/*
* 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/device.h>
#include <linux/export.h>
#include <linux/mutex.h>
#include <linux/pm_qos.h>
#include <linux/pm_runtime.h>
#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>
static DEFINE_MUTEX(acpi_pm_notifier_lock);
/**
* acpi_add_pm_notifier - Register PM notifier for given ACPI device.
* @adev: ACPI device to add the notifier for.
* @context: Context information to pass to the notifier routine.
*
* 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,
acpi_notify_handler handler, void *context)
{
acpi_status status = AE_ALREADY_EXISTS;
mutex_lock(&acpi_pm_notifier_lock);
if (adev->wakeup.flags.notifier_present)
goto out;
status = acpi_install_notify_handler(adev->handle,
ACPI_SYSTEM_NOTIFY,
handler, context);
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_notify_handler handler)
{
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,
handler);
if (ACPI_FAILURE(status))
goto out;
adev->wakeup.flags.notifier_present = false;
out:
mutex_unlock(&acpi_pm_notifier_lock);
return status;
}
/**
* acpi_device_power_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_max_in: Deepest low-power state to take into consideration.
* @d_min_p: Location to store the upper limit of the allowed states range.
* Return value: Preferred power state of the device on success, -ENODEV
* (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
*
* Find the lowest power (highest number) ACPI device power state that the
* device can be in while the system is in the state represented by
* @target_state. If @d_min_p is set, the highest power (lowest number) device
* power state that @dev can be in for the given system sleep state is stored
* at the location pointed to by it.
*
* Callers must ensure that @dev and @adev are valid pointers and that @adev
* actually corresponds to @dev before using this function.
*/
int acpi_device_power_state(struct device *dev, struct acpi_device *adev,
u32 target_state, int d_max_in, int *d_min_p)
{
char acpi_method[] = "_SxD";
unsigned long long d_min, d_max;
bool wakeup = false;
if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
return -EINVAL;
if (d_max_in > ACPI_STATE_D3_HOT) {
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_D3_HOT;
}
acpi_method[2] = '0' + target_state;
/*
* If the sleep state is S0, the lowest limit from ACPI is D3,
* but if the device has _S0W, we will use the value from _S0W
* as the lowest limit from ACPI. Finally, we will constrain
* the lowest limit with the specified one.
*/
d_min = ACPI_STATE_D0;
d_max = ACPI_STATE_D3;
/*
* 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).
*
* NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
* provided -- that's our fault recovery, we ignore retval.
*/
if (target_state > ACPI_STATE_S0) {
acpi_evaluate_integer(adev->handle, acpi_method, NULL, &d_min);
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) {
acpi_status status;
acpi_method[3] = 'W';
status = acpi_evaluate_integer(adev->handle, acpi_method, NULL,
&d_max);
if (ACPI_FAILURE(status)) {
if (target_state != ACPI_STATE_S0 ||
status != AE_NOT_FOUND)
d_max = d_min;
} else if (d_max < d_min) {
/* Warn the user of the broken DSDT */
printk(KERN_WARNING "ACPI: Wrong value from %s\n",
acpi_method);
/* Sanitize it */
d_min = d_max;
}
}
if (d_max_in < d_min)
return -EINVAL;
if (d_min_p)
*d_min_p = d_min;
/* constrain d_max with specified lowest limit (max number) */
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;
}
}
return d_max;
}
EXPORT_SYMBOL_GPL(acpi_device_power_state);
/**
* 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) or -EINVAL on 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)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
struct acpi_device *adev;
if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
return -ENODEV;
}
return acpi_device_power_state(dev, adev, acpi_target_system_state(),
d_max_in, d_min_p);
}
EXPORT_SYMBOL(acpi_pm_device_sleep_state);
#ifdef CONFIG_PM_RUNTIME
/**
* acpi_wakeup_device - Wakeup notification handler for ACPI devices.
* @handle: ACPI handle of the device the notification is for.
* @event: Type of the signaled event.
* @context: Device corresponding to @handle.
*/
static void acpi_wakeup_device(acpi_handle handle, u32 event, void *context)
{
struct device *dev = context;
if (event == ACPI_NOTIFY_DEVICE_WAKE && dev) {
pm_wakeup_event(dev, 0);
pm_runtime_resume(dev);
}
}
/**
* __acpi_device_run_wake - Enable/disable runtime remote wakeup for device.
* @adev: ACPI device to enable/disable the remote wakeup for.
* @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.
*/
int __acpi_device_run_wake(struct acpi_device *adev, bool enable)
{
struct acpi_device_wakeup *wakeup = &adev->wakeup;
if (enable) {
acpi_status res;
int error;
error = acpi_enable_wakeup_device_power(adev, ACPI_STATE_S0);
if (error)
return error;
res = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
if (ACPI_FAILURE(res)) {
acpi_disable_wakeup_device_power(adev);
return -EIO;
}
} else {
acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
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;
acpi_handle handle;
if (!device_run_wake(phys_dev))
return -EINVAL;
handle = DEVICE_ACPI_HANDLE(phys_dev);
if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
dev_dbg(phys_dev, "ACPI handle without context in %s!\n",
__func__);
return -ENODEV;
}
return __acpi_device_run_wake(adev, enable);
}
EXPORT_SYMBOL(acpi_pm_device_run_wake);
#else
static inline void acpi_wakeup_device(acpi_handle handle, u32 event,
void *context) {}
#endif /* CONFIG_PM_RUNTIME */
#ifdef CONFIG_PM_SLEEP
/**
* __acpi_device_sleep_wake - Enable or disable device to wake up the system.
* @dev: Device to enable/desible to wake up the system.
* @target_state: System state the device is supposed to wake up from.
* @enable: Whether to enable or disable @dev to wake up the system.
*/
int __acpi_device_sleep_wake(struct acpi_device *adev, u32 target_state,
bool enable)
{
return enable ?
acpi_enable_wakeup_device_power(adev, target_state) :
acpi_disable_wakeup_device_power(adev);
}
/**
* 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)
{
acpi_handle handle;
struct acpi_device *adev;
int error;
if (!device_can_wakeup(dev))
return -EINVAL;
handle = DEVICE_ACPI_HANDLE(dev);
if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
return -ENODEV;
}
error = __acpi_device_sleep_wake(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_get_node - Get ACPI device node for the given physical device.
* @dev: Device to get the ACPI node for.
*/
struct acpi_device *acpi_dev_pm_get_node(struct device *dev)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
struct acpi_device *adev;
return handle && !acpi_bus_get_device(handle, &adev) ? adev : NULL;
}
/**
* 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 power_state;
if (!acpi_device_power_manageable(adev))
return 0;
power_state = acpi_device_power_state(dev, adev, system_state,
ACPI_STATE_D3, NULL);
if (power_state < ACPI_STATE_D0 || power_state > ACPI_STATE_D3)
return -EIO;
return acpi_device_set_power(adev, power_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;
}
#ifdef CONFIG_PM_RUNTIME
/**
* 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_dev_pm_get_node(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_run_wake(adev, remote_wakeup);
if (remote_wakeup && error)
return -EAGAIN;
error = acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
if (error)
__acpi_device_run_wake(adev, 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_dev_pm_get_node(dev);
int error;
if (!adev)
return 0;
error = acpi_dev_pm_full_power(adev);
__acpi_device_run_wake(adev, 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);
#endif /* CONFIG_PM_RUNTIME */
#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_dev_pm_get_node(dev);
u32 target_state;
bool wakeup;
int error;
if (!adev)
return 0;
target_state = acpi_target_system_state();
wakeup = device_may_wakeup(dev);
error = __acpi_device_sleep_wake(adev, target_state, wakeup);
if (wakeup && error)
return error;
error = acpi_dev_pm_low_power(dev, adev, target_state);
if (error)
__acpi_device_sleep_wake(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_dev_pm_get_node(dev);
int error;
if (!adev)
return 0;
error = acpi_dev_pm_full_power(adev);
__acpi_device_sleep_wake(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)
{
/*
* Follow PCI and resume devices suspended at run time before running
* their system suspend callbacks.
*/
pm_runtime_resume(dev);
return pm_generic_prepare(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
/**
* 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);
#endif /* CONFIG_PM_SLEEP */
static struct dev_pm_domain acpi_general_pm_domain = {
.ops = {
#ifdef CONFIG_PM_RUNTIME
.runtime_suspend = acpi_subsys_runtime_suspend,
.runtime_resume = acpi_subsys_runtime_resume,
.runtime_idle = pm_generic_runtime_idle,
#endif
#ifdef CONFIG_PM_SLEEP
.prepare = acpi_subsys_prepare,
.suspend_late = acpi_subsys_suspend_late,
.resume_early = acpi_subsys_resume_early,
.poweroff_late = acpi_subsys_suspend_late,
.restore_early = acpi_subsys_resume_early,
#endif
},
};
/**
* 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_dev_pm_get_node(dev);
if (!adev)
return -ENODEV;
if (dev->pm_domain)
return -EEXIST;
acpi_add_pm_notifier(adev, acpi_wakeup_device, dev);
dev->pm_domain = &acpi_general_pm_domain;
if (power_on) {
acpi_dev_pm_full_power(adev);
__acpi_device_run_wake(adev, false);
}
return 0;
}
EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
/**
* 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.
*/
void acpi_dev_pm_detach(struct device *dev, bool power_off)
{
struct acpi_device *adev = acpi_dev_pm_get_node(dev);
if (adev && dev->pm_domain == &acpi_general_pm_domain) {
dev->pm_domain = NULL;
acpi_remove_pm_notifier(adev, acpi_wakeup_device);
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_run_wake(adev, false);
acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
}
}
}
EXPORT_SYMBOL_GPL(acpi_dev_pm_detach);
