/* * drivers/base/power/runtime.c - Handling dynamic device power management. * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Open Source Development Lab * */ #include <linux/device.h> #include "power.h" static void runtime_resume(struct device * dev) { dev_dbg(dev, "resuming\n"); if (!dev->power.power_state.event) return; if (!resume_device(dev)) dev->power.power_state = PMSG_ON; } /** * dpm_runtime_resume - Power one device back on. * @dev: Device. * * Bring one device back to the on state by first powering it * on, then restoring state. We only operate on devices that aren't * already on. * FIXME: We need to handle devices that are in an unknown state. */ void dpm_runtime_resume(struct device * dev) { down(&dpm_sem); runtime_resume(dev); up(&dpm_sem); } /** * dpm_runtime_suspend - Put one device in low-power state. * @dev: Device. * @state: State to enter. */ int dpm_runtime_suspend(struct device * dev, pm_message_t state) { int error = 0; down(&dpm_sem); if (dev->power.power_state.event == state.event) goto Done; if (dev->power.power_state.event) runtime_resume(dev); if (!(error = suspend_device(dev, state))) dev->power.power_state = state; Done: up(&dpm_sem); return error; } /** * dpm_set_power_state - Update power_state field. * @dev: Device. * @state: Power state device is in. * * This is an update mechanism for drivers to notify the core * what power state a device is in. Device probing code may not * always be able to tell, but we need accurate information to * work reliably. */ void dpm_set_power_state(struct device * dev, pm_message_t state) { down(&dpm_sem); dev->power.power_state = state; up(&dpm_sem); }