nuttx/arch/arm/src/stm32/stm32_pmstop.c
2014-04-13 16:22:22 -06:00

123 lines
4.3 KiB
C

/****************************************************************************
* arch/arm/src/stm32/stm32_pmstop.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_pmstop
*
* Description:
* Enter STOP mode.
*
* Input Parameters:
* lpds - true: To further reduce power consumption in Stop mode, put the
* internal voltage regulator in low-power mode using the LPDS bit
* of the Power control register (PWR_CR).
*
* Returned Value:
* Zero means that the STOP was successfully entered and the system has
* been re-awakened. The internal volatage regulator is back to its
* original state. Otherwise, STOP mode did not occur and a negated
* errno value is returned to indicate the cause of the failure.
*
****************************************************************************/
int stm32_pmstop(bool lpds)
{
uint32_t regval;
/* Clear the Power Down Deep Sleep (PDDS) and the Low Power Deep Sleep
* (LPDS)) bits in the power control register.
*/
regval = getreg32(STM32_PWR_CR);
regval &= ~(PWR_CR_LPDS | PWR_CR_PDDS);
/* Set the Low Power Deep Sleep (LPDS) bit if so requested */
if (lpds)
{
regval |= PWR_CR_LPDS;
}
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 interrupt or event occurs */
#ifdef CONFIG_PM_WFE
/* Mode: SLEEP + Entry with WFE */
asm("wfe");
#else
/* Mode: SLEEP + Entry with WFI */
asm("wfi");
#endif
return OK;
}