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linux-zen-desktop/drivers/platform/x86/wmi.c

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Initial commit
2023-08-30 17:31:07 +02:00
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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>
*
* 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 <linux/acpi.h>
#include <linux/bits.h>
#include <linux/build_bug.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/uuid.h>
#include <linux/wmi.h>
#include <linux/fs.h>
#include <uapi/linux/wmi.h>
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_PROBED,
};
struct wmi_block {
struct wmi_device dev;
struct list_head list;
struct guid_block gblock;
struct miscdevice char_dev;
struct mutex char_mutex;
struct acpi_device *acpi_device;
wmi_notify_handler handler;
void *handler_data;
u64 req_buf_size;
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 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 const struct acpi_device_id wmi_device_ids[] = {
{"PNP0C14", 0},
{"pnp0c14", 0},
{ }
};
MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
/* allow duplicate GUIDs as these device drivers use struct wmi_driver */
static const char * const allow_duplicates[] = {
"05901221-D566-11D1-B2F0-00A0C9062910", /* wmi-bmof */
"8A42EA14-4F2A-FD45-6422-0087F7A7E608", /* dell-wmi-ddv */
NULL
};
/*
* GUID parsing functions
*/
static acpi_status find_guid(const char *guid_string, struct wmi_block **out)
{
guid_t guid_input;
struct wmi_block *wblock;
if (!guid_string)
return AE_BAD_PARAMETER;
if (guid_parse(guid_string, &guid_input))
return AE_BAD_PARAMETER;
list_for_each_entry(wblock, &wmi_block_list, list) {
if (guid_equal(&wblock->gblock.guid, &guid_input)) {
if (out)
*out = wblock;
return AE_OK;
}
}
return AE_NOT_FOUND;
}
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) {
guid_t guid_input;
if (guid_parse(id->guid_string, &guid_input))
continue;
if (guid_equal(&wblock->gblock.guid, &guid_input))
return id->context;
id++;
}
return NULL;
}
static int get_subobj_info(acpi_handle handle, const char *pathname,
struct acpi_device_info **info)
{
struct acpi_device_info *dummy_info, **info_ptr;
acpi_handle subobj_handle;
acpi_status status;
status = acpi_get_handle(handle, (char *)pathname, &subobj_handle);
if (status == AE_NOT_FOUND)
return -ENOENT;
else if (ACPI_FAILURE(status))
return -EIO;
info_ptr = info ? info : &dummy_info;
status = acpi_get_object_info(subobj_handle, info_ptr);
if (ACPI_FAILURE(status))
return -EIO;
if (!info)
kfree(dummy_info);
return 0;
}
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 = &param,
};
return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, out);
}
/*
* Exported WMI functions
*/
/**
* set_required_buffer_size - Sets the buffer size needed for performing IOCTL
* @wdev: A wmi bus device from a driver
* @length: Required buffer size
*
* Allocates memory needed for buffer, stores the buffer size in that memory
*/
int set_required_buffer_size(struct wmi_device *wdev, u64 length)
{
struct wmi_block *wblock;
wblock = container_of(wdev, struct wmi_block, dev);
wblock->req_buf_size = length;
return 0;
}
EXPORT_SYMBOL_GPL(set_required_buffer_size);
/**
* 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 wmi_block *wblock = NULL;
acpi_status status;
status = find_guid(guid_string, &wblock);
if (ACPI_FAILURE(status))
return status;
return wmidev_evaluate_method(&wblock->dev, instance, method_id,
in, out);
}
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: Buffer containing input for the method call
* @out: Empty buffer to return the method results
*
* Call an ACPI-WMI method
*/
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 (!(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;
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
*
* 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 wmi_block *wblock;
acpi_status status;
status = find_guid(guid_string, &wblock);
if (ACPI_FAILURE(status))
return status;
return __query_block(wblock, instance, out);
}
EXPORT_SYMBOL_GPL(wmi_query_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
* @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 wmi_block *wblock = NULL;
struct guid_block *block;
acpi_handle handle;
struct acpi_object_list input;
union acpi_object params[2];
char method[WMI_ACPI_METHOD_NAME_SIZE];
acpi_status status;
if (!in)
return AE_BAD_DATA;
status = find_guid(guid_string, &wblock);
if (ACPI_FAILURE(status))
return status;
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 = 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(wmi_set_block);
static void wmi_dump_wdg(const struct guid_block *g)
{
pr_info("%pUL:\n", &g->guid);
if (g->flags & ACPI_WMI_EVENT)
pr_info("\tnotify_id: 0x%02X\n", g->notify_id);
else
pr_info("\tobject_id: %2pE\n", g->object_id);
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 = response.pointer;
if (!obj)
return;
pr_info("DEBUG: event 0x%02X ", value);
switch (obj->type) {
case ACPI_TYPE_BUFFER:
pr_cont("BUFFER_TYPE - length %u\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 - %u 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
* @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.
*/
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;
guid_t guid_input;
if (!guid || !handler)
return AE_BAD_PARAMETER;
if (guid_parse(guid, &guid_input))
return AE_BAD_PARAMETER;
list_for_each_entry(block, &wmi_block_list, list) {
acpi_status wmi_status;
if (guid_equal(&block->gblock.guid, &guid_input)) {
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, true);
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_remove_notify_handler - Unregister handler for WMI events
* @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
*
* 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;
guid_t guid_input;
if (!guid)
return AE_BAD_PARAMETER;
if (guid_parse(guid, &guid_input))
return AE_BAD_PARAMETER;
list_for_each_entry(block, &wmi_block_list, list) {
acpi_status wmi_status;
if (guid_equal(&block->gblock.guid, &guid_input)) {
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, false);
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 wmi_block *wblock;
list_for_each_entry(wblock, &wmi_block_list, list) {
struct guid_block *gblock = &wblock->gblock;
if ((gblock->flags & ACPI_WMI_EVENT) && gblock->notify_id == event)
return get_event_data(wblock, 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 ACPI_SUCCESS(find_guid(guid_string, NULL));
}
EXPORT_SYMBOL_GPL(wmi_has_guid);
/**
* wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID
* @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 = NULL;
acpi_status status;
status = find_guid(guid_string, &wblock);
if (ACPI_FAILURE(status))
return NULL;
return acpi_device_uid(wblock->acpi_device);
}
EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
#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)
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) {
guid_t driver_guid;
if (WARN_ON(guid_parse(id->guid_string, &driver_guid)))
continue;
if (guid_equal(&driver_guid, &wblock->gblock.guid))
return 1;
id++;
}
return 0;
}
static int wmi_char_open(struct inode *inode, struct file *filp)
{
const char *driver_name = filp->f_path.dentry->d_iname;
struct wmi_block *wblock;
struct wmi_block *next;
list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
if (!wblock->dev.dev.driver)
continue;
if (strcmp(driver_name, wblock->dev.dev.driver->name) == 0) {
filp->private_data = wblock;
break;
}
}
if (!filp->private_data)
return -ENODEV;
return nonseekable_open(inode, filp);
}
static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
size_t length, loff_t *offset)
{
struct wmi_block *wblock = filp->private_data;
return simple_read_from_buffer(buffer, length, offset,
&wblock->req_buf_size,
sizeof(wblock->req_buf_size));
}
static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct wmi_ioctl_buffer __user *input =
(struct wmi_ioctl_buffer __user *) arg;
struct wmi_block *wblock = filp->private_data;
struct wmi_ioctl_buffer *buf;
struct wmi_driver *wdriver;
int ret;
if (_IOC_TYPE(cmd) != WMI_IOC)
return -ENOTTY;
/* make sure we're not calling a higher instance than exists*/
if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
return -EINVAL;
mutex_lock(&wblock->char_mutex);
buf = wblock->handler_data;
if (get_user(buf->length, &input->length)) {
dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
ret = -EFAULT;
goto out_ioctl;
}
/* if it's too small, abort */
if (buf->length < wblock->req_buf_size) {
dev_err(&wblock->dev.dev,
"Buffer %lld too small, need at least %lld\n",
buf->length, wblock->req_buf_size);
ret = -EINVAL;
goto out_ioctl;
}
/* if it's too big, warn, driver will only use what is needed */
if (buf->length > wblock->req_buf_size)
dev_warn(&wblock->dev.dev,
"Buffer %lld is bigger than required %lld\n",
buf->length, wblock->req_buf_size);
/* copy the structure from userspace */
if (copy_from_user(buf, input, wblock->req_buf_size)) {
dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
wblock->req_buf_size);
ret = -EFAULT;
goto out_ioctl;
}
/* let the driver do any filtering and do the call */
wdriver = drv_to_wdrv(wblock->dev.dev.driver);
if (!try_module_get(wdriver->driver.owner)) {
ret = -EBUSY;
goto out_ioctl;
}
ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
module_put(wdriver->driver.owner);
if (ret)
goto out_ioctl;
/* return the result (only up to our internal buffer size) */
if (copy_to_user(input, buf, wblock->req_buf_size)) {
dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
wblock->req_buf_size);
ret = -EFAULT;
}
out_ioctl:
mutex_unlock(&wblock->char_mutex);
return ret;
}
static const struct file_operations wmi_fops = {
.owner = THIS_MODULE,
.read = wmi_char_read,
.open = wmi_char_open,
.unlocked_ioctl = wmi_ioctl,
.compat_ioctl = compat_ptr_ioctl,
};
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;
char *buf;
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 != 0)
goto probe_failure;
}
/* driver wants a character device made */
if (wdriver->filter_callback) {
/* check that required buffer size declared by driver or MOF */
if (!wblock->req_buf_size) {
dev_err(&wblock->dev.dev,
"Required buffer size not set\n");
ret = -EINVAL;
goto probe_failure;
}
wblock->handler_data = kmalloc(wblock->req_buf_size,
GFP_KERNEL);
if (!wblock->handler_data) {
ret = -ENOMEM;
goto probe_failure;
}
buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
if (!buf) {
ret = -ENOMEM;
goto probe_string_failure;
}
wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
wblock->char_dev.name = buf;
wblock->char_dev.fops = &wmi_fops;
wblock->char_dev.mode = 0444;
ret = misc_register(&wblock->char_dev);
if (ret) {
dev_warn(dev, "failed to register char dev: %d\n", ret);
ret = -ENOMEM;
goto probe_misc_failure;
}
}
set_bit(WMI_PROBED, &wblock->flags);
return 0;
probe_misc_failure:
kfree(buf);
probe_string_failure:
kfree(wblock->handler_data);
probe_failure:
if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
dev_warn(dev, "failed to disable device\n");
return ret;
}
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);
clear_bit(WMI_PROBED, &wblock->flags);
if (wdriver->filter_callback) {
misc_deregister(&wblock->char_dev);
kfree(wblock->char_dev.name);
kfree(wblock->handler_data);
}
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 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)
{
struct acpi_device_info *info;
char method[WMI_ACPI_METHOD_NAME_SIZE];
int result;
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) {
wblock->dev.dev.type = &wmi_type_method;
mutex_init(&wblock->char_mutex);
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);
result = get_subobj_info(device->handle, method, &info);
if (result) {
dev_warn(wmi_bus_dev,
"%s data block query control method not found\n",
method);
return result;
}
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);
result = get_subobj_info(device->handle, method, NULL);
if (result == 0)
wblock->dev.setable = true;
out_init:
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);
else
dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
device_initialize(&wblock->dev.dev);
return 0;
}
static void wmi_free_devices(struct acpi_device *device)
{
struct wmi_block *wblock, *next;
/* Delete devices for all the GUIDs */
list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
if (wblock->acpi_device == device) {
list_del(&wblock->list);
device_unregister(&wblock->dev.dev);
}
}
}
static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid)
{
struct wmi_block *wblock;
list_for_each_entry(wblock, &wmi_block_list, list) {
/* skip warning and register if we know the driver will use struct wmi_driver */
for (int i = 0; allow_duplicates[i] != NULL; i++) {
guid_t tmp;
if (guid_parse(allow_duplicates[i], &tmp))
continue;
if (guid_equal(&tmp, guid))
return false;
}
if (guid_equal(&wblock->gblock.guid, guid)) {
/*
* Because we historically didn't track the relationship
* between GUIDs and ACPI nodes, we don't know whether
* we need to suppress GUIDs that are unique on a
* given node but duplicated across nodes.
*/
dev_warn(&device->dev, "duplicate WMI GUID %pUL (first instance was on %s)\n",
guid, dev_name(&wblock->acpi_device->dev));
return true;
}
}
return false;
}
/*
* Parse the _WDG method for the GUID data blocks
*/
static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
{
struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
const struct guid_block *gblock;
struct wmi_block *wblock, *next;
union acpi_object *obj;
acpi_status status;
int retval = 0;
u32 i, total;
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) {
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]);
if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
continue;
wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
if (!wblock) {
retval = -ENOMEM;
break;
}
wblock->acpi_device = device;
wblock->gblock = gblock[i];
retval = wmi_create_device(wmi_bus_dev, wblock, device);
if (retval) {
kfree(wblock);
continue;
}
list_add_tail(&wblock->list, &wmi_block_list);
if (debug_event) {
wblock->handler = wmi_notify_debug;
wmi_method_enable(wblock, true);
}
}
/*
* Now that all of the devices are created, add them to the
* device tree and probe subdrivers.
*/
list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
if (wblock->acpi_device != device)
continue;
retval = device_add(&wblock->dev.dev);
if (retval) {
dev_err(wmi_bus_dev, "failed to register %pUL\n",
&wblock->gblock.guid);
if (debug_event)
wmi_method_enable(wblock, false);
list_del(&wblock->list);
put_device(&wblock->dev.dev);
}
}
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;
case -ENODEV:
return AE_NOT_FOUND;
case -ETIME:
return AE_TIME;
default:
return AE_OK;
}
}
static void acpi_wmi_notify_handler(acpi_handle handle, u32 event,
void *context)
{
struct wmi_block *wblock = NULL, *iter;
list_for_each_entry(iter, &wmi_block_list, list) {
struct guid_block *block = &iter->gblock;
if (iter->acpi_device->handle == handle &&
(block->flags & ACPI_WMI_EVENT) &&
(block->notify_id == event)) {
wblock = iter;
break;
}
}
if (!wblock)
return;
/* If a driver is bound, then notify the driver. */
if (test_bit(WMI_PROBED, &wblock->flags) && wblock->dev.dev.driver) {
struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
struct acpi_buffer evdata = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_status status;
if (!driver->no_notify_data) {
status = get_event_data(wblock, &evdata);
if (ACPI_FAILURE(status)) {
dev_warn(&wblock->dev.dev, "failed to get event data\n");
return;
}
}
if (driver->notify)
driver->notify(&wblock->dev, evdata.pointer);
kfree(evdata.pointer);
} else if (wblock->handler) {
/* Legacy handler */
wblock->handler(event, wblock->handler_data);
}
if (debug_event)
pr_info("DEBUG: GUID %pUL event 0x%02X\n", &wblock->gblock.guid, event);
acpi_bus_generate_netlink_event(
wblock->acpi_device->pnp.device_class,
dev_name(&wblock->dev.dev),
event, 0);
}
static int acpi_wmi_remove(struct platform_device *device)
{
struct acpi_device *acpi_device = ACPI_COMPANION(&device->dev);
acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
acpi_wmi_notify_handler);
acpi_remove_address_space_handler(acpi_device->handle,
ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
wmi_free_devices(acpi_device);
device_unregister(dev_get_drvdata(&device->dev));
return 0;
}
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;
}
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;
}
status = acpi_install_notify_handler(acpi_device->handle,
ACPI_ALL_NOTIFY,
acpi_wmi_notify_handler,
NULL);
if (ACPI_FAILURE(status)) {
dev_err(&device->dev, "Error installing notify handler\n");
error = -ENODEV;
goto err_remove_ec_handler;
}
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)) {
error = PTR_ERR(wmi_bus_dev);
goto err_remove_notify_handler;
}
dev_set_drvdata(&device->dev, wmi_bus_dev);
error = parse_wdg(wmi_bus_dev, acpi_device);
if (error) {
pr_err("Failed to parse WDG method\n");
goto err_remove_busdev;
}
return 0;
err_remove_busdev:
device_unregister(wmi_bus_dev);
err_remove_notify_handler:
acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
acpi_wmi_notify_handler);
err_remove_ec_handler:
acpi_remove_address_space_handler(acpi_device->handle,
ACPI_ADR_SPACE_EC,
&acpi_wmi_ec_space_handler);
return error;
}
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);
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 = 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);