/**************************************************************************** * drivers/power/pm/pm_changestate.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include "pm.h" #ifdef CONFIG_PM /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: pm_prepall * * Description: * Prepare every driver for the state change. * * Input Parameters: * domain - Identifies the domain of the new PM state * newstate - Identifies the new PM state * * Returned Value: * 0 (OK) means that the callback function for all registered drivers * returned OK (meaning that they accept the state change). Non-zero * means that one of the drivers refused the state change. In this case, * the system will revert to the preceding state. * * Assumptions: * Interrupts are disabled. * ****************************************************************************/ static int pm_prepall(int domain, enum pm_state_e newstate) { FAR dq_entry_t *entry; int ret = OK; if (newstate <= g_pmglobals.domain[domain].state) { /* Visit each registered callback structure in normal order. */ for (entry = dq_peek(&g_pmglobals.registry); entry && ret == OK; entry = dq_next(entry)) { /* Is the prepare callback supported? */ FAR struct pm_callback_s *cb = (FAR struct pm_callback_s *)entry; if (cb->prepare) { /* Yes.. prepare the driver */ ret = cb->prepare(cb, domain, newstate); } } } else { /* Visit each registered callback structure in reverse order. */ for (entry = dq_tail(&g_pmglobals.registry); entry && ret == OK; entry = dq_prev(entry)) { /* Is the prepare callback supported? */ FAR struct pm_callback_s *cb = (FAR struct pm_callback_s *)entry; if (cb->prepare) { /* Yes.. prepare the driver */ ret = cb->prepare(cb, domain, newstate); } } } return ret; } /**************************************************************************** * Name: pm_changeall * * Description: * domain - Identifies the domain of the new PM state * Inform all drivers of the state change. * * Input Parameters: * domain - Identifies the domain of the new PM state * newstate - Identifies the new PM state * * Returned Value: * None * * Assumptions: * Interrupts are disabled. * ****************************************************************************/ static inline void pm_changeall(int domain, enum pm_state_e newstate) { FAR dq_entry_t *entry; if (newstate <= g_pmglobals.domain[domain].state) { /* Visit each registered callback structure in normal order. */ for (entry = dq_peek(&g_pmglobals.registry); entry; entry = dq_next(entry)) { /* Is the notification callback supported? */ FAR struct pm_callback_s *cb = (FAR struct pm_callback_s *)entry; if (cb->notify) { /* Yes.. notify the driver */ cb->notify(cb, domain, newstate); } } } else { /* Visit each registered callback structure in reverse order. */ for (entry = dq_tail(&g_pmglobals.registry); entry; entry = dq_prev(entry)) { /* Is the notification callback supported? */ FAR struct pm_callback_s *cb = (FAR struct pm_callback_s *)entry; if (cb->notify) { /* Yes.. notify the driver */ cb->notify(cb, domain, newstate); } } } } #ifdef CONFIG_PM_PROCFS static void pm_stats(FAR struct pm_domain_s *dom, int curstate, int newstate) { struct timespec ts; clock_systime_timespec(&ts); clock_timespec_subtract(&ts, &dom->start, &ts); if (newstate == PM_RESTORE) { /* Wakeup from WFI */ clock_timespec_add(&ts, &dom->sleep[curstate], &dom->sleep[curstate]); } else { /* Sleep to WFI */ clock_timespec_add(&ts, &dom->wake[curstate], &dom->wake[curstate]); } /* Update start */ clock_systime_timespec(&dom->start); } #else # define pm_stats(dom, curstate, newstate) #endif /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: pm_changestate * * Description: * This function is used by platform-specific power management logic. It * will announce the power management power management state change to all * drivers that have registered for power management event callbacks. * * Input Parameters: * domain - Identifies the domain of the new PM state * newstate - Identifies the new PM state * * Returned Value: * 0 (OK) means that the callback function for all registered drivers * returned OK (meaning that they accept the state change). Non-zero * means that one of the drivers refused the state change. In this case, * the system will revert to the preceding state. * * Assumptions: * It is assumed that interrupts are disabled when this function is * called. This function is probably called from the IDLE loop... the * lowest priority task in the system. Changing driver power management * states may result in renewed system activity and, as a result, can * suspend the IDLE thread before it completes the entire state change * unless interrupts are disabled throughout the state change. * ****************************************************************************/ int pm_changestate(int domain, enum pm_state_e newstate) { irqstate_t flags; int ret = OK; DEBUGASSERT(domain >= 0 && domain < CONFIG_PM_NDOMAINS); /* Disable interrupts throughout this operation... changing driver states * could cause additional driver activity that might interfere with the * state change. When the state change is complete, interrupts will be * re-enabled. */ flags = pm_domain_lock(domain); if (newstate != PM_RESTORE) { /* First, prepare the drivers for the state change. In this phase, * drivers may refuse the state state change. */ ret = pm_prepall(domain, newstate); if (ret != OK) { /* One or more drivers is not ready for this state change. * Revert to the preceding state. */ newstate = g_pmglobals.domain[domain].state; pm_prepall(domain, newstate); } } /* Statistics */ pm_stats(&g_pmglobals.domain[domain], g_pmglobals.domain[domain].state, newstate); /* All drivers have agreed to the state change (or, one or more have * disagreed and the state has been reverted). Set the new state. */ pm_changeall(domain, newstate); /* Notify governor of (possible) state change */ if (g_pmglobals.domain[domain].governor->statechanged) { g_pmglobals.domain[domain].governor->statechanged(domain, newstate); } /* Domain state update after statechanged done */ if (newstate != PM_RESTORE) { g_pmglobals.domain[domain].state = newstate; } /* Restore the interrupt state */ pm_domain_unlock(domain, flags); return ret; } /**************************************************************************** * Name: pm_querystate * * Description: * This function returns the current power management state. * * Input Parameters: * domain - The PM domain to check * * Returned Value: * The current power management state. * ****************************************************************************/ enum pm_state_e pm_querystate(int domain) { DEBUGASSERT(domain >= 0 && domain < CONFIG_PM_NDOMAINS); return g_pmglobals.domain[domain].state; } #endif /* CONFIG_PM */