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acrn-kernel/drivers/acpi/power.c

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/*
* 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/proc_fs.h>
#include <linux/seq_file.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#define _COMPONENT ACPI_POWER_COMPONENT
ACPI_MODULE_NAME("acpi_power")
#define ACPI_POWER_COMPONENT 0x00800000
#define ACPI_POWER_CLASS "power_resource"
#define ACPI_POWER_DRIVER_NAME "ACPI Power Resource Driver"
#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
static int acpi_power_add(struct acpi_device *device);
static int acpi_power_remove(struct acpi_device *device, int type);
static int acpi_power_open_fs(struct inode *inode, struct file *file);
static struct acpi_driver acpi_power_driver = {
.name = ACPI_POWER_DRIVER_NAME,
.class = ACPI_POWER_CLASS,
.ids = ACPI_POWER_HID,
.ops = {
.add = acpi_power_add,
.remove = acpi_power_remove,
},
};
struct acpi_power_resource {
struct acpi_device * device;
acpi_bus_id name;
u32 system_level;
u32 order;
int state;
int references;
};
static struct list_head acpi_power_resource_list;
static const struct file_operations acpi_power_fops = {
.open = acpi_power_open_fs,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
/* --------------------------------------------------------------------------
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 = (struct acpi_power_resource *)acpi_driver_data(device);
if (!resource)
return -ENODEV;
return 0;
}
static int acpi_power_get_state(struct acpi_power_resource *resource)
{
acpi_status status = AE_OK;
unsigned long sta = 0;
if (!resource)
return -EINVAL;
status = acpi_evaluate_integer(resource->device->handle, "_STA", NULL, &sta);
if (ACPI_FAILURE(status))
return -ENODEV;
if (sta & 0x01)
resource->state = ACPI_POWER_RESOURCE_STATE_ON;
else
resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
resource->name, resource->state ? "on" : "off"));
return 0;
}
static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
{
int result = 0;
struct acpi_power_resource *resource = NULL;
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++) {
result = acpi_power_get_context(list->handles[i], &resource);
if (result)
return result;
result = acpi_power_get_state(resource);
if (result)
return result;
*state = resource->state;
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)
{
int result = 0;
acpi_status status = AE_OK;
struct acpi_device *device = NULL;
struct acpi_power_resource *resource = NULL;
result = acpi_power_get_context(handle, &resource);
if (result)
return result;
resource->references++;
if ((resource->references > 1)
|| (resource->state == ACPI_POWER_RESOURCE_STATE_ON)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already on\n",
resource->name));
return 0;
}
status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
if (ACPI_FAILURE(status))
return -ENODEV;
result = acpi_power_get_state(resource);
if (result)
return result;
if (resource->state != ACPI_POWER_RESOURCE_STATE_ON)
return -ENOEXEC;
/* Update the power resource's _device_ power state */
device = resource->device;
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)
{
int result = 0;
acpi_status status = AE_OK;
struct acpi_device *device = NULL;
struct acpi_power_resource *resource = NULL;
result = acpi_power_get_context(handle, &resource);
if (result)
return result;
if (resource->references)
resource->references--;
if (resource->references) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Resource [%s] is still in use, dereferencing\n",
device->pnp.bus_id));
return 0;
}
if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n",
device->pnp.bus_id));
return 0;
}
status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
if (ACPI_FAILURE(status))
return -ENODEV;
result = acpi_power_get_state(resource);
if (result)
return result;
if (resource->state != ACPI_POWER_RESOURCE_STATE_OFF)
return -ENOEXEC;
/* Update the power resource's _device_ power state */
device = resource->device;
device->power.state = ACPI_STATE_D3;
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
resource->name));
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. Enable _PSW (power state wake) for the device if present
*/
int acpi_enable_wakeup_device_power(struct acpi_device *dev)
{
union acpi_object arg = { ACPI_TYPE_INTEGER };
struct acpi_object_list arg_list = { 1, &arg };
acpi_status status = AE_OK;
int i;
int ret = 0;
if (!dev || !dev->wakeup.flags.valid)
return -1;
arg.integer.value = 1;
/* Open power resource */
for (i = 0; i < dev->wakeup.resources.count; i++) {
ret = acpi_power_on(dev->wakeup.resources.handles[i]);
if (ret) {
printk(KERN_ERR PREFIX "Transition power state\n");
dev->wakeup.flags.valid = 0;
return -1;
}
}
/* Execute PSW */
status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
printk(KERN_ERR PREFIX "Evaluate _PSW\n");
dev->wakeup.flags.valid = 0;
ret = -1;
}
return ret;
}
/*
* Shutdown a wakeup device, counterpart of above method
* 1. Disable _PSW (power state wake)
* 2. Shutdown down the power resources
*/
int acpi_disable_wakeup_device_power(struct acpi_device *dev)
{
union acpi_object arg = { ACPI_TYPE_INTEGER };
struct acpi_object_list arg_list = { 1, &arg };
acpi_status status = AE_OK;
int i;
int ret = 0;
if (!dev || !dev->wakeup.flags.valid)
return -1;
arg.integer.value = 0;
/* Execute PSW */
status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
printk(KERN_ERR PREFIX "Evaluate _PSW\n");
dev->wakeup.flags.valid = 0;
return -1;
}
/* Close power resource */
for (i = 0; i < dev->wakeup.resources.count; i++) {
ret = acpi_power_off_device(dev->wakeup.resources.handles[i]);
if (ret) {
printk(KERN_ERR PREFIX "Transition power state\n");
dev->wakeup.flags.valid = 0;
return -1;
}
}
return ret;
}
/* --------------------------------------------------------------------------
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;
device->power.state = ACPI_STATE_UNKNOWN;
if (!cl->count && !tl->count) {
result = -ENODEV;
goto end;
}
/* 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]);
if (result)
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]);
if (result)
goto end;
}
/* We shouldn't change the state till all above operations succeed */
device->power.state = state;
end:
if (result)
printk(KERN_WARNING PREFIX "Transitioning device [%s] to D%d\n",
device->pnp.bus_id, state);
return result;
}
/* --------------------------------------------------------------------------
FS Interface (/proc)
-------------------------------------------------------------------------- */
static struct proc_dir_entry *acpi_power_dir;
static int acpi_power_seq_show(struct seq_file *seq, void *offset)
{
struct acpi_power_resource *resource = NULL;
resource = (struct acpi_power_resource *)seq->private;
if (!resource)
goto end;
seq_puts(seq, "state: ");
switch (resource->state) {
case ACPI_POWER_RESOURCE_STATE_ON:
seq_puts(seq, "on\n");
break;
case ACPI_POWER_RESOURCE_STATE_OFF:
seq_puts(seq, "off\n");
break;
default:
seq_puts(seq, "unknown\n");
break;
}
seq_printf(seq, "system level: S%d\n"
"order: %d\n"
"reference count: %d\n",
resource->system_level,
resource->order, resource->references);
end:
return 0;
}
static int acpi_power_open_fs(struct inode *inode, struct file *file)
{
return single_open(file, acpi_power_seq_show, PDE(inode)->data);
}
static int acpi_power_add_fs(struct acpi_device *device)
{
struct proc_dir_entry *entry = NULL;
if (!device)
return -EINVAL;
if (!acpi_device_dir(device)) {
acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
acpi_power_dir);
if (!acpi_device_dir(device))
return -ENODEV;
}
/* 'status' [R] */
entry = create_proc_entry(ACPI_POWER_FILE_STATUS,
S_IRUGO, acpi_device_dir(device));
if (!entry)
return -EIO;
else {
entry->proc_fops = &acpi_power_fops;
entry->data = acpi_driver_data(device);
}
return 0;
}
static int acpi_power_remove_fs(struct acpi_device *device)
{
if (acpi_device_dir(device)) {
remove_proc_entry(ACPI_POWER_FILE_STATUS,
acpi_device_dir(device));
remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
acpi_device_dir(device) = NULL;
}
return 0;
}
/* --------------------------------------------------------------------------
Driver Interface
-------------------------------------------------------------------------- */
static int acpi_power_add(struct acpi_device *device)
{
int result = 0;
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 = kmalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
if (!resource)
return -ENOMEM;
memset(resource, 0, sizeof(struct acpi_power_resource));
resource->device = device;
strcpy(resource->name, device->pnp.bus_id);
strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
acpi_driver_data(device) = 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(resource);
if (result)
goto end;
switch (resource->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;
}
result = acpi_power_add_fs(device);
if (result)
goto end;
printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
acpi_device_bid(device), resource->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;
if (!device || !acpi_driver_data(device))
return -EINVAL;
resource = (struct acpi_power_resource *)acpi_driver_data(device);
acpi_power_remove_fs(device);
kfree(resource);
return 0;
}
static int __init acpi_power_init(void)
{
int result = 0;
if (acpi_disabled)
return 0;
INIT_LIST_HEAD(&acpi_power_resource_list);
acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
if (!acpi_power_dir)
return -ENODEV;
result = acpi_bus_register_driver(&acpi_power_driver);
if (result < 0) {
remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
return -ENODEV;
}
return 0;
}
subsys_initcall(acpi_power_init);
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