/* * 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 int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable) { int error = acpi_pm_device_sleep_wake(&dev->dev, enable); if (!error) dev_printk(KERN_INFO, &dev->dev, "wake-up capability %s by ACPI\n", enable ? "enabled" : "disabled"); return error; } 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; acpi_integer 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);