/* * Copyright (C) 2017 Kaspar Schleiser * * This file is subject to the terms and conditions of the GNU Lesser * General Public License v2.1. See the file LICENSE in the top level * directory for more details. */ /** * @defgroup sys_pm_layered Layered PM Infrastructure * @ingroup sys * @{ * * This module provides a base infrastructure that MCU's may use to implement * periph/pm. * * This simple power management interface is based on the following assumptions: * * - CPUs define a number of power modes (from zero, the lowest power mode, to * PM_NUM_MODES, the highest) * - there is an implicit extra busy-wait mode (which has the number PM_NUM_MODES) * where the CPU is kept spinning if all modes are blocked. * - individual power modes can be blocked/unblocked, e.g., by peripherals * - if a mode is blocked, so are implicitly all lower modes * - the idle thread automatically selects and sets the lowest unblocked mode * * In order to use this module, you'll need to implement pm_set(). * * @file * @brief Layered low power mode infrastructure * * @author Kaspar Schleiser */ #ifndef PM_LAYERED_H #define PM_LAYERED_H #include #include "periph_cpu.h" #include "architecture.h" #ifdef __cplusplus extern "C" { #endif #ifndef PROVIDES_PM_OFF #define PROVIDES_PM_OFF #endif #ifndef PROVIDES_PM_SET_LOWEST #define PROVIDES_PM_SET_LOWEST #endif /** * @brief Power Management mode blocker typedef */ typedef struct { uint8_t blockers[PM_NUM_MODES]; /**< number of blockers for the mode */ } WORD_ALIGNED pm_blocker_t; /** * @brief Block a power mode * * @param[in] mode power mode to block */ #ifdef MODULE_PM_LAYERED void pm_block(unsigned mode); #else static inline void pm_block(unsigned mode) { (void)mode; } #endif /** * @brief Unblock a power mode * * @param[in] mode power mode to unblock */ #ifdef MODULE_PM_LAYERED void pm_unblock(unsigned mode); #else static inline void pm_unblock(unsigned mode) { (void)mode; } #endif /** * @brief Switches the MCU to a new power mode * * This function will be called by @ref pm_set_lowest() after determining the * lowest non-blocked mode. * * It needs to be implemented for each MCU using this module. * * @param[in] mode Target power mode */ void pm_set(unsigned mode); /** * @brief Get currently blocked PM modes * * @return The current blocker state * * This function atomically retrieves the currently blocked PM modes. */ pm_blocker_t pm_get_blocker(void); #ifdef __cplusplus } #endif #endif /* PM_LAYERED_H */ /** @} */