl_device pointer or NULL on failure
434 static struct ishtp_cl_device *ishtp_bus_add_device(struct ishtp_device *dev,
435 guid_t uuid, char *name)
437 struct ishtp_cl_device *device;
441 spin_lock_irqsave(&dev->device_list_lock, flags);
442 list_for_each_entry(device, &dev->device_list, device_link) {
443 if (!strcmp(name, dev_name(&device->dev))) {
444 device->fw_client = &dev->fw_clients[
445 dev->fw_client_presentation_num - 1];
446 spin_unlock_irqrestore(&dev->device_list_lock, flags);
447 ishtp_cl_device_reset(device);
451 spin_unlock_irqrestore(&dev->device_list_lock, flags);
453 device = kzalloc(sizeof(struct ishtp_cl_device), GFP_KERNEL);
457 device->dev.parent = dev->devc;
458 device->dev.bus = &ishtp_cl_bus_type;
459 device->dev.type = &ishtp_cl_device_type;
460 device->ishtp_dev = dev;
463 &dev->fw_clients[dev->fw_client_presentation_num - 1];
465 dev_set_name(&device->dev, "%s", name);
467 spin_lock_irqsave(&dev->device_list_lock, flags);
468 list_add_tail(&device->device_link, &dev->device_list);
469 spin_unlock_irqrestore(&dev->device_list_lock, flags);
471 status = device_register(&device->dev);
473 spin_lock_irqsave(&dev->device_list_lock, flags);
474 list_del(&device->device_link);
475 spin_unlock_irqrestore(&dev->device_list_lock, flags);
476 dev_err(dev->devc, "Failed to register ISHTP client device\n");
477 put_device(&device->dev);
481 ishtp_device_ready = true;
482 dev_set_drvdata(&device->dev, device);
488 * ishtp_bus_remove_device() - Function to relase device on bus
489 * @device: client device instance
491 * This is a counterpart of ishtp_bus_add_device.
492 * Device is unregistered.
493 * the device structure is freed in 'ishtp_cl_dev_release' function
494 * Called only during error in pci driver init path.
496 static void ishtp_bus_remove_device(struct ishtp_cl_device *device)
498 device_unregister(&device->dev);
502 * ishtp_cl_driver_register() - Client driver register
503 * @driver: the client driver instance
504 * @owner: Owner of this driver module
506 * Once a client driver is probed, it created a client
507 * instance and registers with the bus.
509 * Return: Return value of driver_register or -ENODEV if not ready
511 int ishtp_cl_driver_register(struct ishtp_cl_driver *driver,
512 struct module *owner)
516 if (!ishtp_device_ready)
519 driver->driver.name = driver->name;
520 driver->driver.owner = owner;
521 driver->driver.bus = &ishtp_cl_bus_type;
523 err = driver_register(&driver->driver);
529 EXPORT_SYMBOL(ishtp_cl_driver_register);
532 * ishtp_cl_driver_unregister() - Client driver unregister
533 * @driver: the client driver instance
535 * Unregister client during device removal process.
537 void ishtp_cl_driver_unregister(struct ishtp_cl_driver *driver)
539 driver_unregister(&driver->driver);
541 EXPORT_SYMBOL(ishtp_cl_driver_unregister);
544 * ishtp_bus_event_work() - event work function
545 * @work: work struct pointer
547 * Once an event is received for a client this work
548 * function is called. If the device has registered a
549 * callback then the callback is called.
551 static void ishtp_bus_event_work(struct work_struct *work)
553 struct ishtp_cl_device *device;
555 device = container_of(work, struct ishtp_cl_device, event_work);
557 if (device->event_cb)
558 device->event_cb(device);
562 * ishtp_cl_bus_rx_event() - schedule event work
563 * @device: client device instance
565 * Once an event is received for a client this schedules
566 * a work function to process.
568 void ishtp_cl_bus_rx_event(struct ishtp_cl_device *device)
570 if (!device || !device->event_cb)
573 if (device->event_cb)
574 schedule_work(&device->event_work);
578 * ishtp_register_event_cb() - Register callback
579 * @device: client device instance
580 * @event_cb: Event processor for an client
582 * Register a callback for events, called from client driver
584 * Return: Return 0 or -EALREADY if already registered
586 int ishtp_register_event_cb(struct ishtp_cl_device *device,
587 void (*event_cb)(struct ishtp_cl_device *))
589 if (device->event_cb)
592 device->event_cb = event_cb;
593 INIT_WORK(&device->event_work, ishtp_bus_event_work);
597 EXPORT_SYMBOL(ishtp_register_event_cb);
600 * ishtp_get_device() - update usage count for the device
601 * @cl_device: client device instance
603 * Increment the usage count. The device can't be deleted
605 void ishtp_get_device(struct ishtp_cl_device *cl_device)
607 cl_device->reference_count++;
609 EXPORT_SYMBOL(ishtp_get_device);
612 * ishtp_put_device() - decrement usage count for the device
613 * @cl_device: client device instance
615 * Decrement the usage count. The device can be deleted is count = 0
617 void ishtp_put_device(struct ishtp_cl_device *cl_device)
619 cl_device->reference_count--;
621 EXPORT_SYMBOL(ishtp_put_device);
624 * ishtp_set_drvdata() - set client driver data
625 * @cl_device: client device instance
626 * @data: driver data need to be set
628 * Set client driver data to cl_device->driver_data.
630 void ishtp_set_drvdata(struct ishtp_cl_device *cl_device, void *data)
632 cl_device->driver_data = data;
634 EXPORT_SYMBOL(ishtp_set_drvdata);
637 * ishtp_get_drvdata() - get client driver data
638 * @cl_device: client device instance
640 * Get client driver data from cl_device->driver_data.
642 * Return: pointer of driver data
644 void *ishtp_get_drvdata(struct ishtp_cl_device *cl_device)
646 return cl_device->driver_data;
648 EXPORT_SYMBOL(ishtp_get_drvdata);
651 * ishtp_bus_new_client() - Create a new client
652 * @dev: ISHTP device instance
654 * Once bus protocol enumerates a client, this is called
655 * to add a device for the client.
657 * Return: 0 on success or error code on failure
659 int ishtp_bus_new_client(struct ishtp_device *dev)
663 struct ishtp_cl_device *cl_device;
667 * For all reported clients, create an unconnected client and add its
668 * device to ISHTP bus.
669 * If appropriate driver has loaded, this will trigger its probe().
670 * Otherwise, probe() will be called when driver is loaded
672 i = dev->fw_client_presentation_num - 1;
673 device_uuid = dev->fw_clients[i].props.protocol_name;
674 dev_name = kasprintf(GFP_KERNEL, "{%pUL}", &device_uuid);
678 cl_device = ishtp_bus_add_device(dev, device_uuid, dev_name);
690 * ishtp_cl_device_bind() - bind a device
691 * @cl: ishtp client device
693 * Binds connected ishtp_cl to ISHTP bus device
695 * Return: 0 on success or fault code
697 int ishtp_cl_device_bind(struct ishtp_cl *cl)
699 struct ishtp_cl_device *cl_device;
703 if (!cl->fw_client_id || cl->state != ISHTP_CL_CONNECTED)
707 spin_lock_irqsave(&cl->dev->device_list_lock, flags);
708 list_for_each_entry(cl_device, &cl->dev->device_list,
710 if (cl_device->fw_client &&
711 cl_device->fw_client->client_id == cl->fw_client_id) {
712 cl->device = cl_device;
717 spin_unlock_irqrestore(&cl->dev->device_list_lock, flags);
722 * ishtp_bus_remove_all_clients() - Remove all clients
723 * @ishtp_dev: ishtp device
724 * @warm_reset: Reset due to FW reset dure to errors or S3 suspend
726 * This is part of reset/remove flow. This function the main processing
727 * only targets error processing, if the FW has forced reset or
728 * error to remove connected clients. When warm reset the client devices are
731 void ishtp_bus_remove_all_clients(struct ishtp_device *ishtp_dev,
734 struct ishtp_cl_device *cl_device, *n;
738 spin_lock_irqsave(&ishtp_dev->cl_list_lock, flags);
739 list_for_each_entry(cl, &ishtp_dev->cl_list, link) {
740 cl->state = ISHTP_CL_DISCONNECTED;
743 * Wake any pending process. The waiter would check dev->state
744 * and determine that it's not enabled already,
745 * and will return error to its caller
747 wake_up_interruptible(&cl->wait_ctrl_res);
749 /* Disband any pending read/write requests and free rb */
750 ishtp_cl_flush_queues(cl);
752 /* Remove all free and in_process rings, both Rx and Tx */
753 ishtp_cl_free_rx_ring(cl);
754 ishtp_cl_free_tx_ring(cl);
757 * Free client and ISHTP bus client device structures
758 * don't free host client because it is part of the OS fd
762 spin_unlock_irqrestore(&ishtp_dev->cl_list_lock, flags);
764 /* Release DMA buffers for client messages */
765 ishtp_cl_free_dma_buf(ishtp_dev);
767 /* remove bus clients */
768 spin_lock_irqsave(&ishtp_dev->device_list_lock, flags);
769 list_for_each_entry_safe(cl_device, n, &ishtp_dev->device_list,
771 cl_device->fw_client = NULL;
772 if (warm_reset && cl_device->reference_count)
775 list_del(&cl_device->device_link);
776 spin_unlock_irqrestore(&ishtp_dev->device_list_lock, flags);
777 ishtp_bus_remove_device(cl_device);
778 spin_lock_irqsave(&ishtp_dev->device_list_lock, flags);
780 spin_unlock_irqrestore(&ishtp_dev->device_list_lock, flags);
782 /* Free all client structures */
783 spin_lock_irqsave(&ishtp_dev->fw_clients_lock, flags);
784 kfree(ishtp_dev->fw_clients);
785 ishtp_dev->fw_clients = NULL;
786 ishtp_dev->fw_clients_num = 0;
787 ishtp_dev->fw_client_presentation_num = 0;
788 ishtp_dev->fw_client_index = 0;
789 bitmap_zero(ishtp_dev->fw_clients_map, ISHTP_CLIENTS_MAX);
790 spin_unlock_irqrestore(&ishtp_dev->fw_clients_lock, flags);
792 EXPORT_SYMBOL(ishtp_bus_remove_all_clients);
795 * ishtp_reset_handler() - IPC reset handler
798 * ISHTP Handler for IPC_RESET notification
800 void ishtp_reset_handler(struct ishtp_device *dev)
804 /* Handle FW-initiated reset */
805 dev->dev_state = ISHTP_DEV_RESETTING;
807 /* Clear BH processing queue - no further HBMs */
808 spin_lock_irqsave(&dev->rd_msg_spinlock, flags);
809 dev->rd_msg_fifo_head = dev->rd_msg_fifo_tail = 0;
810 spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
812 /* Handle ISH FW reset against upper layers */
813 ishtp_bus_remove_all_clients(dev, true);
815 EXPORT_SYMBOL(ishtp_reset_handler);
818 * ishtp_reset_compl_handler() - Reset completion handler
821 * ISHTP handler for IPC_RESET sequence completion to start
822 * host message bus start protocol sequence.
824 void ishtp_reset_compl_handler(struct ishtp_device *dev)
826 dev->dev_state = ISHTP_DEV_INIT_CLIENTS;
827 dev->hbm_state = ISHTP_HBM_START;
828 ishtp_hbm_start_req(dev);
830 EXPORT_SYMBOL(ishtp_reset_compl_handler);
833 * ishtp_use_dma_transfer() - Function to use DMA
835 * This interface is used to enable usage of DMA
837 * Return non zero if DMA can be enabled
839 int ishtp_use_dma_transfer(void)
841 return ishtp_use_dma;
845 * ishtp_device() - Return device pointer
847 * This interface is used to return device pointer from ishtp_cl_device
852 struct device *ishtp_device(struct ishtp_cl_device *device)
856 EXPORT_SYMBOL(ishtp_device);
859 * ishtp_get_pci_device() - Return PCI device dev pointer
860 * This interface is used to return PCI device pointer
861 * from ishtp_cl_device instance.
865 struct device *ishtp_get_pci_device(struct ishtp_cl_device *device)
867 return device->ishtp_dev->devc;
869 EXPORT_SYMBOL(ishtp_get_pci_device);
872 * ishtp_trace_callback() - Return trace callback
874 * This interface is used to return trace callback function pointer.
878 void *ishtp_trace_callback(struct ishtp_cl_device *cl_device)
880 return cl_device->ishtp_dev->print_log;
882 EXPORT_SYMBOL(ishtp_trace_callback);
885 * ish_hw_reset() - Call HW reset IPC callback
887 * This interface is used to reset HW in case of error.
889 * Return: value from IPC hw_reset callback
891 int ish_hw_reset(struct ishtp_device *dev)
893 return dev->ops->hw_reset(dev);
895 EXPORT_SYMBOL(ish_hw_reset);
898 * ishtp_bus_register() - Function to register bus
900 * This register ishtp bus
902 * Return: Return output of bus_register
904 static int __init ishtp_bus_register(void)
906 return bus_register(&ishtp_cl_bus_type);
910 * ishtp_bus_unregister() - Function to unregister bus
912 * This unregister ishtp bus
914 static void __exit ishtp_bus_unregister(void)
916 bus_unregister(&ishtp_cl_bus_type);
919 module_init(ishtp_bus_register);
920 module_exit(ishtp_bus_unregister);
922 MODULE_LICENSE("GPL");