/*
* 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
* D-state) than the return value from _SxD.
*
* But if _PRW is enabled at S-state "x", the OS
* must not choose a power lower than _SxD --
* unless the device has an _SxW method specifying
* the lowest power (highest D-state number) the device
* may enter while still able to wake the system.
*
* ie. depending on global OS policy:
*
* if (_PRW at S-state x)
* choose from highest power _SxD to lowest power _SxW
* else // no _PRW at S-state x
* choose highest power _SxD or any lower power
*/
static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
{
int acpi_state;
acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL);
if (acpi_state < 0)
return PCI_POWER_ERROR;
switch (acpi_state) {
case ACPI_STATE_D0:
return PCI_D0;
case ACPI_STATE_D1:
return PCI_D1;
case ACPI_STATE_D2:
return PCI_D2;
case ACPI_STATE_D3:
return PCI_D3hot;
}
return PCI_POWER_ERROR;
}
static bool acpi_pci_power_manageable(struct pci_dev *dev)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
return handle ? acpi_bus_power_manageable(handle) : false;
}
static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
acpi_handle tmp;
static const u8 state_conv[] = {
[PCI_D0] = ACPI_STATE_D0,
[PCI_D1] = ACPI_STATE_D1,
[PCI_D2] = ACPI_STATE_D2,
[PCI_D3hot] = ACPI_STATE_D3,
[PCI_D3cold] = ACPI_STATE_D3
};
int error = -EINVAL;
/* If the ACPI device has _EJ0, ignore the device */
if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
return -ENODEV;
switch (state) {
case PCI_D0:
case PCI_D1:
case PCI_D2:
case PCI_D3hot:
case PCI_D3cold:
error = acpi_bus_set_power(handle, state_conv[state]);
}
if (!error)
dev_printk(KERN_INFO, &dev->dev,
"power state changed by ACPI to D%d\n", state);
return error;
}
static bool acpi_pci_can_wakeup(struct pci_dev *dev)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
return handle ? acpi_bus_can_wakeup(handle) : false;
}
static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
{
while (bus->parent) {
if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
return;
bus = bus->parent;
}
/* We have reached the root bus. */
if (bus->bridge)
acpi_pm_device_sleep_wake(bus->bridge, enable);
}
static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
{
if (acpi_pci_can_wakeup(dev))
return acpi_pm_device_sleep_wake(&dev->dev, enable);
acpi_pci_propagate_wakeup_enable(dev->bus, enable);
return 0;
}
/**
* acpi_dev_run_wake - Enable/disable wake-up for given device.
* @phys_dev: Device to enable/disable the platform to wake-up the system for.
* @enable: Whether enable or disable the wake-up functionality.
*
* Find the ACPI device object corresponding to @pci_dev and try to
* enable/disable the GPE associated with it.
*/
static int acpi_dev_run_wake(struct device *phys_dev, bool enable)
{
struct acpi_device *dev;
acpi_handle handle;
int error = -ENODEV;
if (!device_run_wake(phys_dev))
return -EINVAL;
handle = DEVICE_ACPI_HANDLE(phys_dev);
if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) {
dev_dbg(phys_dev, "ACPI handle has no context in %s!\n",
__func__);
return -ENODEV;
}
if (enable) {
if (!dev->wakeup.run_wake_count++) {
acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
acpi_enable_gpe(dev->wakeup.gpe_device,
dev->wakeup.gpe_number);
}
} else if (dev->wakeup.run_wake_count > 0) {
if (!--dev->wakeup.run_wake_count) {
acpi_disable_gpe(dev->wakeup.gpe_device,
dev->wakeup.gpe_number);
acpi_disable_wakeup_device_power(dev);
}
} else {
error = -EALREADY;
}
return error;
}
static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
{
while (bus->parent) {
struct pci_dev *bridge = bus->self;
if (bridge->pme_interrupt)
return;
if (!acpi_dev_run_wake(&bridge->dev, enable))
return;
bus = bus->parent;
}
/* We have reached the root bus. */
if (bus->bridge)
acpi_dev_run_wake(bus->bridge, enable);
}
static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
{
if (dev->pme_interrupt)
return 0;
if (!acpi_dev_run_wake(&dev->dev, enable))
return 0;
acpi_pci_propagate_run_wake(dev->bus, enable);
return 0;
}
static struct pci_platform_pm_ops acpi_pci_platform_pm = {
.is_manageable = acpi_pci_power_manageable,
.set_state = acpi_pci_set_power_state,
.choose_state = acpi_pci_choose_state,
.can_wakeup = acpi_pci_can_wakeup,
.sleep_wake = acpi_pci_sleep_wake,
.run_wake = acpi_pci_run_wake,
};
/* ACPI bus type */
static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
{
struct pci_dev * pci_dev;
u64 addr;
pci_dev = to_pci_dev(dev);
/* Please ref to ACPI spec for the syntax of _ADR */
addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
*handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
if (!*handle)
return -ENODEV;
return 0;
}
static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
{
int num;
unsigned int seg, bus;
/*
* The string should be the same as root bridge's name
* Please look at 'pci_scan_bus_parented'
*/
num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
if (num != 2)
return -ENODEV;
*handle = acpi_get_pci_rootbridge_handle(seg, bus);
if (!*handle)
return -ENODEV;
return 0;
}
static struct acpi_bus_type acpi_pci_bus = {
.bus = &pci_bus_type,
.find_device = acpi_pci_find_device,
.find_bridge = acpi_pci_find_root_bridge,
};
static int __init acpi_pci_init(void)
{
int ret;
if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
pci_no_msi();
}
if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
pcie_no_aspm();
}
ret = register_acpi_bus_type(&acpi_pci_bus);
if (ret)
return 0;
pci_set_platform_pm(&acpi_pci_platform_pm);
return 0;
}
arch_initcall(acpi_pci_init);
