/* * ACPI-WMI mapping driver * * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk> * * GUID parsing code from ldm.c is: * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org> * Copyright (c) 2001-2007 Anton Altaparmakov * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com> * * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or (at * your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. * * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h> #include <linux/init.h> #include <linux/types.h> #include <linux/device.h> #include <linux/list.h> #include <linux/acpi.h> #include <linux/slab.h> #include <linux/module.h> ACPI_MODULE_NAME("wmi"); MODULE_AUTHOR("Carlos Corbacho"); MODULE_DESCRIPTION("ACPI-WMI Mapping Driver"); MODULE_LICENSE("GPL"); #define ACPI_WMI_CLASS "wmi" static LIST_HEAD(wmi_block_list); struct guid_block { char guid[16]; union { char object_id[2]; struct { unsigned char notify_id; unsigned char reserved; }; }; u8 instance_count; u8 flags; }; struct wmi_block { struct list_head list; struct guid_block gblock; acpi_handle handle; wmi_notify_handler handler; void *handler_data; struct device dev; }; /* * If the GUID data block is marked as expensive, we must enable and * explicitily disable data collection. */ #define ACPI_WMI_EXPENSIVE 0x1 #define ACPI_WMI_METHOD 0x2 /* GUID is a method */ #define ACPI_WMI_STRING 0x4 /* GUID takes & returns a string */ #define ACPI_WMI_EVENT 0x8 /* GUID is an event */ static bool debug_event; module_param(debug_event, bool, 0444); MODULE_PARM_DESC(debug_event, "Log WMI Events [0/1]"); static bool debug_dump_wdg; module_param(debug_dump_wdg, bool, 0444); MODULE_PARM_DESC(debug_dump_wdg, "Dump available WMI interfaces [0/1]"); static int acpi_wmi_remove(struct acpi_device *device); static int acpi_wmi_add(struct acpi_device *device); static void acpi_wmi_notify(struct acpi_device *device, u32 event); static const struct acpi_device_id wmi_device_ids[] = { {"PNP0C14", 0}, {"pnp0c14", 0}, {"", 0}, }; MODULE_DEVICE_TABLE(acpi, wmi_device_ids); static struct acpi_driver acpi_wmi_driver = { .name = "wmi", .class = ACPI_WMI_CLASS, .ids = wmi_device_ids, .ops = { .add = acpi_wmi_add, .remove = acpi_wmi_remove, .notify = acpi_wmi_notify, }, }; /* * GUID parsing functions */ /** * wmi_parse_hexbyte - Convert a ASCII hex number to a byte * @src: Pointer to at least 2 characters to convert. * * Convert a two character ASCII hex string to a number. * * Return: 0-255 Success, the byte was parsed correctly * -1 Error, an invalid character was supplied */ static int wmi_parse_hexbyte(const u8 *src) { int h; int value; /* high part */ h = value = hex_to_bin(src[0]); if (value < 0) return -1; /* low part */ value = hex_to_bin(src[1]); if (value >= 0) return (h << 4) | value; return -1; } /** * wmi_swap_bytes - Rearrange GUID bytes to match GUID binary * @src: Memory block holding binary GUID (16 bytes) * @dest: Memory block to hold byte swapped binary GUID (16 bytes) * * Byte swap a binary GUID to match it's real GUID value */ static void wmi_swap_bytes(u8 *src, u8 *dest) { int i; for (i = 0; i <= 3; i++) memcpy(dest + i, src + (3 - i), 1); for (i = 0; i <= 1; i++) memcpy(dest + 4 + i, src + (5 - i), 1); for (i = 0; i <= 1; i++) memcpy(dest + 6 + i, src + (7 - i), 1); memcpy(dest + 8, src + 8, 8); } /** * wmi_parse_guid - Convert GUID from ASCII to binary * @src: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * @dest: Memory block to hold binary GUID (16 bytes) * * N.B. The GUID need not be NULL terminated. * * Return: 'true' @dest contains binary GUID * 'false' @dest contents are undefined */ static bool wmi_parse_guid(const u8 *src, u8 *dest) { static const int size[] = { 4, 2, 2, 2, 6 }; int i, j, v; if (src[8] != '-' || src[13] != '-' || src[18] != '-' || src[23] != '-') return false; for (j = 0; j < 5; j++, src++) { for (i = 0; i < size[j]; i++, src += 2, *dest++ = v) { v = wmi_parse_hexbyte(src); if (v < 0) return false; } } return true; } /* * Convert a raw GUID to the ACII string representation */ static int wmi_gtoa(const char *in, char *out) { int i; for (i = 3; i >= 0; i--) out += sprintf(out, "%02X", in[i] & 0xFF); out += sprintf(out, "-"); out += sprintf(out, "%02X", in[5] & 0xFF); out += sprintf(out, "%02X", in[4] & 0xFF); out += sprintf(out, "-"); out += sprintf(out, "%02X", in[7] & 0xFF); out += sprintf(out, "%02X", in[6] & 0xFF); out += sprintf(out, "-"); out += sprintf(out, "%02X", in[8] & 0xFF); out += sprintf(out, "%02X", in[9] & 0xFF); out += sprintf(out, "-"); for (i = 10; i <= 15; i++) out += sprintf(out, "%02X", in[i] & 0xFF); *out = '\0'; return 0; } static bool find_guid(const char *guid_string, struct wmi_block **out) { char tmp[16], guid_input[16]; struct wmi_block *wblock; struct guid_block *block; struct list_head *p; wmi_parse_guid(guid_string, tmp); wmi_swap_bytes(tmp, guid_input); list_for_each(p, &wmi_block_list) { wblock = list_entry(p, struct wmi_block, list); block = &wblock->gblock; if (memcmp(block->guid, guid_input, 16) == 0) { if (out) *out = wblock; return true; } } return false; } static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable) { struct guid_block *block = NULL; char method[5]; acpi_status status; acpi_handle handle; block = &wblock->gblock; handle = wblock->handle; snprintf(method, 5, "WE%02X", block->notify_id); status = acpi_execute_simple_method(handle, method, enable); if (status != AE_OK && status != AE_NOT_FOUND) return status; else return AE_OK; } /* * Exported WMI functions */ /** * wmi_evaluate_method - Evaluate a WMI method * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba * @instance: Instance index * @method_id: Method ID to call * &in: Buffer containing input for the method call * &out: Empty buffer to return the method results * * Call an ACPI-WMI method */ acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out) { struct guid_block *block = NULL; struct wmi_block *wblock = NULL; acpi_handle handle; acpi_status status; struct acpi_object_list input; union acpi_object params[3]; char method[5] = "WM"; if (!find_guid(guid_string, &wblock)) return AE_ERROR; block = &wblock->gblock; handle = wblock->handle; if (!(block->flags & ACPI_WMI_METHOD)) return AE_BAD_DATA; if (block->instance_count < instance) return AE_BAD_PARAMETER; input.count = 2; 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; if (in) { input.count = 3; if (block->flags & ACPI_WMI_STRING) { params[2].type = ACPI_TYPE_STRING; } else { params[2].type = ACPI_TYPE_BUFFER; } params[2].buffer.length = in->length; params[2].buffer.pointer = in->pointer; } strncat(method, block->object_id, 2); status = acpi_evaluate_object(handle, method, &input, out); return status; } EXPORT_SYMBOL_GPL(wmi_evaluate_method); /** * wmi_query_block - Return contents of a WMI block * @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 * * Return the contents of an ACPI-WMI data block to a buffer */ acpi_status wmi_query_block(const char *guid_string, u8 instance, struct acpi_buffer *out) { struct guid_block *block = NULL; struct wmi_block *wblock = NULL; acpi_handle handle; acpi_status status, wc_status = AE_ERROR; struct acpi_object_list input; union acpi_object wq_params[1]; char method[5]; char wc_method[5] = "WC"; if (!guid_string || !out) return AE_BAD_PARAMETER; if (!find_guid(guid_string, &wblock)) return AE_ERROR; block = &wblock->gblock; handle = wblock->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 ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to * enable collection. */ if (block->flags & ACPI_WMI_EXPENSIVE) { strncat(wc_method, block->object_id, 2); /* * Some GUIDs break the specification by declaring themselves * expensive, but have no corresponding WCxx method. So we * should not fail if this happens. */ if (acpi_has_method(handle, wc_method)) wc_status = acpi_execute_simple_method(handle, wc_method, 1); } strcpy(method, "WQ"); strncat(method, block->object_id, 2); 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)) { status = acpi_execute_simple_method(handle, wc_method, 0); } return status; } EXPORT_SYMBOL_GPL(wmi_query_block); /** * wmi_set_block - Write to a WMI block * @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 */ acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in) { struct guid_block *block = NULL; struct wmi_block *wblock = NULL; acpi_handle handle; struct acpi_object_list input; union acpi_object params[2]; char method[5] = "WS"; if (!guid_string || !in) return AE_BAD_DATA; if (!find_guid(guid_string, &wblock)) return AE_ERROR; block = &wblock->gblock; handle = wblock->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 = 2; input.pointer = params; params[0].type = ACPI_TYPE_INTEGER; params[0].integer.value = instance; if (block->flags & ACPI_WMI_STRING) { params[1].type = ACPI_TYPE_STRING; } else { params[1].type = ACPI_TYPE_BUFFER; } params[1].buffer.length = in->length; params[1].buffer.pointer = in->pointer; strncat(method, block->object_id, 2); return acpi_evaluate_object(handle, method, &input, NULL); } EXPORT_SYMBOL_GPL(wmi_set_block); static void wmi_dump_wdg(const struct guid_block *g) { char guid_string[37]; wmi_gtoa(g->guid, guid_string); pr_info("%s:\n", guid_string); pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]); pr_info("\tnotify_id: %02X\n", g->notify_id); pr_info("\treserved: %02X\n", g->reserved); pr_info("\tinstance_count: %d\n", g->instance_count); pr_info("\tflags: %#x", g->flags); if (g->flags) { if (g->flags & ACPI_WMI_EXPENSIVE) pr_cont(" ACPI_WMI_EXPENSIVE"); if (g->flags & ACPI_WMI_METHOD) pr_cont(" ACPI_WMI_METHOD"); if (g->flags & ACPI_WMI_STRING) pr_cont(" ACPI_WMI_STRING"); if (g->flags & ACPI_WMI_EVENT) pr_cont(" ACPI_WMI_EVENT"); } pr_cont("\n"); } static void wmi_notify_debug(u32 value, void *context) { struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL }; union acpi_object *obj; acpi_status status; status = wmi_get_event_data(value, &response); if (status != AE_OK) { pr_info("bad event status 0x%x\n", status); return; } obj = (union acpi_object *)response.pointer; if (!obj) return; pr_info("DEBUG Event "); switch(obj->type) { case ACPI_TYPE_BUFFER: pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length); break; case ACPI_TYPE_STRING: pr_cont("STRING_TYPE - %s\n", obj->string.pointer); break; case ACPI_TYPE_INTEGER: pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value); break; case ACPI_TYPE_PACKAGE: pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count); break; default: pr_cont("object type 0x%X\n", obj->type); } kfree(obj); } /** * wmi_install_notify_handler - Register handler for WMI events * @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. */ acpi_status wmi_install_notify_handler(const char *guid, wmi_notify_handler handler, void *data) { struct wmi_block *block; acpi_status status = AE_NOT_EXIST; char tmp[16], guid_input[16]; struct list_head *p; if (!guid || !handler) return AE_BAD_PARAMETER; wmi_parse_guid(guid, tmp); wmi_swap_bytes(tmp, guid_input); list_for_each(p, &wmi_block_list) { acpi_status wmi_status; block = list_entry(p, struct wmi_block, list); if (memcmp(block->gblock.guid, guid_input, 16) == 0) { if (block->handler && block->handler != wmi_notify_debug) return AE_ALREADY_ACQUIRED; block->handler = handler; block->handler_data = data; wmi_status = wmi_method_enable(block, 1); if ((wmi_status != AE_OK) || ((wmi_status == AE_OK) && (status == AE_NOT_EXIST))) status = wmi_status; } } return status; } EXPORT_SYMBOL_GPL(wmi_install_notify_handler); /** * wmi_uninstall_notify_handler - Unregister handler for WMI events * * Unregister handler for events sent to the ACPI-WMI mapper device. */ acpi_status wmi_remove_notify_handler(const char *guid) { struct wmi_block *block; acpi_status status = AE_NOT_EXIST; char tmp[16], guid_input[16]; struct list_head *p; if (!guid) return AE_BAD_PARAMETER; wmi_parse_guid(guid, tmp); wmi_swap_bytes(tmp, guid_input); list_for_each(p, &wmi_block_list) { acpi_status wmi_status; block = list_entry(p, struct wmi_block, list); if (memcmp(block->gblock.guid, guid_input, 16) == 0) { if (!block->handler || block->handler == wmi_notify_debug) return AE_NULL_ENTRY; if (debug_event) { block->handler = wmi_notify_debug; status = AE_OK; } else { wmi_status = wmi_method_enable(block, 0); block->handler = NULL; block->handler_data = NULL; if ((wmi_status != AE_OK) || ((wmi_status == AE_OK) && (status == AE_NOT_EXIST))) status = wmi_status; } } } return status; } EXPORT_SYMBOL_GPL(wmi_remove_notify_handler); /** * wmi_get_event_data - Get WMI data associated with an event * * @event: Event to find * @out: Buffer to hold event data. out->pointer should be freed with kfree() * * Returns extra data associated with an event in WMI. */ acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out) { struct acpi_object_list input; union acpi_object params[1]; struct guid_block *gblock; struct wmi_block *wblock; struct list_head *p; input.count = 1; input.pointer = params; params[0].type = ACPI_TYPE_INTEGER; params[0].integer.value = event; list_for_each(p, &wmi_block_list) { wblock = list_entry(p, struct wmi_block, list); gblock = &wblock->gblock; if ((gblock->flags & ACPI_WMI_EVENT) && (gblock->notify_id == event)) return acpi_evaluate_object(wblock->handle, "_WED", &input, out); } return AE_NOT_FOUND; } 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 */ bool wmi_has_guid(const char *guid_string) { return find_guid(guid_string, NULL); } EXPORT_SYMBOL_GPL(wmi_has_guid); /* * sysfs interface */ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf) { char guid_string[37]; struct wmi_block *wblock; wblock = dev_get_drvdata(dev); if (!wblock) { strcat(buf, "\n"); return strlen(buf); } wmi_gtoa(wblock->gblock.guid, guid_string); return sprintf(buf, "wmi:%s\n", guid_string); } static DEVICE_ATTR_RO(modalias); static struct attribute *wmi_attrs[] = { &dev_attr_modalias.attr, NULL, }; ATTRIBUTE_GROUPS(wmi); static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env) { char guid_string[37]; struct wmi_block *wblock; if (add_uevent_var(env, "MODALIAS=")) return -ENOMEM; wblock = dev_get_drvdata(dev); if (!wblock) return -ENOMEM; wmi_gtoa(wblock->gblock.guid, guid_string); strcpy(&env->buf[env->buflen - 1], "wmi:"); memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36); env->buflen += 40; return 0; } static void wmi_dev_free(struct device *dev) { struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev); kfree(wmi_block); } static struct class wmi_class = { .name = "wmi", .dev_release = wmi_dev_free, .dev_uevent = wmi_dev_uevent, .dev_groups = wmi_groups, }; static int wmi_create_device(const struct guid_block *gblock, struct wmi_block *wblock, acpi_handle handle) { char guid_string[37]; wblock->dev.class = &wmi_class; wmi_gtoa(gblock->guid, guid_string); dev_set_name(&wblock->dev, "%s", guid_string); dev_set_drvdata(&wblock->dev, wblock); return device_register(&wblock->dev); } static void wmi_free_devices(void) { struct wmi_block *wblock, *next; /* Delete devices for all the GUIDs */ list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { list_del(&wblock->list); if (wblock->dev.class) device_unregister(&wblock->dev); else kfree(wblock); } } static bool guid_already_parsed(const char *guid_string) { struct wmi_block *wblock; list_for_each_entry(wblock, &wmi_block_list, list) if (memcmp(wblock->gblock.guid, guid_string, 16) == 0) return true; return false; } /* * Parse the _WDG method for the GUID data blocks */ static int parse_wdg(acpi_handle handle) { struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL}; union acpi_object *obj; const struct guid_block *gblock; struct wmi_block *wblock; acpi_status status; int retval; u32 i, total; status = acpi_evaluate_object(handle, "_WDG", NULL, &out); if (ACPI_FAILURE(status)) return -ENXIO; obj = (union acpi_object *) out.pointer; if (!obj) return -ENXIO; if (obj->type != ACPI_TYPE_BUFFER) { retval = -ENXIO; goto out_free_pointer; } gblock = (const struct guid_block *)obj->buffer.pointer; total = obj->buffer.length / sizeof(struct guid_block); for (i = 0; i < total; i++) { if (debug_dump_wdg) wmi_dump_wdg(&gblock[i]); wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL); if (!wblock) return -ENOMEM; wblock->handle = handle; wblock->gblock = gblock[i]; /* Some WMI devices, like those for nVidia hooks, have a duplicate GUID. It's not clear what we should do in this case yet, so for now, we'll just ignore the duplicate for device creation. */ if (!guid_already_parsed(gblock[i].guid)) { retval = wmi_create_device(&gblock[i], wblock, handle); if (retval) { wmi_free_devices(); goto out_free_pointer; } } list_add_tail(&wblock->list, &wmi_block_list); if (debug_event) { wblock->handler = wmi_notify_debug; wmi_method_enable(wblock, 1); } } retval = 0; out_free_pointer: kfree(out.pointer); return retval; } /* * 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 result = 0, i = 0; u8 temp = 0; if ((address > 0xFF) || !value) return AE_BAD_PARAMETER; if (function != ACPI_READ && function != ACPI_WRITE) return AE_BAD_PARAMETER; if (bits != 8) return AE_BAD_PARAMETER; if (function == ACPI_READ) { result = ec_read(address, &temp); (*value) |= ((u64)temp) << i; } else { temp = 0xff & ((*value) >> i); result = ec_write(address, temp); } switch (result) { case -EINVAL: return AE_BAD_PARAMETER; break; case -ENODEV: return AE_NOT_FOUND; break; case -ETIME: return AE_TIME; break; default: return AE_OK; } } static void acpi_wmi_notify(struct acpi_device *device, u32 event) { struct guid_block *block; struct wmi_block *wblock; struct list_head *p; char guid_string[37]; list_for_each(p, &wmi_block_list) { wblock = list_entry(p, struct wmi_block, list); block = &wblock->gblock; if ((block->flags & ACPI_WMI_EVENT) && (block->notify_id == event)) { if (wblock->handler) wblock->handler(event, wblock->handler_data); if (debug_event) { wmi_gtoa(wblock->gblock.guid, guid_string); pr_info("DEBUG Event GUID: %s\n", guid_string); } acpi_bus_generate_netlink_event( device->pnp.device_class, dev_name(&device->dev), event, 0); break; } } } static int acpi_wmi_remove(struct acpi_device *device) { acpi_remove_address_space_handler(device->handle, ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler); wmi_free_devices(); return 0; } static int acpi_wmi_add(struct acpi_device *device) { acpi_status status; int error; status = acpi_install_address_space_handler(device->handle, ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler, NULL, NULL); if (ACPI_FAILURE(status)) { pr_err("Error installing EC region handler\n"); return -ENODEV; } error = parse_wdg(device->handle); if (error) { acpi_remove_address_space_handler(device->handle, ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler); pr_err("Failed to parse WDG method\n"); return error; } return 0; } static int __init acpi_wmi_init(void) { int error; if (acpi_disabled) return -ENODEV; error = class_register(&wmi_class); if (error) return error; error = acpi_bus_register_driver(&acpi_wmi_driver); if (error) { pr_err("Error loading mapper\n"); class_unregister(&wmi_class); return error; } pr_info("Mapper loaded\n"); return 0; } static void __exit acpi_wmi_exit(void) { acpi_bus_unregister_driver(&acpi_wmi_driver); class_unregister(&wmi_class); pr_info("Mapper unloaded\n"); } subsys_initcall(acpi_wmi_init); module_exit(acpi_wmi_exit);