3 * Purpose: Provide PCI support in ACPI
5 * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
6 * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
7 * Copyright (C) 2004 Intel Corp.
10 #include <linux/delay.h>
11 #include <linux/init.h>
12 #include <linux/pci.h>
13 #include <linux/module.h>
14 #include <linux/pci-aspm.h>
15 #include <acpi/acpi.h>
16 #include <acpi/acpi_bus.h>
18 #include <linux/pci-acpi.h>
22 * _SxD returns the D-state with the highest power
23 * (lowest D-state number) supported in the S-state "x".
25 * If the devices does not have a _PRW
26 * (Power Resources for Wake) supporting system wakeup from "x"
27 * then the OS is free to choose a lower power (higher number
28 * D-state) than the return value from _SxD.
30 * But if _PRW is enabled at S-state "x", the OS
31 * must not choose a power lower than _SxD --
32 * unless the device has an _SxW method specifying
33 * the lowest power (highest D-state number) the device
34 * may enter while still able to wake the system.
36 * ie. depending on global OS policy:
38 * if (_PRW at S-state x)
39 * choose from highest power _SxD to lowest power _SxW
40 * else // no _PRW at S-state x
41 * choose highest power _SxD or any lower power
44 static pci_power_t
acpi_pci_choose_state(struct pci_dev
*pdev
)
48 acpi_state
= acpi_pm_device_sleep_state(&pdev
->dev
, NULL
);
50 return PCI_POWER_ERROR
;
62 return PCI_POWER_ERROR
;
65 static bool acpi_pci_power_manageable(struct pci_dev
*dev
)
67 acpi_handle handle
= DEVICE_ACPI_HANDLE(&dev
->dev
);
69 return handle
? acpi_bus_power_manageable(handle
) : false;
72 static int acpi_pci_set_power_state(struct pci_dev
*dev
, pci_power_t state
)
74 acpi_handle handle
= DEVICE_ACPI_HANDLE(&dev
->dev
);
76 static const u8 state_conv
[] = {
77 [PCI_D0
] = ACPI_STATE_D0
,
78 [PCI_D1
] = ACPI_STATE_D1
,
79 [PCI_D2
] = ACPI_STATE_D2
,
80 [PCI_D3hot
] = ACPI_STATE_D3
,
81 [PCI_D3cold
] = ACPI_STATE_D3
85 /* If the ACPI device has _EJ0, ignore the device */
86 if (!handle
|| ACPI_SUCCESS(acpi_get_handle(handle
, "_EJ0", &tmp
)))
95 error
= acpi_bus_set_power(handle
, state_conv
[state
]);
99 dev_printk(KERN_INFO
, &dev
->dev
,
100 "power state changed by ACPI to D%d\n", state
);
105 static bool acpi_pci_can_wakeup(struct pci_dev
*dev
)
107 acpi_handle handle
= DEVICE_ACPI_HANDLE(&dev
->dev
);
109 return handle
? acpi_bus_can_wakeup(handle
) : false;
112 static int acpi_pci_sleep_wake(struct pci_dev
*dev
, bool enable
)
114 int error
= acpi_pm_device_sleep_wake(&dev
->dev
, enable
);
117 dev_printk(KERN_INFO
, &dev
->dev
,
118 "wake-up capability %s by ACPI\n",
119 enable
? "enabled" : "disabled");
123 static struct pci_platform_pm_ops acpi_pci_platform_pm
= {
124 .is_manageable
= acpi_pci_power_manageable
,
125 .set_state
= acpi_pci_set_power_state
,
126 .choose_state
= acpi_pci_choose_state
,
127 .can_wakeup
= acpi_pci_can_wakeup
,
128 .sleep_wake
= acpi_pci_sleep_wake
,
132 static int acpi_pci_find_device(struct device
*dev
, acpi_handle
*handle
)
134 struct pci_dev
* pci_dev
;
137 pci_dev
= to_pci_dev(dev
);
138 /* Please ref to ACPI spec for the syntax of _ADR */
139 addr
= (PCI_SLOT(pci_dev
->devfn
) << 16) | PCI_FUNC(pci_dev
->devfn
);
140 *handle
= acpi_get_child(DEVICE_ACPI_HANDLE(dev
->parent
), addr
);
146 static int acpi_pci_find_root_bridge(struct device
*dev
, acpi_handle
*handle
)
149 unsigned int seg
, bus
;
152 * The string should be the same as root bridge's name
153 * Please look at 'pci_scan_bus_parented'
155 num
= sscanf(dev_name(dev
), "pci%04x:%02x", &seg
, &bus
);
158 *handle
= acpi_get_pci_rootbridge_handle(seg
, bus
);
164 static struct acpi_bus_type acpi_pci_bus
= {
165 .bus
= &pci_bus_type
,
166 .find_device
= acpi_pci_find_device
,
167 .find_bridge
= acpi_pci_find_root_bridge
,
170 static int __init
acpi_pci_init(void)
174 if (acpi_gbl_FADT
.boot_flags
& BAF_MSI_NOT_SUPPORTED
) {
175 printk(KERN_INFO
"ACPI FADT declares the system doesn't support MSI, so disable it\n");
179 if (acpi_gbl_FADT
.boot_flags
& BAF_PCIE_ASPM_CONTROL
) {
180 printk(KERN_INFO
"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
184 ret
= register_acpi_bus_type(&acpi_pci_bus
);
187 pci_set_platform_pm(&acpi_pci_platform_pm
);
190 arch_initcall(acpi_pci_init
);