diff options
Diffstat (limited to 'drivers/acpi/device_pm.c')
| -rw-r--r-- | drivers/acpi/device_pm.c | 668 |
1 files changed, 668 insertions, 0 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c new file mode 100644 index 000000000000..f09dc987cf17 --- /dev/null +++ b/drivers/acpi/device_pm.c @@ -0,0 +1,668 @@ +/* + * 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. + */ +static 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_SUCCESS(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); |