linux/drivers/acpi/power.c
Rafael J. Wysocki b5d667eb39 ACPI / PM: Take unusual configurations of power resources into account
Commit d2e5f0c (ACPI / PCI: Rework the setup and cleanup of device
wakeup) moved the initial disabling of system wakeup for PCI devices
into a place where it can actually work and that exposed a hidden old
issue with crap^Wunusual system designs where the same power
resources are used for both wakeup power and device power control at
run time.

Namely, say there is one power resource such that the ACPI power
state D0 of a PCI device depends on that power resource (i.e. the
device is in D0 when that power resource is "on") and it is used
as a wakeup power resource for the same device.  Then, calling
acpi_pci_sleep_wake(pci_dev, false) for the device in question will
cause the reference counter of that power resource to drop to 0,
which in turn will cause it to be turned off.  As a result, the
device will go into D3cold at that point, although it should have
stayed in D0.

As it turns out, that happens to USB controllers on some laptops
and USB becomes unusable on those machines as a result, which is
a major regression from v3.8.

To fix this problem, (1) increment the reference counters of wakup
power resources during their initialization if they are "on"
initially, (2) prevent acpi_disable_wakeup_device_power() from
decrementing the reference counters of wakeup power resources that
were not enabled for wakeup power previously, and (3) prevent
acpi_enable_wakeup_device_power() from incrementing the reference
counters of wakeup power resources that already are enabled for
wakeup power.

In addition to that, if it is impossible to determine the initial
states of wakeup power resources, avoid enabling wakeup for devices
whose wakeup power depends on those power resources.

Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Tested-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-23 23:15:21 +01:00

939 lines
24 KiB
C

/*
* acpi_power.c - ACPI Bus Power Management ($Revision: 39 $)
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
/*
* ACPI power-managed devices may be controlled in two ways:
* 1. via "Device Specific (D-State) Control"
* 2. via "Power Resource Control".
* This module is used to manage devices relying on Power Resource Control.
*
* An ACPI "power resource object" describes a software controllable power
* plane, clock plane, or other resource used by a power managed device.
* A device may rely on multiple power resources, and a power resource
* may be shared by multiple devices.
*/
#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 <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include "sleep.h"
#include "internal.h"
#define PREFIX "ACPI: "
#define _COMPONENT ACPI_POWER_COMPONENT
ACPI_MODULE_NAME("power");
#define ACPI_POWER_CLASS "power_resource"
#define ACPI_POWER_DEVICE_NAME "Power Resource"
#define ACPI_POWER_FILE_INFO "info"
#define ACPI_POWER_FILE_STATUS "state"
#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 list_head node;
struct acpi_device *adev;
struct work_struct work;
};
struct acpi_power_resource {
struct acpi_device device;
struct list_head list_node;
struct list_head dependent;
char *name;
u32 system_level;
u32 order;
unsigned int ref_count;
bool wakeup_enabled;
struct mutex resource_lock;
};
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
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;
if (acpi_bus_get_device(handle, &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);
}
}
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];
acpi_handle rhandle;
if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
err = -ENODATA;
break;
}
rhandle = element->reference.handle;
if (!rhandle) {
err = -ENODEV;
break;
}
err = acpi_add_power_resource(rhandle);
if (err)
break;
err = acpi_power_resources_list_add(rhandle, list);
if (err)
break;
}
if (err)
acpi_power_resources_list_free(list);
return err;
}
static int acpi_power_get_state(acpi_handle handle, int *state)
{
acpi_status status = AE_OK;
unsigned long long sta = 0;
char node_name[5];
struct acpi_buffer buffer = { sizeof(node_name), node_name };
if (!handle || !state)
return -EINVAL;
status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
if (ACPI_FAILURE(status))
return -ENODEV;
*state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
ACPI_POWER_RESOURCE_STATE_OFF;
acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
node_name,
*state ? "on" : "off"));
return 0;
}
static int acpi_power_get_list_state(struct list_head *list, int *state)
{
struct acpi_power_resource_entry *entry;
int cur_state;
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;
acpi_handle handle = resource->device.handle;
int result;
mutex_lock(&resource->resource_lock);
result = acpi_power_get_state(handle, &cur_state);
mutex_unlock(&resource->resource_lock);
if (result)
return result;
if (cur_state != ACPI_POWER_RESOURCE_STATE_ON)
break;
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
cur_state ? "on" : "off"));
*state = cur_state;
return 0;
}
static void acpi_power_resume_dependent(struct work_struct *work)
{
struct acpi_power_dependent_device *dep;
struct acpi_device_physical_node *pn;
struct acpi_device *adev;
int state;
dep = container_of(work, struct acpi_power_dependent_device, work);
adev = dep->adev;
if (acpi_power_get_inferred_state(adev, &state))
return;
if (state > ACPI_STATE_D0)
return;
mutex_lock(&adev->physical_node_lock);
list_for_each_entry(pn, &adev->physical_node_list, node)
pm_request_resume(pn->dev);
list_for_each_entry(pn, &adev->power_dependent, node)
pm_request_resume(pn->dev);
mutex_unlock(&adev->physical_node_lock);
}
static int __acpi_power_on(struct acpi_power_resource *resource)
{
acpi_status status = AE_OK;
status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL);
if (ACPI_FAILURE(status))
return -ENODEV;
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
resource->name));
return 0;
}
static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
{
int result = 0;
if (resource->ref_count++) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Power resource [%s] already on",
resource->name));
} else {
result = __acpi_power_on(resource);
if (result) {
resource->ref_count--;
} else {
struct acpi_power_dependent_device *dep;
list_for_each_entry(dep, &resource->dependent, node)
schedule_work(&dep->work);
}
}
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_status status;
status = acpi_evaluate_object(resource->device.handle, "_OFF",
NULL, NULL);
if (ACPI_FAILURE(status))
return -ENODEV;
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned off\n",
resource->name));
return 0;
}
static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
{
int result = 0;
if (!resource->ref_count) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Power resource [%s] already off",
resource->name));
return 0;
}
if (--resource->ref_count) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Power resource [%s] still in use\n",
resource->name));
} 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 void acpi_power_add_dependent(struct acpi_power_resource *resource,
struct acpi_device *adev)
{
struct acpi_power_dependent_device *dep;
mutex_lock(&resource->resource_lock);
list_for_each_entry(dep, &resource->dependent, node)
if (dep->adev == adev)
goto out;
dep = kzalloc(sizeof(*dep), GFP_KERNEL);
if (!dep)
goto out;
dep->adev = adev;
INIT_WORK(&dep->work, acpi_power_resume_dependent);
list_add_tail(&dep->node, &resource->dependent);
out:
mutex_unlock(&resource->resource_lock);
}
static void acpi_power_remove_dependent(struct acpi_power_resource *resource,
struct acpi_device *adev)
{
struct acpi_power_dependent_device *dep;
struct work_struct *work = NULL;
mutex_lock(&resource->resource_lock);
list_for_each_entry(dep, &resource->dependent, node)
if (dep->adev == adev) {
list_del(&dep->node);
work = &dep->work;
break;
}
mutex_unlock(&resource->resource_lock);
if (work) {
cancel_work_sync(work);
kfree(dep);
}
}
static struct attribute *attrs[] = {
NULL,
};
static 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 void acpi_power_hide_list(struct acpi_device *adev, int state)
{
struct acpi_device_power_state *ps = &adev->power.states[state];
struct acpi_power_resource_entry *entry;
if (list_empty(&ps->resources))
return;
list_for_each_entry_reverse(entry, &ps->resources, node) {
struct acpi_device *res_dev = &entry->resource->device;
sysfs_remove_link_from_group(&adev->dev.kobj,
attr_groups[state].name,
dev_name(&res_dev->dev));
}
sysfs_remove_group(&adev->dev.kobj, &attr_groups[state]);
}
static void acpi_power_expose_list(struct acpi_device *adev, int state)
{
struct acpi_device_power_state *ps = &adev->power.states[state];
struct acpi_power_resource_entry *entry;
int ret;
if (list_empty(&ps->resources))
return;
ret = sysfs_create_group(&adev->dev.kobj, &attr_groups[state]);
if (ret)
return;
list_for_each_entry(entry, &ps->resources, node) {
struct acpi_device *res_dev = &entry->resource->device;
ret = sysfs_add_link_to_group(&adev->dev.kobj,
attr_groups[state].name,
&res_dev->dev.kobj,
dev_name(&res_dev->dev));
if (ret) {
acpi_power_hide_list(adev, state);
break;
}
}
}
void acpi_power_add_remove_device(struct acpi_device *adev, bool add)
{
struct acpi_device_power_state *ps;
struct acpi_power_resource_entry *entry;
int state;
if (!adev->power.flags.power_resources)
return;
ps = &adev->power.states[ACPI_STATE_D0];
list_for_each_entry(entry, &ps->resources, node) {
struct acpi_power_resource *resource = entry->resource;
if (add)
acpi_power_add_dependent(resource, adev);
else
acpi_power_remove_dependent(resource, adev);
}
for (state = ACPI_STATE_D0; state <= ACPI_STATE_D3_HOT; state++) {
if (add)
acpi_power_expose_list(adev, state);
else
acpi_power_hide_list(adev, state);
}
}
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;
acpi_handle handle = resource->device.handle;
int result;
int state;
mutex_lock(&resource->resource_lock);
result = acpi_power_get_state(handle, &state);
if (result) {
mutex_unlock(&resource->resource_lock);
return result;
}
if (state == ACPI_POWER_RESOURCE_STATE_ON) {
resource->ref_count++;
resource->wakeup_enabled = true;
}
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 agruments 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 agruments
* 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) {
printk(KERN_ERR PREFIX "_DSW execution failed\n");
dev->wakeup.flags.valid = 0;
return -ENODEV;
}
/* Execute _PSW */
arg_list.count = 1;
in_arg[0].integer.value = enable;
status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
printk(KERN_ERR PREFIX "_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)
{
struct acpi_power_resource_entry *entry;
int err = 0;
if (!dev || !dev->wakeup.flags.valid)
return -EINVAL;
mutex_lock(&acpi_device_lock);
if (dev->wakeup.prepare_count++)
goto out;
list_for_each_entry(entry, &dev->wakeup.resources, node) {
struct acpi_power_resource *resource = entry->resource;
mutex_lock(&resource->resource_lock);
if (!resource->wakeup_enabled) {
err = acpi_power_on_unlocked(resource);
if (!err)
resource->wakeup_enabled = true;
}
mutex_unlock(&resource->resource_lock);
if (err) {
dev_err(&dev->dev,
"Cannot turn wakeup power resources on\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)
dev->wakeup.prepare_count = 0;
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);
if (--dev->wakeup.prepare_count > 0)
goto out;
/*
* Executing the code below even if prepare_count is already zero when
* the function is called may be useful, for example for initialisation.
*/
if (dev->wakeup.prepare_count < 0)
dev->wakeup.prepare_count = 0;
err = acpi_device_sleep_wake(dev, 0, 0, 0);
if (err)
goto out;
list_for_each_entry(entry, &dev->wakeup.resources, node) {
struct acpi_power_resource *resource = entry->resource;
mutex_lock(&resource->resource_lock);
if (resource->wakeup_enabled) {
err = acpi_power_off_unlocked(resource);
if (!err)
resource->wakeup_enabled = false;
}
mutex_unlock(&resource->resource_lock);
if (err) {
dev_err(&dev->dev,
"Cannot turn wakeup power resources off\n");
dev->wakeup.flags.valid = 0;
break;
}
}
out:
mutex_unlock(&acpi_device_lock);
return err;
}
int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
{
int result = 0;
int list_state = 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 = ACPI_STATE_D3;
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;
/* TBD: Resources must be ordered. */
/*
* 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_ids(device);
kfree(resource);
}
static ssize_t acpi_power_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(resource_in_use, 0444, acpi_power_in_use_show, NULL);
static void acpi_power_sysfs_remove(struct acpi_device *device)
{
device_remove_file(&device->dev, &dev_attr_resource_in_use);
}
int acpi_add_power_resource(acpi_handle handle)
{
struct acpi_power_resource *resource;
struct acpi_device *device = NULL;
union acpi_object acpi_object;
struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
acpi_status status;
int state, result = -ENODEV;
acpi_bus_get_device(handle, &device);
if (device)
return 0;
resource = kzalloc(sizeof(*resource), GFP_KERNEL);
if (!resource)
return -ENOMEM;
device = &resource->device;
acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
ACPI_STA_DEFAULT);
mutex_init(&resource->resource_lock);
INIT_LIST_HEAD(&resource->dependent);
resource->name = device->pnp.bus_id;
strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
device->power.state = ACPI_STATE_UNKNOWN;
/* Evalute 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;
result = acpi_power_get_state(handle, &state);
if (result)
goto err;
printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
acpi_device_bid(device), state ? "on" : "off");
device->flags.match_driver = true;
result = acpi_device_add(device, acpi_release_power_resource);
if (result)
goto err;
if (!device_create_file(&device->dev, &dev_attr_resource_in_use))
device->remove = acpi_power_sysfs_remove;
mutex_lock(&power_resource_list_lock);
list_add(&resource->list_node, &acpi_power_resource_list);
mutex_unlock(&power_resource_list_lock);
acpi_device_add_finalize(device);
return 0;
err:
acpi_release_power_resource(&device->dev);
return result;
}
#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, state;
mutex_lock(&resource->resource_lock);
result = acpi_power_get_state(resource->device.handle, &state);
if (result)
continue;
if (state == ACPI_POWER_RESOURCE_STATE_OFF
&& resource->ref_count) {
dev_info(&resource->device.dev, "Turning ON\n");
__acpi_power_on(resource);
} else if (state == ACPI_POWER_RESOURCE_STATE_ON
&& !resource->ref_count) {
dev_info(&resource->device.dev, "Turning OFF\n");
__acpi_power_off(resource);
}
mutex_unlock(&resource->resource_lock);
}
mutex_unlock(&power_resource_list_lock);
}
#endif