linux-stable/drivers/acpi/device_pm.c
Rafael J. Wysocki 20dacb71ad ACPI / PM: Rework device power management to follow ACPI 6
The ACPI 6 specification has made some changes in the device power
management area.  In particular:

 * The D3hot power state is now supposed to be always available
   (instead of D3cold) and D3cold is only regarded as valid if the
   _PR3 object is present for the given device.

 * The required ordering of transitions into power states deeper than
   D0 is now such that for a transition into state Dx the _PSx method
   is supposed to be executed first, if present, and the states of
   the power resources the device depends on are supposed to be
   changed after that.

 * It is now explicitly forbidden to transition devices from
   lower-power (deeper) into higher-power (shallower) power states
   other than D0.

Those changes have been made so the specification reflects the
Windows' device power management code that the vast majority of
systems using ACPI is validated against.

To avoid artificial differences in ACPI device power management
between Windows and Linux, modify the ACPI device power management
code to follow the new specification.  Add comments explaining the
code flow in some unclear places.

This only may affect some real corner cases in which the OS behavior
expected by the firmware is different from the Windows one, but that's
quite unlikely.  The transition ordering change affects transitions
to D1 and D2 which are rarely used (if at all) and into D3hot and
D3cold for devices actually having _PR3, but those are likely to
be validated against Windows anyway.  The other changes may affect
code calling acpi_device_get_power() or acpi_device_update_power()
where ACPI_STATE_D3_HOT may be returned instead of ACPI_STATE_D3_COLD
(that's why the ACPI fan driver needs to be updated too) and since
transitions into ACPI_STATE_D3_HOT may remove power now, it is better
to avoid this one in acpi_pm_device_sleep_state() if the "no power
off" PM QoS flag is set.

The only existing user of acpi_device_can_poweroff() really cares
about the case when _PR3 is present, so the change in that function
should not cause any problems to happen too.

A plus is that PCI_D3hot can be mapped to ACPI_STATE_D3_HOT
now and the compatibility with older systems should be covered
automatically.

In any case, if any real problems result from this, it still will
be better to follow the Windows' behavior (which now is reflected
by the specification too) in general and handle the cases when it
doesn't work via quirks.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-16 01:55:35 +02:00

1136 lines
32 KiB
C

/*
* drivers/acpi/device_pm.c - ACPI device power management routines.
*
* Copyright (C) 2012, Intel Corp.
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/acpi.h>
#include <linux/export.h>
#include <linux/mutex.h>
#include <linux/pm_qos.h>
#include <linux/pm_runtime.h>
#include "internal.h"
#define _COMPONENT ACPI_POWER_COMPONENT
ACPI_MODULE_NAME("device_pm");
/**
* acpi_power_state_string - String representation of ACPI device power state.
* @state: ACPI device power state to return the string representation of.
*/
const char *acpi_power_state_string(int state)
{
switch (state) {
case ACPI_STATE_D0:
return "D0";
case ACPI_STATE_D1:
return "D1";
case ACPI_STATE_D2:
return "D2";
case ACPI_STATE_D3_HOT:
return "D3hot";
case ACPI_STATE_D3_COLD:
return "D3cold";
default:
return "(unknown)";
}
}
/**
* acpi_device_get_power - Get power state of an ACPI device.
* @device: Device to get the power state of.
* @state: Place to store the power state of the device.
*
* This function does not update the device's power.state field, but it may
* update its parent's power.state field (when the parent's power state is
* unknown and the device's power state turns out to be D0).
*/
int acpi_device_get_power(struct acpi_device *device, int *state)
{
int result = ACPI_STATE_UNKNOWN;
if (!device || !state)
return -EINVAL;
if (!device->flags.power_manageable) {
/* TBD: Non-recursive algorithm for walking up hierarchy. */
*state = device->parent ?
device->parent->power.state : ACPI_STATE_D0;
goto out;
}
/*
* Get the device's power state from power resources settings and _PSC,
* if available.
*/
if (device->power.flags.power_resources) {
int error = acpi_power_get_inferred_state(device, &result);
if (error)
return error;
}
if (device->power.flags.explicit_get) {
acpi_handle handle = device->handle;
unsigned long long psc;
acpi_status status;
status = acpi_evaluate_integer(handle, "_PSC", NULL, &psc);
if (ACPI_FAILURE(status))
return -ENODEV;
/*
* The power resources settings may indicate a power state
* shallower than the actual power state of the device, because
* the same power resources may be referenced by other devices.
*
* For systems predating ACPI 4.0 we assume that D3hot is the
* deepest state that can be supported.
*/
if (psc > result && psc < ACPI_STATE_D3_COLD)
result = psc;
else if (result == ACPI_STATE_UNKNOWN)
result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_HOT : psc;
}
/*
* If we were unsure about the device parent's power state up to this
* point, the fact that the device is in D0 implies that the parent has
* to be in D0 too, except if ignore_parent is set.
*/
if (!device->power.flags.ignore_parent && device->parent
&& device->parent->power.state == ACPI_STATE_UNKNOWN
&& result == ACPI_STATE_D0)
device->parent->power.state = ACPI_STATE_D0;
*state = result;
out:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
device->pnp.bus_id, acpi_power_state_string(*state)));
return 0;
}
static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state)
{
if (adev->power.states[state].flags.explicit_set) {
char method[5] = { '_', 'P', 'S', '0' + state, '\0' };
acpi_status status;
status = acpi_evaluate_object(adev->handle, method, NULL, NULL);
if (ACPI_FAILURE(status))
return -ENODEV;
}
return 0;
}
/**
* acpi_device_set_power - Set power state of an ACPI device.
* @device: Device to set the power state of.
* @state: New power state to set.
*
* Callers must ensure that the device is power manageable before using this
* function.
*/
int acpi_device_set_power(struct acpi_device *device, int state)
{
int target_state = state;
int result = 0;
if (!device || !device->flags.power_manageable
|| (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
return -EINVAL;
/* Make sure this is a valid target state */
if (state == device->power.state) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n",
device->pnp.bus_id,
acpi_power_state_string(state)));
return 0;
}
if (state == ACPI_STATE_D3_COLD) {
/*
* For transitions to D3cold we need to execute _PS3 and then
* possibly drop references to the power resources in use.
*/
state = ACPI_STATE_D3_HOT;
/* If _PR3 is not available, use D3hot as the target state. */
if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)
target_state = state;
} else if (!device->power.states[state].flags.valid) {
dev_warn(&device->dev, "Power state %s not supported\n",
acpi_power_state_string(state));
return -ENODEV;
}
if (!device->power.flags.ignore_parent &&
device->parent && (state < device->parent->power.state)) {
dev_warn(&device->dev,
"Cannot transition to power state %s for parent in %s\n",
acpi_power_state_string(state),
acpi_power_state_string(device->parent->power.state));
return -ENODEV;
}
/*
* Transition Power
* ----------------
* In accordance with ACPI 6, _PSx is executed before manipulating power
* resources, unless the target state is D0, in which case _PS0 is
* supposed to be executed after turning the power resources on.
*/
if (state > ACPI_STATE_D0) {
/*
* According to ACPI 6, devices cannot go from lower-power
* (deeper) states to higher-power (shallower) states.
*/
if (state < device->power.state) {
dev_warn(&device->dev, "Cannot transition from %s to %s\n",
acpi_power_state_string(device->power.state),
acpi_power_state_string(state));
return -ENODEV;
}
result = acpi_dev_pm_explicit_set(device, state);
if (result)
goto end;
if (device->power.flags.power_resources)
result = acpi_power_transition(device, target_state);
} else {
if (device->power.flags.power_resources) {
result = acpi_power_transition(device, ACPI_STATE_D0);
if (result)
goto end;
}
result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
}
end:
if (result) {
dev_warn(&device->dev, "Failed to change power state to %s\n",
acpi_power_state_string(state));
} else {
device->power.state = state;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Device [%s] transitioned to %s\n",
device->pnp.bus_id,
acpi_power_state_string(state)));
}
return result;
}
EXPORT_SYMBOL(acpi_device_set_power);
int acpi_bus_set_power(acpi_handle handle, int state)
{
struct acpi_device *device;
int result;
result = acpi_bus_get_device(handle, &device);
if (result)
return result;
return acpi_device_set_power(device, state);
}
EXPORT_SYMBOL(acpi_bus_set_power);
int acpi_bus_init_power(struct acpi_device *device)
{
int state;
int result;
if (!device)
return -EINVAL;
device->power.state = ACPI_STATE_UNKNOWN;
if (!acpi_device_is_present(device))
return -ENXIO;
result = acpi_device_get_power(device, &state);
if (result)
return result;
if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
/* Reference count the power resources. */
result = acpi_power_on_resources(device, state);
if (result)
return result;
if (state == ACPI_STATE_D0) {
/*
* If _PSC is not present and the state inferred from
* power resources appears to be D0, it still may be
* necessary to execute _PS0 at this point, because
* another device using the same power resources may
* have been put into D0 previously and that's why we
* see D0 here.
*/
result = acpi_dev_pm_explicit_set(device, state);
if (result)
return result;
}
} else if (state == ACPI_STATE_UNKNOWN) {
/*
* No power resources and missing _PSC? Cross fingers and make
* it D0 in hope that this is what the BIOS put the device into.
* [We tried to force D0 here by executing _PS0, but that broke
* Toshiba P870-303 in a nasty way.]
*/
state = ACPI_STATE_D0;
}
device->power.state = state;
return 0;
}
/**
* acpi_device_fix_up_power - Force device with missing _PSC into D0.
* @device: Device object whose power state is to be fixed up.
*
* Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
* are assumed to be put into D0 by the BIOS. However, in some cases that may
* not be the case and this function should be used then.
*/
int acpi_device_fix_up_power(struct acpi_device *device)
{
int ret = 0;
if (!device->power.flags.power_resources
&& !device->power.flags.explicit_get
&& device->power.state == ACPI_STATE_D0)
ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
return ret;
}
int acpi_device_update_power(struct acpi_device *device, int *state_p)
{
int state;
int result;
if (device->power.state == ACPI_STATE_UNKNOWN) {
result = acpi_bus_init_power(device);
if (!result && state_p)
*state_p = device->power.state;
return result;
}
result = acpi_device_get_power(device, &state);
if (result)
return result;
if (state == ACPI_STATE_UNKNOWN) {
state = ACPI_STATE_D0;
result = acpi_device_set_power(device, state);
if (result)
return result;
} else {
if (device->power.flags.power_resources) {
/*
* We don't need to really switch the state, bu we need
* to update the power resources' reference counters.
*/
result = acpi_power_transition(device, state);
if (result)
return result;
}
device->power.state = state;
}
if (state_p)
*state_p = state;
return 0;
}
EXPORT_SYMBOL_GPL(acpi_device_update_power);
int acpi_bus_update_power(acpi_handle handle, int *state_p)
{
struct acpi_device *device;
int result;
result = acpi_bus_get_device(handle, &device);
return result ? result : acpi_device_update_power(device, state_p);
}
EXPORT_SYMBOL_GPL(acpi_bus_update_power);
bool acpi_bus_power_manageable(acpi_handle handle)
{
struct acpi_device *device;
int result;
result = acpi_bus_get_device(handle, &device);
return result ? false : device->flags.power_manageable;
}
EXPORT_SYMBOL(acpi_bus_power_manageable);
#ifdef CONFIG_PM
static DEFINE_MUTEX(acpi_pm_notifier_lock);
static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
{
struct acpi_device *adev;
if (val != ACPI_NOTIFY_DEVICE_WAKE)
return;
adev = acpi_bus_get_acpi_device(handle);
if (!adev)
return;
mutex_lock(&acpi_pm_notifier_lock);
if (adev->wakeup.flags.notifier_present) {
__pm_wakeup_event(adev->wakeup.ws, 0);
if (adev->wakeup.context.work.func)
queue_pm_work(&adev->wakeup.context.work);
}
mutex_unlock(&acpi_pm_notifier_lock);
acpi_bus_put_acpi_device(adev);
}
/**
* acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
* @adev: ACPI device to add the notify handler for.
* @dev: Device to generate a wakeup event for while handling the notification.
* @work_func: Work function to execute when handling the notification.
*
* NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
* PM wakeup events. For example, wakeup events may be generated for bridges
* if one of the devices below the bridge is signaling wakeup, even if the
* bridge itself doesn't have a wakeup GPE associated with it.
*/
acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
void (*work_func)(struct work_struct *work))
{
acpi_status status = AE_ALREADY_EXISTS;
if (!dev && !work_func)
return AE_BAD_PARAMETER;
mutex_lock(&acpi_pm_notifier_lock);
if (adev->wakeup.flags.notifier_present)
goto out;
adev->wakeup.ws = wakeup_source_register(dev_name(&adev->dev));
adev->wakeup.context.dev = dev;
if (work_func)
INIT_WORK(&adev->wakeup.context.work, work_func);
status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
acpi_pm_notify_handler, NULL);
if (ACPI_FAILURE(status))
goto out;
adev->wakeup.flags.notifier_present = true;
out:
mutex_unlock(&acpi_pm_notifier_lock);
return status;
}
/**
* acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
* @adev: ACPI device to remove the notifier from.
*/
acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
{
acpi_status status = AE_BAD_PARAMETER;
mutex_lock(&acpi_pm_notifier_lock);
if (!adev->wakeup.flags.notifier_present)
goto out;
status = acpi_remove_notify_handler(adev->handle,
ACPI_SYSTEM_NOTIFY,
acpi_pm_notify_handler);
if (ACPI_FAILURE(status))
goto out;
if (adev->wakeup.context.work.func) {
cancel_work_sync(&adev->wakeup.context.work);
adev->wakeup.context.work.func = NULL;
}
adev->wakeup.context.dev = NULL;
wakeup_source_unregister(adev->wakeup.ws);
adev->wakeup.flags.notifier_present = false;
out:
mutex_unlock(&acpi_pm_notifier_lock);
return status;
}
bool acpi_bus_can_wakeup(acpi_handle handle)
{
struct acpi_device *device;
int result;
result = acpi_bus_get_device(handle, &device);
return result ? false : device->wakeup.flags.valid;
}
EXPORT_SYMBOL(acpi_bus_can_wakeup);
/**
* acpi_dev_pm_get_state - Get preferred power state of ACPI device.
* @dev: Device whose preferred target power state to return.
* @adev: ACPI device node corresponding to @dev.
* @target_state: System state to match the resultant device state.
* @d_min_p: Location to store the highest power state available to the device.
* @d_max_p: Location to store the lowest power state available to the device.
*
* Find the lowest power (highest number) and highest power (lowest number) ACPI
* device power states that the device can be in while the system is in the
* state represented by @target_state. Store the integer numbers representing
* those stats in the memory locations pointed to by @d_max_p and @d_min_p,
* respectively.
*
* Callers must ensure that @dev and @adev are valid pointers and that @adev
* actually corresponds to @dev before using this function.
*
* Returns 0 on success or -ENODATA when one of the ACPI methods fails or
* returns a value that doesn't make sense. The memory locations pointed to by
* @d_max_p and @d_min_p are only modified on success.
*/
static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
u32 target_state, int *d_min_p, int *d_max_p)
{
char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
acpi_handle handle = adev->handle;
unsigned long long ret;
int d_min, d_max;
bool wakeup = false;
acpi_status status;
/*
* If the system state is S0, the lowest power state the device can be
* in is D3cold, unless the device has _S0W and is supposed to signal
* wakeup, in which case the return value of _S0W has to be used as the
* lowest power state available to the device.
*/
d_min = ACPI_STATE_D0;
d_max = ACPI_STATE_D3_COLD;
/*
* If present, _SxD methods return the minimum D-state (highest power
* state) we can use for the corresponding S-states. Otherwise, the
* minimum D-state is D0 (ACPI 3.x).
*/
if (target_state > ACPI_STATE_S0) {
/*
* We rely on acpi_evaluate_integer() not clobbering the integer
* provided if AE_NOT_FOUND is returned.
*/
ret = d_min;
status = acpi_evaluate_integer(handle, method, NULL, &ret);
if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
|| ret > ACPI_STATE_D3_COLD)
return -ENODATA;
/*
* We need to handle legacy systems where D3hot and D3cold are
* the same and 3 is returned in both cases, so fall back to
* D3cold if D3hot is not a valid state.
*/
if (!adev->power.states[ret].flags.valid) {
if (ret == ACPI_STATE_D3_HOT)
ret = ACPI_STATE_D3_COLD;
else
return -ENODATA;
}
d_min = ret;
wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
&& adev->wakeup.sleep_state >= target_state;
} else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
PM_QOS_FLAGS_NONE) {
wakeup = adev->wakeup.flags.valid;
}
/*
* If _PRW says we can wake up the system from the target sleep state,
* the D-state returned by _SxD is sufficient for that (we assume a
* wakeup-aware driver if wake is set). Still, if _SxW exists
* (ACPI 3.x), it should return the maximum (lowest power) D-state that
* can wake the system. _S0W may be valid, too.
*/
if (wakeup) {
method[3] = 'W';
status = acpi_evaluate_integer(handle, method, NULL, &ret);
if (status == AE_NOT_FOUND) {
if (target_state > ACPI_STATE_S0)
d_max = d_min;
} else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
/* Fall back to D3cold if ret is not a valid state. */
if (!adev->power.states[ret].flags.valid)
ret = ACPI_STATE_D3_COLD;
d_max = ret > d_min ? ret : d_min;
} else {
return -ENODATA;
}
}
if (d_min_p)
*d_min_p = d_min;
if (d_max_p)
*d_max_p = d_max;
return 0;
}
/**
* acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
* @dev: Device whose preferred target power state to return.
* @d_min_p: Location to store the upper limit of the allowed states range.
* @d_max_in: Deepest low-power state to take into consideration.
* Return value: Preferred power state of the device on success, -ENODEV
* if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
* incorrect, or -ENODATA on ACPI method failure.
*
* The caller must ensure that @dev is valid before using this function.
*/
int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
{
struct acpi_device *adev;
int ret, d_min, d_max;
if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
return -EINVAL;
if (d_max_in > ACPI_STATE_D2) {
enum pm_qos_flags_status stat;
stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
if (stat == PM_QOS_FLAGS_ALL)
d_max_in = ACPI_STATE_D2;
}
adev = ACPI_COMPANION(dev);
if (!adev) {
dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
return -ENODEV;
}
ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
&d_min, &d_max);
if (ret)
return ret;
if (d_max_in < d_min)
return -EINVAL;
if (d_max > d_max_in) {
for (d_max = d_max_in; d_max > d_min; d_max--) {
if (adev->power.states[d_max].flags.valid)
break;
}
}
if (d_min_p)
*d_min_p = d_min;
return d_max;
}
EXPORT_SYMBOL(acpi_pm_device_sleep_state);
/**
* acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
* @work: Work item to handle.
*/
static void acpi_pm_notify_work_func(struct work_struct *work)
{
struct device *dev;
dev = container_of(work, struct acpi_device_wakeup_context, work)->dev;
if (dev) {
pm_wakeup_event(dev, 0);
pm_runtime_resume(dev);
}
}
/**
* acpi_device_wakeup - Enable/disable wakeup functionality for device.
* @adev: ACPI device to enable/disable wakeup functionality for.
* @target_state: State the system is transitioning into.
* @enable: Whether to enable or disable the wakeup functionality.
*
* Enable/disable the GPE associated with @adev so that it can generate
* wakeup signals for the device in response to external (remote) events and
* enable/disable device wakeup power.
*
* Callers must ensure that @adev is a valid ACPI device node before executing
* this function.
*/
static int acpi_device_wakeup(struct acpi_device *adev, u32 target_state,
bool enable)
{
struct acpi_device_wakeup *wakeup = &adev->wakeup;
if (enable) {
acpi_status res;
int error;
error = acpi_enable_wakeup_device_power(adev, target_state);
if (error)
return error;
if (adev->wakeup.flags.enabled)
return 0;
res = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
if (ACPI_SUCCESS(res)) {
adev->wakeup.flags.enabled = 1;
} else {
acpi_disable_wakeup_device_power(adev);
return -EIO;
}
} else {
if (adev->wakeup.flags.enabled) {
acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
adev->wakeup.flags.enabled = 0;
}
acpi_disable_wakeup_device_power(adev);
}
return 0;
}
/**
* acpi_pm_device_run_wake - Enable/disable remote wakeup for given device.
* @dev: Device to enable/disable the platform to wake up.
* @enable: Whether to enable or disable the wakeup functionality.
*/
int acpi_pm_device_run_wake(struct device *phys_dev, bool enable)
{
struct acpi_device *adev;
if (!device_run_wake(phys_dev))
return -EINVAL;
adev = ACPI_COMPANION(phys_dev);
if (!adev) {
dev_dbg(phys_dev, "ACPI companion missing in %s!\n", __func__);
return -ENODEV;
}
return acpi_device_wakeup(adev, ACPI_STATE_S0, enable);
}
EXPORT_SYMBOL(acpi_pm_device_run_wake);
#ifdef CONFIG_PM_SLEEP
/**
* acpi_pm_device_sleep_wake - Enable or disable device to wake up the system.
* @dev: Device to enable/desible to wake up the system from sleep states.
* @enable: Whether to enable or disable @dev to wake up the system.
*/
int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
{
struct acpi_device *adev;
int error;
if (!device_can_wakeup(dev))
return -EINVAL;
adev = ACPI_COMPANION(dev);
if (!adev) {
dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
return -ENODEV;
}
error = acpi_device_wakeup(adev, acpi_target_system_state(), enable);
if (!error)
dev_info(dev, "System wakeup %s by ACPI\n",
enable ? "enabled" : "disabled");
return error;
}
#endif /* CONFIG_PM_SLEEP */
/**
* acpi_dev_pm_low_power - Put ACPI device into a low-power state.
* @dev: Device to put into a low-power state.
* @adev: ACPI device node corresponding to @dev.
* @system_state: System state to choose the device state for.
*/
static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
u32 system_state)
{
int ret, state;
if (!acpi_device_power_manageable(adev))
return 0;
ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
return ret ? ret : acpi_device_set_power(adev, state);
}
/**
* acpi_dev_pm_full_power - Put ACPI device into the full-power state.
* @adev: ACPI device node to put into the full-power state.
*/
static int acpi_dev_pm_full_power(struct acpi_device *adev)
{
return acpi_device_power_manageable(adev) ?
acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
}
/**
* acpi_dev_runtime_suspend - Put device into a low-power state using ACPI.
* @dev: Device to put into a low-power state.
*
* Put the given device into a runtime low-power state using the standard ACPI
* mechanism. Set up remote wakeup if desired, choose the state to put the
* device into (this checks if remote wakeup is expected to work too), and set
* the power state of the device.
*/
int acpi_dev_runtime_suspend(struct device *dev)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
bool remote_wakeup;
int error;
if (!adev)
return 0;
remote_wakeup = dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) >
PM_QOS_FLAGS_NONE;
error = acpi_device_wakeup(adev, ACPI_STATE_S0, remote_wakeup);
if (remote_wakeup && error)
return -EAGAIN;
error = acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
if (error)
acpi_device_wakeup(adev, ACPI_STATE_S0, false);
return error;
}
EXPORT_SYMBOL_GPL(acpi_dev_runtime_suspend);
/**
* acpi_dev_runtime_resume - Put device into the full-power state using ACPI.
* @dev: Device to put into the full-power state.
*
* Put the given device into the full-power state using the standard ACPI
* mechanism at run time. Set the power state of the device to ACPI D0 and
* disable remote wakeup.
*/
int acpi_dev_runtime_resume(struct device *dev)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
int error;
if (!adev)
return 0;
error = acpi_dev_pm_full_power(adev);
acpi_device_wakeup(adev, ACPI_STATE_S0, false);
return error;
}
EXPORT_SYMBOL_GPL(acpi_dev_runtime_resume);
/**
* acpi_subsys_runtime_suspend - Suspend device using ACPI.
* @dev: Device to suspend.
*
* Carry out the generic runtime suspend procedure for @dev and use ACPI to put
* it into a runtime low-power state.
*/
int acpi_subsys_runtime_suspend(struct device *dev)
{
int ret = pm_generic_runtime_suspend(dev);
return ret ? ret : acpi_dev_runtime_suspend(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
/**
* acpi_subsys_runtime_resume - Resume device using ACPI.
* @dev: Device to Resume.
*
* Use ACPI to put the given device into the full-power state and carry out the
* generic runtime resume procedure for it.
*/
int acpi_subsys_runtime_resume(struct device *dev)
{
int ret = acpi_dev_runtime_resume(dev);
return ret ? ret : pm_generic_runtime_resume(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
#ifdef CONFIG_PM_SLEEP
/**
* acpi_dev_suspend_late - Put device into a low-power state using ACPI.
* @dev: Device to put into a low-power state.
*
* Put the given device into a low-power state during system transition to a
* sleep state using the standard ACPI mechanism. Set up system wakeup if
* desired, choose the state to put the device into (this checks if system
* wakeup is expected to work too), and set the power state of the device.
*/
int acpi_dev_suspend_late(struct device *dev)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
u32 target_state;
bool wakeup;
int error;
if (!adev)
return 0;
target_state = acpi_target_system_state();
wakeup = device_may_wakeup(dev) && acpi_device_can_wakeup(adev);
error = acpi_device_wakeup(adev, target_state, wakeup);
if (wakeup && error)
return error;
error = acpi_dev_pm_low_power(dev, adev, target_state);
if (error)
acpi_device_wakeup(adev, ACPI_STATE_UNKNOWN, false);
return error;
}
EXPORT_SYMBOL_GPL(acpi_dev_suspend_late);
/**
* acpi_dev_resume_early - Put device into the full-power state using ACPI.
* @dev: Device to put into the full-power state.
*
* Put the given device into the full-power state using the standard ACPI
* mechanism during system transition to the working state. Set the power
* state of the device to ACPI D0 and disable remote wakeup.
*/
int acpi_dev_resume_early(struct device *dev)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
int error;
if (!adev)
return 0;
error = acpi_dev_pm_full_power(adev);
acpi_device_wakeup(adev, ACPI_STATE_UNKNOWN, false);
return error;
}
EXPORT_SYMBOL_GPL(acpi_dev_resume_early);
/**
* acpi_subsys_prepare - Prepare device for system transition to a sleep state.
* @dev: Device to prepare.
*/
int acpi_subsys_prepare(struct device *dev)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
u32 sys_target;
int ret, state;
ret = pm_generic_prepare(dev);
if (ret < 0)
return ret;
if (!adev || !pm_runtime_suspended(dev)
|| device_may_wakeup(dev) != !!adev->wakeup.prepare_count)
return 0;
sys_target = acpi_target_system_state();
if (sys_target == ACPI_STATE_S0)
return 1;
if (adev->power.flags.dsw_present)
return 0;
ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
return !ret && state == adev->power.state;
}
EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
/**
* acpi_subsys_complete - Finalize device's resume during system resume.
* @dev: Device to handle.
*/
void acpi_subsys_complete(struct device *dev)
{
/*
* If the device had been runtime-suspended before the system went into
* the sleep state it is going out of and it has never been resumed till
* now, resume it in case the firmware powered it up.
*/
if (dev->power.direct_complete)
pm_request_resume(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_complete);
/**
* acpi_subsys_suspend - Run the device driver's suspend callback.
* @dev: Device to handle.
*
* Follow PCI and resume devices suspended at run time before running their
* system suspend callbacks.
*/
int acpi_subsys_suspend(struct device *dev)
{
pm_runtime_resume(dev);
return pm_generic_suspend(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
/**
* acpi_subsys_suspend_late - Suspend device using ACPI.
* @dev: Device to suspend.
*
* Carry out the generic late suspend procedure for @dev and use ACPI to put
* it into a low-power state during system transition into a sleep state.
*/
int acpi_subsys_suspend_late(struct device *dev)
{
int ret = pm_generic_suspend_late(dev);
return ret ? ret : acpi_dev_suspend_late(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
/**
* acpi_subsys_resume_early - Resume device using ACPI.
* @dev: Device to Resume.
*
* Use ACPI to put the given device into the full-power state and carry out the
* generic early resume procedure for it during system transition into the
* working state.
*/
int acpi_subsys_resume_early(struct device *dev)
{
int ret = acpi_dev_resume_early(dev);
return ret ? ret : pm_generic_resume_early(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_resume_early);
/**
* acpi_subsys_freeze - Run the device driver's freeze callback.
* @dev: Device to handle.
*/
int acpi_subsys_freeze(struct device *dev)
{
/*
* This used to be done in acpi_subsys_prepare() for all devices and
* some drivers may depend on it, so do it here. Ideally, however,
* runtime-suspended devices should not be touched during freeze/thaw
* transitions.
*/
pm_runtime_resume(dev);
return pm_generic_freeze(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
#endif /* CONFIG_PM_SLEEP */
static struct dev_pm_domain acpi_general_pm_domain = {
.ops = {
.runtime_suspend = acpi_subsys_runtime_suspend,
.runtime_resume = acpi_subsys_runtime_resume,
#ifdef CONFIG_PM_SLEEP
.prepare = acpi_subsys_prepare,
.complete = acpi_subsys_complete,
.suspend = acpi_subsys_suspend,
.suspend_late = acpi_subsys_suspend_late,
.resume_early = acpi_subsys_resume_early,
.freeze = acpi_subsys_freeze,
.poweroff = acpi_subsys_suspend,
.poweroff_late = acpi_subsys_suspend_late,
.restore_early = acpi_subsys_resume_early,
#endif
},
};
/**
* acpi_dev_pm_detach - Remove ACPI power management from the device.
* @dev: Device to take care of.
* @power_off: Whether or not to try to remove power from the device.
*
* Remove the device from the general ACPI PM domain and remove its wakeup
* notifier. If @power_off is set, additionally remove power from the device if
* possible.
*
* Callers must ensure proper synchronization of this function with power
* management callbacks.
*/
static void acpi_dev_pm_detach(struct device *dev, bool power_off)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
if (adev && dev->pm_domain == &acpi_general_pm_domain) {
dev->pm_domain = NULL;
acpi_remove_pm_notifier(adev);
if (power_off) {
/*
* If the device's PM QoS resume latency limit or flags
* have been exposed to user space, they have to be
* hidden at this point, so that they don't affect the
* choice of the low-power state to put the device into.
*/
dev_pm_qos_hide_latency_limit(dev);
dev_pm_qos_hide_flags(dev);
acpi_device_wakeup(adev, ACPI_STATE_S0, false);
acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
}
}
}
/**
* acpi_dev_pm_attach - Prepare device for ACPI power management.
* @dev: Device to prepare.
* @power_on: Whether or not to power on the device.
*
* If @dev has a valid ACPI handle that has a valid struct acpi_device object
* attached to it, install a wakeup notification handler for the device and
* add it to the general ACPI PM domain. If @power_on is set, the device will
* be put into the ACPI D0 state before the function returns.
*
* This assumes that the @dev's bus type uses generic power management callbacks
* (or doesn't use any power management callbacks at all).
*
* Callers must ensure proper synchronization of this function with power
* management callbacks.
*/
int acpi_dev_pm_attach(struct device *dev, bool power_on)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
if (!adev)
return -ENODEV;
if (dev->pm_domain)
return -EEXIST;
acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
dev->pm_domain = &acpi_general_pm_domain;
if (power_on) {
acpi_dev_pm_full_power(adev);
acpi_device_wakeup(adev, ACPI_STATE_S0, false);
}
dev->pm_domain->detach = acpi_dev_pm_detach;
return 0;
}
EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
#endif /* CONFIG_PM */