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/bits.h>
21 #include <linux/build_bug.h>
22 #include <linux/device.h>
23 #include <linux/init.h>
24 #include <linux/kernel.h>
25 #include <linux/list.h>
26 #include <linux/module.h>
27 #include <linux/platform_device.h>
28 #include <linux/rwsem.h>
29 #include <linux/slab.h>
30 #include <linux/sysfs.h>
31 #include <linux/types.h>
32 #include <linux/uuid.h>
33 #include <linux/wmi.h>
36 MODULE_AUTHOR("Carlos Corbacho");
37 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
38 MODULE_LICENSE("GPL");
40 static LIST_HEAD(wmi_block_list);
47 unsigned char notify_id;
48 unsigned char reserved;
54 static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
55 static_assert(sizeof(struct guid_block) == 20);
56 static_assert(__alignof__(struct guid_block) == 1);
58 enum { /* wmi_block flags */
59 WMI_READ_TAKES_NO_ARGS,
65 struct wmi_device dev;
66 struct list_head list;
67 struct guid_block gblock;
68 struct acpi_device *acpi_device;
69 struct rw_semaphore notify_lock; /* Protects notify callback add/remove */
70 wmi_notify_handler handler;
78 * If the GUID data block is marked as expensive, we must enable and
79 * explicitily disable data collection.
81 #define ACPI_WMI_EXPENSIVE BIT(0)
82 #define ACPI_WMI_METHOD BIT(1) /* GUID is a method */
83 #define ACPI_WMI_STRING BIT(2) /* GUID takes & returns a string */
84 #define ACPI_WMI_EVENT BIT(3) /* GUID is an event */
86 static const struct acpi_device_id wmi_device_ids[] = {
91 MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
93 #define dev_to_wblock(__dev) container_of_const(__dev, struct wmi_block, dev.dev)
94 #define dev_to_wdev(__dev) container_of_const(__dev, struct wmi_device, dev)
97 * GUID parsing functions
100 static bool guid_parse_and_compare(const char *string, const guid_t *guid)
104 if (guid_parse(string, &guid_input))
107 return guid_equal(&guid_input, guid);
110 static const void *find_guid_context(struct wmi_block *wblock,
111 struct wmi_driver *wdriver)
113 const struct wmi_device_id *id;
115 id = wdriver->id_table;
119 while (*id->guid_string) {
120 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
127 static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
129 struct guid_block *block;
134 block = &wblock->gblock;
135 handle = wblock->acpi_device->handle;
137 snprintf(method, 5, "WE%02X", block->notify_id);
138 status = acpi_execute_simple_method(handle, method, enable);
139 if (status == AE_NOT_FOUND)
145 #define WMI_ACPI_METHOD_NAME_SIZE 5
147 static inline void get_acpi_method_name(const struct wmi_block *wblock,
149 char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
151 static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
152 static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
156 buffer[2] = wblock->gblock.object_id[0];
157 buffer[3] = wblock->gblock.object_id[1];
161 static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
163 if (wblock->gblock.flags & ACPI_WMI_STRING)
164 return ACPI_TYPE_STRING;
166 return ACPI_TYPE_BUFFER;
169 static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out)
171 union acpi_object param = {
173 .type = ACPI_TYPE_INTEGER,
174 .value = wblock->gblock.notify_id,
177 struct acpi_object_list input = {
182 return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
185 static int wmidev_match_guid(struct device *dev, const void *data)
187 struct wmi_block *wblock = dev_to_wblock(dev);
188 const guid_t *guid = data;
190 /* Legacy GUID-based functions are restricted to only see
191 * a single WMI device for each GUID.
193 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
196 if (guid_equal(guid, &wblock->gblock.guid))
202 static int wmidev_match_notify_id(struct device *dev, const void *data)
204 struct wmi_block *wblock = dev_to_wblock(dev);
205 const u32 *notify_id = data;
207 /* Legacy GUID-based functions are restricted to only see
208 * a single WMI device for each GUID.
210 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
213 if (wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *notify_id)
219 static const struct bus_type wmi_bus_type;
221 static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
227 ret = guid_parse(guid_string, &guid);
231 dev = bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid);
233 return ERR_PTR(-ENODEV);
235 return dev_to_wdev(dev);
238 static struct wmi_device *wmi_find_event_by_notify_id(const u32 notify_id)
242 dev = bus_find_device(&wmi_bus_type, NULL, ¬ify_id, wmidev_match_notify_id);
244 return ERR_PTR(-ENODEV);
246 return to_wmi_device(dev);
249 static void wmi_device_put(struct wmi_device *wdev)
251 put_device(&wdev->dev);
255 * Exported WMI functions
259 * wmi_instance_count - Get number of WMI object instances
260 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
262 * Get the number of WMI object instances.
264 * Returns: Number of WMI object instances or negative error code.
266 int wmi_instance_count(const char *guid_string)
268 struct wmi_device *wdev;
271 wdev = wmi_find_device_by_guid(guid_string);
273 return PTR_ERR(wdev);
275 ret = wmidev_instance_count(wdev);
276 wmi_device_put(wdev);
280 EXPORT_SYMBOL_GPL(wmi_instance_count);
283 * wmidev_instance_count - Get number of WMI object instances
284 * @wdev: A wmi bus device from a driver
286 * Get the number of WMI object instances.
288 * Returns: Number of WMI object instances.
290 u8 wmidev_instance_count(struct wmi_device *wdev)
292 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
294 return wblock->gblock.instance_count;
296 EXPORT_SYMBOL_GPL(wmidev_instance_count);
299 * wmi_evaluate_method - Evaluate a WMI method (deprecated)
300 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
301 * @instance: Instance index
302 * @method_id: Method ID to call
303 * @in: Mandatory buffer containing input for the method call
304 * @out: Empty buffer to return the method results
306 * Call an ACPI-WMI method, the caller must free @out.
308 * Return: acpi_status signaling success or error.
310 acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
311 const struct acpi_buffer *in, struct acpi_buffer *out)
313 struct wmi_device *wdev;
316 wdev = wmi_find_device_by_guid(guid_string);
320 status = wmidev_evaluate_method(wdev, instance, method_id, in, out);
322 wmi_device_put(wdev);
326 EXPORT_SYMBOL_GPL(wmi_evaluate_method);
329 * wmidev_evaluate_method - Evaluate a WMI method
330 * @wdev: A wmi bus device from a driver
331 * @instance: Instance index
332 * @method_id: Method ID to call
333 * @in: Mandatory buffer containing input for the method call
334 * @out: Empty buffer to return the method results
336 * Call an ACPI-WMI method, the caller must free @out.
338 * Return: acpi_status signaling success or error.
340 acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
341 const struct acpi_buffer *in, struct acpi_buffer *out)
343 struct guid_block *block;
344 struct wmi_block *wblock;
346 struct acpi_object_list input;
347 union acpi_object params[3];
348 char method[WMI_ACPI_METHOD_NAME_SIZE];
350 wblock = container_of(wdev, struct wmi_block, dev);
351 block = &wblock->gblock;
352 handle = wblock->acpi_device->handle;
357 if (!(block->flags & ACPI_WMI_METHOD))
360 if (block->instance_count <= instance)
361 return AE_BAD_PARAMETER;
364 input.pointer = params;
366 params[0].type = ACPI_TYPE_INTEGER;
367 params[0].integer.value = instance;
368 params[1].type = ACPI_TYPE_INTEGER;
369 params[1].integer.value = method_id;
370 params[2].type = get_param_acpi_type(wblock);
371 params[2].buffer.length = in->length;
372 params[2].buffer.pointer = in->pointer;
374 get_acpi_method_name(wblock, 'M', method);
376 return acpi_evaluate_object(handle, method, &input, out);
378 EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
380 static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
381 struct acpi_buffer *out)
383 struct guid_block *block;
385 acpi_status status, wc_status = AE_ERROR;
386 struct acpi_object_list input;
387 union acpi_object wq_params[1];
388 char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
389 char method[WMI_ACPI_METHOD_NAME_SIZE];
392 return AE_BAD_PARAMETER;
394 block = &wblock->gblock;
395 handle = wblock->acpi_device->handle;
397 if (block->instance_count <= instance)
398 return AE_BAD_PARAMETER;
400 /* Check GUID is a data block */
401 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
405 input.pointer = wq_params;
406 wq_params[0].type = ACPI_TYPE_INTEGER;
407 wq_params[0].integer.value = instance;
409 if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
413 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
416 if (block->flags & ACPI_WMI_EXPENSIVE) {
417 get_acpi_method_name(wblock, 'C', wc_method);
420 * Some GUIDs break the specification by declaring themselves
421 * expensive, but have no corresponding WCxx method. So we
422 * should not fail if this happens.
424 wc_status = acpi_execute_simple_method(handle, wc_method, 1);
427 get_acpi_method_name(wblock, 'Q', method);
428 status = acpi_evaluate_object(handle, method, &input, out);
431 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
432 * the WQxx method failed - we should disable collection anyway.
434 if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
436 * Ignore whether this WCxx call succeeds or not since
437 * the previously executed WQxx method call might have
438 * succeeded, and returning the failing status code
439 * of this call would throw away the result of the WQxx
440 * call, potentially leaking memory.
442 acpi_execute_simple_method(handle, wc_method, 0);
449 * wmi_query_block - Return contents of a WMI block (deprecated)
450 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
451 * @instance: Instance index
452 * @out: Empty buffer to return the contents of the data block to
454 * Query a ACPI-WMI block, the caller must free @out.
456 * Return: ACPI object containing the content of the WMI block.
458 acpi_status wmi_query_block(const char *guid_string, u8 instance,
459 struct acpi_buffer *out)
461 struct wmi_block *wblock;
462 struct wmi_device *wdev;
465 wdev = wmi_find_device_by_guid(guid_string);
469 wblock = container_of(wdev, struct wmi_block, dev);
470 status = __query_block(wblock, instance, out);
472 wmi_device_put(wdev);
476 EXPORT_SYMBOL_GPL(wmi_query_block);
479 * wmidev_block_query - Return contents of a WMI block
480 * @wdev: A wmi bus device from a driver
481 * @instance: Instance index
483 * Query an ACPI-WMI block, the caller must free the result.
485 * Return: ACPI object containing the content of the WMI block.
487 union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
489 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
490 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
492 if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
497 EXPORT_SYMBOL_GPL(wmidev_block_query);
500 * wmi_set_block - Write to a WMI block (deprecated)
501 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
502 * @instance: Instance index
503 * @in: Buffer containing new values for the data block
505 * Write the contents of the input buffer to an ACPI-WMI data block.
507 * Return: acpi_status signaling success or error.
509 acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in)
511 struct wmi_device *wdev;
514 wdev = wmi_find_device_by_guid(guid_string);
518 status = wmidev_block_set(wdev, instance, in);
519 wmi_device_put(wdev);
523 EXPORT_SYMBOL_GPL(wmi_set_block);
526 * wmidev_block_set - Write to a WMI block
527 * @wdev: A wmi bus device from a driver
528 * @instance: Instance index
529 * @in: Buffer containing new values for the data block
531 * Write contents of the input buffer to an ACPI-WMI data block.
533 * Return: acpi_status signaling success or error.
535 acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct acpi_buffer *in)
537 struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
538 acpi_handle handle = wblock->acpi_device->handle;
539 struct guid_block *block = &wblock->gblock;
540 char method[WMI_ACPI_METHOD_NAME_SIZE];
541 struct acpi_object_list input;
542 union acpi_object params[2];
547 if (block->instance_count <= instance)
548 return AE_BAD_PARAMETER;
550 /* Check GUID is a data block */
551 if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
555 input.pointer = params;
556 params[0].type = ACPI_TYPE_INTEGER;
557 params[0].integer.value = instance;
558 params[1].type = get_param_acpi_type(wblock);
559 params[1].buffer.length = in->length;
560 params[1].buffer.pointer = in->pointer;
562 get_acpi_method_name(wblock, 'S', method);
564 return acpi_evaluate_object(handle, method, &input, NULL);
566 EXPORT_SYMBOL_GPL(wmidev_block_set);
569 * wmi_install_notify_handler - Register handler for WMI events (deprecated)
570 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
571 * @handler: Function to handle notifications
572 * @data: Data to be returned to handler when event is fired
574 * Register a handler for events sent to the ACPI-WMI mapper device.
576 * Return: acpi_status signaling success or error.
578 acpi_status wmi_install_notify_handler(const char *guid,
579 wmi_notify_handler handler,
582 struct wmi_block *wblock;
583 struct wmi_device *wdev;
586 wdev = wmi_find_device_by_guid(guid);
590 wblock = container_of(wdev, struct wmi_block, dev);
592 down_write(&wblock->notify_lock);
593 if (wblock->handler) {
594 status = AE_ALREADY_ACQUIRED;
596 wblock->handler = handler;
597 wblock->handler_data = data;
599 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
600 dev_warn(&wblock->dev.dev, "Failed to enable device\n");
604 up_write(&wblock->notify_lock);
606 wmi_device_put(wdev);
610 EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
613 * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated)
614 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
616 * Unregister handler for events sent to the ACPI-WMI mapper device.
618 * Return: acpi_status signaling success or error.
620 acpi_status wmi_remove_notify_handler(const char *guid)
622 struct wmi_block *wblock;
623 struct wmi_device *wdev;
626 wdev = wmi_find_device_by_guid(guid);
630 wblock = container_of(wdev, struct wmi_block, dev);
632 down_write(&wblock->notify_lock);
633 if (!wblock->handler) {
634 status = AE_NULL_ENTRY;
636 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
637 dev_warn(&wblock->dev.dev, "Failed to disable device\n");
639 wblock->handler = NULL;
640 wblock->handler_data = NULL;
644 up_write(&wblock->notify_lock);
646 wmi_device_put(wdev);
650 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
653 * wmi_get_event_data - Get WMI data associated with an event (deprecated)
655 * @event: Event to find
656 * @out: Buffer to hold event data
658 * Get extra data associated with an WMI event, the caller needs to free @out.
660 * Return: acpi_status signaling success or error.
662 acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
664 struct wmi_block *wblock;
665 struct wmi_device *wdev;
668 wdev = wmi_find_event_by_notify_id(event);
672 wblock = container_of(wdev, struct wmi_block, dev);
673 status = get_event_data(wblock, out);
675 wmi_device_put(wdev);
679 EXPORT_SYMBOL_GPL(wmi_get_event_data);
682 * wmi_has_guid - Check if a GUID is available
683 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
685 * Check if a given GUID is defined by _WDG.
687 * Return: True if GUID is available, false otherwise.
689 bool wmi_has_guid(const char *guid_string)
691 struct wmi_device *wdev;
693 wdev = wmi_find_device_by_guid(guid_string);
697 wmi_device_put(wdev);
701 EXPORT_SYMBOL_GPL(wmi_has_guid);
704 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated)
705 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
707 * Find the _UID of ACPI device associated with this WMI GUID.
709 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found.
711 char *wmi_get_acpi_device_uid(const char *guid_string)
713 struct wmi_block *wblock;
714 struct wmi_device *wdev;
717 wdev = wmi_find_device_by_guid(guid_string);
721 wblock = container_of(wdev, struct wmi_block, dev);
722 uid = acpi_device_uid(wblock->acpi_device);
724 wmi_device_put(wdev);
728 EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
730 static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv)
732 return container_of(drv, struct wmi_driver, driver);
738 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
741 struct wmi_block *wblock = dev_to_wblock(dev);
743 return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
745 static DEVICE_ATTR_RO(modalias);
747 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
750 struct wmi_block *wblock = dev_to_wblock(dev);
752 return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
754 static DEVICE_ATTR_RO(guid);
756 static ssize_t instance_count_show(struct device *dev,
757 struct device_attribute *attr, char *buf)
759 struct wmi_block *wblock = dev_to_wblock(dev);
761 return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
763 static DEVICE_ATTR_RO(instance_count);
765 static ssize_t expensive_show(struct device *dev,
766 struct device_attribute *attr, char *buf)
768 struct wmi_block *wblock = dev_to_wblock(dev);
770 return sysfs_emit(buf, "%d\n",
771 (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
773 static DEVICE_ATTR_RO(expensive);
775 static struct attribute *wmi_attrs[] = {
776 &dev_attr_modalias.attr,
778 &dev_attr_instance_count.attr,
779 &dev_attr_expensive.attr,
782 ATTRIBUTE_GROUPS(wmi);
784 static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
787 struct wmi_block *wblock = dev_to_wblock(dev);
789 return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
791 static DEVICE_ATTR_RO(notify_id);
793 static struct attribute *wmi_event_attrs[] = {
794 &dev_attr_notify_id.attr,
797 ATTRIBUTE_GROUPS(wmi_event);
799 static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
802 struct wmi_block *wblock = dev_to_wblock(dev);
804 return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
805 wblock->gblock.object_id[1]);
807 static DEVICE_ATTR_RO(object_id);
809 static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
812 struct wmi_device *wdev = dev_to_wdev(dev);
814 return sysfs_emit(buf, "%d\n", (int)wdev->setable);
816 static DEVICE_ATTR_RO(setable);
818 static struct attribute *wmi_data_attrs[] = {
819 &dev_attr_object_id.attr,
820 &dev_attr_setable.attr,
823 ATTRIBUTE_GROUPS(wmi_data);
825 static struct attribute *wmi_method_attrs[] = {
826 &dev_attr_object_id.attr,
829 ATTRIBUTE_GROUPS(wmi_method);
831 static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
833 const struct wmi_block *wblock = dev_to_wblock(dev);
835 if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
838 if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
844 static void wmi_dev_release(struct device *dev)
846 struct wmi_block *wblock = dev_to_wblock(dev);
851 static int wmi_dev_match(struct device *dev, struct device_driver *driver)
853 struct wmi_driver *wmi_driver = drv_to_wdrv(driver);
854 struct wmi_block *wblock = dev_to_wblock(dev);
855 const struct wmi_device_id *id = wmi_driver->id_table;
860 while (*id->guid_string) {
861 if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
870 static int wmi_dev_probe(struct device *dev)
872 struct wmi_block *wblock = dev_to_wblock(dev);
873 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
876 /* Some older WMI drivers will break if instantiated multiple times,
877 * so they are blocked from probing WMI devices with a duplicated GUID.
879 * New WMI drivers should support being instantiated multiple times.
881 if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags) && !wdriver->no_singleton) {
882 dev_warn(dev, "Legacy driver %s cannot be instantiated multiple times\n",
888 if (wdriver->notify) {
889 if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags) && !wdriver->no_notify_data)
893 if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
894 dev_warn(dev, "failed to enable device -- probing anyway\n");
896 if (wdriver->probe) {
897 ret = wdriver->probe(dev_to_wdev(dev),
898 find_guid_context(wblock, wdriver));
900 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
901 dev_warn(dev, "Failed to disable device\n");
907 down_write(&wblock->notify_lock);
908 wblock->driver_ready = true;
909 up_write(&wblock->notify_lock);
914 static void wmi_dev_remove(struct device *dev)
916 struct wmi_block *wblock = dev_to_wblock(dev);
917 struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
919 down_write(&wblock->notify_lock);
920 wblock->driver_ready = false;
921 up_write(&wblock->notify_lock);
924 wdriver->remove(dev_to_wdev(dev));
926 if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
927 dev_warn(dev, "failed to disable device\n");
930 static struct class wmi_bus_class = {
934 static const struct bus_type wmi_bus_type = {
936 .dev_groups = wmi_groups,
937 .match = wmi_dev_match,
938 .uevent = wmi_dev_uevent,
939 .probe = wmi_dev_probe,
940 .remove = wmi_dev_remove,
943 static const struct device_type wmi_type_event = {
945 .groups = wmi_event_groups,
946 .release = wmi_dev_release,
949 static const struct device_type wmi_type_method = {
951 .groups = wmi_method_groups,
952 .release = wmi_dev_release,
955 static const struct device_type wmi_type_data = {
957 .groups = wmi_data_groups,
958 .release = wmi_dev_release,
962 * _WDG is a static list that is only parsed at startup,
963 * so it's safe to count entries without extra protection.
965 static int guid_count(const guid_t *guid)
967 struct wmi_block *wblock;
970 list_for_each_entry(wblock, &wmi_block_list, list) {
971 if (guid_equal(&wblock->gblock.guid, guid))
978 static int wmi_create_device(struct device *wmi_bus_dev,
979 struct wmi_block *wblock,
980 struct acpi_device *device)
982 char method[WMI_ACPI_METHOD_NAME_SIZE];
983 struct acpi_device_info *info;
984 acpi_handle method_handle;
988 if (wblock->gblock.flags & ACPI_WMI_EVENT) {
989 wblock->dev.dev.type = &wmi_type_event;
993 if (wblock->gblock.flags & ACPI_WMI_METHOD) {
994 get_acpi_method_name(wblock, 'M', method);
995 if (!acpi_has_method(device->handle, method)) {
996 dev_warn(wmi_bus_dev,
997 FW_BUG "%s method block execution control method not found\n",
1003 wblock->dev.dev.type = &wmi_type_method;
1008 * Data Block Query Control Method (WQxx by convention) is
1009 * required per the WMI documentation. If it is not present,
1010 * we ignore this data block.
1012 get_acpi_method_name(wblock, 'Q', method);
1013 status = acpi_get_handle(device->handle, method, &method_handle);
1014 if (ACPI_FAILURE(status)) {
1015 dev_warn(wmi_bus_dev,
1016 FW_BUG "%s data block query control method not found\n",
1022 status = acpi_get_object_info(method_handle, &info);
1023 if (ACPI_FAILURE(status))
1026 wblock->dev.dev.type = &wmi_type_data;
1029 * The Microsoft documentation specifically states:
1031 * Data blocks registered with only a single instance
1032 * can ignore the parameter.
1034 * ACPICA will get mad at us if we call the method with the wrong number
1035 * of arguments, so check what our method expects. (On some Dell
1036 * laptops, WQxx may not be a method at all.)
1038 if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1039 set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1043 get_acpi_method_name(wblock, 'S', method);
1044 if (acpi_has_method(device->handle, method))
1045 wblock->dev.setable = true;
1048 init_rwsem(&wblock->notify_lock);
1049 wblock->driver_ready = false;
1050 wblock->dev.dev.bus = &wmi_bus_type;
1051 wblock->dev.dev.parent = wmi_bus_dev;
1053 count = guid_count(&wblock->gblock.guid);
1055 dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1056 set_bit(WMI_GUID_DUPLICATED, &wblock->flags);
1058 dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1061 device_initialize(&wblock->dev.dev);
1066 static int wmi_add_device(struct platform_device *pdev, struct wmi_device *wdev)
1068 struct device_link *link;
1071 * Many aggregate WMI drivers do not use -EPROBE_DEFER when they
1072 * are unable to find a WMI device during probe, instead they require
1073 * all WMI devices associated with an platform device to become available
1074 * at once. This device link thus prevents WMI drivers from probing until
1075 * the associated platform device has finished probing (and has registered
1076 * all discovered WMI devices).
1079 link = device_link_add(&wdev->dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
1083 return device_add(&wdev->dev);
1087 * Parse the _WDG method for the GUID data blocks
1089 static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
1091 struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
1092 struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
1093 const struct guid_block *gblock;
1094 bool event_data_available;
1095 struct wmi_block *wblock;
1096 union acpi_object *obj;
1101 status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1102 if (ACPI_FAILURE(status))
1109 if (obj->type != ACPI_TYPE_BUFFER) {
1114 event_data_available = acpi_has_method(device->handle, "_WED");
1115 gblock = (const struct guid_block *)obj->buffer.pointer;
1116 total = obj->buffer.length / sizeof(struct guid_block);
1118 for (i = 0; i < total; i++) {
1119 if (!gblock[i].instance_count) {
1120 dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid);
1124 wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1128 wblock->acpi_device = device;
1129 wblock->gblock = gblock[i];
1130 if (gblock[i].flags & ACPI_WMI_EVENT && !event_data_available)
1131 set_bit(WMI_NO_EVENT_DATA, &wblock->flags);
1133 retval = wmi_create_device(wmi_bus_dev, wblock, device);
1139 list_add_tail(&wblock->list, &wmi_block_list);
1141 retval = wmi_add_device(pdev, &wblock->dev);
1143 dev_err(wmi_bus_dev, "failed to register %pUL\n",
1144 &wblock->gblock.guid);
1146 list_del(&wblock->list);
1147 put_device(&wblock->dev.dev);
1157 * WMI can have EmbeddedControl access regions. In which case, we just want to
1158 * hand these off to the EC driver.
1161 acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
1162 u32 bits, u64 *value,
1163 void *handler_context, void *region_context)
1168 if ((address > 0xFF) || !value)
1169 return AE_BAD_PARAMETER;
1171 if (function != ACPI_READ && function != ACPI_WRITE)
1172 return AE_BAD_PARAMETER;
1175 return AE_BAD_PARAMETER;
1177 if (function == ACPI_READ) {
1178 result = ec_read(address, &temp);
1181 temp = 0xff & *value;
1182 result = ec_write(address, temp);
1187 return AE_BAD_PARAMETER;
1189 return AE_NOT_FOUND;
1197 static int wmi_get_notify_data(struct wmi_block *wblock, union acpi_object **obj)
1199 struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
1202 if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags)) {
1207 status = get_event_data(wblock, &data);
1208 if (ACPI_FAILURE(status)) {
1209 dev_warn(&wblock->dev.dev, "Failed to get event data\n");
1213 *obj = data.pointer;
1218 static void wmi_notify_driver(struct wmi_block *wblock, union acpi_object *obj)
1220 struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
1222 if (!obj && !driver->no_notify_data) {
1223 dev_warn(&wblock->dev.dev, "Event contains no event data\n");
1228 driver->notify(&wblock->dev, obj);
1231 static int wmi_notify_device(struct device *dev, void *data)
1233 struct wmi_block *wblock = dev_to_wblock(dev);
1234 union acpi_object *obj;
1238 if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event))
1241 down_read(&wblock->notify_lock);
1242 /* The WMI driver notify handler conflicts with the legacy WMI handler.
1243 * Because of this the WMI driver notify handler takes precedence.
1245 if (wblock->dev.dev.driver && wblock->driver_ready) {
1246 ret = wmi_get_notify_data(wblock, &obj);
1248 wmi_notify_driver(wblock, obj);
1252 if (wblock->handler) {
1253 wblock->handler(*event, wblock->handler_data);
1255 /* The ACPI WMI specification says that _WED should be
1256 * evaluated every time an notification is received, even
1257 * if no consumers are present.
1259 * Some firmware implementations actually depend on this
1260 * by using a queue for events which will fill up if the
1261 * WMI driver core stops evaluating _WED due to missing
1262 * WMI event consumers.
1264 * Because of this we need this seemingly useless call to
1265 * wmi_get_notify_data() which in turn evaluates _WED.
1267 ret = wmi_get_notify_data(wblock, &obj);
1273 up_read(&wblock->notify_lock);
1275 acpi_bus_generate_netlink_event("wmi", acpi_dev_name(wblock->acpi_device), *event, 0);
1280 static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, void *context)
1282 struct device *wmi_bus_dev = context;
1284 device_for_each_child(wmi_bus_dev, &event, wmi_notify_device);
1287 static int wmi_remove_device(struct device *dev, void *data)
1289 struct wmi_block *wblock = dev_to_wblock(dev);
1291 list_del(&wblock->list);
1292 device_unregister(dev);
1297 static void acpi_wmi_remove(struct platform_device *device)
1299 struct device *wmi_bus_device = dev_get_drvdata(&device->dev);
1301 device_for_each_child_reverse(wmi_bus_device, NULL, wmi_remove_device);
1304 static void acpi_wmi_remove_notify_handler(void *data)
1306 struct acpi_device *acpi_device = data;
1308 acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, acpi_wmi_notify_handler);
1311 static void acpi_wmi_remove_address_space_handler(void *data)
1313 struct acpi_device *acpi_device = data;
1315 acpi_remove_address_space_handler(acpi_device->handle, ACPI_ADR_SPACE_EC,
1316 &acpi_wmi_ec_space_handler);
1319 static void acpi_wmi_remove_bus_device(void *data)
1321 struct device *wmi_bus_dev = data;
1323 device_unregister(wmi_bus_dev);
1326 static int acpi_wmi_probe(struct platform_device *device)
1328 struct acpi_device *acpi_device;
1329 struct device *wmi_bus_dev;
1333 acpi_device = ACPI_COMPANION(&device->dev);
1335 dev_err(&device->dev, "ACPI companion is missing\n");
1339 wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), NULL, "wmi_bus-%s",
1340 dev_name(&device->dev));
1341 if (IS_ERR(wmi_bus_dev))
1342 return PTR_ERR(wmi_bus_dev);
1344 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_bus_device, wmi_bus_dev);
1348 dev_set_drvdata(&device->dev, wmi_bus_dev);
1350 status = acpi_install_address_space_handler(acpi_device->handle,
1352 &acpi_wmi_ec_space_handler,
1354 if (ACPI_FAILURE(status)) {
1355 dev_err(&device->dev, "Error installing EC region handler\n");
1358 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_address_space_handler,
1363 status = acpi_install_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1364 acpi_wmi_notify_handler, wmi_bus_dev);
1365 if (ACPI_FAILURE(status)) {
1366 dev_err(&device->dev, "Error installing notify handler\n");
1369 error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_notify_handler,
1374 error = parse_wdg(wmi_bus_dev, device);
1376 dev_err(&device->dev, "Failed to parse _WDG method\n");
1383 int __must_check __wmi_driver_register(struct wmi_driver *driver,
1384 struct module *owner)
1386 driver->driver.owner = owner;
1387 driver->driver.bus = &wmi_bus_type;
1389 return driver_register(&driver->driver);
1391 EXPORT_SYMBOL(__wmi_driver_register);
1394 * wmi_driver_unregister() - Unregister a WMI driver
1395 * @driver: WMI driver to unregister
1397 * Unregisters a WMI driver from the WMI bus.
1399 void wmi_driver_unregister(struct wmi_driver *driver)
1401 driver_unregister(&driver->driver);
1403 EXPORT_SYMBOL(wmi_driver_unregister);
1405 static struct platform_driver acpi_wmi_driver = {
1408 .acpi_match_table = wmi_device_ids,
1410 .probe = acpi_wmi_probe,
1411 .remove_new = acpi_wmi_remove,
1414 static int __init acpi_wmi_init(void)
1421 error = class_register(&wmi_bus_class);
1425 error = bus_register(&wmi_bus_type);
1427 goto err_unreg_class;
1429 error = platform_driver_register(&acpi_wmi_driver);
1431 pr_err("Error loading mapper\n");
1438 bus_unregister(&wmi_bus_type);
1441 class_unregister(&wmi_bus_class);
1446 static void __exit acpi_wmi_exit(void)
1448 platform_driver_unregister(&acpi_wmi_driver);
1449 bus_unregister(&wmi_bus_type);
1450 class_unregister(&wmi_bus_class);
1453 subsys_initcall_sync(acpi_wmi_init);
1454 module_exit(acpi_wmi_exit);