/**************************************************************************** * arch/arm/src/efm32/efm32_idle.c * * Copyright (C) 2014-2016 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include "chip.h" #include "up_internal.h" #include "efm32_pm.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Does the board support an IDLE LED to indicate that the board is in the * IDLE state? */ #if defined(CONFIG_ARCH_LEDS) && defined(LED_IDLE) # define BEGIN_IDLE() board_autoled_on(LED_IDLE) # define END_IDLE() board_autoled_off(LED_IDLE) #else # define BEGIN_IDLE() # define END_IDLE() #endif #define PM_IDLE_DOMAIN 0 /* Revisit */ /**************************************************************************** * Private Data ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: up_idlepm * * Description: * Perform IDLE state power management. * * REVISIT: These power management hooks were taken with no modification * from the EFM32 implementation and need review against EFM32 reduced * power modes. * ****************************************************************************/ #ifdef CONFIG_PM static void up_idlepm(void) { static enum pm_state_e oldstate = PM_NORMAL; enum pm_state_e newstate; irqstate_t flags; int ret; /* Decide, which power saving level can be obtained */ newstate = pm_checkstate(PM_IDLE_DOMAIN); /* Check for state changes */ if (newstate != oldstate) { flags = enter_critical_section(); /* Perform board-specific, state-dependent logic here */ _info("newstate= %d oldstate=%d\n", newstate, oldstate); /* Then force the global state change */ ret = pm_changestate(PM_IDLE_DOMAIN, newstate); if (ret < 0) { /* The new state change failed, revert to the preceding state */ pm_changestate(PM_IDLE_DOMAIN, oldstate); } else { /* Save the new state */ oldstate = newstate; } /* MCU-specific power management logic */ switch (newstate) { case PM_NORMAL: break; case PM_IDLE: break; case PM_STANDBY: efm32_pmstop(true); break; case PM_SLEEP: efm32_pmstandby(); break; default: break; } leave_critical_section(flags); } } #else # define up_idlepm() #endif /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: up_idle * * Description: * up_idle() is the logic that will be executed when their is no other * ready-to-run task. This is processor idle time and will continue until * some interrupt occurs to cause a context switch from the idle task. * * Processing in this state may be processor-specific. e.g., this is where * power management operations might be performed. * ****************************************************************************/ void up_idle(void) { /* Perform IDLE mode power management */ up_idlepm(); /* Sleep until an interrupt occurs to save power. */ BEGIN_IDLE(); asm("WFI"); END_IDLE(); }