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v6.13.7
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  ACPI-WMI mapping driver
   4 *
   5 *  Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
   6 *
   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>
  11 *
  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.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  15 */
  16
  17#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
  18
  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/module.h>
  26#include <linux/platform_device.h>
  27#include <linux/rwsem.h>
  28#include <linux/slab.h>
  29#include <linux/sysfs.h>
  30#include <linux/types.h>
  31#include <linux/uuid.h>
  32#include <linux/wmi.h>
  33#include <linux/fs.h>
 
 
  34
 
  35MODULE_AUTHOR("Carlos Corbacho");
  36MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
  37MODULE_LICENSE("GPL");
  38
 
 
 
 
 
  39struct guid_block {
  40	guid_t guid;
  41	union {
  42		char object_id[2];
  43		struct {
  44			unsigned char notify_id;
  45			unsigned char reserved;
  46		};
  47	};
  48	u8 instance_count;
  49	u8 flags;
  50} __packed;
  51static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
  52static_assert(sizeof(struct guid_block) == 20);
  53static_assert(__alignof__(struct guid_block) == 1);
  54
  55enum {	/* wmi_block flags */
  56	WMI_READ_TAKES_NO_ARGS,
  57	WMI_GUID_DUPLICATED,
  58	WMI_NO_EVENT_DATA,
  59};
  60
  61struct wmi_block {
  62	struct wmi_device dev;
  63	struct guid_block gblock;
  64	struct acpi_device *acpi_device;
  65	struct rw_semaphore notify_lock;	/* Protects notify callback add/remove */
  66	wmi_notify_handler handler;
  67	void *handler_data;
  68	bool driver_ready;
  69	unsigned long flags;
  70};
  71
  72struct wmi_guid_count_context {
  73	const guid_t *guid;
  74	int count;
  75};
  76
  77/*
  78 * If the GUID data block is marked as expensive, we must enable and
  79 * explicitily disable data collection.
  80 */
  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 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  85
  86static const struct acpi_device_id wmi_device_ids[] = {
  87	{"PNP0C14", 0},
  88	{"pnp0c14", 0},
  89	{ }
  90};
  91MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
  92
  93#define dev_to_wblock(__dev)	container_of_const(__dev, struct wmi_block, dev.dev)
 
 
 
 
 
 
 
 
 
  94
  95/*
  96 * GUID parsing functions
  97 */
  98
  99static bool guid_parse_and_compare(const char *string, const guid_t *guid)
 
 
 
 
 
 
 
 
 
 100{
 101	guid_t guid_input;
 
 102
 103	if (guid_parse(string, &guid_input))
 104		return false;
 
 
 105
 106	return guid_equal(&guid_input, guid);
 
 
 
 
 107}
 108
 109static const void *find_guid_context(struct wmi_block *wblock,
 110				     struct wmi_driver *wdriver)
 
 
 
 
 
 
 111{
 112	const struct wmi_device_id *id;
 113
 114	id = wdriver->id_table;
 115	if (!id)
 116		return NULL;
 117
 118	while (*id->guid_string) {
 119		if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
 120			return id->context;
 121		id++;
 122	}
 123	return NULL;
 124}
 125
 126static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable)
 127{
 128	struct guid_block *block;
 129	char method[5];
 130	acpi_status status;
 131	acpi_handle handle;
 132
 133	block = &wblock->gblock;
 134	handle = wblock->acpi_device->handle;
 135
 136	snprintf(method, 5, "WE%02X", block->notify_id);
 137	status = acpi_execute_simple_method(handle, method, enable);
 138	if (status == AE_NOT_FOUND)
 139		return AE_OK;
 140
 141	return status;
 142}
 143
 144#define WMI_ACPI_METHOD_NAME_SIZE 5
 145
 146static inline void get_acpi_method_name(const struct wmi_block *wblock,
 147					const char method,
 148					char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
 
 
 
 
 
 
 149{
 150	static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
 151	static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
 152
 153	buffer[0] = 'W';
 154	buffer[1] = method;
 155	buffer[2] = wblock->gblock.object_id[0];
 156	buffer[3] = wblock->gblock.object_id[1];
 157	buffer[4] = '\0';
 158}
 159
 160static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock)
 161{
 162	if (wblock->gblock.flags & ACPI_WMI_STRING)
 163		return ACPI_TYPE_STRING;
 164	else
 165		return ACPI_TYPE_BUFFER;
 
 
 
 166}
 167
 168static int wmidev_match_guid(struct device *dev, const void *data)
 
 
 
 169{
 170	struct wmi_block *wblock = dev_to_wblock(dev);
 171	const guid_t *guid = data;
 172
 173	/* Legacy GUID-based functions are restricted to only see
 174	 * a single WMI device for each GUID.
 175	 */
 176	if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
 177		return 0;
 
 
 
 
 
 
 
 
 178
 179	if (guid_equal(guid, &wblock->gblock.guid))
 180		return 1;
 181
 
 182	return 0;
 183}
 184
 185static const struct bus_type wmi_bus_type;
 186
 187static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
 188{
 189	struct device *dev;
 190	guid_t guid;
 191	int ret;
 192
 193	ret = guid_parse(guid_string, &guid);
 194	if (ret < 0)
 195		return ERR_PTR(ret);
 196
 197	dev = bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid);
 198	if (!dev)
 199		return ERR_PTR(-ENODEV);
 200
 201	return to_wmi_device(dev);
 
 
 
 
 
 
 
 
 
 
 202}
 203
 204static void wmi_device_put(struct wmi_device *wdev)
 205{
 206	put_device(&wdev->dev);
 207}
 
 
 208
 209/*
 210 * Exported WMI functions
 211 */
 212
 213/**
 214 * wmi_instance_count - Get number of WMI object instances
 215 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 216 *
 217 * Get the number of WMI object instances.
 218 *
 219 * Returns: Number of WMI object instances or negative error code.
 220 */
 221int wmi_instance_count(const char *guid_string)
 222{
 223	struct wmi_device *wdev;
 224	int ret;
 225
 226	wdev = wmi_find_device_by_guid(guid_string);
 227	if (IS_ERR(wdev))
 228		return PTR_ERR(wdev);
 229
 230	ret = wmidev_instance_count(wdev);
 231	wmi_device_put(wdev);
 232
 233	return ret;
 
 
 
 234}
 235EXPORT_SYMBOL_GPL(wmi_instance_count);
 236
 237/**
 238 * wmidev_instance_count - Get number of WMI object instances
 239 * @wdev: A wmi bus device from a driver
 240 *
 241 * Get the number of WMI object instances.
 242 *
 243 * Returns: Number of WMI object instances.
 244 */
 245u8 wmidev_instance_count(struct wmi_device *wdev)
 246{
 247	struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 248
 249	return wblock->gblock.instance_count;
 250}
 251EXPORT_SYMBOL_GPL(wmidev_instance_count);
 252
 253/**
 254 * wmi_evaluate_method - Evaluate a WMI method (deprecated)
 255 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 256 * @instance: Instance index
 257 * @method_id: Method ID to call
 258 * @in: Mandatory buffer containing input for the method call
 259 * @out: Empty buffer to return the method results
 260 *
 261 * Call an ACPI-WMI method, the caller must free @out.
 262 *
 263 * Return: acpi_status signaling success or error.
 264 */
 265acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
 266				const struct acpi_buffer *in, struct acpi_buffer *out)
 267{
 268	struct wmi_device *wdev;
 269	acpi_status status;
 270
 271	wdev = wmi_find_device_by_guid(guid_string);
 272	if (IS_ERR(wdev))
 273		return AE_ERROR;
 274
 275	status = wmidev_evaluate_method(wdev, instance, method_id, in, out);
 276
 277	wmi_device_put(wdev);
 278
 279	return status;
 280}
 281EXPORT_SYMBOL_GPL(wmi_evaluate_method);
 282
 283/**
 284 * wmidev_evaluate_method - Evaluate a WMI method
 285 * @wdev: A wmi bus device from a driver
 286 * @instance: Instance index
 287 * @method_id: Method ID to call
 288 * @in: Mandatory buffer containing input for the method call
 289 * @out: Empty buffer to return the method results
 290 *
 291 * Call an ACPI-WMI method, the caller must free @out.
 292 *
 293 * Return: acpi_status signaling success or error.
 294 */
 295acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
 296				   const struct acpi_buffer *in, struct acpi_buffer *out)
 297{
 298	struct guid_block *block;
 299	struct wmi_block *wblock;
 300	acpi_handle handle;
 
 301	struct acpi_object_list input;
 302	union acpi_object params[3];
 303	char method[WMI_ACPI_METHOD_NAME_SIZE];
 304
 305	wblock = container_of(wdev, struct wmi_block, dev);
 306	block = &wblock->gblock;
 307	handle = wblock->acpi_device->handle;
 308
 309	if (!in)
 310		return AE_BAD_DATA;
 311
 312	if (!(block->flags & ACPI_WMI_METHOD))
 313		return AE_BAD_DATA;
 314
 315	if (block->instance_count <= instance)
 316		return AE_BAD_PARAMETER;
 317
 318	input.count = 3;
 319	input.pointer = params;
 320
 321	params[0].type = ACPI_TYPE_INTEGER;
 322	params[0].integer.value = instance;
 323	params[1].type = ACPI_TYPE_INTEGER;
 324	params[1].integer.value = method_id;
 325	params[2].type = get_param_acpi_type(wblock);
 326	params[2].buffer.length = in->length;
 327	params[2].buffer.pointer = in->pointer;
 328
 329	get_acpi_method_name(wblock, 'M', method);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 330
 331	return acpi_evaluate_object(handle, method, &input, out);
 332}
 333EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
 334
 335static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
 336				 struct acpi_buffer *out)
 
 
 
 
 
 
 
 
 337{
 338	struct guid_block *block;
 
 339	acpi_handle handle;
 340	acpi_status status, wc_status = AE_ERROR;
 341	struct acpi_object_list input;
 342	union acpi_object wq_params[1];
 343	char wc_method[WMI_ACPI_METHOD_NAME_SIZE];
 344	char method[WMI_ACPI_METHOD_NAME_SIZE];
 345
 346	if (!out)
 347		return AE_BAD_PARAMETER;
 348
 
 
 
 349	block = &wblock->gblock;
 350	handle = wblock->acpi_device->handle;
 351
 352	if (block->instance_count <= instance)
 353		return AE_BAD_PARAMETER;
 354
 355	/* Check GUID is a data block */
 356	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 357		return AE_ERROR;
 358
 359	input.count = 1;
 360	input.pointer = wq_params;
 361	wq_params[0].type = ACPI_TYPE_INTEGER;
 362	wq_params[0].integer.value = instance;
 363
 364	if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
 365		input.count = 0;
 366
 367	/*
 368	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
 369	 * enable collection.
 370	 */
 371	if (block->flags & ACPI_WMI_EXPENSIVE) {
 372		get_acpi_method_name(wblock, 'C', wc_method);
 373
 374		/*
 375		 * Some GUIDs break the specification by declaring themselves
 376		 * expensive, but have no corresponding WCxx method. So we
 377		 * should not fail if this happens.
 378		 */
 379		wc_status = acpi_execute_simple_method(handle, wc_method, 1);
 
 
 380	}
 381
 382	get_acpi_method_name(wblock, 'Q', method);
 
 
 383	status = acpi_evaluate_object(handle, method, &input, out);
 384
 385	/*
 386	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
 387	 * the WQxx method failed - we should disable collection anyway.
 388	 */
 389	if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
 390		/*
 391		 * Ignore whether this WCxx call succeeds or not since
 392		 * the previously executed WQxx method call might have
 393		 * succeeded, and returning the failing status code
 394		 * of this call would throw away the result of the WQxx
 395		 * call, potentially leaking memory.
 396		 */
 397		acpi_execute_simple_method(handle, wc_method, 0);
 398	}
 399
 400	return status;
 401}
 402
 403/**
 404 * wmi_query_block - Return contents of a WMI block (deprecated)
 405 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 406 * @instance: Instance index
 407 * @out: Empty buffer to return the contents of the data block to
 408 *
 409 * Query a ACPI-WMI block, the caller must free @out.
 410 *
 411 * Return: ACPI object containing the content of the WMI block.
 412 */
 413acpi_status wmi_query_block(const char *guid_string, u8 instance,
 414			    struct acpi_buffer *out)
 415{
 416	struct wmi_block *wblock;
 417	struct wmi_device *wdev;
 418	acpi_status status;
 419
 420	wdev = wmi_find_device_by_guid(guid_string);
 421	if (IS_ERR(wdev))
 422		return AE_ERROR;
 423
 424	wblock = container_of(wdev, struct wmi_block, dev);
 425	status = __query_block(wblock, instance, out);
 426
 427	wmi_device_put(wdev);
 428
 429	return status;
 430}
 431EXPORT_SYMBOL_GPL(wmi_query_block);
 432
 433/**
 434 * wmidev_block_query - Return contents of a WMI block
 435 * @wdev: A wmi bus device from a driver
 436 * @instance: Instance index
 437 *
 438 * Query an ACPI-WMI block, the caller must free the result.
 439 *
 440 * Return: ACPI object containing the content of the WMI block.
 441 */
 442union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
 443{
 444	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 445	struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 446
 447	if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
 448		return NULL;
 449
 450	return out.pointer;
 451}
 452EXPORT_SYMBOL_GPL(wmidev_block_query);
 453
 454/**
 455 * wmi_set_block - Write to a WMI block (deprecated)
 456 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 457 * @instance: Instance index
 458 * @in: Buffer containing new values for the data block
 459 *
 460 * Write the contents of the input buffer to an ACPI-WMI data block.
 461 *
 462 * Return: acpi_status signaling success or error.
 463 */
 464acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in)
 465{
 466	struct wmi_device *wdev;
 467	acpi_status status;
 468
 469	wdev = wmi_find_device_by_guid(guid_string);
 470	if (IS_ERR(wdev))
 471		return AE_ERROR;
 472
 473	status =  wmidev_block_set(wdev, instance, in);
 474	wmi_device_put(wdev);
 475
 476	return status;
 477}
 478EXPORT_SYMBOL_GPL(wmi_set_block);
 479
 480/**
 481 * wmidev_block_set - Write to a WMI block
 482 * @wdev: A wmi bus device from a driver
 483 * @instance: Instance index
 484 * @in: Buffer containing new values for the data block
 485 *
 486 * Write contents of the input buffer to an ACPI-WMI data block.
 487 *
 488 * Return: acpi_status signaling success or error.
 489 */
 490acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct acpi_buffer *in)
 
 491{
 492	struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
 493	acpi_handle handle = wblock->acpi_device->handle;
 494	struct guid_block *block = &wblock->gblock;
 495	char method[WMI_ACPI_METHOD_NAME_SIZE];
 496	struct acpi_object_list input;
 497	union acpi_object params[2];
 
 498
 499	if (!in)
 500		return AE_BAD_DATA;
 501
 502	if (block->instance_count <= instance)
 
 
 
 
 
 
 503		return AE_BAD_PARAMETER;
 504
 505	/* Check GUID is a data block */
 506	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
 507		return AE_ERROR;
 508
 509	input.count = 2;
 510	input.pointer = params;
 511	params[0].type = ACPI_TYPE_INTEGER;
 512	params[0].integer.value = instance;
 513	params[1].type = get_param_acpi_type(wblock);
 
 
 
 
 
 514	params[1].buffer.length = in->length;
 515	params[1].buffer.pointer = in->pointer;
 516
 517	get_acpi_method_name(wblock, 'S', method);
 518
 519	return acpi_evaluate_object(handle, method, &input, NULL);
 520}
 521EXPORT_SYMBOL_GPL(wmidev_block_set);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 522
 523/**
 524 * wmi_install_notify_handler - Register handler for WMI events (deprecated)
 525 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 526 * @handler: Function to handle notifications
 527 * @data: Data to be returned to handler when event is fired
 528 *
 529 * Register a handler for events sent to the ACPI-WMI mapper device.
 530 *
 531 * Return: acpi_status signaling success or error.
 532 */
 533acpi_status wmi_install_notify_handler(const char *guid,
 534				       wmi_notify_handler handler,
 535				       void *data)
 536{
 537	struct wmi_block *wblock;
 538	struct wmi_device *wdev;
 539	acpi_status status;
 540
 541	wdev = wmi_find_device_by_guid(guid);
 542	if (IS_ERR(wdev))
 543		return AE_ERROR;
 544
 545	wblock = container_of(wdev, struct wmi_block, dev);
 546
 547	down_write(&wblock->notify_lock);
 548	if (wblock->handler) {
 549		status = AE_ALREADY_ACQUIRED;
 550	} else {
 551		wblock->handler = handler;
 552		wblock->handler_data = data;
 553
 554		if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
 555			dev_warn(&wblock->dev.dev, "Failed to enable device\n");
 556
 557		status = AE_OK;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 558	}
 559	up_write(&wblock->notify_lock);
 560
 561	wmi_device_put(wdev);
 562
 563	return status;
 564}
 565EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 566
 567/**
 568 * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated)
 569 * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 570 *
 571 * Unregister handler for events sent to the ACPI-WMI mapper device.
 572 *
 573 * Return: acpi_status signaling success or error.
 574 */
 575acpi_status wmi_remove_notify_handler(const char *guid)
 576{
 577	struct wmi_block *wblock;
 578	struct wmi_device *wdev;
 579	acpi_status status;
 580
 581	wdev = wmi_find_device_by_guid(guid);
 582	if (IS_ERR(wdev))
 583		return AE_ERROR;
 584
 585	wblock = container_of(wdev, struct wmi_block, dev);
 586
 587	down_write(&wblock->notify_lock);
 588	if (!wblock->handler) {
 589		status = AE_NULL_ENTRY;
 590	} else {
 591		if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
 592			dev_warn(&wblock->dev.dev, "Failed to disable device\n");
 593
 594		wblock->handler = NULL;
 595		wblock->handler_data = NULL;
 596
 597		status = AE_OK;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 598	}
 599	up_write(&wblock->notify_lock);
 600
 601	wmi_device_put(wdev);
 602
 603	return status;
 604}
 605EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
 606
 607/**
 608 * wmi_has_guid - Check if a GUID is available
 609 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 610 *
 611 * Check if a given GUID is defined by _WDG.
 
 612 *
 613 * Return: True if GUID is available, false otherwise.
 614 */
 615bool wmi_has_guid(const char *guid_string)
 616{
 617	struct wmi_device *wdev;
 
 
 
 
 618
 619	wdev = wmi_find_device_by_guid(guid_string);
 620	if (IS_ERR(wdev))
 621		return false;
 
 622
 623	wmi_device_put(wdev);
 
 
 624
 625	return true;
 
 
 
 
 
 
 626}
 627EXPORT_SYMBOL_GPL(wmi_has_guid);
 628
 629/**
 630 * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated)
 631 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 632 *
 633 * Find the _UID of ACPI device associated with this WMI GUID.
 634 *
 635 * Return: The ACPI _UID field value or NULL if the WMI GUID was not found.
 636 */
 637char *wmi_get_acpi_device_uid(const char *guid_string)
 638{
 639	struct wmi_block *wblock;
 640	struct wmi_device *wdev;
 641	char *uid;
 642
 643	wdev = wmi_find_device_by_guid(guid_string);
 644	if (IS_ERR(wdev))
 645		return NULL;
 646
 647	wblock = container_of(wdev, struct wmi_block, dev);
 648	uid = acpi_device_uid(wblock->acpi_device);
 649
 650	wmi_device_put(wdev);
 651
 652	return uid;
 653}
 654EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
 655
 656/*
 657 * sysfs interface
 658 */
 659static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 660			     char *buf)
 661{
 662	struct wmi_block *wblock = dev_to_wblock(dev);
 663
 664	return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
 665}
 666static DEVICE_ATTR_RO(modalias);
 667
 668static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
 669			 char *buf)
 670{
 671	struct wmi_block *wblock = dev_to_wblock(dev);
 672
 673	return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
 674}
 675static DEVICE_ATTR_RO(guid);
 676
 677static ssize_t instance_count_show(struct device *dev,
 678				   struct device_attribute *attr, char *buf)
 679{
 680	struct wmi_block *wblock = dev_to_wblock(dev);
 681
 682	return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
 683}
 684static DEVICE_ATTR_RO(instance_count);
 685
 686static ssize_t expensive_show(struct device *dev,
 687			      struct device_attribute *attr, char *buf)
 688{
 689	struct wmi_block *wblock = dev_to_wblock(dev);
 690
 691	return sysfs_emit(buf, "%d\n",
 692			  (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
 693}
 694static DEVICE_ATTR_RO(expensive);
 695
 696static ssize_t driver_override_show(struct device *dev, struct device_attribute *attr,
 697				    char *buf)
 698{
 699	struct wmi_device *wdev = to_wmi_device(dev);
 700	ssize_t ret;
 701
 702	device_lock(dev);
 703	ret = sysfs_emit(buf, "%s\n", wdev->driver_override);
 704	device_unlock(dev);
 705
 706	return ret;
 707}
 708
 709static ssize_t driver_override_store(struct device *dev, struct device_attribute *attr,
 710				     const char *buf, size_t count)
 711{
 712	struct wmi_device *wdev = to_wmi_device(dev);
 713	int ret;
 714
 715	ret = driver_set_override(dev, &wdev->driver_override, buf, count);
 716	if (ret < 0)
 717		return ret;
 718
 719	return count;
 720}
 721static DEVICE_ATTR_RW(driver_override);
 722
 723static struct attribute *wmi_attrs[] = {
 724	&dev_attr_modalias.attr,
 725	&dev_attr_guid.attr,
 726	&dev_attr_instance_count.attr,
 727	&dev_attr_expensive.attr,
 728	&dev_attr_driver_override.attr,
 729	NULL
 730};
 731ATTRIBUTE_GROUPS(wmi);
 732
 733static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
 734			      char *buf)
 735{
 736	struct wmi_block *wblock = dev_to_wblock(dev);
 737
 738	return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
 739}
 740static DEVICE_ATTR_RO(notify_id);
 741
 742static struct attribute *wmi_event_attrs[] = {
 743	&dev_attr_notify_id.attr,
 744	NULL
 745};
 746ATTRIBUTE_GROUPS(wmi_event);
 747
 748static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
 749			      char *buf)
 750{
 751	struct wmi_block *wblock = dev_to_wblock(dev);
 752
 753	return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
 754			  wblock->gblock.object_id[1]);
 755}
 756static DEVICE_ATTR_RO(object_id);
 757
 758static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
 759			    char *buf)
 760{
 761	struct wmi_device *wdev = to_wmi_device(dev);
 762
 763	return sysfs_emit(buf, "%d\n", (int)wdev->setable);
 764}
 765static DEVICE_ATTR_RO(setable);
 766
 767static struct attribute *wmi_data_attrs[] = {
 768	&dev_attr_object_id.attr,
 769	&dev_attr_setable.attr,
 770	NULL
 771};
 772ATTRIBUTE_GROUPS(wmi_data);
 773
 774static struct attribute *wmi_method_attrs[] = {
 775	&dev_attr_object_id.attr,
 776	NULL
 777};
 778ATTRIBUTE_GROUPS(wmi_method);
 779
 780static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
 781{
 782	const struct wmi_block *wblock = dev_to_wblock(dev);
 783
 784	if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
 785		return -ENOMEM;
 786
 787	if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
 
 788		return -ENOMEM;
 789
 790	return 0;
 791}
 792
 793static void wmi_dev_release(struct device *dev)
 794{
 795	struct wmi_block *wblock = dev_to_wblock(dev);
 796
 797	kfree(wblock->dev.driver_override);
 798	kfree(wblock);
 799}
 800
 801static int wmi_dev_match(struct device *dev, const struct device_driver *driver)
 802{
 803	const struct wmi_driver *wmi_driver = to_wmi_driver(driver);
 804	struct wmi_block *wblock = dev_to_wblock(dev);
 805	const struct wmi_device_id *id = wmi_driver->id_table;
 806
 807	/* When driver_override is set, only bind to the matching driver */
 808	if (wblock->dev.driver_override)
 809		return !strcmp(wblock->dev.driver_override, driver->name);
 810
 811	if (id == NULL)
 812		return 0;
 813
 814	while (*id->guid_string) {
 815		if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
 816			return 1;
 817
 818		id++;
 819	}
 820
 821	return 0;
 822}
 823
 824static int wmi_dev_probe(struct device *dev)
 825{
 826	struct wmi_block *wblock = dev_to_wblock(dev);
 827	struct wmi_driver *wdriver = to_wmi_driver(dev->driver);
 828	int ret = 0;
 829
 830	/* Some older WMI drivers will break if instantiated multiple times,
 831	 * so they are blocked from probing WMI devices with a duplicated GUID.
 832	 *
 833	 * New WMI drivers should support being instantiated multiple times.
 834	 */
 835	if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags) && !wdriver->no_singleton) {
 836		dev_warn(dev, "Legacy driver %s cannot be instantiated multiple times\n",
 837			 dev->driver->name);
 838
 839		return -ENODEV;
 840	}
 841
 842	if (wdriver->notify) {
 843		if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags) && !wdriver->no_notify_data)
 844			return -ENODEV;
 845	}
 846
 847	if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
 848		dev_warn(dev, "failed to enable device -- probing anyway\n");
 849
 850	if (wdriver->probe) {
 851		ret = wdriver->probe(to_wmi_device(dev),
 852				find_guid_context(wblock, wdriver));
 853		if (ret) {
 854			if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
 855				dev_warn(dev, "Failed to disable device\n");
 856
 857			return ret;
 858		}
 859	}
 860
 861	down_write(&wblock->notify_lock);
 862	wblock->driver_ready = true;
 863	up_write(&wblock->notify_lock);
 864
 865	return 0;
 866}
 867
 868static void wmi_dev_remove(struct device *dev)
 869{
 870	struct wmi_block *wblock = dev_to_wblock(dev);
 871	struct wmi_driver *wdriver = to_wmi_driver(dev->driver);
 872
 873	down_write(&wblock->notify_lock);
 874	wblock->driver_ready = false;
 875	up_write(&wblock->notify_lock);
 876
 877	if (wdriver->remove)
 878		wdriver->remove(to_wmi_device(dev));
 879
 880	if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
 881		dev_warn(dev, "failed to disable device\n");
 882}
 883
 884static void wmi_dev_shutdown(struct device *dev)
 885{
 886	struct wmi_driver *wdriver;
 887	struct wmi_block *wblock;
 888
 889	if (dev->driver) {
 890		wdriver = to_wmi_driver(dev->driver);
 891		wblock = dev_to_wblock(dev);
 892
 893		/*
 894		 * Some machines return bogus WMI event data when disabling
 895		 * the WMI event. Because of this we must prevent the associated
 896		 * WMI driver from receiving new WMI events before disabling it.
 897		 */
 898		down_write(&wblock->notify_lock);
 899		wblock->driver_ready = false;
 900		up_write(&wblock->notify_lock);
 901
 902		if (wdriver->shutdown)
 903			wdriver->shutdown(to_wmi_device(dev));
 904
 905		if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
 906			dev_warn(dev, "Failed to disable device\n");
 907	}
 908}
 909
 910static struct class wmi_bus_class = {
 911	.name = "wmi_bus",
 912};
 913
 914static const struct bus_type wmi_bus_type = {
 915	.name = "wmi",
 
 
 916	.dev_groups = wmi_groups,
 917	.match = wmi_dev_match,
 918	.uevent = wmi_dev_uevent,
 919	.probe = wmi_dev_probe,
 920	.remove = wmi_dev_remove,
 921	.shutdown = wmi_dev_shutdown,
 922};
 923
 924static const struct device_type wmi_type_event = {
 925	.name = "event",
 926	.groups = wmi_event_groups,
 927	.release = wmi_dev_release,
 928};
 929
 930static const struct device_type wmi_type_method = {
 931	.name = "method",
 932	.groups = wmi_method_groups,
 933	.release = wmi_dev_release,
 934};
 935
 936static const struct device_type wmi_type_data = {
 937	.name = "data",
 938	.groups = wmi_data_groups,
 939	.release = wmi_dev_release,
 940};
 941
 942static int wmi_count_guids(struct device *dev, void *data)
 943{
 944	struct wmi_guid_count_context *context = data;
 945	struct wmi_block *wblock = dev_to_wblock(dev);
 946
 947	if (guid_equal(&wblock->gblock.guid, context->guid))
 948		context->count++;
 949
 950	return 0;
 951}
 952
 953static int guid_count(const guid_t *guid)
 954{
 955	struct wmi_guid_count_context context = {
 956		.guid = guid,
 957		.count = 0,
 958	};
 959	int ret;
 960
 961	ret = bus_for_each_dev(&wmi_bus_type, NULL, &context, wmi_count_guids);
 962	if (ret < 0)
 963		return ret;
 964
 965	return context.count;
 966}
 967
 968static int wmi_create_device(struct device *wmi_bus_dev,
 969			     struct wmi_block *wblock,
 970			     struct acpi_device *device)
 971{
 972	char method[WMI_ACPI_METHOD_NAME_SIZE];
 973	struct acpi_device_info *info;
 974	acpi_handle method_handle;
 975	acpi_status status;
 976	int count;
 977
 978	if (wblock->gblock.flags & ACPI_WMI_EVENT) {
 979		wblock->dev.dev.type = &wmi_type_event;
 980		goto out_init;
 981	}
 982
 983	if (wblock->gblock.flags & ACPI_WMI_METHOD) {
 984		get_acpi_method_name(wblock, 'M', method);
 985		if (!acpi_has_method(device->handle, method)) {
 986			dev_warn(wmi_bus_dev,
 987				 FW_BUG "%s method block execution control method not found\n",
 988				 method);
 989
 990			return -ENXIO;
 991		}
 992
 993		wblock->dev.dev.type = &wmi_type_method;
 994		goto out_init;
 995	}
 996
 997	/*
 998	 * Data Block Query Control Method (WQxx by convention) is
 999	 * required per the WMI documentation. If it is not present,
1000	 * we ignore this data block.
1001	 */
1002	get_acpi_method_name(wblock, 'Q', method);
1003	status = acpi_get_handle(device->handle, method, &method_handle);
1004	if (ACPI_FAILURE(status)) {
1005		dev_warn(wmi_bus_dev,
1006			 FW_BUG "%s data block query control method not found\n",
1007			 method);
1008
1009		return -ENXIO;
1010	}
1011
1012	status = acpi_get_object_info(method_handle, &info);
1013	if (ACPI_FAILURE(status))
1014		return -EIO;
1015
1016	wblock->dev.dev.type = &wmi_type_data;
1017
1018	/*
1019	 * The Microsoft documentation specifically states:
1020	 *
1021	 *   Data blocks registered with only a single instance
1022	 *   can ignore the parameter.
1023	 *
1024	 * ACPICA will get mad at us if we call the method with the wrong number
1025	 * of arguments, so check what our method expects.  (On some Dell
1026	 * laptops, WQxx may not be a method at all.)
1027	 */
1028	if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
1029		set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
1030
1031	kfree(info);
1032
1033	get_acpi_method_name(wblock, 'S', method);
1034	if (acpi_has_method(device->handle, method))
1035		wblock->dev.setable = true;
1036
1037 out_init:
1038	init_rwsem(&wblock->notify_lock);
1039	wblock->driver_ready = false;
1040	wblock->dev.dev.bus = &wmi_bus_type;
1041	wblock->dev.dev.parent = wmi_bus_dev;
1042
1043	count = guid_count(&wblock->gblock.guid);
1044	if (count < 0)
1045		return count;
1046
1047	if (count) {
1048		dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
1049		set_bit(WMI_GUID_DUPLICATED, &wblock->flags);
1050	} else {
1051		dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
1052	}
1053
1054	device_initialize(&wblock->dev.dev);
1055
1056	return 0;
1057}
1058
1059static int wmi_add_device(struct platform_device *pdev, struct wmi_device *wdev)
1060{
1061	struct device_link *link;
1062
1063	/*
1064	 * Many aggregate WMI drivers do not use -EPROBE_DEFER when they
1065	 * are unable to find a WMI device during probe, instead they require
1066	 * all WMI devices associated with an platform device to become available
1067	 * at once. This device link thus prevents WMI drivers from probing until
1068	 * the associated platform device has finished probing (and has registered
1069	 * all discovered WMI devices).
1070	 */
1071
1072	link = device_link_add(&wdev->dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
1073	if (!link)
1074		return -EINVAL;
1075
1076	return device_add(&wdev->dev);
1077}
1078
1079/*
1080 * Parse the _WDG method for the GUID data blocks
1081 */
1082static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
1083{
1084	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
1085	struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
 
1086	const struct guid_block *gblock;
1087	bool event_data_available;
1088	struct wmi_block *wblock;
1089	union acpi_object *obj;
1090	acpi_status status;
1091	u32 i, total;
1092	int retval;
 
1093
1094	status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
1095	if (ACPI_FAILURE(status))
1096		return -ENXIO;
1097
1098	obj = out.pointer;
1099	if (!obj)
1100		return -ENXIO;
1101
1102	if (obj->type != ACPI_TYPE_BUFFER) {
1103		kfree(obj);
1104		return -ENXIO;
1105	}
1106
1107	event_data_available = acpi_has_method(device->handle, "_WED");
1108	gblock = (const struct guid_block *)obj->buffer.pointer;
1109	total = obj->buffer.length / sizeof(struct guid_block);
1110
1111	for (i = 0; i < total; i++) {
1112		if (!gblock[i].instance_count) {
1113			dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid);
1114			continue;
1115		}
1116
1117		wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
1118		if (!wblock)
1119			continue;
1120
1121		wblock->acpi_device = device;
1122		wblock->gblock = gblock[i];
1123		if (gblock[i].flags & ACPI_WMI_EVENT && !event_data_available)
1124			set_bit(WMI_NO_EVENT_DATA, &wblock->flags);
1125
1126		retval = wmi_create_device(wmi_bus_dev, wblock, device);
1127		if (retval) {
1128			kfree(wblock);
1129			continue;
 
 
 
 
 
 
 
 
1130		}
1131
1132		retval = wmi_add_device(pdev, &wblock->dev);
1133		if (retval) {
1134			dev_err(wmi_bus_dev, "failed to register %pUL\n",
1135				&wblock->gblock.guid);
1136
1137			put_device(&wblock->dev.dev);
 
 
1138		}
1139	}
1140
1141	kfree(obj);
1142
1143	return 0;
 
 
 
1144}
1145
1146static int wmi_get_notify_data(struct wmi_block *wblock, union acpi_object **obj)
 
 
 
 
 
 
 
1147{
1148	struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
1149	union acpi_object param = {
1150		.integer = {
1151			.type = ACPI_TYPE_INTEGER,
1152			.value = wblock->gblock.notify_id,
1153		}
1154	};
1155	struct acpi_object_list input = {
1156		.count = 1,
1157		.pointer = &param,
1158	};
1159	acpi_status status;
1160
1161	status = acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, &data);
1162	if (ACPI_FAILURE(status)) {
1163		dev_warn(&wblock->dev.dev, "Failed to get event data\n");
1164		return -EIO;
1165	}
1166
1167	*obj = data.pointer;
1168
1169	return 0;
1170}
1171
1172static void wmi_notify_driver(struct wmi_block *wblock, union acpi_object *obj)
1173{
1174	struct wmi_driver *driver = to_wmi_driver(wblock->dev.dev.driver);
1175
1176	if (!obj && !driver->no_notify_data) {
1177		dev_warn(&wblock->dev.dev, "Event contains no event data\n");
1178		return;
 
 
 
1179	}
1180
1181	if (driver->notify)
1182		driver->notify(&wblock->dev, obj);
1183}
1184
1185static int wmi_notify_device(struct device *dev, void *data)
1186{
1187	struct wmi_block *wblock = dev_to_wblock(dev);
1188	union acpi_object *obj = NULL;
1189	u32 *event = data;
1190	int ret;
1191
1192	if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event))
1193		return 0;
1194
1195	/* The ACPI WMI specification says that _WED should be
1196	 * evaluated every time an notification is received, even
1197	 * if no consumers are present.
1198	 *
1199	 * Some firmware implementations actually depend on this
1200	 * by using a queue for events which will fill up if the
1201	 * WMI driver core stops evaluating _WED due to missing
1202	 * WMI event consumers.
1203	 */
1204	if (!test_bit(WMI_NO_EVENT_DATA, &wblock->flags)) {
1205		ret = wmi_get_notify_data(wblock, &obj);
1206		if (ret < 0)
1207			return -EIO;
1208	}
1209
1210	down_read(&wblock->notify_lock);
1211
1212	if (wblock->dev.dev.driver && wblock->driver_ready)
1213		wmi_notify_driver(wblock, obj);
1214
1215	if (wblock->handler)
1216		wblock->handler(obj, wblock->handler_data);
1217
1218	up_read(&wblock->notify_lock);
1219
1220	kfree(obj);
1221
1222	acpi_bus_generate_netlink_event("wmi", acpi_dev_name(wblock->acpi_device), *event, 0);
1223
1224	return -EBUSY;
1225}
1226
1227static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, void *context)
1228{
1229	struct device *wmi_bus_dev = context;
 
 
 
1230
1231	device_for_each_child(wmi_bus_dev, &event, wmi_notify_device);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1232}
1233
1234static int wmi_remove_device(struct device *dev, void *data)
1235{
1236	device_unregister(dev);
 
 
1237
1238	return 0;
1239}
1240
1241static void acpi_wmi_remove(struct platform_device *device)
1242{
1243	struct device *wmi_bus_device = dev_get_drvdata(&device->dev);
1244
1245	device_for_each_child_reverse(wmi_bus_device, NULL, wmi_remove_device);
1246}
1247
1248static void acpi_wmi_remove_notify_handler(void *data)
1249{
1250	struct acpi_device *acpi_device = data;
1251
1252	acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, acpi_wmi_notify_handler);
1253}
1254
1255static void acpi_wmi_remove_bus_device(void *data)
1256{
1257	struct device *wmi_bus_dev = data;
1258
1259	device_unregister(wmi_bus_dev);
1260}
1261
1262static int acpi_wmi_probe(struct platform_device *device)
1263{
1264	struct acpi_device *acpi_device;
1265	struct device *wmi_bus_dev;
1266	acpi_status status;
1267	int error;
1268
1269	acpi_device = ACPI_COMPANION(&device->dev);
1270	if (!acpi_device) {
1271		dev_err(&device->dev, "ACPI companion is missing\n");
1272		return -ENODEV;
1273	}
1274
1275	wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), NULL, "wmi_bus-%s",
1276				    dev_name(&device->dev));
1277	if (IS_ERR(wmi_bus_dev))
1278		return PTR_ERR(wmi_bus_dev);
1279
1280	error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_bus_device, wmi_bus_dev);
1281	if (error < 0)
1282		return error;
1283
1284	dev_set_drvdata(&device->dev, wmi_bus_dev);
1285
1286	status = acpi_install_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
1287					     acpi_wmi_notify_handler, wmi_bus_dev);
1288	if (ACPI_FAILURE(status)) {
1289		dev_err(&device->dev, "Error installing notify handler\n");
1290		return -ENODEV;
1291	}
1292	error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_notify_handler,
1293					 acpi_device);
1294	if (error < 0)
1295		return error;
1296
1297	error = parse_wdg(wmi_bus_dev, device);
1298	if (error) {
1299		dev_err(&device->dev, "Failed to parse _WDG method\n");
 
 
 
1300		return error;
1301	}
1302
1303	return 0;
1304}
1305
1306int __must_check __wmi_driver_register(struct wmi_driver *driver,
1307				       struct module *owner)
1308{
1309	driver->driver.owner = owner;
1310	driver->driver.bus = &wmi_bus_type;
1311
1312	return driver_register(&driver->driver);
1313}
1314EXPORT_SYMBOL(__wmi_driver_register);
1315
1316/**
1317 * wmi_driver_unregister() - Unregister a WMI driver
1318 * @driver: WMI driver to unregister
1319 *
1320 * Unregisters a WMI driver from the WMI bus.
1321 */
1322void wmi_driver_unregister(struct wmi_driver *driver)
1323{
1324	driver_unregister(&driver->driver);
1325}
1326EXPORT_SYMBOL(wmi_driver_unregister);
1327
1328static struct platform_driver acpi_wmi_driver = {
1329	.driver = {
1330		.name = "acpi-wmi",
1331		.acpi_match_table = wmi_device_ids,
1332	},
1333	.probe = acpi_wmi_probe,
1334	.remove = acpi_wmi_remove,
1335};
1336
1337static int __init acpi_wmi_init(void)
1338{
1339	int error;
1340
1341	if (acpi_disabled)
1342		return -ENODEV;
1343
1344	error = class_register(&wmi_bus_class);
1345	if (error)
1346		return error;
1347
1348	error = bus_register(&wmi_bus_type);
1349	if (error)
1350		goto err_unreg_class;
1351
1352	error = platform_driver_register(&acpi_wmi_driver);
1353	if (error) {
1354		pr_err("Error loading mapper\n");
1355		goto err_unreg_bus;
 
1356	}
1357
 
1358	return 0;
1359
1360err_unreg_bus:
1361	bus_unregister(&wmi_bus_type);
1362
1363err_unreg_class:
1364	class_unregister(&wmi_bus_class);
1365
1366	return error;
1367}
1368
1369static void __exit acpi_wmi_exit(void)
1370{
1371	platform_driver_unregister(&acpi_wmi_driver);
1372	bus_unregister(&wmi_bus_type);
1373	class_unregister(&wmi_bus_class);
 
1374}
1375
1376subsys_initcall_sync(acpi_wmi_init);
1377module_exit(acpi_wmi_exit);
v3.15
 
  1/*
  2 *  ACPI-WMI mapping driver
  3 *
  4 *  Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
  5 *
  6 *  GUID parsing code from ldm.c is:
  7 *   Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
  8 *   Copyright (c) 2001-2007 Anton Altaparmakov
  9 *   Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
 10 *
 11 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 12 *
 13 *  This program is free software; you can redistribute it and/or modify
 14 *  it under the terms of the GNU General Public License as published by
 15 *  the Free Software Foundation; either version 2 of the License, or (at
 16 *  your option) any later version.
 17 *
 18 *  This program is distributed in the hope that it will be useful, but
 19 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 20 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 21 *  General Public License for more details.
 22 *
 23 *  You should have received a copy of the GNU General Public License along
 24 *  with this program; if not, write to the Free Software Foundation, Inc.,
 25 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 26 *
 27 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 28 */
 29
 30#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
 31
 
 
 
 
 
 32#include <linux/kernel.h>
 33#include <linux/init.h>
 
 
 
 
 34#include <linux/types.h>
 35#include <linux/device.h>
 36#include <linux/list.h>
 37#include <linux/acpi.h>
 38#include <linux/slab.h>
 39#include <linux/module.h>
 40
 41ACPI_MODULE_NAME("wmi");
 42MODULE_AUTHOR("Carlos Corbacho");
 43MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
 44MODULE_LICENSE("GPL");
 45
 46#define ACPI_WMI_CLASS "wmi"
 47
 48static DEFINE_MUTEX(wmi_data_lock);
 49static LIST_HEAD(wmi_block_list);
 50
 51struct guid_block {
 52	char guid[16];
 53	union {
 54		char object_id[2];
 55		struct {
 56			unsigned char notify_id;
 57			unsigned char reserved;
 58		};
 59	};
 60	u8 instance_count;
 61	u8 flags;
 
 
 
 
 
 
 
 
 
 62};
 63
 64struct wmi_block {
 65	struct list_head list;
 66	struct guid_block gblock;
 67	acpi_handle handle;
 
 68	wmi_notify_handler handler;
 69	void *handler_data;
 70	struct device dev;
 
 71};
 72
 
 
 
 
 73
 74/*
 75 * If the GUID data block is marked as expensive, we must enable and
 76 * explicitily disable data collection.
 77 */
 78#define ACPI_WMI_EXPENSIVE   0x1
 79#define ACPI_WMI_METHOD      0x2	/* GUID is a method */
 80#define ACPI_WMI_STRING      0x4	/* GUID takes & returns a string */
 81#define ACPI_WMI_EVENT       0x8	/* GUID is an event */
 82
 83static bool debug_event;
 84module_param(debug_event, bool, 0444);
 85MODULE_PARM_DESC(debug_event,
 86		 "Log WMI Events [0/1]");
 87
 88static bool debug_dump_wdg;
 89module_param(debug_dump_wdg, bool, 0444);
 90MODULE_PARM_DESC(debug_dump_wdg,
 91		 "Dump available WMI interfaces [0/1]");
 92
 93static int acpi_wmi_remove(struct acpi_device *device);
 94static int acpi_wmi_add(struct acpi_device *device);
 95static void acpi_wmi_notify(struct acpi_device *device, u32 event);
 96
 97static const struct acpi_device_id wmi_device_ids[] = {
 98	{"PNP0C14", 0},
 99	{"pnp0c14", 0},
100	{"", 0},
101};
102MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
103
104static struct acpi_driver acpi_wmi_driver = {
105	.name = "wmi",
106	.class = ACPI_WMI_CLASS,
107	.ids = wmi_device_ids,
108	.ops = {
109		.add = acpi_wmi_add,
110		.remove = acpi_wmi_remove,
111		.notify = acpi_wmi_notify,
112	},
113};
114
115/*
116 * GUID parsing functions
117 */
118
119/**
120 * wmi_parse_hexbyte - Convert a ASCII hex number to a byte
121 * @src:  Pointer to at least 2 characters to convert.
122 *
123 * Convert a two character ASCII hex string to a number.
124 *
125 * Return:  0-255  Success, the byte was parsed correctly
126 *          -1     Error, an invalid character was supplied
127 */
128static int wmi_parse_hexbyte(const u8 *src)
129{
130	int h;
131	int value;
132
133	/* high part */
134	h = value = hex_to_bin(src[0]);
135	if (value < 0)
136		return -1;
137
138	/* low part */
139	value = hex_to_bin(src[1]);
140	if (value >= 0)
141		return (h << 4) | value;
142	return -1;
143}
144
145/**
146 * wmi_swap_bytes - Rearrange GUID bytes to match GUID binary
147 * @src:   Memory block holding binary GUID (16 bytes)
148 * @dest:  Memory block to hold byte swapped binary GUID (16 bytes)
149 *
150 * Byte swap a binary GUID to match it's real GUID value
151 */
152static void wmi_swap_bytes(u8 *src, u8 *dest)
153{
154	int i;
155
156	for (i = 0; i <= 3; i++)
157		memcpy(dest + i, src + (3 - i), 1);
 
158
159	for (i = 0; i <= 1; i++)
160		memcpy(dest + 4 + i, src + (5 - i), 1);
 
 
 
 
 
161
162	for (i = 0; i <= 1; i++)
163		memcpy(dest + 6 + i, src + (7 - i), 1);
 
 
 
 
164
165	memcpy(dest + 8, src + 8, 8);
 
 
 
 
 
 
 
 
166}
167
168/**
169 * wmi_parse_guid - Convert GUID from ASCII to binary
170 * @src:   36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
171 * @dest:  Memory block to hold binary GUID (16 bytes)
172 *
173 * N.B. The GUID need not be NULL terminated.
174 *
175 * Return:  'true'   @dest contains binary GUID
176 *          'false'  @dest contents are undefined
177 */
178static bool wmi_parse_guid(const u8 *src, u8 *dest)
179{
180	static const int size[] = { 4, 2, 2, 2, 6 };
181	int i, j, v;
182
183	if (src[8]  != '-' || src[13] != '-' ||
184		src[18] != '-' || src[23] != '-')
185		return false;
 
 
 
186
187	for (j = 0; j < 5; j++, src++) {
188		for (i = 0; i < size[j]; i++, src += 2, *dest++ = v) {
189			v = wmi_parse_hexbyte(src);
190			if (v < 0)
191				return false;
192		}
193	}
194
195	return true;
196}
197
198/*
199 * Convert a raw GUID to the ACII string representation
200 */
201static int wmi_gtoa(const char *in, char *out)
202{
203	int i;
 
204
205	for (i = 3; i >= 0; i--)
206		out += sprintf(out, "%02X", in[i] & 0xFF);
207
208	out += sprintf(out, "-");
209	out += sprintf(out, "%02X", in[5] & 0xFF);
210	out += sprintf(out, "%02X", in[4] & 0xFF);
211	out += sprintf(out, "-");
212	out += sprintf(out, "%02X", in[7] & 0xFF);
213	out += sprintf(out, "%02X", in[6] & 0xFF);
214	out += sprintf(out, "-");
215	out += sprintf(out, "%02X", in[8] & 0xFF);
216	out += sprintf(out, "%02X", in[9] & 0xFF);
217	out += sprintf(out, "-");
218
219	for (i = 10; i <= 15; i++)
220		out += sprintf(out, "%02X", in[i] & 0xFF);
221
222	*out = '\0';
223	return 0;
224}
225
226static bool find_guid(const char *guid_string, struct wmi_block **out)
 
 
227{
228	char tmp[16], guid_input[16];
229	struct wmi_block *wblock;
230	struct guid_block *block;
231	struct list_head *p;
 
 
 
232
233	wmi_parse_guid(guid_string, tmp);
234	wmi_swap_bytes(tmp, guid_input);
 
235
236	list_for_each(p, &wmi_block_list) {
237		wblock = list_entry(p, struct wmi_block, list);
238		block = &wblock->gblock;
239
240		if (memcmp(block->guid, guid_input, 16) == 0) {
241			if (out)
242				*out = wblock;
243			return 1;
244		}
245	}
246	return 0;
247}
248
249static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
250{
251	struct guid_block *block = NULL;
252	char method[5];
253	acpi_status status;
254	acpi_handle handle;
255
256	block = &wblock->gblock;
257	handle = wblock->handle;
 
258
259	if (!block)
260		return AE_NOT_EXIST;
 
 
 
 
 
 
 
 
 
 
261
 
 
 
262
263	snprintf(method, 5, "WE%02X", block->notify_id);
264	status = acpi_execute_simple_method(handle, method, enable);
265
266	if (status != AE_OK && status != AE_NOT_FOUND)
267		return status;
268	else
269		return AE_OK;
270}
 
271
272/*
273 * Exported WMI functions
 
 
 
 
 
274 */
 
 
 
 
 
 
 
 
275/**
276 * wmi_evaluate_method - Evaluate a WMI method
277 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
278 * @instance: Instance index
279 * @method_id: Method ID to call
280 * &in: Buffer containing input for the method call
281 * &out: Empty buffer to return the method results
282 *
283 * Call an ACPI-WMI method
 
 
284 */
285acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
286u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
287{
288	struct guid_block *block = NULL;
289	struct wmi_block *wblock = NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
290	acpi_handle handle;
291	acpi_status status;
292	struct acpi_object_list input;
293	union acpi_object params[3];
294	char method[5] = "WM";
295
296	if (!find_guid(guid_string, &wblock))
297		return AE_ERROR;
 
298
299	block = &wblock->gblock;
300	handle = wblock->handle;
301
302	if (!(block->flags & ACPI_WMI_METHOD))
303		return AE_BAD_DATA;
304
305	if (block->instance_count < instance)
306		return AE_BAD_PARAMETER;
307
308	input.count = 2;
309	input.pointer = params;
 
310	params[0].type = ACPI_TYPE_INTEGER;
311	params[0].integer.value = instance;
312	params[1].type = ACPI_TYPE_INTEGER;
313	params[1].integer.value = method_id;
 
 
 
314
315	if (in) {
316		input.count = 3;
317
318		if (block->flags & ACPI_WMI_STRING) {
319			params[2].type = ACPI_TYPE_STRING;
320		} else {
321			params[2].type = ACPI_TYPE_BUFFER;
322		}
323		params[2].buffer.length = in->length;
324		params[2].buffer.pointer = in->pointer;
325	}
326
327	strncat(method, block->object_id, 2);
328
329	status = acpi_evaluate_object(handle, method, &input, out);
330
331	return status;
332}
333EXPORT_SYMBOL_GPL(wmi_evaluate_method);
334
335/**
336 * wmi_query_block - Return contents of a WMI block
337 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
338 * @instance: Instance index
339 * &out: Empty buffer to return the contents of the data block to
340 *
341 * Return the contents of an ACPI-WMI data block to a buffer
342 */
343acpi_status wmi_query_block(const char *guid_string, u8 instance,
344struct acpi_buffer *out)
345{
346	struct guid_block *block = NULL;
347	struct wmi_block *wblock = NULL;
348	acpi_handle handle;
349	acpi_status status, wc_status = AE_ERROR;
350	struct acpi_object_list input;
351	union acpi_object wq_params[1];
352	char method[5];
353	char wc_method[5] = "WC";
354
355	if (!guid_string || !out)
356		return AE_BAD_PARAMETER;
357
358	if (!find_guid(guid_string, &wblock))
359		return AE_ERROR;
360
361	block = &wblock->gblock;
362	handle = wblock->handle;
363
364	if (block->instance_count < instance)
365		return AE_BAD_PARAMETER;
366
367	/* Check GUID is a data block */
368	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
369		return AE_ERROR;
370
371	input.count = 1;
372	input.pointer = wq_params;
373	wq_params[0].type = ACPI_TYPE_INTEGER;
374	wq_params[0].integer.value = instance;
375
 
 
 
376	/*
377	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
378	 * enable collection.
379	 */
380	if (block->flags & ACPI_WMI_EXPENSIVE) {
381		strncat(wc_method, block->object_id, 2);
382
383		/*
384		 * Some GUIDs break the specification by declaring themselves
385		 * expensive, but have no corresponding WCxx method. So we
386		 * should not fail if this happens.
387		 */
388		if (acpi_has_method(handle, wc_method))
389			wc_status = acpi_execute_simple_method(handle,
390								wc_method, 1);
391	}
392
393	strcpy(method, "WQ");
394	strncat(method, block->object_id, 2);
395
396	status = acpi_evaluate_object(handle, method, &input, out);
397
398	/*
399	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
400	 * the WQxx method failed - we should disable collection anyway.
401	 */
402	if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
403		status = acpi_execute_simple_method(handle, wc_method, 0);
 
 
 
 
 
 
 
404	}
405
406	return status;
407}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
408EXPORT_SYMBOL_GPL(wmi_query_block);
409
410/**
411 * wmi_set_block - Write to a WMI block
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
412 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
413 * @instance: Instance index
414 * &in: Buffer containing new values for the data block
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
415 *
416 * Write the contents of the input buffer to an ACPI-WMI data block
 
 
417 */
418acpi_status wmi_set_block(const char *guid_string, u8 instance,
419const struct acpi_buffer *in)
420{
421	struct guid_block *block = NULL;
422	struct wmi_block *wblock = NULL;
423	acpi_handle handle;
 
424	struct acpi_object_list input;
425	union acpi_object params[2];
426	char method[5] = "WS";
427
428	if (!guid_string || !in)
429		return AE_BAD_DATA;
430
431	if (!find_guid(guid_string, &wblock))
432		return AE_ERROR;
433
434	block = &wblock->gblock;
435	handle = wblock->handle;
436
437	if (block->instance_count < instance)
438		return AE_BAD_PARAMETER;
439
440	/* Check GUID is a data block */
441	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
442		return AE_ERROR;
443
444	input.count = 2;
445	input.pointer = params;
446	params[0].type = ACPI_TYPE_INTEGER;
447	params[0].integer.value = instance;
448
449	if (block->flags & ACPI_WMI_STRING) {
450		params[1].type = ACPI_TYPE_STRING;
451	} else {
452		params[1].type = ACPI_TYPE_BUFFER;
453	}
454	params[1].buffer.length = in->length;
455	params[1].buffer.pointer = in->pointer;
456
457	strncat(method, block->object_id, 2);
458
459	return acpi_evaluate_object(handle, method, &input, NULL);
460}
461EXPORT_SYMBOL_GPL(wmi_set_block);
462
463static void wmi_dump_wdg(const struct guid_block *g)
464{
465	char guid_string[37];
466
467	wmi_gtoa(g->guid, guid_string);
468
469	pr_info("%s:\n", guid_string);
470	pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]);
471	pr_info("\tnotify_id: %02X\n", g->notify_id);
472	pr_info("\treserved: %02X\n", g->reserved);
473	pr_info("\tinstance_count: %d\n", g->instance_count);
474	pr_info("\tflags: %#x", g->flags);
475	if (g->flags) {
476		if (g->flags & ACPI_WMI_EXPENSIVE)
477			pr_cont(" ACPI_WMI_EXPENSIVE");
478		if (g->flags & ACPI_WMI_METHOD)
479			pr_cont(" ACPI_WMI_METHOD");
480		if (g->flags & ACPI_WMI_STRING)
481			pr_cont(" ACPI_WMI_STRING");
482		if (g->flags & ACPI_WMI_EVENT)
483			pr_cont(" ACPI_WMI_EVENT");
484	}
485	pr_cont("\n");
486
487}
488
489static void wmi_notify_debug(u32 value, void *context)
490{
491	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
492	union acpi_object *obj;
493	acpi_status status;
494
495	status = wmi_get_event_data(value, &response);
496	if (status != AE_OK) {
497		pr_info("bad event status 0x%x\n", status);
498		return;
499	}
500
501	obj = (union acpi_object *)response.pointer;
502
503	if (!obj)
504		return;
505
506	pr_info("DEBUG Event ");
507	switch(obj->type) {
508	case ACPI_TYPE_BUFFER:
509		pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
510		break;
511	case ACPI_TYPE_STRING:
512		pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
513		break;
514	case ACPI_TYPE_INTEGER:
515		pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
516		break;
517	case ACPI_TYPE_PACKAGE:
518		pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
519		break;
520	default:
521		pr_cont("object type 0x%X\n", obj->type);
522	}
523	kfree(obj);
524}
525
526/**
527 * wmi_install_notify_handler - Register handler for WMI events
 
528 * @handler: Function to handle notifications
529 * @data: Data to be returned to handler when event is fired
530 *
531 * Register a handler for events sent to the ACPI-WMI mapper device.
 
 
532 */
533acpi_status wmi_install_notify_handler(const char *guid,
534wmi_notify_handler handler, void *data)
 
535{
536	struct wmi_block *block;
537	acpi_status status = AE_NOT_EXIST;
538	char tmp[16], guid_input[16];
539	struct list_head *p;
 
 
 
540
541	if (!guid || !handler)
542		return AE_BAD_PARAMETER;
 
 
 
 
 
 
543
544	wmi_parse_guid(guid, tmp);
545	wmi_swap_bytes(tmp, guid_input);
546
547	list_for_each(p, &wmi_block_list) {
548		acpi_status wmi_status;
549		block = list_entry(p, struct wmi_block, list);
550
551		if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
552			if (block->handler &&
553			    block->handler != wmi_notify_debug)
554				return AE_ALREADY_ACQUIRED;
555
556			block->handler = handler;
557			block->handler_data = data;
558
559			wmi_status = wmi_method_enable(block, 1);
560			if ((wmi_status != AE_OK) ||
561			    ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
562				status = wmi_status;
563		}
564	}
 
 
 
565
566	return status;
567}
568EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
569
570/**
571 * wmi_uninstall_notify_handler - Unregister handler for WMI events
 
572 *
573 * Unregister handler for events sent to the ACPI-WMI mapper device.
 
 
574 */
575acpi_status wmi_remove_notify_handler(const char *guid)
576{
577	struct wmi_block *block;
578	acpi_status status = AE_NOT_EXIST;
579	char tmp[16], guid_input[16];
580	struct list_head *p;
 
 
 
 
 
581
582	if (!guid)
583		return AE_BAD_PARAMETER;
 
 
 
 
584
585	wmi_parse_guid(guid, tmp);
586	wmi_swap_bytes(tmp, guid_input);
587
588	list_for_each(p, &wmi_block_list) {
589		acpi_status wmi_status;
590		block = list_entry(p, struct wmi_block, list);
591
592		if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
593			if (!block->handler ||
594			    block->handler == wmi_notify_debug)
595				return AE_NULL_ENTRY;
596
597			if (debug_event) {
598				block->handler = wmi_notify_debug;
599				status = AE_OK;
600			} else {
601				wmi_status = wmi_method_enable(block, 0);
602				block->handler = NULL;
603				block->handler_data = NULL;
604				if ((wmi_status != AE_OK) ||
605				    ((wmi_status == AE_OK) &&
606				     (status == AE_NOT_EXIST)))
607					status = wmi_status;
608			}
609		}
610	}
 
 
 
611
612	return status;
613}
614EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
615
616/**
617 * wmi_get_event_data - Get WMI data associated with an event
 
618 *
619 * @event: Event to find
620 * @out: Buffer to hold event data. out->pointer should be freed with kfree()
621 *
622 * Returns extra data associated with an event in WMI.
623 */
624acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
625{
626	struct acpi_object_list input;
627	union acpi_object params[1];
628	struct guid_block *gblock;
629	struct wmi_block *wblock;
630	struct list_head *p;
631
632	input.count = 1;
633	input.pointer = params;
634	params[0].type = ACPI_TYPE_INTEGER;
635	params[0].integer.value = event;
636
637	list_for_each(p, &wmi_block_list) {
638		wblock = list_entry(p, struct wmi_block, list);
639		gblock = &wblock->gblock;
640
641		if ((gblock->flags & ACPI_WMI_EVENT) &&
642			(gblock->notify_id == event))
643			return acpi_evaluate_object(wblock->handle, "_WED",
644				&input, out);
645	}
646
647	return AE_NOT_FOUND;
648}
649EXPORT_SYMBOL_GPL(wmi_get_event_data);
650
651/**
652 * wmi_has_guid - Check if a GUID is available
653 * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
654 *
655 * Check if a given GUID is defined by _WDG
 
 
656 */
657bool wmi_has_guid(const char *guid_string)
658{
659	return find_guid(guid_string, NULL);
 
 
 
 
 
 
 
 
 
 
 
 
 
660}
661EXPORT_SYMBOL_GPL(wmi_has_guid);
662
663/*
664 * sysfs interface
665 */
666static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
667			     char *buf)
668{
669	char guid_string[37];
670	struct wmi_block *wblock;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
671
672	wblock = dev_get_drvdata(dev);
673	if (!wblock) {
674		strcat(buf, "\n");
675		return strlen(buf);
676	}
677
678	wmi_gtoa(wblock->gblock.guid, guid_string);
 
 
679
680	return sprintf(buf, "wmi:%s\n", guid_string);
681}
682static DEVICE_ATTR_RO(modalias);
683
684static struct attribute *wmi_attrs[] = {
685	&dev_attr_modalias.attr,
686	NULL,
 
 
 
 
687};
688ATTRIBUTE_GROUPS(wmi);
689
690static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
691{
692	char guid_string[37];
 
 
 
 
 
 
 
 
 
 
 
 
 
 
693
694	struct wmi_block *wblock;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
695
696	if (add_uevent_var(env, "MODALIAS="))
697		return -ENOMEM;
698
699	wblock = dev_get_drvdata(dev);
700	if (!wblock)
701		return -ENOMEM;
702
703	wmi_gtoa(wblock->gblock.guid, guid_string);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
704
705	strcpy(&env->buf[env->buflen - 1], "wmi:");
706	memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
707	env->buflen += 40;
 
 
 
 
 
 
708
709	return 0;
710}
711
712static void wmi_dev_free(struct device *dev)
713{
714	struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
715
716	kfree(wmi_block);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
717}
718
719static struct class wmi_class = {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
720	.name = "wmi",
721	.dev_release = wmi_dev_free,
722	.dev_uevent = wmi_dev_uevent,
723	.dev_groups = wmi_groups,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
724};
725
726static int wmi_create_device(const struct guid_block *gblock,
727			     struct wmi_block *wblock, acpi_handle handle)
 
 
 
 
 
728{
729	char guid_string[37];
 
730
731	wblock->dev.class = &wmi_class;
 
732
733	wmi_gtoa(gblock->guid, guid_string);
734	dev_set_name(&wblock->dev, "%s", guid_string);
 
 
 
 
 
 
 
 
735
736	dev_set_drvdata(&wblock->dev, wblock);
 
 
737
738	return device_register(&wblock->dev);
739}
740
741static void wmi_free_devices(void)
 
 
742{
743	struct wmi_block *wblock, *next;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
744
745	/* Delete devices for all the GUIDs */
746	list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
747		list_del(&wblock->list);
748		if (wblock->dev.class)
749			device_unregister(&wblock->dev);
750		else
751			kfree(wblock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
752	}
 
 
 
 
753}
754
755static bool guid_already_parsed(const char *guid_string)
756{
757	struct wmi_block *wblock;
 
 
 
 
 
 
 
 
 
758
759	list_for_each_entry(wblock, &wmi_block_list, list)
760		if (memcmp(wblock->gblock.guid, guid_string, 16) == 0)
761			return true;
762
763	return false;
764}
765
766/*
767 * Parse the _WDG method for the GUID data blocks
768 */
769static int parse_wdg(acpi_handle handle)
770{
 
771	struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
772	union acpi_object *obj;
773	const struct guid_block *gblock;
 
774	struct wmi_block *wblock;
 
775	acpi_status status;
 
776	int retval;
777	u32 i, total;
778
779	status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
780	if (ACPI_FAILURE(status))
781		return -ENXIO;
782
783	obj = (union acpi_object *) out.pointer;
784	if (!obj)
785		return -ENXIO;
786
787	if (obj->type != ACPI_TYPE_BUFFER) {
788		retval = -ENXIO;
789		goto out_free_pointer;
790	}
791
 
792	gblock = (const struct guid_block *)obj->buffer.pointer;
793	total = obj->buffer.length / sizeof(struct guid_block);
794
795	for (i = 0; i < total; i++) {
796		if (debug_dump_wdg)
797			wmi_dump_wdg(&gblock[i]);
 
 
798
799		wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
800		if (!wblock)
801			return -ENOMEM;
802
803		wblock->handle = handle;
804		wblock->gblock = gblock[i];
 
 
805
806		/*
807		  Some WMI devices, like those for nVidia hooks, have a
808		  duplicate GUID. It's not clear what we should do in this
809		  case yet, so for now, we'll just ignore the duplicate
810		  for device creation.
811		*/
812		if (!guid_already_parsed(gblock[i].guid)) {
813			retval = wmi_create_device(&gblock[i], wblock, handle);
814			if (retval) {
815				wmi_free_devices();
816				goto out_free_pointer;
817			}
818		}
819
820		list_add_tail(&wblock->list, &wmi_block_list);
 
 
 
821
822		if (debug_event) {
823			wblock->handler = wmi_notify_debug;
824			wmi_method_enable(wblock, 1);
825		}
826	}
827
828	retval = 0;
829
830out_free_pointer:
831	kfree(out.pointer);
832
833	return retval;
834}
835
836/*
837 * WMI can have EmbeddedControl access regions. In which case, we just want to
838 * hand these off to the EC driver.
839 */
840static acpi_status
841acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
842		      u32 bits, u64 *value,
843		      void *handler_context, void *region_context)
844{
845	int result = 0, i = 0;
846	u8 temp = 0;
 
 
 
 
 
 
 
 
 
 
847
848	if ((address > 0xFF) || !value)
849		return AE_BAD_PARAMETER;
 
 
 
 
 
850
851	if (function != ACPI_READ && function != ACPI_WRITE)
852		return AE_BAD_PARAMETER;
853
854	if (bits != 8)
855		return AE_BAD_PARAMETER;
 
856
857	if (function == ACPI_READ) {
858		result = ec_read(address, &temp);
859		(*value) |= ((u64)temp) << i;
860	} else {
861		temp = 0xff & ((*value) >> i);
862		result = ec_write(address, temp);
863	}
864
865	switch (result) {
866	case -EINVAL:
867		return AE_BAD_PARAMETER;
868		break;
869	case -ENODEV:
870		return AE_NOT_FOUND;
871		break;
872	case -ETIME:
873		return AE_TIME;
874		break;
875	default:
876		return AE_OK;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
877	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
878}
879
880static void acpi_wmi_notify(struct acpi_device *device, u32 event)
881{
882	struct guid_block *block;
883	struct wmi_block *wblock;
884	struct list_head *p;
885	char guid_string[37];
886
887	list_for_each(p, &wmi_block_list) {
888		wblock = list_entry(p, struct wmi_block, list);
889		block = &wblock->gblock;
890
891		if ((block->flags & ACPI_WMI_EVENT) &&
892			(block->notify_id == event)) {
893			if (wblock->handler)
894				wblock->handler(event, wblock->handler_data);
895			if (debug_event) {
896				wmi_gtoa(wblock->gblock.guid, guid_string);
897				pr_info("DEBUG Event GUID: %s\n", guid_string);
898			}
899
900			acpi_bus_generate_netlink_event(
901				device->pnp.device_class, dev_name(&device->dev),
902				event, 0);
903			break;
904		}
905	}
906}
907
908static int acpi_wmi_remove(struct acpi_device *device)
909{
910	acpi_remove_address_space_handler(device->handle,
911				ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
912	wmi_free_devices();
913
914	return 0;
915}
916
917static int acpi_wmi_add(struct acpi_device *device)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
918{
 
 
919	acpi_status status;
920	int error;
921
922	status = acpi_install_address_space_handler(device->handle,
923						    ACPI_ADR_SPACE_EC,
924						    &acpi_wmi_ec_space_handler,
925						    NULL, NULL);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
926	if (ACPI_FAILURE(status)) {
927		pr_err("Error installing EC region handler\n");
928		return -ENODEV;
929	}
 
 
 
 
930
931	error = parse_wdg(device->handle);
932	if (error) {
933		acpi_remove_address_space_handler(device->handle,
934						  ACPI_ADR_SPACE_EC,
935						  &acpi_wmi_ec_space_handler);
936		pr_err("Failed to parse WDG method\n");
937		return error;
938	}
939
940	return 0;
941}
942
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
943static int __init acpi_wmi_init(void)
944{
945	int error;
946
947	if (acpi_disabled)
948		return -ENODEV;
949
950	error = class_register(&wmi_class);
951	if (error)
952		return error;
953
954	error = acpi_bus_register_driver(&acpi_wmi_driver);
 
 
 
 
955	if (error) {
956		pr_err("Error loading mapper\n");
957		class_unregister(&wmi_class);
958		return error;
959	}
960
961	pr_info("Mapper loaded\n");
962	return 0;
 
 
 
 
 
 
 
 
963}
964
965static void __exit acpi_wmi_exit(void)
966{
967	acpi_bus_unregister_driver(&acpi_wmi_driver);
968	class_unregister(&wmi_class);
969
970	pr_info("Mapper unloaded\n");
971}
972
973subsys_initcall(acpi_wmi_init);
974module_exit(acpi_wmi_exit);