Select Git revision
power.c 17.27 KiB
/*
* 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 <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include "sleep.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
int acpi_power_nocheck;
module_param_named(power_nocheck, acpi_power_nocheck, bool, 000);
static int acpi_power_add(struct acpi_device *device);
static int acpi_power_remove(struct acpi_device *device, int type);
static int acpi_power_resume(struct acpi_device *device);
static const struct acpi_device_id power_device_ids[] = {
{ACPI_POWER_HID, 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, power_device_ids);
static struct acpi_driver acpi_power_driver = {
.name = "power",
.class = ACPI_POWER_CLASS,
.ids = power_device_ids,
.ops = {
.add = acpi_power_add,
.remove = acpi_power_remove,
.resume = acpi_power_resume,
},
};
struct acpi_power_reference {
struct list_head node;
struct acpi_device *device;
};
struct acpi_power_resource {
struct acpi_device * device;
acpi_bus_id name;
u32 system_level;
u32 order;
struct mutex resource_lock;
struct list_head reference;
};
static struct list_head acpi_power_resource_list;
/* --------------------------------------------------------------------------
Power Resource Management
-------------------------------------------------------------------------- */
static int
acpi_power_get_context(acpi_handle handle,
struct acpi_power_resource **resource)
{
int result = 0;
struct acpi_device *device = NULL;
if (!resource)
return -ENODEV;
result = acpi_bus_get_device(handle, &device);
if (result) {
printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
return result;
}
*resource = acpi_driver_data(device);
if (!*resource)
return -ENODEV;
return 0;
}
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 acpi_handle_list *list, int *state)
{
int result = 0, state1;
u32 i = 0;
if (!list || !state)
return -EINVAL;
/* The state of the list is 'on' IFF all resources are 'on'. */
for (i = 0; i < list->count; i++) {
/*
* The state of the power resource can be obtained by
* using the ACPI handle. In such case it is unnecessary to
* get the Power resource first and then get its state again.
*/
result = acpi_power_get_state(list->handles[i], &state1);
if (result)
return result;
*state = state1;
if (*state != ACPI_POWER_RESOURCE_STATE_ON)
break;
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
*state ? "on" : "off"));
return result;
}
static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
{
int result = 0;
int found = 0;
acpi_status status = AE_OK;
struct acpi_power_resource *resource = NULL;
struct list_head *node, *next;
struct acpi_power_reference *ref;
result = acpi_power_get_context(handle, &resource);
if (result)
return result;
mutex_lock(&resource->resource_lock);
list_for_each_safe(node, next, &resource->reference) {
ref = container_of(node, struct acpi_power_reference, node);
if (dev->handle == ref->device->handle) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
dev->pnp.bus_id, resource->name));
found = 1;
break;
}
}
if (!found) {
ref = kmalloc(sizeof (struct acpi_power_reference),
irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
if (!ref) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
mutex_unlock(&resource->resource_lock);
return -ENOMEM;
}
list_add_tail(&ref->node, &resource->reference);
ref->device = dev;
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
dev->pnp.bus_id, resource->name));
}
mutex_unlock(&resource->resource_lock);
status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
if (ACPI_FAILURE(status))
return -ENODEV;
/* Update the power resource's _device_ power state */
resource->device->power.state = ACPI_STATE_D0;
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
resource->name));
return 0;
}
static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
{
int result = 0;
acpi_status status = AE_OK;
struct acpi_power_resource *resource = NULL;
struct list_head *node, *next;
struct acpi_power_reference *ref;
result = acpi_power_get_context(handle, &resource);
if (result)
return result;
mutex_lock(&resource->resource_lock);
list_for_each_safe(node, next, &resource->reference) {
ref = container_of(node, struct acpi_power_reference, node);
if (dev->handle == ref->device->handle) {
list_del(&ref->node);
kfree(ref);
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
dev->pnp.bus_id, resource->name));
break;
}
}
if (!list_empty(&resource->reference)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
resource->name));
mutex_unlock(&resource->resource_lock);
return 0;
}
mutex_unlock(&resource->resource_lock);
status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
if (ACPI_FAILURE(status))
return -ENODEV;
/* Update the power resource's _device_ power state */
resource->device->power.state = ACPI_STATE_D3;
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
resource->name));
return 0;
}
/**
* 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)
{
int i, err = 0;
if (!dev || !dev->wakeup.flags.valid)
return -EINVAL;
mutex_lock(&acpi_device_lock);
if (dev->wakeup.prepare_count++)
goto out;
/* Open power resource */
for (i = 0; i < dev->wakeup.resources.count; i++) {
int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
if (ret) {
printk(KERN_ERR PREFIX "Transition power state\n");
dev->wakeup.flags.valid = 0;
err = -ENODEV;
goto err_out;
}
}
/*
* Passing 3 as the third argument below means the device may be placed
* in arbitrary power state afterwards.
*/
err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
err_out:
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)
{
int i, 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;
/* Close power resource */
for (i = 0; i < dev->wakeup.resources.count; i++) {
int ret = acpi_power_off_device(
dev->wakeup.resources.handles[i], dev);
if (ret) {
printk(KERN_ERR PREFIX "Transition power state\n");
dev->wakeup.flags.valid = 0;
err = -ENODEV;
goto out;
}
}
out:
mutex_unlock(&acpi_device_lock);
return err;
}
/* --------------------------------------------------------------------------
Device Power Management
-------------------------------------------------------------------------- */
int acpi_power_get_inferred_state(struct acpi_device *device)
{
int result = 0;
struct acpi_handle_list *list = NULL;
int list_state = 0;
int i = 0;
if (!device)
return -EINVAL;
device->power.state = ACPI_STATE_UNKNOWN;
/*
* 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; i++) {
list = &device->power.states[i].resources;
if (list->count < 1)
continue;
result = acpi_power_get_list_state(list, &list_state);
if (result)
return result;
if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
device->power.state = i;
return 0;
}
}
device->power.state = ACPI_STATE_D3;
return 0;
}
int acpi_power_transition(struct acpi_device *device, int state)
{
int result = 0;
struct acpi_handle_list *cl = NULL; /* Current Resources */
struct acpi_handle_list *tl = NULL; /* Target Resources */
int i = 0;
if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
return -EINVAL;
if ((device->power.state < ACPI_STATE_D0) || (device->power.state > ACPI_STATE_D3))
return -ENODEV;
cl = &device->power.states[device->power.state].resources;
tl = &device->power.states[state].resources;
/* 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).
*/
for (i = 0; i < tl->count; i++) {
result = acpi_power_on(tl->handles[i], device);
if (result)
goto end;
}
if (device->power.state == state) {
goto end;
}
/*
* Then we dereference all power resources used in the current list.
*/
for (i = 0; i < cl->count; i++) {
result = acpi_power_off_device(cl->handles[i], device);
if (result)
goto end;
}
end:
if (result)
device->power.state = ACPI_STATE_UNKNOWN;
else {
/* We shouldn't change the state till all above operations succeed */
device->power.state = state;
}
return result;
}
/* --------------------------------------------------------------------------
Driver Interface
-------------------------------------------------------------------------- */
static int acpi_power_add(struct acpi_device *device)
{
int result = 0, state;
acpi_status status = AE_OK;
struct acpi_power_resource *resource = NULL;
union acpi_object acpi_object;
struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
if (!device)
return -EINVAL;
resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
if (!resource)
return -ENOMEM;
resource->device = device;
mutex_init(&resource->resource_lock);
INIT_LIST_HEAD(&resource->reference);
strcpy(resource->name, device->pnp.bus_id);
strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
device->driver_data = resource;
/* Evalute the object to get the system level and resource order. */
status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
if (ACPI_FAILURE(status)) {
result = -ENODEV;
goto end;
}
resource->system_level = acpi_object.power_resource.system_level;
resource->order = acpi_object.power_resource.resource_order;
result = acpi_power_get_state(device->handle, &state);
if (result)
goto end;
switch (state) {
case ACPI_POWER_RESOURCE_STATE_ON:
device->power.state = ACPI_STATE_D0;
break;
case ACPI_POWER_RESOURCE_STATE_OFF:
device->power.state = ACPI_STATE_D3;
break;
default:
device->power.state = ACPI_STATE_UNKNOWN;
break;
}
printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
acpi_device_bid(device), state ? "on" : "off");
end:
if (result)
kfree(resource);
return result;
}
static int acpi_power_remove(struct acpi_device *device, int type)
{
struct acpi_power_resource *resource = NULL;
struct list_head *node, *next;
if (!device || !acpi_driver_data(device))
return -EINVAL;
resource = acpi_driver_data(device);
mutex_lock(&resource->resource_lock);
list_for_each_safe(node, next, &resource->reference) {
struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
list_del(&ref->node);
kfree(ref);
}
mutex_unlock(&resource->resource_lock);
kfree(resource);
return 0;
}
static int acpi_power_resume(struct acpi_device *device)
{
int result = 0, state;
struct acpi_power_resource *resource = NULL;
struct acpi_power_reference *ref;
if (!device || !acpi_driver_data(device))
return -EINVAL;
resource = acpi_driver_data(device);
result = acpi_power_get_state(device->handle, &state);
if (result)
return result;
mutex_lock(&resource->resource_lock);
if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
!list_empty(&resource->reference)) {
ref = container_of(resource->reference.next, struct acpi_power_reference, node);
mutex_unlock(&resource->resource_lock);
result = acpi_power_on(device->handle, ref->device);
return result;
}
mutex_unlock(&resource->resource_lock);
return 0;
}
int __init acpi_power_init(void)
{
INIT_LIST_HEAD(&acpi_power_resource_list);
return acpi_bus_register_driver(&acpi_power_driver);
}