blob: 23507d29f0006beda96116103399ac7a4848e433 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* drivers/acpi/power.c - ACPI Power Resources management.
*
* Copyright (C) 2001 - 2015 Intel Corp.
* Author: Andy Grover <andrew.grover@intel.com>
* Author: Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*/
/*
* ACPI power-managed devices may be controlled in two ways:
* 1. via "Device Specific (D-State) Control"
* 2. via "Power Resource Control".
* The code below deals with ACPI Power Resources control.
*
* An ACPI "power resource object" represents a software controllable power
* plane, clock plane, or other resource depended on by a device.
*
* A device may rely on multiple power resources, and a power resource
* may be shared by multiple devices.
*/
#define pr_fmt(fmt) "ACPI: PM: " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/sysfs.h>
#include <linux/acpi.h>
#include "sleep.h"
#include "internal.h"
#define ACPI_POWER_CLASS "power_resource"
#define ACPI_POWER_DEVICE_NAME "Power Resource"
#define ACPI_POWER_RESOURCE_STATE_OFF 0x00
#define ACPI_POWER_RESOURCE_STATE_ON 0x01
#define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
struct acpi_power_dependent_device {
struct device *dev;
struct list_head node;
};
struct acpi_power_resource {
struct acpi_device device;
struct list_head list_node;
u32 system_level;
u32 order;
unsigned int ref_count;
u8 state;
struct mutex resource_lock;
struct list_head dependents;
};
struct acpi_power_resource_entry {
struct list_head node;
struct acpi_power_resource *resource;
};
static LIST_HEAD(acpi_power_resource_list);
static DEFINE_MUTEX(power_resource_list_lock);
/* --------------------------------------------------------------------------
Power Resource Management
-------------------------------------------------------------------------- */
static inline const char *resource_dev_name(struct acpi_power_resource *pr)
{
return dev_name(&pr->device.dev);
}
static inline
struct acpi_power_resource *to_power_resource(struct acpi_device *device)
{
return container_of(device, struct acpi_power_resource, device);
}
static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
{
struct acpi_device *device = acpi_fetch_acpi_dev(handle);
if (!device)
return NULL;
return to_power_resource(device);
}
static int acpi_power_resources_list_add(acpi_handle handle,
struct list_head *list)
{
struct acpi_power_resource *resource = acpi_power_get_context(handle);
struct acpi_power_resource_entry *entry;
if (!resource || !list)
return -EINVAL;
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return -ENOMEM;
entry->resource = resource;
if (!list_empty(list)) {
struct acpi_power_resource_entry *e;
list_for_each_entry(e, list, node)
if (e->resource->order > resource->order) {
list_add_tail(&entry->node, &e->node);
return 0;
}
}
list_add_tail(&entry->node, list);
return 0;
}
void acpi_power_resources_list_free(struct list_head *list)
{
struct acpi_power_resource_entry *entry, *e;
list_for_each_entry_safe(entry, e, list, node) {
list_del(&entry->node);
kfree(entry);
}
}
static bool acpi_power_resource_is_dup(union acpi_object *package,
unsigned int start, unsigned int i)
{
acpi_handle rhandle, dup;
unsigned int j;
/* The caller is expected to check the package element types */
rhandle = package->package.elements[i].reference.handle;
for (j = start; j < i; j++) {
dup = package->package.elements[j].reference.handle;
if (dup == rhandle)
return true;
}
return false;
}
int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
struct list_head *list)
{
unsigned int i;
int err = 0;
for (i = start; i < package->package.count; i++) {
union acpi_object *element = &package->package.elements[i];
struct acpi_device *rdev;
acpi_handle rhandle;
if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
err = -ENODATA;
break;
}
rhandle = element->reference.handle;
if (!rhandle) {
err = -ENODEV;
break;
}
/* Some ACPI tables contain duplicate power resource references */
if (acpi_power_resource_is_dup(package, start, i))
continue;
rdev = acpi_add_power_resource(rhandle);
if (!rdev) {
err = -ENODEV;
break;
}
err = acpi_power_resources_list_add(rhandle, list);
if (err)
break;
}
if (err)
acpi_power_resources_list_free(list);
return err;
}
static int __get_state(acpi_handle handle, u8 *state)
{
acpi_status status = AE_OK;
unsigned long long sta = 0;
u8 cur_state;
status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
if (ACPI_FAILURE(status))
return -ENODEV;
cur_state = sta & ACPI_POWER_RESOURCE_STATE_ON;
acpi_handle_debug(handle, "Power resource is %s\n",
cur_state ? "on" : "off");
*state = cur_state;
return 0;
}
static int acpi_power_get_state(struct acpi_power_resource *resource, u8 *state)
{
if (resource->state == ACPI_POWER_RESOURCE_STATE_UNKNOWN) {
int ret;
ret = __get_state(resource->device.handle, &resource->state);
if (ret)
return ret;
}
*state = resource->state;
return 0;
}
static int acpi_power_get_list_state(struct list_head *list, u8 *state)
{
struct acpi_power_resource_entry *entry;
u8 cur_state = ACPI_POWER_RESOURCE_STATE_OFF;
if (!list || !state)
return -EINVAL;
/* The state of the list is 'on' IFF all resources are 'on'. */
list_for_each_entry(entry, list, node) {
struct acpi_power_resource *resource = entry->resource;
int result;
mutex_lock(&resource->resource_lock);
result = acpi_power_get_state(resource, &cur_state);
mutex_unlock(&resource->resource_lock);
if (result)
return result;
if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
break;
}
pr_debug("Power resource list is %s\n", cur_state ? "on" : "off");
*state = cur_state;
return 0;
}
static int
acpi_power_resource_add_dependent(struct acpi_power_resource *resource,
struct device *dev)
{
struct acpi_power_dependent_device *dep;
int ret = 0;
mutex_lock(&resource->resource_lock);
list_for_each_entry(dep, &resource->dependents, node) {
/* Only add it once */
if (dep->dev == dev)
goto unlock;
}
dep = kzalloc(sizeof(*dep), GFP_KERNEL);
if (!dep) {
ret = -ENOMEM;
goto unlock;
}
dep->dev = dev;
list_add_tail(&dep->node, &resource->dependents);
dev_dbg(dev, "added power dependency to [%s]\n",
resource_dev_name(resource));
unlock:
mutex_unlock(&resource->resource_lock);
return ret;
}
static void
acpi_power_resource_remove_dependent(struct acpi_power_resource *resource,
struct device *dev)
{
struct acpi_power_dependent_device *dep;
mutex_lock(&resource->resource_lock);
list_for_each_entry(dep, &resource->dependents, node) {
if (dep->dev == dev) {
list_del(&dep->node);
kfree(dep);
dev_dbg(dev, "removed power dependency to [%s]\n",
resource_dev_name(resource));
break;
}
}
mutex_unlock(&resource->resource_lock);
}
/**
* acpi_device_power_add_dependent - Add dependent device of this ACPI device
* @adev: ACPI device pointer
* @dev: Dependent device
*
* If @adev has non-empty _PR0 the @dev is added as dependent device to all
* power resources returned by it. This means that whenever these power
* resources are turned _ON the dependent devices get runtime resumed. This
* is needed for devices such as PCI to allow its driver to re-initialize
* it after it went to D0uninitialized.
*
* If @adev does not have _PR0 this does nothing.
*
* Returns %0 in case of success and negative errno otherwise.
*/
int acpi_device_power_add_dependent(struct acpi_device *adev,
struct device *dev)
{
struct acpi_power_resource_entry *entry;
struct list_head *resources;
int ret;
if (!adev->flags.power_manageable)
return 0;
resources = &adev->power.states[ACPI_STATE_D0].resources;
list_for_each_entry(entry, resources, node) {
ret = acpi_power_resource_add_dependent(entry->resource, dev);
if (ret)
goto err;
}
return 0;
err:
list_for_each_entry(entry, resources, node)
acpi_power_resource_remove_dependent(entry->resource, dev);
return ret;
}
/**
* acpi_device_power_remove_dependent - Remove dependent device
* @adev: ACPI device pointer
* @dev: Dependent device
*
* Does the opposite of acpi_device_power_add_dependent() and removes the
* dependent device if it is found. Can be called to @adev that does not
* have _PR0 as well.
*/
void acpi_device_power_remove_dependent(struct acpi_device *adev,
struct device *dev)
{
struct acpi_power_resource_entry *entry;
struct list_head *resources;
if (!adev->flags.power_manageable)
return;
resources = &adev->power.states[ACPI_STATE_D0].resources;
list_for_each_entry_reverse(entry, resources, node)
acpi_power_resource_remove_dependent(entry->resource, dev);
}
static int __acpi_power_on(struct acpi_power_resource *resource)
{
acpi_handle handle = resource->device.handle;
struct acpi_power_dependent_device *dep;
acpi_status status = AE_OK;
status = acpi_evaluate_object(handle, "_ON", NULL, NULL);
if (ACPI_FAILURE(status)) {
resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
return -ENODEV;
}
resource->state = ACPI_POWER_RESOURCE_STATE_ON;
acpi_handle_debug(handle, "Power resource turned on\n");
/*
* If there are other dependents on this power resource we need to
* resume them now so that their drivers can re-initialize the
* hardware properly after it went back to D0.
*/
if (list_empty(&resource->dependents) ||
list_is_singular(&resource->dependents))
return 0;
list_for_each_entry(dep, &resource->dependents, node) {
dev_dbg(dep->dev, "runtime resuming because [%s] turned on\n",
resource_dev_name(resource));
pm_request_resume(dep->dev);
}
return 0;
}
static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
{
int result = 0;
if (resource->ref_count++) {
acpi_handle_debug(resource->device.handle,
"Power resource already on\n");
} else {
result = __acpi_power_on(resource);
if (result)
resource->ref_count--;
}
return result;
}
static int acpi_power_on(struct acpi_power_resource *resource)
{
int result;
mutex_lock(&resource->resource_lock);
result = acpi_power_on_unlocked(resource);
mutex_unlock(&resource->resource_lock);
return result;
}
static int __acpi_power_off(struct acpi_power_resource *resource)
{
acpi_handle handle = resource->device.handle;
acpi_status status;
status = acpi_evaluate_object(handle, "_OFF", NULL, NULL);
if (ACPI_FAILURE(status)) {
resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
return -ENODEV;
}
resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
acpi_handle_debug(handle, "Power resource turned off\n");
return 0;
}
static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
{
int result = 0;
if (!resource->ref_count) {
acpi_handle_debug(resource->device.handle,
"Power resource already off\n");
return 0;
}
if (--resource->ref_count) {
acpi_handle_debug(resource->device.handle,
"Power resource still in use\n");
} else {
result = __acpi_power_off(resource);
if (result)
resource->ref_count++;
}
return result;
}
static int acpi_power_off(struct acpi_power_resource *resource)
{
int result;
mutex_lock(&resource->resource_lock);
result = acpi_power_off_unlocked(resource);
mutex_unlock(&resource->resource_lock);
return result;
}
static int acpi_power_off_list(struct list_head *list)
{
struct acpi_power_resource_entry *entry;
int result = 0;
list_for_each_entry_reverse(entry, list, node) {
result = acpi_power_off(entry->resource);
if (result)
goto err;
}
return 0;
err:
list_for_each_entry_continue(entry, list, node)
acpi_power_on(entry->resource);
return result;
}
static int acpi_power_on_list(struct list_head *list)
{
struct acpi_power_resource_entry *entry;
int result = 0;
list_for_each_entry(entry, list, node) {
result = acpi_power_on(entry->resource);
if (result)
goto err;
}
return 0;
err:
list_for_each_entry_continue_reverse(entry, list, node)
acpi_power_off(entry->resource);
return result;
}
static struct attribute *attrs[] = {
NULL,
};
static const struct attribute_group attr_groups[] = {
[ACPI_STATE_D0] = {
.name = "power_resources_D0",
.attrs = attrs,
},
[ACPI_STATE_D1] = {
.name = "power_resources_D1",
.attrs = attrs,
},
[ACPI_STATE_D2] = {
.name = "power_resources_D2",
.attrs = attrs,
},
[ACPI_STATE_D3_HOT] = {
.name = "power_resources_D3hot",
.attrs = attrs,
},
};
static const struct attribute_group wakeup_attr_group = {
.name = "power_resources_wakeup",
.attrs = attrs,
};
static void acpi_power_hide_list(struct acpi_device *adev,
struct list_head *resources,
const struct attribute_group *attr_group)
{
struct acpi_power_resource_entry *entry;
if (list_empty(resources))
return;
list_for_each_entry_reverse(entry, resources, node) {
struct acpi_device *res_dev = &entry->resource->device;
sysfs_remove_link_from_group(&adev->dev.kobj,
attr_group->name,
dev_name(&res_dev->dev));
}
sysfs_remove_group(&adev->dev.kobj, attr_group);
}
static void acpi_power_expose_list(struct acpi_device *adev,
struct list_head *resources,
const struct attribute_group *attr_group)
{
struct acpi_power_resource_entry *entry;
int ret;
if (list_empty(resources))
return;
ret = sysfs_create_group(&adev->dev.kobj, attr_group);
if (ret)
return;
list_for_each_entry(entry, resources, node) {
struct acpi_device *res_dev = &entry->resource->device;
ret = sysfs_add_link_to_group(&adev->dev.kobj,
attr_group->name,
&res_dev->dev.kobj,
dev_name(&res_dev->dev));
if (ret) {
acpi_power_hide_list(adev, resources, attr_group);
break;
}
}
}
static void acpi_power_expose_hide(struct acpi_device *adev,
struct list_head *resources,
const struct attribute_group *attr_group,
bool expose)
{
if (expose)
acpi_power_expose_list(adev, resources, attr_group);
else
acpi_power_hide_list(adev, resources, attr_group);
}
void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
{
int state;
if (adev->wakeup.flags.valid)
acpi_power_expose_hide(adev, &adev->wakeup.resources,
&wakeup_attr_group, add);
if (!adev->power.flags.power_resources)
return;
for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++)
acpi_power_expose_hide(adev,
&adev->power.states[state].resources,
&attr_groups[state], add);
}
int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
{
struct acpi_power_resource_entry *entry;
int system_level = 5;
list_for_each_entry(entry, list, node) {
struct acpi_power_resource *resource = entry->resource;
u8 state;
mutex_lock(&resource->resource_lock);
/*
* Make sure that the power resource state and its reference
* counter value are consistent with each other.
*/
if (!resource->ref_count &&
!acpi_power_get_state(resource, &state) &&
state == ACPI_POWER_RESOURCE_STATE_ON)
__acpi_power_off(resource);
if (system_level > resource->system_level)
system_level = resource->system_level;
mutex_unlock(&resource->resource_lock);
}
*system_level_p = system_level;
return 0;
}
/* --------------------------------------------------------------------------
Device Power Management
-------------------------------------------------------------------------- */
/**
* acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
* ACPI 3.0) _PSW (Power State Wake)
* @dev: Device to handle.
* @enable: 0 - disable, 1 - enable the wake capabilities of the device.
* @sleep_state: Target sleep state of the system.
* @dev_state: Target power state of the device.
*
* Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
* State Wake) for the device, if present. On failure reset the device's
* wakeup.flags.valid flag.
*
* RETURN VALUE:
* 0 if either _DSW or _PSW has been successfully executed
* 0 if neither _DSW nor _PSW has been found
* -ENODEV if the execution of either _DSW or _PSW has failed
*/
int acpi_device_sleep_wake(struct acpi_device *dev,
int enable, int sleep_state, int dev_state)
{
union acpi_object in_arg[3];
struct acpi_object_list arg_list = { 3, in_arg };
acpi_status status = AE_OK;
/*
* Try to execute _DSW first.
*
* Three arguments are needed for the _DSW object:
* Argument 0: enable/disable the wake capabilities
* Argument 1: target system state
* Argument 2: target device state
* When _DSW object is called to disable the wake capabilities, maybe
* the first argument is filled. The values of the other two arguments
* are meaningless.
*/
in_arg[0].type = ACPI_TYPE_INTEGER;
in_arg[0].integer.value = enable;
in_arg[1].type = ACPI_TYPE_INTEGER;
in_arg[1].integer.value = sleep_state;
in_arg[2].type = ACPI_TYPE_INTEGER;
in_arg[2].integer.value = dev_state;
status = acpi_evaluate_object(dev->handle, "_DSW", &arg_list, NULL);
if (ACPI_SUCCESS(status)) {
return 0;
} else if (status != AE_NOT_FOUND) {
acpi_handle_info(dev->handle, "_DSW execution failed\n");
dev->wakeup.flags.valid = 0;
return -ENODEV;
}
/* Execute _PSW */
status = acpi_execute_simple_method(dev->handle, "_PSW", enable);
if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
acpi_handle_info(dev->handle, "_PSW execution failed\n");
dev->wakeup.flags.valid = 0;
return -ENODEV;
}
return 0;
}
/*
* Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
* 1. Power on the power resources required for the wakeup device
* 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
* State Wake) for the device, if present
*/
int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
{
int err = 0;
if (!dev || !dev->wakeup.flags.valid)
return -EINVAL;
mutex_lock(&acpi_device_lock);
dev_dbg(&dev->dev, "Enabling wakeup power (count %d)\n",
dev->wakeup.prepare_count);
if (dev->wakeup.prepare_count++)
goto out;
err = acpi_power_on_list(&dev->wakeup.resources);
if (err) {
dev_err(&dev->dev, "Cannot turn on wakeup power resources\n");
dev->wakeup.flags.valid = 0;
goto out;
}
/*
* Passing 3 as the third argument below means the device may be
* put into arbitrary power state afterward.
*/
err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
if (err) {
acpi_power_off_list(&dev->wakeup.resources);
dev->wakeup.prepare_count = 0;
goto out;
}
dev_dbg(&dev->dev, "Wakeup power enabled\n");
out:
mutex_unlock(&acpi_device_lock);
return err;
}
/*
* Shutdown a wakeup device, counterpart of above method
* 1. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
* State Wake) for the device, if present
* 2. Shutdown down the power resources
*/
int acpi_disable_wakeup_device_power(struct acpi_device *dev)
{
struct acpi_power_resource_entry *entry;
int err = 0;
if (!dev || !dev->wakeup.flags.valid)
return -EINVAL;
mutex_lock(&acpi_device_lock);
dev_dbg(&dev->dev, "Disabling wakeup power (count %d)\n",
dev->wakeup.prepare_count);
/* Do nothing if wakeup power has not been enabled for this device. */
if (dev->wakeup.prepare_count <= 0)
goto out;
if (--dev->wakeup.prepare_count > 0)
goto out;
err = acpi_device_sleep_wake(dev, 0, 0, 0);
if (err)
goto out;
/*
* All of the power resources in the list need to be turned off even if
* there are errors.
*/
list_for_each_entry(entry, &dev->wakeup.resources, node) {
int ret;
ret = acpi_power_off(entry->resource);
if (ret && !err)
err = ret;
}
if (err) {
dev_err(&dev->dev, "Cannot turn off wakeup power resources\n");
dev->wakeup.flags.valid = 0;
goto out;
}
dev_dbg(&dev->dev, "Wakeup power disabled\n");
out:
mutex_unlock(&acpi_device_lock);
return err;
}
int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
{
u8 list_state = ACPI_POWER_RESOURCE_STATE_OFF;
int result = 0;
int i = 0;
if (!device || !state)
return -EINVAL;
/*
* We know a device's inferred power state when all the resources
* required for a given D-state are 'on'.
*/
for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
struct list_head *list = &device->power.states[i].resources;
if (list_empty(list))
continue;
result = acpi_power_get_list_state(list, &list_state);
if (result)
return result;
if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
*state = i;
return 0;
}
}
*state = device->power.states[ACPI_STATE_D3_COLD].flags.valid ?
ACPI_STATE_D3_COLD : ACPI_STATE_D3_HOT;
return 0;
}
int acpi_power_on_resources(struct acpi_device *device, int state)
{
if (!device || state < ACPI_STATE_D0 || state > ACPI_STATE_D3_HOT)
return -EINVAL;
return acpi_power_on_list(&device->power.states[state].resources);
}
int acpi_power_transition(struct acpi_device *device, int state)
{
int result = 0;
if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
return -EINVAL;
if (device->power.state == state || !device->flags.power_manageable)
return 0;
if ((device->power.state < ACPI_STATE_D0)
|| (device->power.state > ACPI_STATE_D3_COLD))
return -ENODEV;
/*
* First we reference all power resources required in the target list
* (e.g. so the device doesn't lose power while transitioning). Then,
* we dereference all power resources used in the current list.
*/
if (state < ACPI_STATE_D3_COLD)
result = acpi_power_on_list(
&device->power.states[state].resources);
if (!result && device->power.state < ACPI_STATE_D3_COLD)
acpi_power_off_list(
&device->power.states[device->power.state].resources);
/* We shouldn't change the state unless the above operations succeed. */
device->power.state = result ? ACPI_STATE_UNKNOWN : state;
return result;
}
static void acpi_release_power_resource(struct device *dev)
{
struct acpi_device *device = to_acpi_device(dev);
struct acpi_power_resource *resource;
resource = container_of(device, struct acpi_power_resource, device);
mutex_lock(&power_resource_list_lock);
list_del(&resource->list_node);
mutex_unlock(&power_resource_list_lock);
acpi_free_pnp_ids(&device->pnp);
kfree(resource);
}
static ssize_t resource_in_use_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct acpi_power_resource *resource;
resource = to_power_resource(to_acpi_device(dev));
return sprintf(buf, "%u\n", !!resource->ref_count);
}
static DEVICE_ATTR_RO(resource_in_use);
static void acpi_power_sysfs_remove(struct acpi_device *device)
{
device_remove_file(&device->dev, &dev_attr_resource_in_use);
}
static void acpi_power_add_resource_to_list(struct acpi_power_resource *resource)
{
mutex_lock(&power_resource_list_lock);
if (!list_empty(&acpi_power_resource_list)) {
struct acpi_power_resource *r;
list_for_each_entry(r, &acpi_power_resource_list, list_node)
if (r->order > resource->order) {
list_add_tail(&resource->list_node, &r->list_node);
goto out;
}
}
list_add_tail(&resource->list_node, &acpi_power_resource_list);
out:
mutex_unlock(&power_resource_list_lock);
}
struct acpi_device *acpi_add_power_resource(acpi_handle handle)
{
struct acpi_device *device = acpi_fetch_acpi_dev(handle);
struct acpi_power_resource *resource;
union acpi_object acpi_object;
struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
acpi_status status;
u8 state_dummy;
int result;
if (device)
return device;
resource = kzalloc(sizeof(*resource), GFP_KERNEL);
if (!resource)
return NULL;
device = &resource->device;
acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
acpi_release_power_resource);
mutex_init(&resource->resource_lock);
INIT_LIST_HEAD(&resource->list_node);
INIT_LIST_HEAD(&resource->dependents);
strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
device->power.state = ACPI_STATE_UNKNOWN;
device->flags.match_driver = true;
/* Evaluate the object to get the system level and resource order. */
status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
if (ACPI_FAILURE(status))
goto err;
resource->system_level = acpi_object.power_resource.system_level;
resource->order = acpi_object.power_resource.resource_order;
resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
/* Get the initial state or just flip it on if that fails. */
if (acpi_power_get_state(resource, &state_dummy))
__acpi_power_on(resource);
acpi_handle_info(handle, "New power resource\n");
result = acpi_tie_acpi_dev(device);
if (result)
goto err;
result = acpi_device_add(device);
if (result)
goto err;
if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
device->remove = acpi_power_sysfs_remove;
acpi_power_add_resource_to_list(resource);
acpi_device_add_finalize(device);
return device;
err:
acpi_release_power_resource(&device->dev);
return NULL;
}
#ifdef CONFIG_ACPI_SLEEP
void acpi_resume_power_resources(void)
{
struct acpi_power_resource *resource;
mutex_lock(&power_resource_list_lock);
list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
int result;
u8 state;
mutex_lock(&resource->resource_lock);
resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
result = acpi_power_get_state(resource, &state);
if (result) {
mutex_unlock(&resource->resource_lock);
continue;
}
if (state == ACPI_POWER_RESOURCE_STATE_OFF
&& resource->ref_count) {
acpi_handle_debug(resource->device.handle, "Turning ON\n");
__acpi_power_on(resource);
}
mutex_unlock(&resource->resource_lock);
}
mutex_unlock(&power_resource_list_lock);
}
#endif
/**
* acpi_turn_off_unused_power_resources - Turn off power resources not in use.
*/
void acpi_turn_off_unused_power_resources(void)
{
struct acpi_power_resource *resource;
mutex_lock(&power_resource_list_lock);
list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
mutex_lock(&resource->resource_lock);
if (!resource->ref_count &&
resource->state == ACPI_POWER_RESOURCE_STATE_ON) {
acpi_handle_debug(resource->device.handle, "Turning OFF\n");
__acpi_power_off(resource);
}
mutex_unlock(&resource->resource_lock);
}
mutex_unlock(&power_resource_list_lock);
}