// SPDX-License-Identifier: GPL-2.0-or-later /* * ACPI-WMI mapping driver * * Copyright (C) 2007-2008 Carlos Corbacho * * GUID parsing code from ldm.c is: * Copyright (C) 2001,2002 Richard Russon * Copyright (c) 2001-2007 Anton Altaparmakov * Copyright (C) 2001,2002 Jakob Kemi * * WMI bus infrastructure by Andrew Lutomirski and Darren Hart: * Copyright (C) 2015 Andrew Lutomirski * Copyright (C) 2017 VMware, Inc. All Rights Reserved. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include MODULE_AUTHOR("Carlos Corbacho"); MODULE_DESCRIPTION("ACPI-WMI Mapping Driver"); MODULE_LICENSE("GPL"); static LIST_HEAD(wmi_block_list); struct guid_block { guid_t guid; union { char object_id[2]; struct { unsigned char notify_id; unsigned char reserved; }; }; u8 instance_count; u8 flags; } __packed; static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16); static_assert(sizeof(struct guid_block) == 20); static_assert(__alignof__(struct guid_block) == 1); enum { /* wmi_block flags */ WMI_READ_TAKES_NO_ARGS, WMI_GUID_DUPLICATED, WMI_NO_EVENT_DATA, }; struct wmi_block { struct wmi_device dev; struct list_head list; struct guid_block gblock; struct acpi_device *acpi_device; struct rw_semaphore notify_lock; /* Protects notify callback add/remove */ wmi_notify_handler handler; void *handler_data; bool driver_ready; unsigned long flags; }; /* * If the GUID data block is marked as expensive, we must enable and * explicitily disable data collection. */ #define ACPI_WMI_EXPENSIVE BIT(0) #define ACPI_WMI_METHOD BIT(1) /* GUID is a method */ #define ACPI_WMI_STRING BIT(2) /* GUID takes & returns a string */ #define ACPI_WMI_EVENT BIT(3) /* GUID is an event */ static const struct acpi_device_id wmi_device_ids[] = { {"PNP0C14", 0}, {"pnp0c14", 0}, { } }; MODULE_DEVICE_TABLE(acpi, wmi_device_ids); #define dev_to_wblock(__dev) container_of_const(__dev, struct wmi_block, dev.dev) #define dev_to_wdev(__dev) container_of_const(__dev, struct wmi_device, dev) /* * GUID parsing functions */ static bool guid_parse_and_compare(const char *string, const guid_t *guid) { guid_t guid_input; if (guid_parse(string, &guid_input)) return false; return guid_equal(&guid_input, guid); } static const void *find_guid_context(struct wmi_block *wblock, struct wmi_driver *wdriver) { const struct wmi_device_id *id; id = wdriver->id_table; if (!id) return NULL; while (*id->guid_string) { if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid)) return id->context; id++; } return NULL; } static acpi_status wmi_method_enable(struct wmi_block *wblock, bool enable) { struct guid_block *block; char method[5]; acpi_status status; acpi_handle handle; block = &wblock->gblock; handle = wblock->acpi_device->handle; snprintf(method, 5, "WE%02X", block->notify_id); status = acpi_execute_simple_method(handle, method, enable); if (status == AE_NOT_FOUND) return AE_OK; return status; } #define WMI_ACPI_METHOD_NAME_SIZE 5 static inline void get_acpi_method_name(const struct wmi_block *wblock, const char method, char buffer[static WMI_ACPI_METHOD_NAME_SIZE]) { static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2); static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5); buffer[0] = 'W'; buffer[1] = method; buffer[2] = wblock->gblock.object_id[0]; buffer[3] = wblock->gblock.object_id[1]; buffer[4] = '\0'; } static inline acpi_object_type get_param_acpi_type(const struct wmi_block *wblock) { if (wblock->gblock.flags & ACPI_WMI_STRING) return ACPI_TYPE_STRING; else return ACPI_TYPE_BUFFER; } static acpi_status get_event_data(const struct wmi_block *wblock, struct acpi_buffer *out) { union acpi_object param = { .integer = { .type = ACPI_TYPE_INTEGER, .value = wblock->gblock.notify_id, } }; struct acpi_object_list input = { .count = 1, .pointer = ¶m, }; return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out); } static int wmidev_match_guid(struct device *dev, const void *data) { struct wmi_block *wblock = dev_to_wblock(dev); const guid_t *guid = data; /* Legacy GUID-based functions are restricted to only see * a single WMI device for each GUID. */ if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags)) return 0; if (guid_equal(guid, &wblock->gblock.guid)) return 1; return 0; } static int wmidev_match_notify_id(struct device *dev, const void *data) { struct wmi_block *wblock = dev_to_wblock(dev); const u32 *notify_id = data; /* Legacy GUID-based functions are restricted to only see * a single WMI device for each GUID. */ if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags)) return 0; if (wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *notify_id) return 1; return 0; } static const struct bus_type wmi_bus_type; static struct wmi_device *wmi_find_device_by_guid(const char *guid_string) { struct device *dev; guid_t guid; int ret; ret = guid_parse(guid_string, &guid); if (ret < 0) return ERR_PTR(ret); dev = bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid); if (!dev) return ERR_PTR(-ENODEV); return dev_to_wdev(dev); } static struct wmi_device *wmi_find_event_by_notify_id(const u32 notify_id) { struct device *dev; dev = bus_find_device(&wmi_bus_type, NULL, ¬ify_id, wmidev_match_notify_id); if (!dev) return ERR_PTR(-ENODEV); return to_wmi_device(dev); } static void wmi_device_put(struct wmi_device *wdev) { put_device(&wdev->dev); } /* * Exported WMI functions */ /** * wmi_instance_count - Get number of WMI object instances * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * * Get the number of WMI object instances. * * Returns: Number of WMI object instances or negative error code. */ int wmi_instance_count(const char *guid_string) { struct wmi_device *wdev; int ret; wdev = wmi_find_device_by_guid(guid_string); if (IS_ERR(wdev)) return PTR_ERR(wdev); ret = wmidev_instance_count(wdev); wmi_device_put(wdev); return ret; } EXPORT_SYMBOL_GPL(wmi_instance_count); /** * wmidev_instance_count - Get number of WMI object instances * @wdev: A wmi bus device from a driver * * Get the number of WMI object instances. * * Returns: Number of WMI object instances. */ u8 wmidev_instance_count(struct wmi_device *wdev) { struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev); return wblock->gblock.instance_count; } EXPORT_SYMBOL_GPL(wmidev_instance_count); /** * wmi_evaluate_method - Evaluate a WMI method (deprecated) * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * @instance: Instance index * @method_id: Method ID to call * @in: Mandatory buffer containing input for the method call * @out: Empty buffer to return the method results * * Call an ACPI-WMI method, the caller must free @out. * * Return: acpi_status signaling success or error. */ acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out) { struct wmi_device *wdev; acpi_status status; wdev = wmi_find_device_by_guid(guid_string); if (IS_ERR(wdev)) return AE_ERROR; status = wmidev_evaluate_method(wdev, instance, method_id, in, out); wmi_device_put(wdev); return status; } EXPORT_SYMBOL_GPL(wmi_evaluate_method); /** * wmidev_evaluate_method - Evaluate a WMI method * @wdev: A wmi bus device from a driver * @instance: Instance index * @method_id: Method ID to call * @in: Mandatory buffer containing input for the method call * @out: Empty buffer to return the method results * * Call an ACPI-WMI method, the caller must free @out. * * Return: acpi_status signaling success or error. */ acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out) { struct guid_block *block; struct wmi_block *wblock; acpi_handle handle; struct acpi_object_list input; union acpi_object params[3]; char method[WMI_ACPI_METHOD_NAME_SIZE]; wblock = container_of(wdev, struct wmi_block, dev); block = &wblock->gblock; handle = wblock->acpi_device->handle; if (!in) return AE_BAD_DATA; if (!(block->flags & ACPI_WMI_METHOD)) return AE_BAD_DATA; if (block->instance_count <= instance) return AE_BAD_PARAMETER; input.count = 3; input.pointer = params; params[0].type = ACPI_TYPE_INTEGER; params[0].integer.value = instance; params[1].type = ACPI_TYPE_INTEGER; params[1].integer.value = method_id; params[2].type = get_param_acpi_type(wblock); params[2].buffer.length = in->length; params[2].buffer.pointer = in->pointer; get_acpi_method_name(wblock, 'M', method); return acpi_evaluate_object(handle, method, &input, out); } EXPORT_SYMBOL_GPL(wmidev_evaluate_method); static acpi_status __query_block(struct wmi_block *wblock, u8 instance, struct acpi_buffer *out) { struct guid_block *block; acpi_handle handle; acpi_status status, wc_status = AE_ERROR; struct acpi_object_list input; union acpi_object wq_params[1]; char wc_method[WMI_ACPI_METHOD_NAME_SIZE]; char method[WMI_ACPI_METHOD_NAME_SIZE]; if (!out) return AE_BAD_PARAMETER; block = &wblock->gblock; handle = wblock->acpi_device->handle; if (block->instance_count <= instance) return AE_BAD_PARAMETER; /* Check GUID is a data block */ if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD)) return AE_ERROR; input.count = 1; input.pointer = wq_params; wq_params[0].type = ACPI_TYPE_INTEGER; wq_params[0].integer.value = instance; if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags)) input.count = 0; /* * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to * enable collection. */ if (block->flags & ACPI_WMI_EXPENSIVE) { get_acpi_method_name(wblock, 'C', wc_method); /* * Some GUIDs break the specification by declaring themselves * expensive, but have no corresponding WCxx method. So we * should not fail if this happens. */ wc_status = acpi_execute_simple_method(handle, wc_method, 1); } get_acpi_method_name(wblock, 'Q', method); status = acpi_evaluate_object(handle, method, &input, out); /* * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if * the WQxx method failed - we should disable collection anyway. */ if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) { /* * Ignore whether this WCxx call succeeds or not since * the previously executed WQxx method call might have * succeeded, and returning the failing status code * of this call would throw away the result of the WQxx * call, potentially leaking memory. */ acpi_execute_simple_method(handle, wc_method, 0); } return status; } /** * wmi_query_block - Return contents of a WMI block (deprecated) * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * @instance: Instance index * @out: Empty buffer to return the contents of the data block to * * Query a ACPI-WMI block, the caller must free @out. * * Return: ACPI object containing the content of the WMI block. */ acpi_status wmi_query_block(const char *guid_string, u8 instance, struct acpi_buffer *out) { struct wmi_block *wblock; struct wmi_device *wdev; acpi_status status; wdev = wmi_find_device_by_guid(guid_string); if (IS_ERR(wdev)) return AE_ERROR; wblock = container_of(wdev, struct wmi_block, dev); status = __query_block(wblock, instance, out); wmi_device_put(wdev); return status; } EXPORT_SYMBOL_GPL(wmi_query_block); /** * wmidev_block_query - Return contents of a WMI block * @wdev: A wmi bus device from a driver * @instance: Instance index * * Query an ACPI-WMI block, the caller must free the result. * * Return: ACPI object containing the content of the WMI block. */ union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance) { struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL }; struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev); if (ACPI_FAILURE(__query_block(wblock, instance, &out))) return NULL; return out.pointer; } EXPORT_SYMBOL_GPL(wmidev_block_query); /** * wmi_set_block - Write to a WMI block (deprecated) * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * @instance: Instance index * @in: Buffer containing new values for the data block * * Write the contents of the input buffer to an ACPI-WMI data block. * * Return: acpi_status signaling success or error. */ acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in) { struct wmi_device *wdev; acpi_status status; wdev = wmi_find_device_by_guid(guid_string); if (IS_ERR(wdev)) return AE_ERROR; status = wmidev_block_set(wdev, instance, in); wmi_device_put(wdev); return status; } EXPORT_SYMBOL_GPL(wmi_set_block); /** * wmidev_block_set - Write to a WMI block * @wdev: A wmi bus device from a driver * @instance: Instance index * @in: Buffer containing new values for the data block * * Write contents of the input buffer to an ACPI-WMI data block. * * Return: acpi_status signaling success or error. */ acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct acpi_buffer *in) { struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev); acpi_handle handle = wblock->acpi_device->handle; struct guid_block *block = &wblock->gblock; char method[WMI_ACPI_METHOD_NAME_SIZE]; struct acpi_object_list input; union acpi_object params[2]; if (!in) return AE_BAD_DATA; if (block->instance_count <= instance) return AE_BAD_PARAMETER; /* Check GUID is a data block */ if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD)) return AE_ERROR; input.count = 2; input.pointer = params; params[0].type = ACPI_TYPE_INTEGER; params[0].integer.value = instance; params[1].type = get_param_acpi_type(wblock); params[1].buffer.length = in->length; params[1].buffer.pointer = in->pointer; get_acpi_method_name(wblock, 'S', method); return acpi_evaluate_object(handle, method, &input, NULL); } EXPORT_SYMBOL_GPL(wmidev_block_set); /** * wmi_install_notify_handler - Register handler for WMI events (deprecated) * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * @handler: Function to handle notifications * @data: Data to be returned to handler when event is fired * * Register a handler for events sent to the ACPI-WMI mapper device. * * Return: acpi_status signaling success or error. */ acpi_status wmi_install_notify_handler(const char *guid, wmi_notify_handler handler, void *data) { struct wmi_block *wblock; struct wmi_device *wdev; acpi_status status; wdev = wmi_find_device_by_guid(guid); if (IS_ERR(wdev)) return AE_ERROR; wblock = container_of(wdev, struct wmi_block, dev); down_write(&wblock->notify_lock); if (wblock->handler) { status = AE_ALREADY_ACQUIRED; } else { wblock->handler = handler; wblock->handler_data = data; if (ACPI_FAILURE(wmi_method_enable(wblock, true))) dev_warn(&wblock->dev.dev, "Failed to enable device\n"); status = AE_OK; } up_write(&wblock->notify_lock); wmi_device_put(wdev); return status; } EXPORT_SYMBOL_GPL(wmi_install_notify_handler); /** * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated) * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * * Unregister handler for events sent to the ACPI-WMI mapper device. * * Return: acpi_status signaling success or error. */ acpi_status wmi_remove_notify_handler(const char *guid) { struct wmi_block *wblock; struct wmi_device *wdev; acpi_status status; wdev = wmi_find_device_by_guid(guid); if (IS_ERR(wdev)) return AE_ERROR; wblock = container_of(wdev, struct wmi_block, dev); down_write(&wblock->notify_lock); if (!wblock->handler) { status = AE_NULL_ENTRY; } else { if (ACPI_FAILURE(wmi_method_enable(wblock, false))) dev_warn(&wblock->dev.dev, "Failed to disable device\n"); wblock->handler = NULL; wblock->handler_data = NULL; status = AE_OK; } up_write(&wblock->notify_lock); wmi_device_put(wdev); return status; } EXPORT_SYMBOL_GPL(wmi_remove_notify_handler); /** * wmi_get_event_data - Get WMI data associated with an event (deprecated) * * @event: Event to find * @out: Buffer to hold event data * * Get extra data associated with an WMI event, the caller needs to free @out. * * Return: acpi_status signaling success or error. */ acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out) { struct wmi_block *wblock; struct wmi_device *wdev; acpi_status status; wdev = wmi_find_event_by_notify_id(event); if (IS_ERR(wdev)) return AE_NOT_FOUND; wblock = container_of(wdev, struct wmi_block, dev); status = get_event_data(wblock, out); wmi_device_put(wdev); return status; } EXPORT_SYMBOL_GPL(wmi_get_event_data); /** * wmi_has_guid - Check if a GUID is available * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * * Check if a given GUID is defined by _WDG. * * Return: True if GUID is available, false otherwise. */ bool wmi_has_guid(const char *guid_string) { struct wmi_device *wdev; wdev = wmi_find_device_by_guid(guid_string); if (IS_ERR(wdev)) return false; wmi_device_put(wdev); return true; } EXPORT_SYMBOL_GPL(wmi_has_guid); /** * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated) * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * * Find the _UID of ACPI device associated with this WMI GUID. * * Return: The ACPI _UID field value or NULL if the WMI GUID was not found. */ char *wmi_get_acpi_device_uid(const char *guid_string) { struct wmi_block *wblock; struct wmi_device *wdev; char *uid; wdev = wmi_find_device_by_guid(guid_string); if (IS_ERR(wdev)) return NULL; wblock = container_of(wdev, struct wmi_block, dev); uid = acpi_device_uid(wblock->acpi_device); wmi_device_put(wdev); return uid; } EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid); static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv) { return container_of(drv, struct wmi_driver, driver); } /* * sysfs interface */ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf) { struct wmi_block *wblock = dev_to_wblock(dev); return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid); } static DEVICE_ATTR_RO(modalias); static ssize_t guid_show(struct device *dev, struct device_attribute *attr, char *buf) { struct wmi_block *wblock = dev_to_wblock(dev); return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid); } static DEVICE_ATTR_RO(guid); static ssize_t instance_count_show(struct device *dev, struct device_attribute *attr, char *buf) { struct wmi_block *wblock = dev_to_wblock(dev); return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count); } static DEVICE_ATTR_RO(instance_count); static ssize_t expensive_show(struct device *dev, struct device_attribute *attr, char *buf) { struct wmi_block *wblock = dev_to_wblock(dev); return sysfs_emit(buf, "%d\n", (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0); } static DEVICE_ATTR_RO(expensive); static struct attribute *wmi_attrs[] = { &dev_attr_modalias.attr, &dev_attr_guid.attr, &dev_attr_instance_count.attr, &dev_attr_expensive.attr, NULL }; ATTRIBUTE_GROUPS(wmi); static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr, char *buf) { struct wmi_block *wblock = dev_to_wblock(dev); return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id); } static DEVICE_ATTR_RO(notify_id); static struct attribute *wmi_event_attrs[] = { &dev_attr_notify_id.attr, NULL }; ATTRIBUTE_GROUPS(wmi_event); static ssize_t object_id_show(struct device *dev, struct device_attribute *attr, char *buf) { struct wmi_block *wblock = dev_to_wblock(dev); return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0], wblock->gblock.object_id[1]); } static DEVICE_ATTR_RO(object_id); static ssize_t setable_show(struct device *dev, struct device_attribute *attr, char *buf) { struct wmi_device *wdev = dev_to_wdev(dev); return sysfs_emit(buf, "%d\n", (int)wdev->setable); } static DEVICE_ATTR_RO(setable); static struct attribute *wmi_data_attrs[] = { &dev_attr_object_id.attr, &dev_attr_setable.attr, NULL }; ATTRIBUTE_GROUPS(wmi_data); static struct attribute *wmi_method_attrs[] = { &dev_attr_object_id.attr, NULL }; ATTRIBUTE_GROUPS(wmi_method); static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env) { const struct wmi_block *wblock = dev_to_wblock(dev); if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid)) return -ENOMEM; if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid)) return -ENOMEM; return 0; } static void wmi_dev_release(struct device *dev) { struct wmi_block *wblock = dev_to_wblock(dev); kfree(wblock); } static int wmi_dev_match(struct device *dev, struct device_driver *driver) { struct wmi_driver *wmi_driver = drv_to_wdrv(driver); struct wmi_block *wblock = dev_to_wblock(dev); const struct wmi_device_id *id = wmi_driver->id_table; if (id == NULL) return 0; while (*id->guid_string) { if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid)) return 1; id++; } return 0; } static int wmi_dev_probe(struct device *dev) { struct wmi_block *wblock = dev_to_wblock(dev); struct wmi_driver *wdriver = drv_to_wdrv(dev->driver); int ret = 0; /* Some older WMI drivers will break if instantiated multiple times, * so they are blocked from probing WMI devices with a duplicated GUID. * * New WMI drivers should support being instantiated multiple times. */ if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags) && !wdriver->no_singleton) { dev_warn(dev, "Legacy driver %s cannot be instantiated multiple times\n", dev->driver->name); return -ENODEV; } if (wdriver->notify) { if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags) && !wdriver->no_notify_data) return -ENODEV; } if (ACPI_FAILURE(wmi_method_enable(wblock, true))) dev_warn(dev, "failed to enable device -- probing anyway\n"); if (wdriver->probe) { ret = wdriver->probe(dev_to_wdev(dev), find_guid_context(wblock, wdriver)); if (ret) { if (ACPI_FAILURE(wmi_method_enable(wblock, false))) dev_warn(dev, "Failed to disable device\n"); return ret; } } down_write(&wblock->notify_lock); wblock->driver_ready = true; up_write(&wblock->notify_lock); return 0; } static void wmi_dev_remove(struct device *dev) { struct wmi_block *wblock = dev_to_wblock(dev); struct wmi_driver *wdriver = drv_to_wdrv(dev->driver); down_write(&wblock->notify_lock); wblock->driver_ready = false; up_write(&wblock->notify_lock); if (wdriver->remove) wdriver->remove(dev_to_wdev(dev)); if (ACPI_FAILURE(wmi_method_enable(wblock, false))) dev_warn(dev, "failed to disable device\n"); } static struct class wmi_bus_class = { .name = "wmi_bus", }; static const struct bus_type wmi_bus_type = { .name = "wmi", .dev_groups = wmi_groups, .match = wmi_dev_match, .uevent = wmi_dev_uevent, .probe = wmi_dev_probe, .remove = wmi_dev_remove, }; static const struct device_type wmi_type_event = { .name = "event", .groups = wmi_event_groups, .release = wmi_dev_release, }; static const struct device_type wmi_type_method = { .name = "method", .groups = wmi_method_groups, .release = wmi_dev_release, }; static const struct device_type wmi_type_data = { .name = "data", .groups = wmi_data_groups, .release = wmi_dev_release, }; /* * _WDG is a static list that is only parsed at startup, * so it's safe to count entries without extra protection. */ static int guid_count(const guid_t *guid) { struct wmi_block *wblock; int count = 0; list_for_each_entry(wblock, &wmi_block_list, list) { if (guid_equal(&wblock->gblock.guid, guid)) count++; } return count; } static int wmi_create_device(struct device *wmi_bus_dev, struct wmi_block *wblock, struct acpi_device *device) { char method[WMI_ACPI_METHOD_NAME_SIZE]; struct acpi_device_info *info; acpi_handle method_handle; acpi_status status; uint count; if (wblock->gblock.flags & ACPI_WMI_EVENT) { wblock->dev.dev.type = &wmi_type_event; goto out_init; } if (wblock->gblock.flags & ACPI_WMI_METHOD) { get_acpi_method_name(wblock, 'M', method); if (!acpi_has_method(device->handle, method)) { dev_warn(wmi_bus_dev, FW_BUG "%s method block execution control method not found\n", method); return -ENXIO; } wblock->dev.dev.type = &wmi_type_method; goto out_init; } /* * Data Block Query Control Method (WQxx by convention) is * required per the WMI documentation. If it is not present, * we ignore this data block. */ get_acpi_method_name(wblock, 'Q', method); status = acpi_get_handle(device->handle, method, &method_handle); if (ACPI_FAILURE(status)) { dev_warn(wmi_bus_dev, FW_BUG "%s data block query control method not found\n", method); return -ENXIO; } status = acpi_get_object_info(method_handle, &info); if (ACPI_FAILURE(status)) return -EIO; wblock->dev.dev.type = &wmi_type_data; /* * The Microsoft documentation specifically states: * * Data blocks registered with only a single instance * can ignore the parameter. * * ACPICA will get mad at us if we call the method with the wrong number * of arguments, so check what our method expects. (On some Dell * laptops, WQxx may not be a method at all.) */ if (info->type != ACPI_TYPE_METHOD || info->param_count == 0) set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags); kfree(info); get_acpi_method_name(wblock, 'S', method); if (acpi_has_method(device->handle, method)) wblock->dev.setable = true; out_init: init_rwsem(&wblock->notify_lock); wblock->driver_ready = false; wblock->dev.dev.bus = &wmi_bus_type; wblock->dev.dev.parent = wmi_bus_dev; count = guid_count(&wblock->gblock.guid); if (count) { dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count); set_bit(WMI_GUID_DUPLICATED, &wblock->flags); } else { dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid); } device_initialize(&wblock->dev.dev); return 0; } static int wmi_add_device(struct platform_device *pdev, struct wmi_device *wdev) { struct device_link *link; /* * Many aggregate WMI drivers do not use -EPROBE_DEFER when they * are unable to find a WMI device during probe, instead they require * all WMI devices associated with an platform device to become available * at once. This device link thus prevents WMI drivers from probing until * the associated platform device has finished probing (and has registered * all discovered WMI devices). */ link = device_link_add(&wdev->dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER); if (!link) return -EINVAL; return device_add(&wdev->dev); } /* * Parse the _WDG method for the GUID data blocks */ static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev) { struct acpi_device *device = ACPI_COMPANION(&pdev->dev); struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL}; const struct guid_block *gblock; bool event_data_available; struct wmi_block *wblock; union acpi_object *obj; acpi_status status; u32 i, total; int retval; status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out); if (ACPI_FAILURE(status)) return -ENXIO; obj = out.pointer; if (!obj) return -ENXIO; if (obj->type != ACPI_TYPE_BUFFER) { kfree(obj); return -ENXIO; } event_data_available = acpi_has_method(device->handle, "_WED"); gblock = (const struct guid_block *)obj->buffer.pointer; total = obj->buffer.length / sizeof(struct guid_block); for (i = 0; i < total; i++) { if (!gblock[i].instance_count) { dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid); continue; } wblock = kzalloc(sizeof(*wblock), GFP_KERNEL); if (!wblock) continue; wblock->acpi_device = device; wblock->gblock = gblock[i]; if (gblock[i].flags & ACPI_WMI_EVENT && !event_data_available) set_bit(WMI_NO_EVENT_DATA, &wblock->flags); retval = wmi_create_device(wmi_bus_dev, wblock, device); if (retval) { kfree(wblock); continue; } list_add_tail(&wblock->list, &wmi_block_list); retval = wmi_add_device(pdev, &wblock->dev); if (retval) { dev_err(wmi_bus_dev, "failed to register %pUL\n", &wblock->gblock.guid); list_del(&wblock->list); put_device(&wblock->dev.dev); } } kfree(obj); return 0; } static int ec_read_multiple(u8 address, u8 *buffer, size_t bytes) { size_t i; int ret; for (i = 0; i < bytes; i++) { ret = ec_read(address + i, &buffer[i]); if (ret < 0) return ret; } return 0; } static int ec_write_multiple(u8 address, u8 *buffer, size_t bytes) { size_t i; int ret; for (i = 0; i < bytes; i++) { ret = ec_write(address + i, buffer[i]); if (ret < 0) return ret; } return 0; } /* * WMI can have EmbeddedControl access regions. In which case, we just want to * hand these off to the EC driver. */ static acpi_status acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address, u32 bits, u64 *value, void *handler_context, void *region_context) { int bytes = bits / BITS_PER_BYTE; int ret; if (!value) return AE_NULL_ENTRY; if (!bytes || bytes > sizeof(*value)) return AE_BAD_PARAMETER; if (address > U8_MAX || address + bytes - 1 > U8_MAX) return AE_BAD_PARAMETER; if (function != ACPI_READ && function != ACPI_WRITE) return AE_BAD_PARAMETER; if (function == ACPI_READ) ret = ec_read_multiple(address, (u8 *)value, bytes); else ret = ec_write_multiple(address, (u8 *)value, bytes); switch (ret) { case -EINVAL: return AE_BAD_PARAMETER; case -ENODEV: return AE_NOT_FOUND; case -ETIME: return AE_TIME; case 0: return AE_OK; default: return AE_ERROR; } } static int wmi_get_notify_data(struct wmi_block *wblock, union acpi_object **obj) { struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL }; acpi_status status; if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags)) { *obj = NULL; return 0; } status = get_event_data(wblock, &data); if (ACPI_FAILURE(status)) { dev_warn(&wblock->dev.dev, "Failed to get event data\n"); return -EIO; } *obj = data.pointer; return 0; } static void wmi_notify_driver(struct wmi_block *wblock, union acpi_object *obj) { struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver); if (!obj && !driver->no_notify_data) { dev_warn(&wblock->dev.dev, "Event contains no event data\n"); return; } if (driver->notify) driver->notify(&wblock->dev, obj); } static int wmi_notify_device(struct device *dev, void *data) { struct wmi_block *wblock = dev_to_wblock(dev); union acpi_object *obj; u32 *event = data; int ret; if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event)) return 0; down_read(&wblock->notify_lock); /* The WMI driver notify handler conflicts with the legacy WMI handler. * Because of this the WMI driver notify handler takes precedence. */ if (wblock->dev.dev.driver && wblock->driver_ready) { ret = wmi_get_notify_data(wblock, &obj); if (ret >= 0) { wmi_notify_driver(wblock, obj); kfree(obj); } } else { if (wblock->handler) { wblock->handler(*event, wblock->handler_data); } else { /* The ACPI WMI specification says that _WED should be * evaluated every time an notification is received, even * if no consumers are present. * * Some firmware implementations actually depend on this * by using a queue for events which will fill up if the * WMI driver core stops evaluating _WED due to missing * WMI event consumers. * * Because of this we need this seemingly useless call to * wmi_get_notify_data() which in turn evaluates _WED. */ ret = wmi_get_notify_data(wblock, &obj); if (ret >= 0) kfree(obj); } } up_read(&wblock->notify_lock); acpi_bus_generate_netlink_event("wmi", acpi_dev_name(wblock->acpi_device), *event, 0); return -EBUSY; } static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, void *context) { struct device *wmi_bus_dev = context; device_for_each_child(wmi_bus_dev, &event, wmi_notify_device); } static int wmi_remove_device(struct device *dev, void *data) { struct wmi_block *wblock = dev_to_wblock(dev); list_del(&wblock->list); device_unregister(dev); return 0; } static void acpi_wmi_remove(struct platform_device *device) { struct device *wmi_bus_device = dev_get_drvdata(&device->dev); device_for_each_child_reverse(wmi_bus_device, NULL, wmi_remove_device); } static void acpi_wmi_remove_notify_handler(void *data) { struct acpi_device *acpi_device = data; acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, acpi_wmi_notify_handler); } static void acpi_wmi_remove_address_space_handler(void *data) { struct acpi_device *acpi_device = data; acpi_remove_address_space_handler(acpi_device->handle, ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler); } static void acpi_wmi_remove_bus_device(void *data) { struct device *wmi_bus_dev = data; device_unregister(wmi_bus_dev); } static int acpi_wmi_probe(struct platform_device *device) { struct acpi_device *acpi_device; struct device *wmi_bus_dev; acpi_status status; int error; acpi_device = ACPI_COMPANION(&device->dev); if (!acpi_device) { dev_err(&device->dev, "ACPI companion is missing\n"); return -ENODEV; } wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), NULL, "wmi_bus-%s", dev_name(&device->dev)); if (IS_ERR(wmi_bus_dev)) return PTR_ERR(wmi_bus_dev); error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_bus_device, wmi_bus_dev); if (error < 0) return error; dev_set_drvdata(&device->dev, wmi_bus_dev); status = acpi_install_address_space_handler(acpi_device->handle, ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler, NULL, NULL); if (ACPI_FAILURE(status)) { dev_err(&device->dev, "Error installing EC region handler\n"); return -ENODEV; } error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_address_space_handler, acpi_device); if (error < 0) return error; status = acpi_install_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, acpi_wmi_notify_handler, wmi_bus_dev); if (ACPI_FAILURE(status)) { dev_err(&device->dev, "Error installing notify handler\n"); return -ENODEV; } error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_notify_handler, acpi_device); if (error < 0) return error; error = parse_wdg(wmi_bus_dev, device); if (error) { dev_err(&device->dev, "Failed to parse _WDG method\n"); return error; } return 0; } int __must_check __wmi_driver_register(struct wmi_driver *driver, struct module *owner) { driver->driver.owner = owner; driver->driver.bus = &wmi_bus_type; return driver_register(&driver->driver); } EXPORT_SYMBOL(__wmi_driver_register); /** * wmi_driver_unregister() - Unregister a WMI driver * @driver: WMI driver to unregister * * Unregisters a WMI driver from the WMI bus. */ void wmi_driver_unregister(struct wmi_driver *driver) { driver_unregister(&driver->driver); } EXPORT_SYMBOL(wmi_driver_unregister); static struct platform_driver acpi_wmi_driver = { .driver = { .name = "acpi-wmi", .acpi_match_table = wmi_device_ids, }, .probe = acpi_wmi_probe, .remove_new = acpi_wmi_remove, }; static int __init acpi_wmi_init(void) { int error; if (acpi_disabled) return -ENODEV; error = class_register(&wmi_bus_class); if (error) return error; error = bus_register(&wmi_bus_type); if (error) goto err_unreg_class; error = platform_driver_register(&acpi_wmi_driver); if (error) { pr_err("Error loading mapper\n"); goto err_unreg_bus; } return 0; err_unreg_bus: bus_unregister(&wmi_bus_type); err_unreg_class: class_unregister(&wmi_bus_class); return error; } static void __exit acpi_wmi_exit(void) { platform_driver_unregister(&acpi_wmi_driver); bus_unregister(&wmi_bus_type); class_unregister(&wmi_bus_class); } subsys_initcall_sync(acpi_wmi_init); module_exit(acpi_wmi_exit);