diff options
Diffstat (limited to 'drivers/acpi/utils.c')
| -rw-r--r-- | drivers/acpi/utils.c | 922 |
1 files changed, 922 insertions, 0 deletions
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c new file mode 100644 index 000000000..d5411a166 --- /dev/null +++ b/drivers/acpi/utils.c @@ -0,0 +1,922 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * acpi_utils.c - ACPI Utility Functions ($Revision: 10 $) + * + * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> + * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/hardirq.h> +#include <linux/acpi.h> +#include <linux/dynamic_debug.h> + +#include "internal.h" +#include "sleep.h" + +#define _COMPONENT ACPI_BUS_COMPONENT +ACPI_MODULE_NAME("utils"); + +/* -------------------------------------------------------------------------- + Object Evaluation Helpers + -------------------------------------------------------------------------- */ +static void +acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s) +{ +#ifdef ACPI_DEBUG_OUTPUT + char prefix[80] = {'\0'}; + struct acpi_buffer buffer = {sizeof(prefix), prefix}; + acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer); + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluate [%s.%s]: %s\n", + (char *) prefix, p, acpi_format_exception(s))); +#else + return; +#endif +} + +acpi_status +acpi_extract_package(union acpi_object *package, + struct acpi_buffer *format, struct acpi_buffer *buffer) +{ + u32 size_required = 0; + u32 tail_offset = 0; + char *format_string = NULL; + u32 format_count = 0; + u32 i = 0; + u8 *head = NULL; + u8 *tail = NULL; + + + if (!package || (package->type != ACPI_TYPE_PACKAGE) + || (package->package.count < 1)) { + printk(KERN_WARNING PREFIX "Invalid package argument\n"); + return AE_BAD_PARAMETER; + } + + if (!format || !format->pointer || (format->length < 1)) { + printk(KERN_WARNING PREFIX "Invalid format argument\n"); + return AE_BAD_PARAMETER; + } + + if (!buffer) { + printk(KERN_WARNING PREFIX "Invalid buffer argument\n"); + return AE_BAD_PARAMETER; + } + + format_count = (format->length / sizeof(char)) - 1; + if (format_count > package->package.count) { + printk(KERN_WARNING PREFIX "Format specifies more objects [%d]" + " than exist in package [%d].\n", + format_count, package->package.count); + return AE_BAD_DATA; + } + + format_string = format->pointer; + + /* + * Calculate size_required. + */ + for (i = 0; i < format_count; i++) { + + union acpi_object *element = &(package->package.elements[i]); + + switch (element->type) { + + case ACPI_TYPE_INTEGER: + switch (format_string[i]) { + case 'N': + size_required += sizeof(u64); + tail_offset += sizeof(u64); + break; + case 'S': + size_required += + sizeof(char *) + sizeof(u64) + + sizeof(char); + tail_offset += sizeof(char *); + break; + default: + printk(KERN_WARNING PREFIX "Invalid package element" + " [%d]: got number, expecting" + " [%c]\n", + i, format_string[i]); + return AE_BAD_DATA; + } + break; + + case ACPI_TYPE_STRING: + case ACPI_TYPE_BUFFER: + switch (format_string[i]) { + case 'S': + size_required += + sizeof(char *) + + (element->string.length * sizeof(char)) + + sizeof(char); + tail_offset += sizeof(char *); + break; + case 'B': + size_required += + sizeof(u8 *) + element->buffer.length; + tail_offset += sizeof(u8 *); + break; + default: + printk(KERN_WARNING PREFIX "Invalid package element" + " [%d] got string/buffer," + " expecting [%c]\n", + i, format_string[i]); + return AE_BAD_DATA; + } + break; + case ACPI_TYPE_LOCAL_REFERENCE: + switch (format_string[i]) { + case 'R': + size_required += sizeof(void *); + tail_offset += sizeof(void *); + break; + default: + printk(KERN_WARNING PREFIX "Invalid package element" + " [%d] got reference," + " expecting [%c]\n", + i, format_string[i]); + return AE_BAD_DATA; + } + break; + + case ACPI_TYPE_PACKAGE: + default: + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "Found unsupported element at index=%d\n", + i)); + /* TBD: handle nested packages... */ + return AE_SUPPORT; + } + } + + /* + * Validate output buffer. + */ + if (buffer->length == ACPI_ALLOCATE_BUFFER) { + buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required); + if (!buffer->pointer) + return AE_NO_MEMORY; + buffer->length = size_required; + } else { + if (buffer->length < size_required) { + buffer->length = size_required; + return AE_BUFFER_OVERFLOW; + } else if (buffer->length != size_required || + !buffer->pointer) { + return AE_BAD_PARAMETER; + } + } + + head = buffer->pointer; + tail = buffer->pointer + tail_offset; + + /* + * Extract package data. + */ + for (i = 0; i < format_count; i++) { + + u8 **pointer = NULL; + union acpi_object *element = &(package->package.elements[i]); + + switch (element->type) { + + case ACPI_TYPE_INTEGER: + switch (format_string[i]) { + case 'N': + *((u64 *) head) = + element->integer.value; + head += sizeof(u64); + break; + case 'S': + pointer = (u8 **) head; + *pointer = tail; + *((u64 *) tail) = + element->integer.value; + head += sizeof(u64 *); + tail += sizeof(u64); + /* NULL terminate string */ + *tail = (char)0; + tail += sizeof(char); + break; + default: + /* Should never get here */ + break; + } + break; + + case ACPI_TYPE_STRING: + case ACPI_TYPE_BUFFER: + switch (format_string[i]) { + case 'S': + pointer = (u8 **) head; + *pointer = tail; + memcpy(tail, element->string.pointer, + element->string.length); + head += sizeof(char *); + tail += element->string.length * sizeof(char); + /* NULL terminate string */ + *tail = (char)0; + tail += sizeof(char); + break; + case 'B': + pointer = (u8 **) head; + *pointer = tail; + memcpy(tail, element->buffer.pointer, + element->buffer.length); + head += sizeof(u8 *); + tail += element->buffer.length; + break; + default: + /* Should never get here */ + break; + } + break; + case ACPI_TYPE_LOCAL_REFERENCE: + switch (format_string[i]) { + case 'R': + *(void **)head = + (void *)element->reference.handle; + head += sizeof(void *); + break; + default: + /* Should never get here */ + break; + } + break; + case ACPI_TYPE_PACKAGE: + /* TBD: handle nested packages... */ + default: + /* Should never get here */ + break; + } + } + + return AE_OK; +} + +EXPORT_SYMBOL(acpi_extract_package); + +acpi_status +acpi_evaluate_integer(acpi_handle handle, + acpi_string pathname, + struct acpi_object_list *arguments, unsigned long long *data) +{ + acpi_status status = AE_OK; + union acpi_object element; + struct acpi_buffer buffer = { 0, NULL }; + + if (!data) + return AE_BAD_PARAMETER; + + buffer.length = sizeof(union acpi_object); + buffer.pointer = &element; + status = acpi_evaluate_object(handle, pathname, arguments, &buffer); + if (ACPI_FAILURE(status)) { + acpi_util_eval_error(handle, pathname, status); + return status; + } + + if (element.type != ACPI_TYPE_INTEGER) { + acpi_util_eval_error(handle, pathname, AE_BAD_DATA); + return AE_BAD_DATA; + } + + *data = element.integer.value; + + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]\n", *data)); + + return AE_OK; +} + +EXPORT_SYMBOL(acpi_evaluate_integer); + +acpi_status +acpi_evaluate_reference(acpi_handle handle, + acpi_string pathname, + struct acpi_object_list *arguments, + struct acpi_handle_list *list) +{ + acpi_status status = AE_OK; + union acpi_object *package = NULL; + union acpi_object *element = NULL; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + u32 i = 0; + + + if (!list) { + return AE_BAD_PARAMETER; + } + + /* Evaluate object. */ + + status = acpi_evaluate_object(handle, pathname, arguments, &buffer); + if (ACPI_FAILURE(status)) + goto end; + + package = buffer.pointer; + + if ((buffer.length == 0) || !package) { + status = AE_BAD_DATA; + acpi_util_eval_error(handle, pathname, status); + goto end; + } + if (package->type != ACPI_TYPE_PACKAGE) { + status = AE_BAD_DATA; + acpi_util_eval_error(handle, pathname, status); + goto end; + } + if (!package->package.count) { + status = AE_BAD_DATA; + acpi_util_eval_error(handle, pathname, status); + goto end; + } + + if (package->package.count > ACPI_MAX_HANDLES) { + kfree(package); + return AE_NO_MEMORY; + } + list->count = package->package.count; + + /* Extract package data. */ + + for (i = 0; i < list->count; i++) { + + element = &(package->package.elements[i]); + + if (element->type != ACPI_TYPE_LOCAL_REFERENCE) { + status = AE_BAD_DATA; + acpi_util_eval_error(handle, pathname, status); + break; + } + + if (!element->reference.handle) { + status = AE_NULL_ENTRY; + acpi_util_eval_error(handle, pathname, status); + break; + } + /* Get the acpi_handle. */ + + list->handles[i] = element->reference.handle; + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found reference [%p]\n", + list->handles[i])); + } + + end: + if (ACPI_FAILURE(status)) { + list->count = 0; + //kfree(list->handles); + } + + kfree(buffer.pointer); + + return status; +} + +EXPORT_SYMBOL(acpi_evaluate_reference); + +acpi_status +acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld) +{ + acpi_status status; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + union acpi_object *output; + + status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer); + + if (ACPI_FAILURE(status)) + return status; + + output = buffer.pointer; + + if (!output || output->type != ACPI_TYPE_PACKAGE + || !output->package.count + || output->package.elements[0].type != ACPI_TYPE_BUFFER + || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) { + status = AE_TYPE; + goto out; + } + + status = acpi_decode_pld_buffer( + output->package.elements[0].buffer.pointer, + output->package.elements[0].buffer.length, + pld); + +out: + kfree(buffer.pointer); + return status; +} +EXPORT_SYMBOL(acpi_get_physical_device_location); + +/** + * acpi_evaluate_ost: Evaluate _OST for hotplug operations + * @handle: ACPI device handle + * @source_event: source event code + * @status_code: status code + * @status_buf: optional detailed information (NULL if none) + * + * Evaluate _OST for hotplug operations. All ACPI hotplug handlers + * must call this function when evaluating _OST for hotplug operations. + * When the platform does not support _OST, this function has no effect. + */ +acpi_status +acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code, + struct acpi_buffer *status_buf) +{ + union acpi_object params[3] = { + {.type = ACPI_TYPE_INTEGER,}, + {.type = ACPI_TYPE_INTEGER,}, + {.type = ACPI_TYPE_BUFFER,} + }; + struct acpi_object_list arg_list = {3, params}; + + params[0].integer.value = source_event; + params[1].integer.value = status_code; + if (status_buf != NULL) { + params[2].buffer.pointer = status_buf->pointer; + params[2].buffer.length = status_buf->length; + } else { + params[2].buffer.pointer = NULL; + params[2].buffer.length = 0; + } + + return acpi_evaluate_object(handle, "_OST", &arg_list, NULL); +} +EXPORT_SYMBOL(acpi_evaluate_ost); + +/** + * acpi_handle_path: Return the object path of handle + * @handle: ACPI device handle + * + * Caller must free the returned buffer + */ +static char *acpi_handle_path(acpi_handle handle) +{ + struct acpi_buffer buffer = { + .length = ACPI_ALLOCATE_BUFFER, + .pointer = NULL + }; + + if (in_interrupt() || + acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK) + return NULL; + return buffer.pointer; +} + +/** + * acpi_handle_printk: Print message with ACPI prefix and object path + * @level: log level + * @handle: ACPI device handle + * @fmt: format string + * + * This function is called through acpi_handle_<level> macros and prints + * a message with ACPI prefix and object path. This function acquires + * the global namespace mutex to obtain an object path. In interrupt + * context, it shows the object path as <n/a>. + */ +void +acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + const char *path; + + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; + + path = acpi_handle_path(handle); + printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf); + + va_end(args); + kfree(path); +} +EXPORT_SYMBOL(acpi_handle_printk); + +#if defined(CONFIG_DYNAMIC_DEBUG) +/** + * __acpi_handle_debug: pr_debug with ACPI prefix and object path + * @descriptor: Dynamic Debug descriptor + * @handle: ACPI device handle + * @fmt: format string + * + * This function is called through acpi_handle_debug macro and debug + * prints a message with ACPI prefix and object path. This function + * acquires the global namespace mutex to obtain an object path. In + * interrupt context, it shows the object path as <n/a>. + */ +void +__acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle, + const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + const char *path; + + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; + + path = acpi_handle_path(handle); + __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf); + + va_end(args); + kfree(path); +} +EXPORT_SYMBOL(__acpi_handle_debug); +#endif + +/** + * acpi_has_method: Check whether @handle has a method named @name + * @handle: ACPI device handle + * @name: name of object or method + * + * Check whether @handle has a method named @name. + */ +bool acpi_has_method(acpi_handle handle, char *name) +{ + acpi_handle tmp; + + return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp)); +} +EXPORT_SYMBOL(acpi_has_method); + +acpi_status acpi_execute_simple_method(acpi_handle handle, char *method, + u64 arg) +{ + union acpi_object obj = { .type = ACPI_TYPE_INTEGER }; + struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, }; + + obj.integer.value = arg; + + return acpi_evaluate_object(handle, method, &arg_list, NULL); +} +EXPORT_SYMBOL(acpi_execute_simple_method); + +/** + * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations + * @handle: ACPI device handle + * + * Evaluate device's _EJ0 method for hotplug operations. + */ +acpi_status acpi_evaluate_ej0(acpi_handle handle) +{ + acpi_status status; + + status = acpi_execute_simple_method(handle, "_EJ0", 1); + if (status == AE_NOT_FOUND) + acpi_handle_warn(handle, "No _EJ0 support for device\n"); + else if (ACPI_FAILURE(status)) + acpi_handle_warn(handle, "Eject failed (0x%x)\n", status); + + return status; +} + +/** + * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device + * @handle: ACPI device handle + * @lock: lock device if non-zero, otherwise unlock device + * + * Evaluate device's _LCK method if present to lock/unlock device + */ +acpi_status acpi_evaluate_lck(acpi_handle handle, int lock) +{ + acpi_status status; + + status = acpi_execute_simple_method(handle, "_LCK", !!lock); + if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { + if (lock) + acpi_handle_warn(handle, + "Locking device failed (0x%x)\n", status); + else + acpi_handle_warn(handle, + "Unlocking device failed (0x%x)\n", status); + } + + return status; +} + +/** + * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence + * @handle: ACPI device handle + * @space_id: ACPI address space id to register OpRegion presence for + * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or + * ACPI_REG_DISCONNECT + * + * Evaluate device's _REG method to register OpRegion presence. + */ +acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function) +{ + struct acpi_object_list arg_list; + union acpi_object params[2]; + + params[0].type = ACPI_TYPE_INTEGER; + params[0].integer.value = space_id; + params[1].type = ACPI_TYPE_INTEGER; + params[1].integer.value = function; + arg_list.count = 2; + arg_list.pointer = params; + + return acpi_evaluate_object(handle, "_REG", &arg_list, NULL); +} +EXPORT_SYMBOL(acpi_evaluate_reg); + +/** + * acpi_evaluate_dsm - evaluate device's _DSM method + * @handle: ACPI device handle + * @guid: GUID of requested functions, should be 16 bytes + * @rev: revision number of requested function + * @func: requested function number + * @argv4: the function specific parameter + * + * Evaluate device's _DSM method with specified GUID, revision id and + * function number. Caller needs to free the returned object. + * + * Though ACPI defines the fourth parameter for _DSM should be a package, + * some old BIOSes do expect a buffer or an integer etc. + */ +union acpi_object * +acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func, + union acpi_object *argv4) +{ + acpi_status ret; + struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL}; + union acpi_object params[4]; + struct acpi_object_list input = { + .count = 4, + .pointer = params, + }; + + params[0].type = ACPI_TYPE_BUFFER; + params[0].buffer.length = 16; + params[0].buffer.pointer = (u8 *)guid; + params[1].type = ACPI_TYPE_INTEGER; + params[1].integer.value = rev; + params[2].type = ACPI_TYPE_INTEGER; + params[2].integer.value = func; + if (argv4) { + params[3] = *argv4; + } else { + params[3].type = ACPI_TYPE_PACKAGE; + params[3].package.count = 0; + params[3].package.elements = NULL; + } + + ret = acpi_evaluate_object(handle, "_DSM", &input, &buf); + if (ACPI_SUCCESS(ret)) + return (union acpi_object *)buf.pointer; + + if (ret != AE_NOT_FOUND) + acpi_handle_warn(handle, + "failed to evaluate _DSM (0x%x)\n", ret); + + return NULL; +} +EXPORT_SYMBOL(acpi_evaluate_dsm); + +/** + * acpi_check_dsm - check if _DSM method supports requested functions. + * @handle: ACPI device handle + * @guid: GUID of requested functions, should be 16 bytes at least + * @rev: revision number of requested functions + * @funcs: bitmap of requested functions + * + * Evaluate device's _DSM method to check whether it supports requested + * functions. Currently only support 64 functions at maximum, should be + * enough for now. + */ +bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs) +{ + int i; + u64 mask = 0; + union acpi_object *obj; + + if (funcs == 0) + return false; + + obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL); + if (!obj) + return false; + + /* For compatibility, old BIOSes may return an integer */ + if (obj->type == ACPI_TYPE_INTEGER) + mask = obj->integer.value; + else if (obj->type == ACPI_TYPE_BUFFER) + for (i = 0; i < obj->buffer.length && i < 8; i++) + mask |= (((u64)obj->buffer.pointer[i]) << (i * 8)); + ACPI_FREE(obj); + + /* + * Bit 0 indicates whether there's support for any functions other than + * function 0 for the specified GUID and revision. + */ + if ((mask & 0x1) && (mask & funcs) == funcs) + return true; + + return false; +} +EXPORT_SYMBOL(acpi_check_dsm); + +/** + * acpi_dev_hid_uid_match - Match device by supplied HID and UID + * @adev: ACPI device to match. + * @hid2: Hardware ID of the device. + * @uid2: Unique ID of the device, pass NULL to not check _UID. + * + * Matches HID and UID in @adev with given @hid2 and @uid2. + * Returns true if matches. + */ +bool acpi_dev_hid_uid_match(struct acpi_device *adev, + const char *hid2, const char *uid2) +{ + const char *hid1 = acpi_device_hid(adev); + const char *uid1 = acpi_device_uid(adev); + + if (strcmp(hid1, hid2)) + return false; + + if (!uid2) + return true; + + return uid1 && !strcmp(uid1, uid2); +} +EXPORT_SYMBOL(acpi_dev_hid_uid_match); + +/** + * acpi_dev_found - Detect presence of a given ACPI device in the namespace. + * @hid: Hardware ID of the device. + * + * Return %true if the device was present at the moment of invocation. + * Note that if the device is pluggable, it may since have disappeared. + * + * For this function to work, acpi_bus_scan() must have been executed + * which happens in the subsys_initcall() subsection. Hence, do not + * call from a subsys_initcall() or earlier (use acpi_get_devices() + * instead). Calling from module_init() is fine (which is synonymous + * with device_initcall()). + */ +bool acpi_dev_found(const char *hid) +{ + struct acpi_device_bus_id *acpi_device_bus_id; + bool found = false; + + mutex_lock(&acpi_device_lock); + list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) + if (!strcmp(acpi_device_bus_id->bus_id, hid)) { + found = true; + break; + } + mutex_unlock(&acpi_device_lock); + + return found; +} +EXPORT_SYMBOL(acpi_dev_found); + +struct acpi_dev_match_info { + struct acpi_device_id hid[2]; + const char *uid; + s64 hrv; +}; + +static int acpi_dev_match_cb(struct device *dev, const void *data) +{ + struct acpi_device *adev = to_acpi_device(dev); + const struct acpi_dev_match_info *match = data; + unsigned long long hrv; + acpi_status status; + + if (acpi_match_device_ids(adev, match->hid)) + return 0; + + if (match->uid && (!adev->pnp.unique_id || + strcmp(adev->pnp.unique_id, match->uid))) + return 0; + + if (match->hrv == -1) + return 1; + + status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv); + if (ACPI_FAILURE(status)) + return 0; + + return hrv == match->hrv; +} + +/** + * acpi_dev_present - Detect that a given ACPI device is present + * @hid: Hardware ID of the device. + * @uid: Unique ID of the device, pass NULL to not check _UID + * @hrv: Hardware Revision of the device, pass -1 to not check _HRV + * + * Return %true if a matching device was present at the moment of invocation. + * Note that if the device is pluggable, it may since have disappeared. + * + * Note that unlike acpi_dev_found() this function checks the status + * of the device. So for devices which are present in the dsdt, but + * which are disabled (their _STA callback returns 0) this function + * will return false. + * + * For this function to work, acpi_bus_scan() must have been executed + * which happens in the subsys_initcall() subsection. Hence, do not + * call from a subsys_initcall() or earlier (use acpi_get_devices() + * instead). Calling from module_init() is fine (which is synonymous + * with device_initcall()). + */ +bool acpi_dev_present(const char *hid, const char *uid, s64 hrv) +{ + struct acpi_dev_match_info match = {}; + struct device *dev; + + strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id)); + match.uid = uid; + match.hrv = hrv; + + dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb); + put_device(dev); + return !!dev; +} +EXPORT_SYMBOL(acpi_dev_present); + +/** + * acpi_dev_get_first_match_dev - Return the first match of ACPI device + * @hid: Hardware ID of the device. + * @uid: Unique ID of the device, pass NULL to not check _UID + * @hrv: Hardware Revision of the device, pass -1 to not check _HRV + * + * Return the first match of ACPI device if a matching device was present + * at the moment of invocation, or NULL otherwise. + * + * The caller is responsible to call put_device() on the returned device. + * + * See additional information in acpi_dev_present() as well. + */ +struct acpi_device * +acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv) +{ + struct acpi_dev_match_info match = {}; + struct device *dev; + + strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id)); + match.uid = uid; + match.hrv = hrv; + + dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb); + return dev ? to_acpi_device(dev) : NULL; +} +EXPORT_SYMBOL(acpi_dev_get_first_match_dev); + +/* + * acpi_backlight= handling, this is done here rather then in video_detect.c + * because __setup cannot be used in modules. + */ +char acpi_video_backlight_string[16]; +EXPORT_SYMBOL(acpi_video_backlight_string); + +static int __init acpi_backlight(char *str) +{ + strlcpy(acpi_video_backlight_string, str, + sizeof(acpi_video_backlight_string)); + return 1; +} +__setup("acpi_backlight=", acpi_backlight); + +/** + * acpi_match_platform_list - Check if the system matches with a given list + * @plat: pointer to acpi_platform_list table terminated by a NULL entry + * + * Return the matched index if the system is found in the platform list. + * Otherwise, return a negative error code. + */ +int acpi_match_platform_list(const struct acpi_platform_list *plat) +{ + struct acpi_table_header hdr; + int idx = 0; + + if (acpi_disabled) + return -ENODEV; + + for (; plat->oem_id[0]; plat++, idx++) { + if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr))) + continue; + + if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE)) + continue; + + if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE)) + continue; + + if ((plat->pred == all_versions) || + (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) || + (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) || + (plat->pred == equal && hdr.oem_revision == plat->oem_revision)) + return idx; + } + + return -ENODEV; +} +EXPORT_SYMBOL(acpi_match_platform_list); |