1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * ACPI-WMI mapping driver
5 * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
7 * GUID parsing code from ldm.c is:
8 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
9 * Copyright (c) 2001-2007 Anton Altaparmakov
10 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
12 * WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
13 * Copyright (C) 2015 Andrew Lutomirski
14 * Copyright (C) 2017 VMware, Inc. All Rights Reserved.
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19 #include <linux/acpi.h>
20 #include <linux/device.h>
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/list.h>
24 #include <linux/miscdevice.h>
25 #include <linux/module.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28 #include <linux/types.h>
29 #include <linux/uaccess.h>
30 #include <linux/uuid.h>
31 #include <linux/wmi.h>
33 #include <uapi/linux/wmi.h>
35 MODULE_AUTHOR("Carlos Corbacho");
36 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
37 MODULE_LICENSE("GPL");
39 static LIST_HEAD(wmi_block_list);
46 unsigned char notify_id;
47 unsigned char reserved;
55 struct wmi_device dev;
56 struct list_head list;
57 struct guid_block gblock;
58 struct miscdevice char_dev;
59 struct mutex char_mutex;
60 struct acpi_device *acpi_device;
61 wmi_notify_handler handler;
65 bool read_takes_no_args;
70 * If the GUID data block is marked as expensive, we must enable and
71 * explicitily disable data collection.
73 #define ACPI_WMI_EXPENSIVE 0x1
74 #define ACPI_WMI_METHOD 0x2 /* GUID is a method */
75 #define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */
76 #define ACPI_WMI_EVENT 0x8 /* GUID is an event */
78 static bool debug_event;
79 module_param(debug_event, bool, 0444);
80 MODULE_PARM_DESC(debug_event,
81 "Log WMI Events [0/1]");
83 static bool debug_dump_wdg;
84 module_param(debug_dump_wdg, bool, 0444);
85 MODULE_PARM_DESC(debug_dump_wdg,
86 "Dump available WMI interfaces [0/1]");
88 static int acpi_wmi_remove(struct platform_device *device);
89 static int acpi_wmi_probe(struct platform_device *device);
91 static const struct acpi_device_id wmi_device_ids[] = {
96 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
98 static struct platform_driver acpi_wmi_driver = {
101 .acpi_match_table = wmi_device_ids,
103 .probe = acpi_wmi_probe,
104 .remove = acpi_wmi_remove,
108 * GUID parsing functions
111 static bool find_guid(const char *guid_string, struct wmi_block **out)
114 struct wmi_block *wblock;
115 struct guid_block *block;
117 if (guid_parse(guid_string, &guid_input))
120 list_for_each_entry(wblock, &wmi_block_list, list) {
121 block = &wblock->gblock;
123 if (memcmp(block->guid, &guid_input, 16) == 0) {
132 static const void *find_guid_context(struct wmi_block *wblock,
133 struct wmi_driver *wdriver)
135 const struct wmi_device_id *id;
138 if (wblock == NULL || wdriver == NULL)
140 if (wdriver->id_table == NULL)
143 id = wdriver->id_table;
144 while (*id->guid_string) {
145 if (guid_parse(id->guid_string, &guid_input))
147 if (!memcmp(wblock->gblock.guid, &guid_input, 16))
154 static int get_subobj_info(acpi_handle handle, const char *pathname,
155 struct acpi_device_info **info)
157 struct acpi_device_info *dummy_info, **info_ptr;
158 acpi_handle subobj_handle;
161 status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
162 if (status == AE_NOT_FOUND)
164 else if (ACPI_FAILURE(status))
167 info_ptr = info ? info : &dummy_info;
168 status = acpi_get_object_info(subobj_handle, info_ptr);
169 if (ACPI_FAILURE(status))
178 static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
180 struct guid_block *block = NULL;
185 block = &wblock->gblock;
186 handle = wblock->acpi_device->handle;
188 snprintf(method, 5, "WE%02X", block->notify_id);
189 status = acpi_execute_simple_method(handle, method, enable);
191 if (status != AE_OK && status != AE_NOT_FOUND)
198 * Exported WMI functions
202 * set_required_buffer_size - Sets the buffer size needed for performing IOCTL
203 * @wdev: A wmi bus device from a driver
204 * @length: Required buffer size
206 * Allocates memory needed for buffer, stores the buffer size in that memory
208 int set_required_buffer_size(struct wmi_device *wdev, u64 length)
210 struct wmi_block *wblock;
212 wblock = container_of(wdev, struct wmi_block, dev);
213 wblock->req_buf_size = length;
217 EXPORT_SYMBOL_GPL(set_required_buffer_size);
220 * wmi_evaluate_method - Evaluate a WMI method
221 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
222 * @instance: Instance index
223 * @method_id: Method ID to call
224 * @in: Buffer containing input for the method call
225 * @out: Empty buffer to return the method results
227 * Call an ACPI-WMI method
229 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
230 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
232 struct wmi_block *wblock = NULL;
234 if (!find_guid(guid_string, &wblock))
236 return wmidev_evaluate_method(&wblock->dev, instance, method_id,
239 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
242 * wmidev_evaluate_method - Evaluate a WMI method
243 * @wdev: A wmi bus device from a driver
244 * @instance: Instance index
245 * @method_id: Method ID to call
246 * @in: Buffer containing input for the method call
247 * @out: Empty buffer to return the method results
249 * Call an ACPI-WMI method
251 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
252 u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
254 struct guid_block *block = NULL;
255 struct wmi_block *wblock = NULL;
258 struct acpi_object_list input;
259 union acpi_object params[3];
260 char method[5] = "WM";
262 wblock = container_of(wdev, struct wmi_block, dev);
263 block = &wblock->gblock;
264 handle = wblock->acpi_device->handle;
266 if (!(block->flags & ACPI_WMI_METHOD))
269 if (block->instance_count <= instance)
270 return AE_BAD_PARAMETER;
273 input.pointer = params;
274 params[0].type = ACPI_TYPE_INTEGER;
275 params[0].integer.value = instance;
276 params[1].type = ACPI_TYPE_INTEGER;
277 params[1].integer.value = method_id;
282 if (block->flags & ACPI_WMI_STRING) {
283 params[2].type = ACPI_TYPE_STRING;
285 params[2].type = ACPI_TYPE_BUFFER;
287 params[2].buffer.length = in->length;
288 params[2].buffer.pointer = in->pointer;
291 strncat(method, block->object_id, 2);
293 status = acpi_evaluate_object(handle, method, &input, out);
297 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
299 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
300 struct acpi_buffer *out)
302 struct guid_block *block = NULL;
304 acpi_status status, wc_status = AE_ERROR;
305 struct acpi_object_list input;
306 union acpi_object wq_params[1];
308 char wc_method[5] = "WC";
311 return AE_BAD_PARAMETER;
313 block = &wblock->gblock;
314 handle = wblock->acpi_device->handle;
316 if (block->instance_count <= instance)
317 return AE_BAD_PARAMETER;
319 /* Check GUID is a data block */
320 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
324 input.pointer = wq_params;
325 wq_params[0].type = ACPI_TYPE_INTEGER;
326 wq_params[0].integer.value = instance;
328 if (instance == 0 && wblock->read_takes_no_args)
332 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
335 if (block->flags & ACPI_WMI_EXPENSIVE) {
336 strncat(wc_method, block->object_id, 2);
339 * Some GUIDs break the specification by declaring themselves
340 * expensive, but have no corresponding WCxx method. So we
341 * should not fail if this happens.
343 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
346 strcpy(method, "WQ");
347 strncat(method, block->object_id, 2);
349 status = acpi_evaluate_object(handle, method, &input, out);
352 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
353 * the WQxx method failed - we should disable collection anyway.
355 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
356 status = acpi_execute_simple_method(handle, wc_method, 0);
363 * wmi_query_block - Return contents of a WMI block (deprecated)
364 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
365 * @instance: Instance index
366 * @out: Empty buffer to return the contents of the data block to
368 * Return the contents of an ACPI-WMI data block to a buffer
370 acpi_status wmi_query_block(const char *guid_string, u8 instance,
371 struct acpi_buffer *out)
373 struct wmi_block *wblock;
376 return AE_BAD_PARAMETER;
378 if (!find_guid(guid_string, &wblock))
381 return __query_block(wblock, instance, out);
383 EXPORT_SYMBOL_GPL(wmi_query_block);
385 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
387 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
388 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
390 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
393 return (union acpi_object *)out.pointer;
395 EXPORT_SYMBOL_GPL(wmidev_block_query);
398 * wmi_set_block - Write to a WMI block
399 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
400 * @instance: Instance index
401 * @in: Buffer containing new values for the data block
403 * Write the contents of the input buffer to an ACPI-WMI data block
405 acpi_status wmi_set_block(const char *guid_string, u8 instance,
406 const struct acpi_buffer *in)
408 struct guid_block *block = NULL;
409 struct wmi_block *wblock = NULL;
411 struct acpi_object_list input;
412 union acpi_object params[2];
413 char method[5] = "WS";
415 if (!guid_string || !in)
418 if (!find_guid(guid_string, &wblock))
421 block = &wblock->gblock;
422 handle = wblock->acpi_device->handle;
424 if (block->instance_count <= instance)
425 return AE_BAD_PARAMETER;
427 /* Check GUID is a data block */
428 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
432 input.pointer = params;
433 params[0].type = ACPI_TYPE_INTEGER;
434 params[0].integer.value = instance;
436 if (block->flags & ACPI_WMI_STRING) {
437 params[1].type = ACPI_TYPE_STRING;
439 params[1].type = ACPI_TYPE_BUFFER;
441 params[1].buffer.length = in->length;
442 params[1].buffer.pointer = in->pointer;
444 strncat(method, block->object_id, 2);
446 return acpi_evaluate_object(handle, method, &input, NULL);
448 EXPORT_SYMBOL_GPL(wmi_set_block);
450 static void wmi_dump_wdg(const struct guid_block *g)
452 pr_info("%pUL:\n", g->guid);
453 if (g->flags & ACPI_WMI_EVENT)
454 pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
456 pr_info("\tobject_id: %2pE\n", g->object_id);
457 pr_info("\tinstance_count: %d\n", g->instance_count);
458 pr_info("\tflags: %#x", g->flags);
460 if (g->flags & ACPI_WMI_EXPENSIVE)
461 pr_cont(" ACPI_WMI_EXPENSIVE");
462 if (g->flags & ACPI_WMI_METHOD)
463 pr_cont(" ACPI_WMI_METHOD");
464 if (g->flags & ACPI_WMI_STRING)
465 pr_cont(" ACPI_WMI_STRING");
466 if (g->flags & ACPI_WMI_EVENT)
467 pr_cont(" ACPI_WMI_EVENT");
473 static void wmi_notify_debug(u32 value, void *context)
475 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
476 union acpi_object *obj;
479 status = wmi_get_event_data(value, &response);
480 if (status != AE_OK) {
481 pr_info("bad event status 0x%x\n", status);
485 obj = (union acpi_object *)response.pointer;
490 pr_info("DEBUG Event ");
492 case ACPI_TYPE_BUFFER:
493 pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
495 case ACPI_TYPE_STRING:
496 pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
498 case ACPI_TYPE_INTEGER:
499 pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
501 case ACPI_TYPE_PACKAGE:
502 pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
505 pr_cont("object type 0x%X\n", obj->type);
511 * wmi_install_notify_handler - Register handler for WMI events
512 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
513 * @handler: Function to handle notifications
514 * @data: Data to be returned to handler when event is fired
516 * Register a handler for events sent to the ACPI-WMI mapper device.
518 acpi_status wmi_install_notify_handler(const char *guid,
519 wmi_notify_handler handler, void *data)
521 struct wmi_block *block;
522 acpi_status status = AE_NOT_EXIST;
525 if (!guid || !handler)
526 return AE_BAD_PARAMETER;
528 if (guid_parse(guid, &guid_input))
529 return AE_BAD_PARAMETER;
531 list_for_each_entry(block, &wmi_block_list, list) {
532 acpi_status wmi_status;
534 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
535 if (block->handler &&
536 block->handler != wmi_notify_debug)
537 return AE_ALREADY_ACQUIRED;
539 block->handler = handler;
540 block->handler_data = data;
542 wmi_status = wmi_method_enable(block, 1);
543 if ((wmi_status != AE_OK) ||
544 ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
551 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
554 * wmi_uninstall_notify_handler - Unregister handler for WMI events
555 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
557 * Unregister handler for events sent to the ACPI-WMI mapper device.
559 acpi_status wmi_remove_notify_handler(const char *guid)
561 struct wmi_block *block;
562 acpi_status status = AE_NOT_EXIST;
566 return AE_BAD_PARAMETER;
568 if (guid_parse(guid, &guid_input))
569 return AE_BAD_PARAMETER;
571 list_for_each_entry(block, &wmi_block_list, list) {
572 acpi_status wmi_status;
574 if (memcmp(block->gblock.guid, &guid_input, 16) == 0) {
575 if (!block->handler ||
576 block->handler == wmi_notify_debug)
577 return AE_NULL_ENTRY;
580 block->handler = wmi_notify_debug;
583 wmi_status = wmi_method_enable(block, 0);
584 block->handler = NULL;
585 block->handler_data = NULL;
586 if ((wmi_status != AE_OK) ||
587 ((wmi_status == AE_OK) &&
588 (status == AE_NOT_EXIST)))
596 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
599 * wmi_get_event_data - Get WMI data associated with an event
601 * @event: Event to find
602 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
604 * Returns extra data associated with an event in WMI.
606 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
608 struct acpi_object_list input;
609 union acpi_object params[1];
610 struct guid_block *gblock;
611 struct wmi_block *wblock;
614 input.pointer = params;
615 params[0].type = ACPI_TYPE_INTEGER;
616 params[0].integer.value = event;
618 list_for_each_entry(wblock, &wmi_block_list, list) {
619 gblock = &wblock->gblock;
621 if ((gblock->flags & ACPI_WMI_EVENT) &&
622 (gblock->notify_id == event))
623 return acpi_evaluate_object(wblock->acpi_device->handle,
624 "_WED", &input, out);
629 EXPORT_SYMBOL_GPL(wmi_get_event_data);
632 * wmi_has_guid - Check if a GUID is available
633 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
635 * Check if a given GUID is defined by _WDG
637 bool wmi_has_guid(const char *guid_string)
639 return find_guid(guid_string, NULL);
641 EXPORT_SYMBOL_GPL(wmi_has_guid);
644 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
645 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
647 * Find the _UID of ACPI device associated with this WMI GUID.
649 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found
651 char *wmi_get_acpi_device_uid(const char *guid_string)
653 struct wmi_block *wblock = NULL;
655 if (!find_guid(guid_string, &wblock))
658 return acpi_device_uid(wblock->acpi_device);
660 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
662 static struct wmi_block *dev_to_wblock(struct device *dev)
664 return container_of(dev, struct wmi_block, dev.dev);
667 static struct wmi_device *dev_to_wdev(struct device *dev)
669 return container_of(dev, struct wmi_device, dev);
675 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
678 struct wmi_block *wblock = dev_to_wblock(dev);
680 return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
682 static DEVICE_ATTR_RO(modalias);
684 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
687 struct wmi_block *wblock = dev_to_wblock(dev);
689 return sprintf(buf, "%pUL\n", wblock->gblock.guid);
691 static DEVICE_ATTR_RO(guid);
693 static ssize_t instance_count_show(struct device *dev,
694 struct device_attribute *attr, char *buf)
696 struct wmi_block *wblock = dev_to_wblock(dev);
698 return sprintf(buf, "%d\n", (int)wblock->gblock.instance_count);
700 static DEVICE_ATTR_RO(instance_count);
702 static ssize_t expensive_show(struct device *dev,
703 struct device_attribute *attr, char *buf)
705 struct wmi_block *wblock = dev_to_wblock(dev);
707 return sprintf(buf, "%d\n",
708 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
710 static DEVICE_ATTR_RO(expensive);
712 static struct attribute *wmi_attrs[] = {
713 &dev_attr_modalias.attr,
715 &dev_attr_instance_count.attr,
716 &dev_attr_expensive.attr,
719 ATTRIBUTE_GROUPS(wmi);
721 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
724 struct wmi_block *wblock = dev_to_wblock(dev);
726 return sprintf(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
728 static DEVICE_ATTR_RO(notify_id);
730 static struct attribute *wmi_event_attrs[] = {
731 &dev_attr_notify_id.attr,
734 ATTRIBUTE_GROUPS(wmi_event);
736 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
739 struct wmi_block *wblock = dev_to_wblock(dev);
741 return sprintf(buf, "%c%c\n", wblock->gblock.object_id[0],
742 wblock->gblock.object_id[1]);
744 static DEVICE_ATTR_RO(object_id);
746 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
749 struct wmi_device *wdev = dev_to_wdev(dev);
751 return sprintf(buf, "%d\n", (int)wdev->setable);
753 static DEVICE_ATTR_RO(setable);
755 static struct attribute *wmi_data_attrs[] = {
756 &dev_attr_object_id.attr,
757 &dev_attr_setable.attr,
760 ATTRIBUTE_GROUPS(wmi_data);
762 static struct attribute *wmi_method_attrs[] = {
763 &dev_attr_object_id.attr,
766 ATTRIBUTE_GROUPS(wmi_method);
768 static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
770 struct wmi_block *wblock = dev_to_wblock(dev);
772 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
775 if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
781 static void wmi_dev_release(struct device *dev)
783 struct wmi_block *wblock = dev_to_wblock(dev);
788 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
790 struct wmi_driver *wmi_driver =
791 container_of(driver, struct wmi_driver, driver);
792 struct wmi_block *wblock = dev_to_wblock(dev);
793 const struct wmi_device_id *id = wmi_driver->id_table;
798 while (*id->guid_string) {
801 if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
803 if (!memcmp(&driver_guid, wblock->gblock.guid, 16))
811 static int wmi_char_open(struct inode *inode, struct file *filp)
813 const char *driver_name = filp->f_path.dentry->d_iname;
814 struct wmi_block *wblock = NULL;
815 struct wmi_block *next = NULL;
817 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
818 if (!wblock->dev.dev.driver)
820 if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
821 filp->private_data = wblock;
826 if (!filp->private_data)
829 return nonseekable_open(inode, filp);
832 static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
833 size_t length, loff_t *offset)
835 struct wmi_block *wblock = filp->private_data;
837 return simple_read_from_buffer(buffer, length, offset,
838 &wblock->req_buf_size,
839 sizeof(wblock->req_buf_size));
842 static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
844 struct wmi_ioctl_buffer __user *input =
845 (struct wmi_ioctl_buffer __user *) arg;
846 struct wmi_block *wblock = filp->private_data;
847 struct wmi_ioctl_buffer *buf = NULL;
848 struct wmi_driver *wdriver = NULL;
851 if (_IOC_TYPE(cmd) != WMI_IOC)
854 /* make sure we're not calling a higher instance than exists*/
855 if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
858 mutex_lock(&wblock->char_mutex);
859 buf = wblock->handler_data;
860 if (get_user(buf->length, &input->length)) {
861 dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
865 /* if it's too small, abort */
866 if (buf->length < wblock->req_buf_size) {
867 dev_err(&wblock->dev.dev,
868 "Buffer %lld too small, need at least %lld\n",
869 buf->length, wblock->req_buf_size);
873 /* if it's too big, warn, driver will only use what is needed */
874 if (buf->length > wblock->req_buf_size)
875 dev_warn(&wblock->dev.dev,
876 "Buffer %lld is bigger than required %lld\n",
877 buf->length, wblock->req_buf_size);
879 /* copy the structure from userspace */
880 if (copy_from_user(buf, input, wblock->req_buf_size)) {
881 dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
882 wblock->req_buf_size);
887 /* let the driver do any filtering and do the call */
888 wdriver = container_of(wblock->dev.dev.driver,
889 struct wmi_driver, driver);
890 if (!try_module_get(wdriver->driver.owner)) {
894 ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
895 module_put(wdriver->driver.owner);
899 /* return the result (only up to our internal buffer size) */
900 if (copy_to_user(input, buf, wblock->req_buf_size)) {
901 dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
902 wblock->req_buf_size);
907 mutex_unlock(&wblock->char_mutex);
911 static const struct file_operations wmi_fops = {
912 .owner = THIS_MODULE,
913 .read = wmi_char_read,
914 .open = wmi_char_open,
915 .unlocked_ioctl = wmi_ioctl,
916 .compat_ioctl = compat_ptr_ioctl,
919 static int wmi_dev_probe(struct device *dev)
921 struct wmi_block *wblock = dev_to_wblock(dev);
922 struct wmi_driver *wdriver =
923 container_of(dev->driver, struct wmi_driver, driver);
927 if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
928 dev_warn(dev, "failed to enable device -- probing anyway\n");
930 if (wdriver->probe) {
931 ret = wdriver->probe(dev_to_wdev(dev),
932 find_guid_context(wblock, wdriver));
937 /* driver wants a character device made */
938 if (wdriver->filter_callback) {
939 /* check that required buffer size declared by driver or MOF */
940 if (!wblock->req_buf_size) {
941 dev_err(&wblock->dev.dev,
942 "Required buffer size not set\n");
947 wblock->handler_data = kmalloc(wblock->req_buf_size,
949 if (!wblock->handler_data) {
954 buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
957 goto probe_string_failure;
959 wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
960 wblock->char_dev.name = buf;
961 wblock->char_dev.fops = &wmi_fops;
962 wblock->char_dev.mode = 0444;
963 ret = misc_register(&wblock->char_dev);
965 dev_warn(dev, "failed to register char dev: %d\n", ret);
967 goto probe_misc_failure;
975 probe_string_failure:
976 kfree(wblock->handler_data);
978 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
979 dev_warn(dev, "failed to disable device\n");
983 static void wmi_dev_remove(struct device *dev)
985 struct wmi_block *wblock = dev_to_wblock(dev);
986 struct wmi_driver *wdriver =
987 container_of(dev->driver, struct wmi_driver, driver);
989 if (wdriver->filter_callback) {
990 misc_deregister(&wblock->char_dev);
991 kfree(wblock->char_dev.name);
992 kfree(wblock->handler_data);
996 wdriver->remove(dev_to_wdev(dev));
998 if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
999 dev_warn(dev, "failed to disable device\n");
1002 static struct class wmi_bus_class = {
1006 static struct bus_type wmi_bus_type = {
1008 .dev_groups = wmi_groups,
1009 .match = wmi_dev_match,
1010 .uevent = wmi_dev_uevent,
1011 .probe = wmi_dev_probe,
1012 .remove = wmi_dev_remove,
1015 static const struct device_type wmi_type_event = {
1017 .groups = wmi_event_groups,
1018 .release = wmi_dev_release,
1021 static const struct device_type wmi_type_method = {
1023 .groups = wmi_method_groups,
1024 .release = wmi_dev_release,
1027 static const struct device_type wmi_type_data = {
1029 .groups = wmi_data_groups,
1030 .release = wmi_dev_release,
1033 static int wmi_create_device(struct device *wmi_bus_dev,
1034 const struct guid_block *gblock,
1035 struct wmi_block *wblock,
1036 struct acpi_device *device)
1038 struct acpi_device_info *info;
1042 if (gblock->flags & ACPI_WMI_EVENT) {
1043 wblock->dev.dev.type = &wmi_type_event;
1047 if (gblock->flags & ACPI_WMI_METHOD) {
1048 wblock->dev.dev.type = &wmi_type_method;
1049 mutex_init(&wblock->char_mutex);
1054 * Data Block Query Control Method (WQxx by convention) is
1055 * required per the WMI documentation. If it is not present,
1056 * we ignore this data block.
1058 strcpy(method, "WQ");
1059 strncat(method, wblock->gblock.object_id, 2);
1060 result = get_subobj_info(device->handle, method, &info);
1063 dev_warn(wmi_bus_dev,
1064 "%s data block query control method not found\n",
1069 wblock->dev.dev.type = &wmi_type_data;
1072 * The Microsoft documentation specifically states:
1074 * Data blocks registered with only a single instance
1075 * can ignore the parameter.
1077 * ACPICA will get mad at us if we call the method with the wrong number
1078 * of arguments, so check what our method expects. (On some Dell
1079 * laptops, WQxx may not be a method at all.)
1081 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1082 wblock->read_takes_no_args = true;
1086 strcpy(method, "WS");
1087 strncat(method, wblock->gblock.object_id, 2);
1088 result = get_subobj_info(device->handle, method, NULL);
1091 wblock->dev.setable = true;
1094 wblock->dev.dev.bus = &wmi_bus_type;
1095 wblock->dev.dev.parent = wmi_bus_dev;
1097 dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
1099 device_initialize(&wblock->dev.dev);
1104 static void wmi_free_devices(struct acpi_device *device)
1106 struct wmi_block *wblock, *next;
1108 /* Delete devices for all the GUIDs */
1109 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1110 if (wblock->acpi_device == device) {
1111 list_del(&wblock->list);
1112 device_unregister(&wblock->dev.dev);
1117 static bool guid_already_parsed(struct acpi_device *device, const u8 *guid)
1119 struct wmi_block *wblock;
1121 list_for_each_entry(wblock, &wmi_block_list, list) {
1122 if (memcmp(wblock->gblock.guid, guid, 16) == 0) {
1124 * Because we historically didn't track the relationship
1125 * between GUIDs and ACPI nodes, we don't know whether
1126 * we need to suppress GUIDs that are unique on a
1127 * given node but duplicated across nodes.
1129 dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
1130 guid, dev_name(&wblock->acpi_device->dev));
1139 * Parse the _WDG method for the GUID data blocks
1141 static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
1143 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1144 const struct guid_block *gblock;
1145 struct wmi_block *wblock, *next;
1146 union acpi_object *obj;
1151 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1152 if (ACPI_FAILURE(status))
1155 obj = (union acpi_object *) out.pointer;
1159 if (obj->type != ACPI_TYPE_BUFFER) {
1161 goto out_free_pointer;
1164 gblock = (const struct guid_block *)obj->buffer.pointer;
1165 total = obj->buffer.length / sizeof(struct guid_block);
1167 for (i = 0; i < total; i++) {
1169 wmi_dump_wdg(&gblock[i]);
1172 * Some WMI devices, like those for nVidia hooks, have a
1173 * duplicate GUID. It's not clear what we should do in this
1174 * case yet, so for now, we'll just ignore the duplicate
1175 * for device creation.
1177 if (guid_already_parsed(device, gblock[i].guid))
1180 wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
1186 wblock->acpi_device = device;
1187 wblock->gblock = gblock[i];
1189 retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);
1195 list_add_tail(&wblock->list, &wmi_block_list);
1198 wblock->handler = wmi_notify_debug;
1199 wmi_method_enable(wblock, 1);
1204 * Now that all of the devices are created, add them to the
1205 * device tree and probe subdrivers.
1207 list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
1208 if (wblock->acpi_device != device)
1211 retval = device_add(&wblock->dev.dev);
1213 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1214 wblock->gblock.guid);
1216 wmi_method_enable(wblock, 0);
1217 list_del(&wblock->list);
1218 put_device(&wblock->dev.dev);
1228 * WMI can have EmbeddedControl access regions. In which case, we just want to
1229 * hand these off to the EC driver.
1232 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1233 u32 bits, u64 *value,
1234 void *handler_context, void *region_context)
1236 int result = 0, i = 0;
1239 if ((address > 0xFF) || !value)
1240 return AE_BAD_PARAMETER;
1242 if (function != ACPI_READ && function != ACPI_WRITE)
1243 return AE_BAD_PARAMETER;
1246 return AE_BAD_PARAMETER;
1248 if (function == ACPI_READ) {
1249 result = ec_read(address, &temp);
1250 (*value) |= ((u64)temp) << i;
1252 temp = 0xff & ((*value) >> i);
1253 result = ec_write(address, temp);
1258 return AE_BAD_PARAMETER;
1260 return AE_NOT_FOUND;
1268 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
1271 struct guid_block *block;
1272 struct wmi_block *wblock;
1273 bool found_it = false;
1275 list_for_each_entry(wblock, &wmi_block_list, list) {
1276 block = &wblock->gblock;
1278 if (wblock->acpi_device->handle == handle &&
1279 (block->flags & ACPI_WMI_EVENT) &&
1280 (block->notify_id == event))
1290 /* If a driver is bound, then notify the driver. */
1291 if (wblock->dev.dev.driver) {
1292 struct wmi_driver *driver;
1293 struct acpi_object_list input;
1294 union acpi_object params[1];
1295 struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
1298 driver = container_of(wblock->dev.dev.driver,
1299 struct wmi_driver, driver);
1302 input.pointer = params;
1303 params[0].type = ACPI_TYPE_INTEGER;
1304 params[0].integer.value = event;
1306 status = acpi_evaluate_object(wblock->acpi_device->handle,
1307 "_WED", &input, &evdata);
1308 if (ACPI_FAILURE(status)) {
1309 dev_warn(&wblock->dev.dev,
1310 "failed to get event data\n");
1315 driver->notify(&wblock->dev,
1316 (union acpi_object *)evdata.pointer);
1318 kfree(evdata.pointer);
1319 } else if (wblock->handler) {
1320 /* Legacy handler */
1321 wblock->handler(event, wblock->handler_data);
1325 pr_info("DEBUG Event GUID: %pUL\n", wblock->gblock.guid);
1327 acpi_bus_generate_netlink_event(
1328 wblock->acpi_device->pnp.device_class,
1329 dev_name(&wblock->dev.dev),
1334 static int acpi_wmi_remove(struct platform_device *device)
1336 struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
1338 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1339 acpi_wmi_notify_handler);
1340 acpi_remove_address_space_handler(acpi_device->handle,
1341 ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
1342 wmi_free_devices(acpi_device);
1343 device_unregister((struct device *)dev_get_drvdata(&device->dev));
1348 static int acpi_wmi_probe(struct platform_device *device)
1350 struct acpi_device *acpi_device;
1351 struct device *wmi_bus_dev;
1355 acpi_device = ACPI_COMPANION(&device->dev);
1357 dev_err(&device->dev, "ACPI companion is missing\n");
1361 status = acpi_install_address_space_handler(acpi_device->handle,
1363 &acpi_wmi_ec_space_handler,
1365 if (ACPI_FAILURE(status)) {
1366 dev_err(&device->dev, "Error installing EC region handler\n");
1370 status = acpi_install_notify_handler(acpi_device->handle,
1372 acpi_wmi_notify_handler,
1374 if (ACPI_FAILURE(status)) {
1375 dev_err(&device->dev, "Error installing notify handler\n");
1377 goto err_remove_ec_handler;
1380 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
1381 NULL, "wmi_bus-%s", dev_name(&device->dev));
1382 if (IS_ERR(wmi_bus_dev)) {
1383 error = PTR_ERR(wmi_bus_dev);
1384 goto err_remove_notify_handler;
1386 dev_set_drvdata(&device->dev, wmi_bus_dev);
1388 error = parse_wdg(wmi_bus_dev, acpi_device);
1390 pr_err("Failed to parse WDG method\n");
1391 goto err_remove_busdev;
1397 device_unregister(wmi_bus_dev);
1399 err_remove_notify_handler:
1400 acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,
1401 acpi_wmi_notify_handler);
1403 err_remove_ec_handler:
1404 acpi_remove_address_space_handler(acpi_device->handle,
1406 &acpi_wmi_ec_space_handler);
1411 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1412 struct module *owner)
1414 driver->driver.owner = owner;
1415 driver->driver.bus = &wmi_bus_type;
1417 return driver_register(&driver->driver);
1419 EXPORT_SYMBOL(__wmi_driver_register);
1421 void wmi_driver_unregister(struct wmi_driver *driver)
1423 driver_unregister(&driver->driver);
1425 EXPORT_SYMBOL(wmi_driver_unregister);
1427 static int __init acpi_wmi_init(void)
1434 error = class_register(&wmi_bus_class);
1438 error = bus_register(&wmi_bus_type);
1440 goto err_unreg_class;
1442 error = platform_driver_register(&acpi_wmi_driver);
1444 pr_err("Error loading mapper\n");
1451 bus_unregister(&wmi_bus_type);
1454 class_unregister(&wmi_bus_class);
1459 static void __exit acpi_wmi_exit(void)
1461 platform_driver_unregister(&acpi_wmi_driver);
1462 bus_unregister(&wmi_bus_type);
1463 class_unregister(&wmi_bus_class);
1466 subsys_initcall_sync(acpi_wmi_init);
1467 module_exit(acpi_wmi_exit);