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>
19 #include <linux/pm_runtime.h>
22 static DEFINE_MUTEX(pci_acpi_pm_notify_mtx
);
25 * pci_acpi_wake_bus - Wake-up notification handler for root buses.
26 * @handle: ACPI handle of a device the notification is for.
27 * @event: Type of the signaled event.
28 * @context: PCI root bus to wake up devices on.
30 static void pci_acpi_wake_bus(acpi_handle handle
, u32 event
, void *context
)
32 struct pci_bus
*pci_bus
= context
;
34 if (event
== ACPI_NOTIFY_DEVICE_WAKE
&& pci_bus
)
35 pci_pme_wakeup_bus(pci_bus
);
39 * pci_acpi_wake_dev - Wake-up notification handler for PCI devices.
40 * @handle: ACPI handle of a device the notification is for.
41 * @event: Type of the signaled event.
42 * @context: PCI device object to wake up.
44 static void pci_acpi_wake_dev(acpi_handle handle
, u32 event
, void *context
)
46 struct pci_dev
*pci_dev
= context
;
48 if (event
!= ACPI_NOTIFY_DEVICE_WAKE
|| !pci_dev
)
51 if (!pci_dev
->pm_cap
|| !pci_dev
->pme_support
52 || pci_check_pme_status(pci_dev
)) {
53 if (pci_dev
->pme_poll
)
54 pci_dev
->pme_poll
= false;
56 pci_wakeup_event(pci_dev
);
57 pm_runtime_resume(&pci_dev
->dev
);
60 if (pci_dev
->subordinate
)
61 pci_pme_wakeup_bus(pci_dev
->subordinate
);
65 * add_pm_notifier - Register PM notifier for given ACPI device.
66 * @dev: ACPI device to add the notifier for.
67 * @context: PCI device or bus to check for PME status if an event is signaled.
69 * NOTE: @dev need not be a run-wake or wake-up device to be a valid source of
70 * PM wake-up events. For example, wake-up events may be generated for bridges
71 * if one of the devices below the bridge is signaling PME, even if the bridge
72 * itself doesn't have a wake-up GPE associated with it.
74 static acpi_status
add_pm_notifier(struct acpi_device
*dev
,
75 acpi_notify_handler handler
,
78 acpi_status status
= AE_ALREADY_EXISTS
;
80 mutex_lock(&pci_acpi_pm_notify_mtx
);
82 if (dev
->wakeup
.flags
.notifier_present
)
85 status
= acpi_install_notify_handler(dev
->handle
,
88 if (ACPI_FAILURE(status
))
91 dev
->wakeup
.flags
.notifier_present
= true;
94 mutex_unlock(&pci_acpi_pm_notify_mtx
);
99 * remove_pm_notifier - Unregister PM notifier from given ACPI device.
100 * @dev: ACPI device to remove the notifier from.
102 static acpi_status
remove_pm_notifier(struct acpi_device
*dev
,
103 acpi_notify_handler handler
)
105 acpi_status status
= AE_BAD_PARAMETER
;
107 mutex_lock(&pci_acpi_pm_notify_mtx
);
109 if (!dev
->wakeup
.flags
.notifier_present
)
112 status
= acpi_remove_notify_handler(dev
->handle
,
115 if (ACPI_FAILURE(status
))
118 dev
->wakeup
.flags
.notifier_present
= false;
121 mutex_unlock(&pci_acpi_pm_notify_mtx
);
126 * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
127 * @dev: ACPI device to add the notifier for.
128 * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
130 acpi_status
pci_acpi_add_bus_pm_notifier(struct acpi_device
*dev
,
131 struct pci_bus
*pci_bus
)
133 return add_pm_notifier(dev
, pci_acpi_wake_bus
, pci_bus
);
137 * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
138 * @dev: ACPI device to remove the notifier from.
140 acpi_status
pci_acpi_remove_bus_pm_notifier(struct acpi_device
*dev
)
142 return remove_pm_notifier(dev
, pci_acpi_wake_bus
);
146 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
147 * @dev: ACPI device to add the notifier for.
148 * @pci_dev: PCI device to check for the PME status if an event is signaled.
150 acpi_status
pci_acpi_add_pm_notifier(struct acpi_device
*dev
,
151 struct pci_dev
*pci_dev
)
153 return add_pm_notifier(dev
, pci_acpi_wake_dev
, pci_dev
);
157 * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
158 * @dev: ACPI device to remove the notifier from.
160 acpi_status
pci_acpi_remove_pm_notifier(struct acpi_device
*dev
)
162 return remove_pm_notifier(dev
, pci_acpi_wake_dev
);
166 * _SxD returns the D-state with the highest power
167 * (lowest D-state number) supported in the S-state "x".
169 * If the devices does not have a _PRW
170 * (Power Resources for Wake) supporting system wakeup from "x"
171 * then the OS is free to choose a lower power (higher number
172 * D-state) than the return value from _SxD.
174 * But if _PRW is enabled at S-state "x", the OS
175 * must not choose a power lower than _SxD --
176 * unless the device has an _SxW method specifying
177 * the lowest power (highest D-state number) the device
178 * may enter while still able to wake the system.
180 * ie. depending on global OS policy:
182 * if (_PRW at S-state x)
183 * choose from highest power _SxD to lowest power _SxW
184 * else // no _PRW at S-state x
185 * choose highest power _SxD or any lower power
188 static pci_power_t
acpi_pci_choose_state(struct pci_dev
*pdev
)
192 acpi_state
= acpi_pm_device_sleep_state(&pdev
->dev
, NULL
);
194 return PCI_POWER_ERROR
;
196 switch (acpi_state
) {
205 case ACPI_STATE_D3_COLD
:
208 return PCI_POWER_ERROR
;
211 static bool acpi_pci_power_manageable(struct pci_dev
*dev
)
213 acpi_handle handle
= DEVICE_ACPI_HANDLE(&dev
->dev
);
215 return handle
? acpi_bus_power_manageable(handle
) : false;
218 static int acpi_pci_set_power_state(struct pci_dev
*dev
, pci_power_t state
)
220 acpi_handle handle
= DEVICE_ACPI_HANDLE(&dev
->dev
);
222 static const u8 state_conv
[] = {
223 [PCI_D0
] = ACPI_STATE_D0
,
224 [PCI_D1
] = ACPI_STATE_D1
,
225 [PCI_D2
] = ACPI_STATE_D2
,
226 [PCI_D3hot
] = ACPI_STATE_D3
,
227 [PCI_D3cold
] = ACPI_STATE_D3
231 /* If the ACPI device has _EJ0, ignore the device */
232 if (!handle
|| ACPI_SUCCESS(acpi_get_handle(handle
, "_EJ0", &tmp
)))
241 error
= acpi_bus_set_power(handle
, state_conv
[state
]);
245 dev_printk(KERN_INFO
, &dev
->dev
,
246 "power state changed by ACPI to D%d\n", state
);
251 static bool acpi_pci_can_wakeup(struct pci_dev
*dev
)
253 acpi_handle handle
= DEVICE_ACPI_HANDLE(&dev
->dev
);
255 return handle
? acpi_bus_can_wakeup(handle
) : false;
258 static void acpi_pci_propagate_wakeup_enable(struct pci_bus
*bus
, bool enable
)
260 while (bus
->parent
) {
261 if (!acpi_pm_device_sleep_wake(&bus
->self
->dev
, enable
))
266 /* We have reached the root bus. */
268 acpi_pm_device_sleep_wake(bus
->bridge
, enable
);
271 static int acpi_pci_sleep_wake(struct pci_dev
*dev
, bool enable
)
273 if (acpi_pci_can_wakeup(dev
))
274 return acpi_pm_device_sleep_wake(&dev
->dev
, enable
);
276 acpi_pci_propagate_wakeup_enable(dev
->bus
, enable
);
280 static void acpi_pci_propagate_run_wake(struct pci_bus
*bus
, bool enable
)
282 while (bus
->parent
) {
283 struct pci_dev
*bridge
= bus
->self
;
285 if (bridge
->pme_interrupt
)
287 if (!acpi_pm_device_run_wake(&bridge
->dev
, enable
))
292 /* We have reached the root bus. */
294 acpi_pm_device_run_wake(bus
->bridge
, enable
);
297 static int acpi_pci_run_wake(struct pci_dev
*dev
, bool enable
)
299 if (dev
->pme_interrupt
)
302 if (!acpi_pm_device_run_wake(&dev
->dev
, enable
))
305 acpi_pci_propagate_run_wake(dev
->bus
, enable
);
309 static struct pci_platform_pm_ops acpi_pci_platform_pm
= {
310 .is_manageable
= acpi_pci_power_manageable
,
311 .set_state
= acpi_pci_set_power_state
,
312 .choose_state
= acpi_pci_choose_state
,
313 .can_wakeup
= acpi_pci_can_wakeup
,
314 .sleep_wake
= acpi_pci_sleep_wake
,
315 .run_wake
= acpi_pci_run_wake
,
319 static int acpi_pci_find_device(struct device
*dev
, acpi_handle
*handle
)
321 struct pci_dev
* pci_dev
;
324 pci_dev
= to_pci_dev(dev
);
325 /* Please ref to ACPI spec for the syntax of _ADR */
326 addr
= (PCI_SLOT(pci_dev
->devfn
) << 16) | PCI_FUNC(pci_dev
->devfn
);
327 *handle
= acpi_get_child(DEVICE_ACPI_HANDLE(dev
->parent
), addr
);
333 static int acpi_pci_find_root_bridge(struct device
*dev
, acpi_handle
*handle
)
336 unsigned int seg
, bus
;
339 * The string should be the same as root bridge's name
340 * Please look at 'pci_scan_bus_parented'
342 num
= sscanf(dev_name(dev
), "pci%04x:%02x", &seg
, &bus
);
345 *handle
= acpi_get_pci_rootbridge_handle(seg
, bus
);
351 static struct acpi_bus_type acpi_pci_bus
= {
352 .bus
= &pci_bus_type
,
353 .find_device
= acpi_pci_find_device
,
354 .find_bridge
= acpi_pci_find_root_bridge
,
357 static int __init
acpi_pci_init(void)
361 if (acpi_gbl_FADT
.boot_flags
& ACPI_FADT_NO_MSI
) {
362 printk(KERN_INFO
"ACPI FADT declares the system doesn't support MSI, so disable it\n");
366 if (acpi_gbl_FADT
.boot_flags
& ACPI_FADT_NO_ASPM
) {
367 printk(KERN_INFO
"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
371 ret
= register_acpi_bus_type(&acpi_pci_bus
);
374 pci_set_platform_pm(&acpi_pci_platform_pm
);
377 arch_initcall(acpi_pci_init
);