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/*
* 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 "pci.h"
/*
* _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;
}
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,
};
/* 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);
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