linux/drivers/acpi/power.c

900 lines
22 KiB
C

/*
* 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>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* 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.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
/*
* 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_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 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'. */
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_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\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 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 */
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);
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