| /**************************************************************************** |
| * arch/arm/src/stm32/stm32_pmstandby.c |
| * |
| * Copyright (C) 2012 Gregory Nutt. All rights reserved. |
| * Author: Gregory Nutt <gnutt@nuttx.org> |
| * |
| * 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 <nuttx/config.h> |
| |
| #include <stdbool.h> |
| |
| #include "up_arch.h" |
| #include "nvic.h" |
| #include "stm32_pwr.h" |
| #include "stm32_pm.h" |
| |
| /**************************************************************************** |
| * Pre-processor Definitions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Private Data |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Private Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Public Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Name: stm32_pmstandby |
| * |
| * Description: |
| * Enter STANDBY mode. |
| * |
| * Input Parameters: |
| * None |
| * |
| * Returned Value. |
| * On success, this function will not return (STANDBY mode can only be |
| * terminated with a reset event). Otherwise, STANDBY mode did not occur |
| * and a negated errno value is returned to indicate the cause of the |
| * failure. |
| * |
| ****************************************************************************/ |
| |
| int stm32_pmstandby(void) |
| { |
| uint32_t regval; |
| |
| /* Clear the Wake-Up Flag by setting the CWUF bit in the power control |
| * register. |
| */ |
| |
| regval = getreg32(STM32_PWR_CR); |
| regval |= PWR_CR_CWUF; |
| putreg32(regval, STM32_PWR_CR); |
| |
| /* Set the Power Down Deep Sleep (PDDS) bit in the power control register. */ |
| |
| regval |= PWR_CR_PDDS; |
| putreg32(regval, STM32_PWR_CR); |
| |
| /* Set SLEEPDEEP bit of Cortex System Control Register */ |
| |
| regval = getreg32(NVIC_SYSCON); |
| regval |= NVIC_SYSCON_SLEEPDEEP; |
| putreg32(regval, NVIC_SYSCON); |
| |
| /* Sleep until the wakeup reset occurs */ |
| |
| asm("wfi"); |
| return OK; /* Won't get here */ |
| } |