omap: i2c: add a timeout to the busy waiting
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / pci / pci-acpi.c
blob2e7a3bf13824945ac18ff54187146585e03d31f6
1 /*
2 * File: pci-acpi.c
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.
8 */
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>
20 #include "pci.h"
22 static DEFINE_MUTEX(pci_acpi_pm_notify_mtx);
24 /**
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);
38 /**
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 pci_check_pme_status(pci_dev);
50 pm_runtime_resume(&pci_dev->dev);
51 if (pci_dev->subordinate)
52 pci_pme_wakeup_bus(pci_dev->subordinate);
56 /**
57 * add_pm_notifier - Register PM notifier for given ACPI device.
58 * @dev: ACPI device to add the notifier for.
59 * @context: PCI device or bus to check for PME status if an event is signaled.
61 * NOTE: @dev need not be a run-wake or wake-up device to be a valid source of
62 * PM wake-up events. For example, wake-up events may be generated for bridges
63 * if one of the devices below the bridge is signaling PME, even if the bridge
64 * itself doesn't have a wake-up GPE associated with it.
66 static acpi_status add_pm_notifier(struct acpi_device *dev,
67 acpi_notify_handler handler,
68 void *context)
70 acpi_status status = AE_ALREADY_EXISTS;
72 mutex_lock(&pci_acpi_pm_notify_mtx);
74 if (dev->wakeup.flags.notifier_present)
75 goto out;
77 status = acpi_install_notify_handler(dev->handle,
78 ACPI_SYSTEM_NOTIFY,
79 handler, context);
80 if (ACPI_FAILURE(status))
81 goto out;
83 dev->wakeup.flags.notifier_present = true;
85 out:
86 mutex_unlock(&pci_acpi_pm_notify_mtx);
87 return status;
90 /**
91 * remove_pm_notifier - Unregister PM notifier from given ACPI device.
92 * @dev: ACPI device to remove the notifier from.
94 static acpi_status remove_pm_notifier(struct acpi_device *dev,
95 acpi_notify_handler handler)
97 acpi_status status = AE_BAD_PARAMETER;
99 mutex_lock(&pci_acpi_pm_notify_mtx);
101 if (!dev->wakeup.flags.notifier_present)
102 goto out;
104 status = acpi_remove_notify_handler(dev->handle,
105 ACPI_SYSTEM_NOTIFY,
106 handler);
107 if (ACPI_FAILURE(status))
108 goto out;
110 dev->wakeup.flags.notifier_present = false;
112 out:
113 mutex_unlock(&pci_acpi_pm_notify_mtx);
114 return status;
118 * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
119 * @dev: ACPI device to add the notifier for.
120 * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
122 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
123 struct pci_bus *pci_bus)
125 return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
129 * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
130 * @dev: ACPI device to remove the notifier from.
132 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
134 return remove_pm_notifier(dev, pci_acpi_wake_bus);
138 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
139 * @dev: ACPI device to add the notifier for.
140 * @pci_dev: PCI device to check for the PME status if an event is signaled.
142 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
143 struct pci_dev *pci_dev)
145 return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
149 * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
150 * @dev: ACPI device to remove the notifier from.
152 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
154 return remove_pm_notifier(dev, pci_acpi_wake_dev);
158 * _SxD returns the D-state with the highest power
159 * (lowest D-state number) supported in the S-state "x".
161 * If the devices does not have a _PRW
162 * (Power Resources for Wake) supporting system wakeup from "x"
163 * then the OS is free to choose a lower power (higher number
164 * D-state) than the return value from _SxD.
166 * But if _PRW is enabled at S-state "x", the OS
167 * must not choose a power lower than _SxD --
168 * unless the device has an _SxW method specifying
169 * the lowest power (highest D-state number) the device
170 * may enter while still able to wake the system.
172 * ie. depending on global OS policy:
174 * if (_PRW at S-state x)
175 * choose from highest power _SxD to lowest power _SxW
176 * else // no _PRW at S-state x
177 * choose highest power _SxD or any lower power
180 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
182 int acpi_state;
184 acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL);
185 if (acpi_state < 0)
186 return PCI_POWER_ERROR;
188 switch (acpi_state) {
189 case ACPI_STATE_D0:
190 return PCI_D0;
191 case ACPI_STATE_D1:
192 return PCI_D1;
193 case ACPI_STATE_D2:
194 return PCI_D2;
195 case ACPI_STATE_D3:
196 return PCI_D3hot;
198 return PCI_POWER_ERROR;
201 static bool acpi_pci_power_manageable(struct pci_dev *dev)
203 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
205 return handle ? acpi_bus_power_manageable(handle) : false;
208 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
210 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
211 acpi_handle tmp;
212 static const u8 state_conv[] = {
213 [PCI_D0] = ACPI_STATE_D0,
214 [PCI_D1] = ACPI_STATE_D1,
215 [PCI_D2] = ACPI_STATE_D2,
216 [PCI_D3hot] = ACPI_STATE_D3,
217 [PCI_D3cold] = ACPI_STATE_D3
219 int error = -EINVAL;
221 /* If the ACPI device has _EJ0, ignore the device */
222 if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
223 return -ENODEV;
225 switch (state) {
226 case PCI_D0:
227 case PCI_D1:
228 case PCI_D2:
229 case PCI_D3hot:
230 case PCI_D3cold:
231 error = acpi_bus_set_power(handle, state_conv[state]);
234 if (!error)
235 dev_printk(KERN_INFO, &dev->dev,
236 "power state changed by ACPI to D%d\n", state);
238 return error;
241 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
243 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
245 return handle ? acpi_bus_can_wakeup(handle) : false;
248 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
250 while (bus->parent) {
251 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
252 return;
253 bus = bus->parent;
256 /* We have reached the root bus. */
257 if (bus->bridge)
258 acpi_pm_device_sleep_wake(bus->bridge, enable);
261 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
263 if (acpi_pci_can_wakeup(dev))
264 return acpi_pm_device_sleep_wake(&dev->dev, enable);
266 acpi_pci_propagate_wakeup_enable(dev->bus, enable);
267 return 0;
271 * acpi_dev_run_wake - Enable/disable wake-up for given device.
272 * @phys_dev: Device to enable/disable the platform to wake-up the system for.
273 * @enable: Whether enable or disable the wake-up functionality.
275 * Find the ACPI device object corresponding to @pci_dev and try to
276 * enable/disable the GPE associated with it.
278 static int acpi_dev_run_wake(struct device *phys_dev, bool enable)
280 struct acpi_device *dev;
281 acpi_handle handle;
282 int error = -ENODEV;
284 if (!device_run_wake(phys_dev))
285 return -EINVAL;
287 handle = DEVICE_ACPI_HANDLE(phys_dev);
288 if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) {
289 dev_dbg(phys_dev, "ACPI handle has no context in %s!\n",
290 __func__);
291 return -ENODEV;
294 if (enable) {
295 if (!dev->wakeup.run_wake_count++) {
296 acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
297 acpi_enable_gpe(dev->wakeup.gpe_device,
298 dev->wakeup.gpe_number,
299 ACPI_GPE_TYPE_RUNTIME);
301 } else if (dev->wakeup.run_wake_count > 0) {
302 if (!--dev->wakeup.run_wake_count) {
303 acpi_disable_gpe(dev->wakeup.gpe_device,
304 dev->wakeup.gpe_number,
305 ACPI_GPE_TYPE_RUNTIME);
306 acpi_disable_wakeup_device_power(dev);
308 } else {
309 error = -EALREADY;
312 return error;
315 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
317 while (bus->parent) {
318 struct pci_dev *bridge = bus->self;
320 if (bridge->pme_interrupt)
321 return;
322 if (!acpi_dev_run_wake(&bridge->dev, enable))
323 return;
324 bus = bus->parent;
327 /* We have reached the root bus. */
328 if (bus->bridge)
329 acpi_dev_run_wake(bus->bridge, enable);
332 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
334 if (dev->pme_interrupt)
335 return 0;
337 if (!acpi_dev_run_wake(&dev->dev, enable))
338 return 0;
340 acpi_pci_propagate_run_wake(dev->bus, enable);
341 return 0;
344 static struct pci_platform_pm_ops acpi_pci_platform_pm = {
345 .is_manageable = acpi_pci_power_manageable,
346 .set_state = acpi_pci_set_power_state,
347 .choose_state = acpi_pci_choose_state,
348 .can_wakeup = acpi_pci_can_wakeup,
349 .sleep_wake = acpi_pci_sleep_wake,
350 .run_wake = acpi_pci_run_wake,
353 /* ACPI bus type */
354 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
356 struct pci_dev * pci_dev;
357 u64 addr;
359 pci_dev = to_pci_dev(dev);
360 /* Please ref to ACPI spec for the syntax of _ADR */
361 addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
362 *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
363 if (!*handle)
364 return -ENODEV;
365 return 0;
368 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
370 int num;
371 unsigned int seg, bus;
374 * The string should be the same as root bridge's name
375 * Please look at 'pci_scan_bus_parented'
377 num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
378 if (num != 2)
379 return -ENODEV;
380 *handle = acpi_get_pci_rootbridge_handle(seg, bus);
381 if (!*handle)
382 return -ENODEV;
383 return 0;
386 static struct acpi_bus_type acpi_pci_bus = {
387 .bus = &pci_bus_type,
388 .find_device = acpi_pci_find_device,
389 .find_bridge = acpi_pci_find_root_bridge,
392 static int __init acpi_pci_init(void)
394 int ret;
396 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
397 printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
398 pci_no_msi();
401 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
402 printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
403 pcie_no_aspm();
406 ret = register_acpi_bus_type(&acpi_pci_bus);
407 if (ret)
408 return 0;
409 pci_set_platform_pm(&acpi_pci_platform_pm);
410 return 0;
412 arch_initcall(acpi_pci_init);