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linux/drivers/acpi/power.c
Mika Westerberg 4533771c1e ACPI / PM: Introduce concept of a _PR0 dependent device 
If there are shared power resources between otherwise unrelated devices
turning them on causes the other devices sharing them to be powered up
as well. In case of PCI devices go into D0uninitialized state meaning
that if they were configured to trigger wake that configuration is lost
at this point.

For this reason introduce a concept of "_PR0 dependent device" that can
be added to any ACPI device that has power resources. The dependent
device will be included in a list of dependent devices for all power
resources returned by the ACPI device's _PR0 (assuming it has one).
Whenever a power resource having dependent devices is turned physically
on (its _ON method is called) we runtime resume all of them to allow
their driver or in case of PCI the PCI core to re-initialize the device
and its wake configuration.

This adds two functions that can be used to add and remove these
dependent devices. Note the dependent device does not necessary need
share power resources so this functionality can be used to add "software
dependencies" as well if needed.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-27 12:31:57 +02:00

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// 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.
*/
#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 _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 device *dev;
struct list_head node;
};
struct acpi_power_resource {
struct acpi_device device;
struct list_head list_node;
char *name;
u32 system_level;
u32 order;
unsigned int ref_count;
bool wakeup_enabled;
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
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);
}
}
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];
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;
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'. */
cur_state = 0;
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 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->name);
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->name);
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)
{
struct acpi_power_dependent_device *dep;
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));
/*
* 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->name);
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_DEBUG_PRINT((ACPI_DB_INFO,
"Power resource [%s] already on\n",
resource->name));
} 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_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\n",
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 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;
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 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) {
printk(KERN_ERR PREFIX "_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)) {
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 = 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 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);
}
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);
}
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->list_node);
INIT_LIST_HEAD(&resource->dependents);
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;
acpi_power_add_resource_to_list(resource);
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) {
mutex_unlock(&resource->resource_lock);
continue;
}
if (state == ACPI_POWER_RESOURCE_STATE_OFF
&& resource->ref_count) {
dev_info(&resource->device.dev, "Turning ON\n");
__acpi_power_on(resource);
}
mutex_unlock(&resource->resource_lock);
}
mutex_unlock(&power_resource_list_lock);
}
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) {
int result, state;
mutex_lock(&resource->resource_lock);
result = acpi_power_get_state(resource->device.handle, &state);
if (result) {
mutex_unlock(&resource->resource_lock);
continue;
}
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
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