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) {
49
if (pci_dev->pme_poll)
50
pci_dev->pme_poll = false;
52
pci_wakeup_event(pci_dev);
53
pci_check_pme_status(pci_dev);
54
pm_runtime_resume(&pci_dev->dev);
55
if (pci_dev->subordinate)
56
pci_pme_wakeup_bus(pci_dev->subordinate);
61
* add_pm_notifier - Register PM notifier for given ACPI device.
62
* @dev: ACPI device to add the notifier for.
63
* @context: PCI device or bus to check for PME status if an event is signaled.
65
* NOTE: @dev need not be a run-wake or wake-up device to be a valid source of
66
* PM wake-up events. For example, wake-up events may be generated for bridges
67
* if one of the devices below the bridge is signaling PME, even if the bridge
68
* itself doesn't have a wake-up GPE associated with it.
70
static acpi_status add_pm_notifier(struct acpi_device *dev,
71
acpi_notify_handler handler,
74
acpi_status status = AE_ALREADY_EXISTS;
76
mutex_lock(&pci_acpi_pm_notify_mtx);
78
if (dev->wakeup.flags.notifier_present)
81
status = acpi_install_notify_handler(dev->handle,
84
if (ACPI_FAILURE(status))
87
dev->wakeup.flags.notifier_present = true;
90
mutex_unlock(&pci_acpi_pm_notify_mtx);
95
* remove_pm_notifier - Unregister PM notifier from given ACPI device.
96
* @dev: ACPI device to remove the notifier from.
98
static acpi_status remove_pm_notifier(struct acpi_device *dev,
99
acpi_notify_handler handler)
101
acpi_status status = AE_BAD_PARAMETER;
103
mutex_lock(&pci_acpi_pm_notify_mtx);
105
if (!dev->wakeup.flags.notifier_present)
108
status = acpi_remove_notify_handler(dev->handle,
111
if (ACPI_FAILURE(status))
114
dev->wakeup.flags.notifier_present = false;
117
mutex_unlock(&pci_acpi_pm_notify_mtx);
122
* pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
123
* @dev: ACPI device to add the notifier for.
124
* @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
126
acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
127
struct pci_bus *pci_bus)
129
return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
133
* pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
134
* @dev: ACPI device to remove the notifier from.
136
acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
138
return remove_pm_notifier(dev, pci_acpi_wake_bus);
142
* pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
143
* @dev: ACPI device to add the notifier for.
144
* @pci_dev: PCI device to check for the PME status if an event is signaled.
146
acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
147
struct pci_dev *pci_dev)
149
return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
153
* pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
154
* @dev: ACPI device to remove the notifier from.
156
acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
158
return remove_pm_notifier(dev, pci_acpi_wake_dev);
162
* _SxD returns the D-state with the highest power
163
* (lowest D-state number) supported in the S-state "x".
165
* If the devices does not have a _PRW
166
* (Power Resources for Wake) supporting system wakeup from "x"
167
* then the OS is free to choose a lower power (higher number
168
* D-state) than the return value from _SxD.
170
* But if _PRW is enabled at S-state "x", the OS
171
* must not choose a power lower than _SxD --
172
* unless the device has an _SxW method specifying
173
* the lowest power (highest D-state number) the device
174
* may enter while still able to wake the system.
176
* ie. depending on global OS policy:
178
* if (_PRW at S-state x)
179
* choose from highest power _SxD to lowest power _SxW
180
* else // no _PRW at S-state x
181
* choose highest power _SxD or any lower power
184
static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
188
acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL);
190
return PCI_POWER_ERROR;
192
switch (acpi_state) {
201
case ACPI_STATE_D3_COLD:
204
return PCI_POWER_ERROR;
207
static bool acpi_pci_power_manageable(struct pci_dev *dev)
209
acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
211
return handle ? acpi_bus_power_manageable(handle) : false;
214
static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
216
acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
218
static const u8 state_conv[] = {
219
[PCI_D0] = ACPI_STATE_D0,
220
[PCI_D1] = ACPI_STATE_D1,
221
[PCI_D2] = ACPI_STATE_D2,
222
[PCI_D3hot] = ACPI_STATE_D3,
223
[PCI_D3cold] = ACPI_STATE_D3
227
/* If the ACPI device has _EJ0, ignore the device */
228
if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
237
error = acpi_bus_set_power(handle, state_conv[state]);
241
dev_printk(KERN_INFO, &dev->dev,
242
"power state changed by ACPI to D%d\n", state);
247
static bool acpi_pci_can_wakeup(struct pci_dev *dev)
249
acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
251
return handle ? acpi_bus_can_wakeup(handle) : false;
254
static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
256
while (bus->parent) {
257
if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
262
/* We have reached the root bus. */
264
acpi_pm_device_sleep_wake(bus->bridge, enable);
267
static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
269
if (acpi_pci_can_wakeup(dev))
270
return acpi_pm_device_sleep_wake(&dev->dev, enable);
272
acpi_pci_propagate_wakeup_enable(dev->bus, enable);
277
* acpi_dev_run_wake - Enable/disable wake-up for given device.
278
* @phys_dev: Device to enable/disable the platform to wake-up the system for.
279
* @enable: Whether enable or disable the wake-up functionality.
281
* Find the ACPI device object corresponding to @pci_dev and try to
282
* enable/disable the GPE associated with it.
284
static int acpi_dev_run_wake(struct device *phys_dev, bool enable)
286
struct acpi_device *dev;
289
if (!device_run_wake(phys_dev))
292
handle = DEVICE_ACPI_HANDLE(phys_dev);
293
if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) {
294
dev_dbg(phys_dev, "ACPI handle has no context in %s!\n",
300
acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
301
acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
303
acpi_disable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
304
acpi_disable_wakeup_device_power(dev);
310
static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
312
while (bus->parent) {
313
struct pci_dev *bridge = bus->self;
315
if (bridge->pme_interrupt)
317
if (!acpi_dev_run_wake(&bridge->dev, enable))
322
/* We have reached the root bus. */
324
acpi_dev_run_wake(bus->bridge, enable);
327
static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
329
if (dev->pme_interrupt)
332
if (!acpi_dev_run_wake(&dev->dev, enable))
335
acpi_pci_propagate_run_wake(dev->bus, enable);
339
static struct pci_platform_pm_ops acpi_pci_platform_pm = {
340
.is_manageable = acpi_pci_power_manageable,
341
.set_state = acpi_pci_set_power_state,
342
.choose_state = acpi_pci_choose_state,
343
.can_wakeup = acpi_pci_can_wakeup,
344
.sleep_wake = acpi_pci_sleep_wake,
345
.run_wake = acpi_pci_run_wake,
349
static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
351
struct pci_dev * pci_dev;
354
pci_dev = to_pci_dev(dev);
355
/* Please ref to ACPI spec for the syntax of _ADR */
356
addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
357
*handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
363
static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
366
unsigned int seg, bus;
369
* The string should be the same as root bridge's name
370
* Please look at 'pci_scan_bus_parented'
372
num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
375
*handle = acpi_get_pci_rootbridge_handle(seg, bus);
381
static struct acpi_bus_type acpi_pci_bus = {
382
.bus = &pci_bus_type,
383
.find_device = acpi_pci_find_device,
384
.find_bridge = acpi_pci_find_root_bridge,
387
static int __init acpi_pci_init(void)
391
if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
392
printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
396
if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
397
printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
402
ret = register_acpi_bus_type(&acpi_pci_bus);
405
pci_set_platform_pm(&acpi_pci_platform_pm);
408
arch_initcall(acpi_pci_init);