/*
* File: pci-acpi.c
* Purpose: Provide PCI support in ACPI
*
* Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
* Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
* Copyright (C) 2004 Intel Corp.
*/
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/pci-aspm.h>
#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>
#include <linux/pci-acpi.h>
#include <linux/pm_runtime.h>
#include "pci.h"
static DEFINE_MUTEX(pci_acpi_pm_notify_mtx);
/**
* pci_acpi_wake_bus - Wake-up notification handler for root buses.
* @handle: ACPI handle of a device the notification is for.
* @event: Type of the signaled event.
* @context: PCI root bus to wake up devices on.
*/
static void pci_acpi_wake_bus(acpi_handle handle, u32 event, void *context)
{
struct pci_bus *pci_bus = context;
if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_bus)
pci_pme_wakeup_bus(pci_bus);
}
/**
* pci_acpi_wake_dev - Wake-up notification handler for PCI devices.
* @handle: ACPI handle of a device the notification is for.
* @event: Type of the signaled event.
* @context: PCI device object to wake up.
*/
static void pci_acpi_wake_dev(acpi_handle handle, u32 event, void *context)
{
struct pci_dev *pci_dev = context;
if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_dev) {
pci_check_pme_status(pci_dev);
pm_runtime_resume(&pci_dev->dev);
pci_wakeup_event(pci_dev);
if (pci_dev->subordinate)
pci_pme_wakeup_bus(pci_dev->subordinate);
}
}
/**
* add_pm_notifier - Register PM notifier for given ACPI device.
* @dev: ACPI device to add the notifier for.
* @context: PCI device or bus to check for PME status if an event is signaled.
*
* NOTE: @dev need not be a run-wake or wake-up device to be a valid source of
* PM wake-up events. For example, wake-up events may be generated for bridges
* if one of the devices below the bridge is signaling PME, even if the bridge
* itself doesn't have a wake-up GPE associated with it.
*/
static acpi_status add_pm_notifier(struct acpi_device *dev,
acpi_notify_handler handler,
void *context)
{
acpi_status status = AE_ALREADY_EXISTS;
mutex_lock(&pci_acpi_pm_notify_mtx);
if (dev->wakeup.flags.notifier_present)
goto out;
status = acpi_install_notify_handler(dev->handle,
ACPI_SYSTEM_NOTIFY,
handler, context);
if (ACPI_FAILURE(status))
goto out;
dev->wakeup.flags.notifier_present = true;
out:
mutex_unlock(&pci_acpi_pm_notify_mtx);
return status;
}
/**
* remove_pm_notifier - Unregister PM notifier from given ACPI device.
* @dev: ACPI device to remove the notifier from.
*/
static acpi_status remove_pm_notifier(struct acpi_device *dev,
acpi_notify_handler handler)
{
acpi_status status = AE_BAD_PARAMETER;
mutex_lock(&pci_acpi_pm_notify_mtx);
if (!dev->wakeup.flags.notifier_present)
goto out;
status = acpi_remove_notify_handler(dev->handle,
ACPI_SYSTEM_NOTIFY,
handler);
if (ACPI_FAILURE(status))
goto out;
dev->wakeup.flags.notifier_present = false;
out:
mutex_unlock(&pci_acpi_pm_notify_mtx);
return status;
}
/**
* pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
* @dev: ACPI device to add the notifier for.
* @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
*/
acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
struct pci_bus *pci_bus)
{
return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
}
/**
* pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
* @dev: ACPI device to remove the notifier from.
*/
acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
{
return remove_pm_notifier(dev, pci_acpi_wake_bus);
}
/**
* pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
* @dev: ACPI device to add the notifier for.
* @pci_dev: PCI device to check for the PME status if an event is signaled.
*/
acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
struct pci_dev *pci_dev)
{
return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
}
/**
* pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
* @dev: ACPI device to remove the notifier from.
*/
acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
{
return remove_pm_notifier(dev, pci_acpi_wake_dev);
}
/*
* _SxD returns the D-state with the highest power
* (lowest D-state number) supported in the S-state "x".
*
* If the devices does not have a _PRW
* (Power Resources for Wake) supporting system wakeup from "x"
* then the OS is free to choose a lower power (higher number