1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
9 #define pr_fmt(fmt) "ACPI: utils: " fmt
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/hardirq.h>
17 #include <linux/acpi.h>
18 #include <linux/dynamic_debug.h>
23 /* --------------------------------------------------------------------------
24 Object Evaluation Helpers
25 -------------------------------------------------------------------------- */
26 static void acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
28 acpi_handle_debug(h, "Evaluate [%s]: %s\n", p, acpi_format_exception(s));
32 acpi_extract_package(union acpi_object *package,
33 struct acpi_buffer *format, struct acpi_buffer *buffer)
35 u32 size_required = 0;
37 char *format_string = NULL;
44 if (!package || (package->type != ACPI_TYPE_PACKAGE)
45 || (package->package.count < 1)) {
46 pr_debug("Invalid package argument\n");
47 return AE_BAD_PARAMETER;
50 if (!format || !format->pointer || (format->length < 1)) {
51 pr_debug("Invalid format argument\n");
52 return AE_BAD_PARAMETER;
56 pr_debug("Invalid buffer argument\n");
57 return AE_BAD_PARAMETER;
60 format_count = (format->length / sizeof(char)) - 1;
61 if (format_count > package->package.count) {
62 pr_debug("Format specifies more objects [%d] than present [%d]\n",
63 format_count, package->package.count);
67 format_string = format->pointer;
70 * Calculate size_required.
72 for (i = 0; i < format_count; i++) {
74 union acpi_object *element = &(package->package.elements[i]);
76 switch (element->type) {
78 case ACPI_TYPE_INTEGER:
79 switch (format_string[i]) {
81 size_required += sizeof(u64);
82 tail_offset += sizeof(u64);
86 sizeof(char *) + sizeof(u64) +
88 tail_offset += sizeof(char *);
91 pr_debug("Invalid package element [%d]: got number, expected [%c]\n",
97 case ACPI_TYPE_STRING:
98 case ACPI_TYPE_BUFFER:
99 switch (format_string[i]) {
103 (element->string.length * sizeof(char)) +
105 tail_offset += sizeof(char *);
109 sizeof(u8 *) + element->buffer.length;
110 tail_offset += sizeof(u8 *);
113 pr_debug("Invalid package element [%d] got string/buffer, expected [%c]\n",
114 i, format_string[i]);
118 case ACPI_TYPE_LOCAL_REFERENCE:
119 switch (format_string[i]) {
121 size_required += sizeof(void *);
122 tail_offset += sizeof(void *);
125 pr_debug("Invalid package element [%d] got reference, expected [%c]\n",
126 i, format_string[i]);
131 case ACPI_TYPE_PACKAGE:
133 pr_debug("Unsupported element at index=%d\n", i);
134 /* TBD: handle nested packages... */
140 * Validate output buffer.
142 if (buffer->length == ACPI_ALLOCATE_BUFFER) {
143 buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
144 if (!buffer->pointer)
146 buffer->length = size_required;
148 if (buffer->length < size_required) {
149 buffer->length = size_required;
150 return AE_BUFFER_OVERFLOW;
151 } else if (buffer->length != size_required ||
153 return AE_BAD_PARAMETER;
157 head = buffer->pointer;
158 tail = buffer->pointer + tail_offset;
161 * Extract package data.
163 for (i = 0; i < format_count; i++) {
166 union acpi_object *element = &(package->package.elements[i]);
168 switch (element->type) {
170 case ACPI_TYPE_INTEGER:
171 switch (format_string[i]) {
174 element->integer.value;
178 pointer = (u8 **) head;
181 element->integer.value;
182 head += sizeof(u64 *);
184 /* NULL terminate string */
186 tail += sizeof(char);
189 /* Should never get here */
194 case ACPI_TYPE_STRING:
195 case ACPI_TYPE_BUFFER:
196 switch (format_string[i]) {
198 pointer = (u8 **) head;
200 memcpy(tail, element->string.pointer,
201 element->string.length);
202 head += sizeof(char *);
203 tail += element->string.length * sizeof(char);
204 /* NULL terminate string */
206 tail += sizeof(char);
209 pointer = (u8 **) head;
211 memcpy(tail, element->buffer.pointer,
212 element->buffer.length);
213 head += sizeof(u8 *);
214 tail += element->buffer.length;
217 /* Should never get here */
221 case ACPI_TYPE_LOCAL_REFERENCE:
222 switch (format_string[i]) {
225 (void *)element->reference.handle;
226 head += sizeof(void *);
229 /* Should never get here */
233 case ACPI_TYPE_PACKAGE:
234 /* TBD: handle nested packages... */
236 /* Should never get here */
244 EXPORT_SYMBOL(acpi_extract_package);
247 acpi_evaluate_integer(acpi_handle handle,
248 acpi_string pathname,
249 struct acpi_object_list *arguments, unsigned long long *data)
251 acpi_status status = AE_OK;
252 union acpi_object element;
253 struct acpi_buffer buffer = { 0, NULL };
256 return AE_BAD_PARAMETER;
258 buffer.length = sizeof(union acpi_object);
259 buffer.pointer = &element;
260 status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
261 if (ACPI_FAILURE(status)) {
262 acpi_util_eval_error(handle, pathname, status);
266 if (element.type != ACPI_TYPE_INTEGER) {
267 acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
271 *data = element.integer.value;
273 acpi_handle_debug(handle, "Return value [%llu]\n", *data);
278 EXPORT_SYMBOL(acpi_evaluate_integer);
280 int acpi_get_local_address(acpi_handle handle, u32 *addr)
282 unsigned long long adr;
285 status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
286 if (ACPI_FAILURE(status))
292 EXPORT_SYMBOL(acpi_get_local_address);
294 #define ACPI_MAX_SUB_BUF_SIZE 9
296 const char *acpi_get_subsystem_id(acpi_handle handle)
298 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
299 union acpi_object *obj;
304 status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);
305 if (ACPI_FAILURE(status)) {
306 acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);
307 return ERR_PTR(-ENODATA);
310 obj = buffer.pointer;
311 if (obj->type == ACPI_TYPE_STRING) {
312 len = strlen(obj->string.pointer);
313 if (len < ACPI_MAX_SUB_BUF_SIZE && len > 0) {
314 sub = kstrdup(obj->string.pointer, GFP_KERNEL);
316 sub = ERR_PTR(-ENOMEM);
318 acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n", len);
319 sub = ERR_PTR(-ENODATA);
322 acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
323 sub = ERR_PTR(-ENODATA);
326 acpi_os_free(buffer.pointer);
330 EXPORT_SYMBOL_GPL(acpi_get_subsystem_id);
333 acpi_evaluate_reference(acpi_handle handle,
334 acpi_string pathname,
335 struct acpi_object_list *arguments,
336 struct acpi_handle_list *list)
338 acpi_status status = AE_OK;
339 union acpi_object *package = NULL;
340 union acpi_object *element = NULL;
341 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
346 return AE_BAD_PARAMETER;
348 /* Evaluate object. */
350 status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
351 if (ACPI_FAILURE(status))
354 package = buffer.pointer;
356 if ((buffer.length == 0) || !package) {
357 status = AE_BAD_DATA;
358 acpi_util_eval_error(handle, pathname, status);
361 if (package->type != ACPI_TYPE_PACKAGE) {
362 status = AE_BAD_DATA;
363 acpi_util_eval_error(handle, pathname, status);
366 if (!package->package.count) {
367 status = AE_BAD_DATA;
368 acpi_util_eval_error(handle, pathname, status);
372 list->handles = kcalloc(package->package.count, sizeof(*list->handles), GFP_KERNEL);
373 if (!list->handles) {
377 list->count = package->package.count;
379 /* Extract package data. */
381 for (i = 0; i < list->count; i++) {
383 element = &(package->package.elements[i]);
385 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
386 status = AE_BAD_DATA;
387 acpi_util_eval_error(handle, pathname, status);
391 if (!element->reference.handle) {
392 status = AE_NULL_ENTRY;
393 acpi_util_eval_error(handle, pathname, status);
396 /* Get the acpi_handle. */
398 list->handles[i] = element->reference.handle;
399 acpi_handle_debug(list->handles[i], "Found in reference list\n");
403 if (ACPI_FAILURE(status)) {
405 kfree(list->handles);
406 list->handles = NULL;
409 kfree(buffer.pointer);
414 EXPORT_SYMBOL(acpi_evaluate_reference);
417 * acpi_handle_list_equal - Check if two ACPI handle lists are the same
418 * @list1: First list to compare.
419 * @list2: Second list to compare.
421 * Return true if the given ACPI handle lists are of the same size and
422 * contain the same ACPI handles in the same order. Otherwise, return false.
424 bool acpi_handle_list_equal(struct acpi_handle_list *list1,
425 struct acpi_handle_list *list2)
427 return list1->count == list2->count &&
428 !memcmp(list1->handles, list2->handles,
429 list1->count * sizeof(acpi_handle));
431 EXPORT_SYMBOL_GPL(acpi_handle_list_equal);
434 * acpi_handle_list_replace - Replace one ACPI handle list with another
435 * @dst: ACPI handle list to replace.
436 * @src: Source ACPI handle list.
438 * Free the handles table in @dst, move the handles table from @src to @dst,
439 * copy count from @src to @dst and clear @src.
441 void acpi_handle_list_replace(struct acpi_handle_list *dst,
442 struct acpi_handle_list *src)
447 dst->count = src->count;
448 dst->handles = src->handles;
453 EXPORT_SYMBOL_GPL(acpi_handle_list_replace);
456 * acpi_handle_list_free - Free the handles table in an ACPI handle list
457 * @list: ACPI handle list to free.
459 * Free the handles table in @list and clear its count field.
461 void acpi_handle_list_free(struct acpi_handle_list *list)
466 kfree(list->handles);
469 EXPORT_SYMBOL_GPL(acpi_handle_list_free);
472 acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
475 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
476 union acpi_object *output;
478 status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
480 if (ACPI_FAILURE(status))
483 output = buffer.pointer;
485 if (!output || output->type != ACPI_TYPE_PACKAGE
486 || !output->package.count
487 || output->package.elements[0].type != ACPI_TYPE_BUFFER
488 || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
493 status = acpi_decode_pld_buffer(
494 output->package.elements[0].buffer.pointer,
495 output->package.elements[0].buffer.length,
499 kfree(buffer.pointer);
502 EXPORT_SYMBOL(acpi_get_physical_device_location);
505 * acpi_evaluate_ost: Evaluate _OST for hotplug operations
506 * @handle: ACPI device handle
507 * @source_event: source event code
508 * @status_code: status code
509 * @status_buf: optional detailed information (NULL if none)
511 * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
512 * must call this function when evaluating _OST for hotplug operations.
513 * When the platform does not support _OST, this function has no effect.
516 acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
517 struct acpi_buffer *status_buf)
519 union acpi_object params[3] = {
520 {.type = ACPI_TYPE_INTEGER,},
521 {.type = ACPI_TYPE_INTEGER,},
522 {.type = ACPI_TYPE_BUFFER,}
524 struct acpi_object_list arg_list = {3, params};
526 params[0].integer.value = source_event;
527 params[1].integer.value = status_code;
528 if (status_buf != NULL) {
529 params[2].buffer.pointer = status_buf->pointer;
530 params[2].buffer.length = status_buf->length;
532 params[2].buffer.pointer = NULL;
533 params[2].buffer.length = 0;
536 return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
538 EXPORT_SYMBOL(acpi_evaluate_ost);
541 * acpi_handle_path: Return the object path of handle
542 * @handle: ACPI device handle
544 * Caller must free the returned buffer
546 static char *acpi_handle_path(acpi_handle handle)
548 struct acpi_buffer buffer = {
549 .length = ACPI_ALLOCATE_BUFFER,
553 if (in_interrupt() ||
554 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
556 return buffer.pointer;
560 * acpi_handle_printk: Print message with ACPI prefix and object path
562 * @handle: ACPI device handle
563 * @fmt: format string
565 * This function is called through acpi_handle_<level> macros and prints
566 * a message with ACPI prefix and object path. This function acquires
567 * the global namespace mutex to obtain an object path. In interrupt
568 * context, it shows the object path as <n/a>.
571 acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
573 struct va_format vaf;
581 path = acpi_handle_path(handle);
582 printk("%sACPI: %s: %pV", level, path ? path : "<n/a>", &vaf);
587 EXPORT_SYMBOL(acpi_handle_printk);
589 #if defined(CONFIG_DYNAMIC_DEBUG)
591 * __acpi_handle_debug: pr_debug with ACPI prefix and object path
592 * @descriptor: Dynamic Debug descriptor
593 * @handle: ACPI device handle
594 * @fmt: format string
596 * This function is called through acpi_handle_debug macro and debug
597 * prints a message with ACPI prefix and object path. This function
598 * acquires the global namespace mutex to obtain an object path. In
599 * interrupt context, it shows the object path as <n/a>.
602 __acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
603 const char *fmt, ...)
605 struct va_format vaf;
613 path = acpi_handle_path(handle);
614 __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
619 EXPORT_SYMBOL(__acpi_handle_debug);
623 * acpi_evaluation_failure_warn - Log evaluation failure warning.
624 * @handle: Parent object handle.
625 * @name: Name of the object whose evaluation has failed.
626 * @status: Status value returned by the failing object evaluation.
628 void acpi_evaluation_failure_warn(acpi_handle handle, const char *name,
631 acpi_handle_warn(handle, "%s evaluation failed: %s\n", name,
632 acpi_format_exception(status));
634 EXPORT_SYMBOL_GPL(acpi_evaluation_failure_warn);
637 * acpi_has_method: Check whether @handle has a method named @name
638 * @handle: ACPI device handle
639 * @name: name of object or method
641 * Check whether @handle has a method named @name.
643 bool acpi_has_method(acpi_handle handle, char *name)
647 return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
649 EXPORT_SYMBOL(acpi_has_method);
651 acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
654 union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
655 struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
657 obj.integer.value = arg;
659 return acpi_evaluate_object(handle, method, &arg_list, NULL);
661 EXPORT_SYMBOL(acpi_execute_simple_method);
664 * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
665 * @handle: ACPI device handle
667 * Evaluate device's _EJ0 method for hotplug operations.
669 acpi_status acpi_evaluate_ej0(acpi_handle handle)
673 status = acpi_execute_simple_method(handle, "_EJ0", 1);
674 if (status == AE_NOT_FOUND)
675 acpi_handle_warn(handle, "No _EJ0 support for device\n");
676 else if (ACPI_FAILURE(status))
677 acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
683 * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
684 * @handle: ACPI device handle
685 * @lock: lock device if non-zero, otherwise unlock device
687 * Evaluate device's _LCK method if present to lock/unlock device
689 acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
693 status = acpi_execute_simple_method(handle, "_LCK", !!lock);
694 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
696 acpi_handle_warn(handle,
697 "Locking device failed (0x%x)\n", status);
699 acpi_handle_warn(handle,
700 "Unlocking device failed (0x%x)\n", status);
707 * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence
708 * @handle: ACPI device handle
709 * @space_id: ACPI address space id to register OpRegion presence for
710 * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or
711 * ACPI_REG_DISCONNECT
713 * Evaluate device's _REG method to register OpRegion presence.
715 acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function)
717 struct acpi_object_list arg_list;
718 union acpi_object params[2];
720 params[0].type = ACPI_TYPE_INTEGER;
721 params[0].integer.value = space_id;
722 params[1].type = ACPI_TYPE_INTEGER;
723 params[1].integer.value = function;
725 arg_list.pointer = params;
727 return acpi_evaluate_object(handle, "_REG", &arg_list, NULL);
729 EXPORT_SYMBOL(acpi_evaluate_reg);
732 * acpi_evaluate_dsm - evaluate device's _DSM method
733 * @handle: ACPI device handle
734 * @guid: GUID of requested functions, should be 16 bytes
735 * @rev: revision number of requested function
736 * @func: requested function number
737 * @argv4: the function specific parameter
739 * Evaluate device's _DSM method with specified GUID, revision id and
740 * function number. Caller needs to free the returned object.
742 * Though ACPI defines the fourth parameter for _DSM should be a package,
743 * some old BIOSes do expect a buffer or an integer etc.
746 acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
747 union acpi_object *argv4)
750 struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
751 union acpi_object params[4];
752 struct acpi_object_list input = {
757 params[0].type = ACPI_TYPE_BUFFER;
758 params[0].buffer.length = 16;
759 params[0].buffer.pointer = (u8 *)guid;
760 params[1].type = ACPI_TYPE_INTEGER;
761 params[1].integer.value = rev;
762 params[2].type = ACPI_TYPE_INTEGER;
763 params[2].integer.value = func;
767 params[3].type = ACPI_TYPE_PACKAGE;
768 params[3].package.count = 0;
769 params[3].package.elements = NULL;
772 ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
773 if (ACPI_SUCCESS(ret))
774 return (union acpi_object *)buf.pointer;
776 if (ret != AE_NOT_FOUND)
777 acpi_handle_warn(handle,
778 "failed to evaluate _DSM %pUb (0x%x)\n", guid, ret);
782 EXPORT_SYMBOL(acpi_evaluate_dsm);
785 * acpi_check_dsm - check if _DSM method supports requested functions.
786 * @handle: ACPI device handle
787 * @guid: GUID of requested functions, should be 16 bytes at least
788 * @rev: revision number of requested functions
789 * @funcs: bitmap of requested functions
791 * Evaluate device's _DSM method to check whether it supports requested
792 * functions. Currently only support 64 functions at maximum, should be
795 bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
799 union acpi_object *obj;
804 obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);
808 /* For compatibility, old BIOSes may return an integer */
809 if (obj->type == ACPI_TYPE_INTEGER)
810 mask = obj->integer.value;
811 else if (obj->type == ACPI_TYPE_BUFFER)
812 for (i = 0; i < obj->buffer.length && i < 8; i++)
813 mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
817 * Bit 0 indicates whether there's support for any functions other than
818 * function 0 for the specified GUID and revision.
820 if ((mask & 0x1) && (mask & funcs) == funcs)
825 EXPORT_SYMBOL(acpi_check_dsm);
828 * acpi_dev_uid_match - Match device by supplied UID
829 * @adev: ACPI device to match.
830 * @uid2: Unique ID of the device.
832 * Matches UID in @adev with given @uid2.
835 * - %true if matches.
836 * - %false otherwise.
838 bool acpi_dev_uid_match(struct acpi_device *adev, const char *uid2)
840 const char *uid1 = acpi_device_uid(adev);
842 return uid1 && uid2 && !strcmp(uid1, uid2);
844 EXPORT_SYMBOL_GPL(acpi_dev_uid_match);
847 * acpi_dev_hid_uid_match - Match device by supplied HID and UID
848 * @adev: ACPI device to match.
849 * @hid2: Hardware ID of the device.
850 * @uid2: Unique ID of the device, pass NULL to not check _UID.
852 * Matches HID and UID in @adev with given @hid2 and @uid2. Absence of @uid2
853 * will be treated as a match. If user wants to validate @uid2, it should be
854 * done before calling this function.
857 * - %true if matches or @uid2 is NULL.
858 * - %false otherwise.
860 bool acpi_dev_hid_uid_match(struct acpi_device *adev,
861 const char *hid2, const char *uid2)
863 const char *hid1 = acpi_device_hid(adev);
865 if (strcmp(hid1, hid2))
871 return acpi_dev_uid_match(adev, uid2);
873 EXPORT_SYMBOL(acpi_dev_hid_uid_match);
876 * acpi_dev_uid_to_integer - treat ACPI device _UID as integer
877 * @adev: ACPI device to get _UID from
878 * @integer: output buffer for integer
880 * Considers _UID as integer and converts it to @integer.
882 * Returns 0 on success, or negative error code otherwise.
884 int acpi_dev_uid_to_integer(struct acpi_device *adev, u64 *integer)
891 uid = acpi_device_uid(adev);
895 return kstrtou64(uid, 0, integer);
897 EXPORT_SYMBOL(acpi_dev_uid_to_integer);
900 * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
901 * @hid: Hardware ID of the device.
903 * Return %true if the device was present at the moment of invocation.
904 * Note that if the device is pluggable, it may since have disappeared.
906 * For this function to work, acpi_bus_scan() must have been executed
907 * which happens in the subsys_initcall() subsection. Hence, do not
908 * call from a subsys_initcall() or earlier (use acpi_get_devices()
909 * instead). Calling from module_init() is fine (which is synonymous
910 * with device_initcall()).
912 bool acpi_dev_found(const char *hid)
914 struct acpi_device_bus_id *acpi_device_bus_id;
917 mutex_lock(&acpi_device_lock);
918 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
919 if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
923 mutex_unlock(&acpi_device_lock);
927 EXPORT_SYMBOL(acpi_dev_found);
929 struct acpi_dev_match_info {
930 struct acpi_device_id hid[2];
935 static int acpi_dev_match_cb(struct device *dev, const void *data)
937 struct acpi_device *adev = to_acpi_device(dev);
938 const struct acpi_dev_match_info *match = data;
939 unsigned long long hrv;
942 if (acpi_match_device_ids(adev, match->hid))
945 if (match->uid && !acpi_dev_uid_match(adev, match->uid))
948 if (match->hrv == -1)
951 status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);
952 if (ACPI_FAILURE(status))
955 return hrv == match->hrv;
959 * acpi_dev_present - Detect that a given ACPI device is present
960 * @hid: Hardware ID of the device.
961 * @uid: Unique ID of the device, pass NULL to not check _UID
962 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
964 * Return %true if a matching device was present at the moment of invocation.
965 * Note that if the device is pluggable, it may since have disappeared.
967 * Note that unlike acpi_dev_found() this function checks the status
968 * of the device. So for devices which are present in the DSDT, but
969 * which are disabled (their _STA callback returns 0) this function
972 * For this function to work, acpi_bus_scan() must have been executed
973 * which happens in the subsys_initcall() subsection. Hence, do not
974 * call from a subsys_initcall() or earlier (use acpi_get_devices()
975 * instead). Calling from module_init() is fine (which is synonymous
976 * with device_initcall()).
978 bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
980 struct acpi_dev_match_info match = {};
983 strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
987 dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
991 EXPORT_SYMBOL(acpi_dev_present);
994 * acpi_dev_get_next_match_dev - Return the next match of ACPI device
995 * @adev: Pointer to the previous ACPI device matching this @hid, @uid and @hrv
996 * @hid: Hardware ID of the device.
997 * @uid: Unique ID of the device, pass NULL to not check _UID
998 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
1000 * Return the next match of ACPI device if another matching device was present
1001 * at the moment of invocation, or NULL otherwise.
1003 * The caller is responsible for invoking acpi_dev_put() on the returned device.
1004 * On the other hand the function invokes acpi_dev_put() on the given @adev
1005 * assuming that its reference counter had been increased beforehand.
1007 * See additional information in acpi_dev_present() as well.
1009 struct acpi_device *
1010 acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv)
1012 struct device *start = adev ? &adev->dev : NULL;
1013 struct acpi_dev_match_info match = {};
1016 strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
1020 dev = bus_find_device(&acpi_bus_type, start, &match, acpi_dev_match_cb);
1022 return dev ? to_acpi_device(dev) : NULL;
1024 EXPORT_SYMBOL(acpi_dev_get_next_match_dev);
1027 * acpi_dev_get_first_match_dev - Return the first match of ACPI device
1028 * @hid: Hardware ID of the device.
1029 * @uid: Unique ID of the device, pass NULL to not check _UID
1030 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
1032 * Return the first match of ACPI device if a matching device was present
1033 * at the moment of invocation, or NULL otherwise.
1035 * The caller is responsible for invoking acpi_dev_put() on the returned device.
1037 * See additional information in acpi_dev_present() as well.
1039 struct acpi_device *
1040 acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
1042 return acpi_dev_get_next_match_dev(NULL, hid, uid, hrv);
1044 EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
1047 * acpi_reduced_hardware - Return if this is an ACPI-reduced-hw machine
1049 * Return true when running on an ACPI-reduced-hw machine, false otherwise.
1051 bool acpi_reduced_hardware(void)
1053 return acpi_gbl_reduced_hardware;
1055 EXPORT_SYMBOL_GPL(acpi_reduced_hardware);
1058 * acpi_backlight= handling, this is done here rather then in video_detect.c
1059 * because __setup cannot be used in modules.
1061 char acpi_video_backlight_string[16];
1062 EXPORT_SYMBOL(acpi_video_backlight_string);
1064 static int __init acpi_backlight(char *str)
1066 strscpy(acpi_video_backlight_string, str,
1067 sizeof(acpi_video_backlight_string));
1070 __setup("acpi_backlight=", acpi_backlight);
1073 * acpi_match_platform_list - Check if the system matches with a given list
1074 * @plat: pointer to acpi_platform_list table terminated by a NULL entry
1076 * Return the matched index if the system is found in the platform list.
1077 * Otherwise, return a negative error code.
1079 int acpi_match_platform_list(const struct acpi_platform_list *plat)
1081 struct acpi_table_header hdr;
1087 for (; plat->oem_id[0]; plat++, idx++) {
1088 if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))
1091 if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
1094 if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))
1097 if ((plat->pred == all_versions) ||
1098 (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||
1099 (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||
1100 (plat->pred == equal && hdr.oem_revision == plat->oem_revision))
1106 EXPORT_SYMBOL(acpi_match_platform_list);