https://github.com/torvalds/linux
Tip revision: d206a76d7d2726f3b096037f2079ce0bd3ba329b authored by Linus Torvalds on 25 February 2024, 23:46:06 UTC
Linux 6.8-rc6
Linux 6.8-rc6
Tip revision: d206a76
wmi.c
// 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/module.h>
#include <linux/platform_device.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/types.h>
#include <linux/uuid.h>
#include <linux/wmi.h>
#include <linux/fs.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,
};
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);
/* 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 */
"44FADEB1-B204-40F2-8581-394BBDC1B651", /* intel-wmi-sbl-fw-update */
"86CCFD48-205E-4A77-9C48-2021CBEDE341", /* intel-wmi-thunderbolt */
"F1DDEE52-063C-4784-A11E-8A06684B9B01", /* dell-smm-hwmon */
NULL
};
#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 int get_subobj_info(acpi_handle handle, const char *pathname,
struct acpi_device_info **info)
{
acpi_handle subobj_handle;
acpi_status status;
status = acpi_get_handle(handle, pathname, &subobj_handle);
if (status == AE_NOT_FOUND)
return -ENOENT;
if (ACPI_FAILURE(status))
return -EIO;
status = acpi_get_object_info(subobj_handle, info);
if (ACPI_FAILURE(status))
return -EIO;
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 = ¶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;
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;
if (wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *notify_id)
return 1;
return 0;
}
static 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: 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: 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 (!(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
*
* 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;
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 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;
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);
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);
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);
}
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++) {
if (guid_parse_and_compare(allow_duplicates[i], 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 platform_device *pdev)
{
struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
const struct guid_block *gblock;
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;
}
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;
}
if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
continue;
wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
if (!wblock) {
dev_err(wmi_bus_dev, "Failed to allocate %pUL\n", &gblock[i].guid);
continue;
}
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);
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;
}
/*
* 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;
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 = temp;
} else {
temp = 0xff & *value;
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 wmi_notify_driver(struct wmi_block *wblock)
{
struct wmi_driver *driver = drv_to_wdrv(wblock->dev.dev.driver);
struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_status status;
if (!driver->no_notify_data) {
status = get_event_data(wblock, &data);
if (ACPI_FAILURE(status)) {
dev_warn(&wblock->dev.dev, "Failed to get event data\n");
return;
}
}
if (driver->notify)
driver->notify(&wblock->dev, data.pointer);
kfree(data.pointer);
}
static int wmi_notify_device(struct device *dev, void *data)
{
struct wmi_block *wblock = dev_to_wblock(dev);
u32 *event = data;
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) {
wmi_notify_driver(wblock);
} else {
if (wblock->handler)
wblock->handler(*event, wblock->handler_data);
}
up_read(&wblock->notify_lock);
acpi_bus_generate_netlink_event(wblock->acpi_device->pnp.device_class,
dev_name(&wblock->dev.dev), *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) {
pr_err("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);