File content as of revision 189:f392fc9709a3:

/**
  ******************************************************************************
  * @file    stm32f2xx_hal_pwr_ex.c
  * @author  MCD Application Team
  * @version V1.2.1
  * @date    14-April-2017
  * @brief   Extended PWR HAL module driver.
  *          This file provides firmware functions to manage the following 
  *          functionalities of PWR extension peripheral:           
  *           + Peripheral Extended features functions
  *         
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT(c) 2017 STMicroelectronics</center></h2>
  *
  * 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 of STMicroelectronics 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 HOLDER 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.
  *
  ******************************************************************************
  */ 

/* Includes ------------------------------------------------------------------*/
#include "stm32f2xx_hal.h"

/** @addtogroup STM32F2xx_HAL_Driver
  * @{
  */

/** @defgroup PWREx PWREx
  * @brief PWR HAL module driver
  * @{
  */

#ifdef HAL_PWR_MODULE_ENABLED

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/** @addtogroup PWREx_Private_Constants
  * @{
  */    
#define PWR_BKPREG_TIMEOUT_VALUE     1000U
/**
  * @}
  */

   
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/** @defgroup PWREx_Exported_Functions PWR Exported Functions
  *  @{
  */

/** @defgroup PWREx_Exported_Functions_Group1 Peripheral Extended features functions 
  *  @brief Peripheral Extended features functions 
  *
@verbatim   

 ===============================================================================
                 ##### Peripheral extended features functions #####
 ===============================================================================

    *** Main and Backup Regulators configuration ***
    ================================================
    [..] 
      (+) The backup domain includes 4 Kbytes of backup SRAM accessible only from 
          the CPU, and address in 32-bit, 16-bit or 8-bit mode. Its content is 
          retained even in Standby or VBAT mode when the low power backup regulator
          is enabled. It can be considered as an internal EEPROM when VBAT is 
          always present. You can use the HAL_PWREx_EnableBkUpReg() function to 
          enable the low power backup regulator. 

      (+) When the backup domain is supplied by VDD (analog switch connected to VDD) 
          the backup SRAM is powered from VDD which replaces the VBAT power supply to 
          save battery life.

      (+) The backup SRAM is not mass erased by a tamper event. It is read 
          protected to prevent confidential data, such as cryptographic private 
          key, from being accessed. The backup SRAM can be erased only through 
          the Flash interface when a protection level change from level 1 to 
          level 0 is requested. 
      -@- Refer to the description of Read protection (RDP) in the Flash 
          programming manual.

        Refer to the product datasheets for more details.

    *** FLASH Power Down configuration ****
    =======================================
    [..] 
      (+) By setting the FPDS bit in the PWR_CR register by using the 
          HAL_PWREx_EnableFlashPowerDown() function, the Flash memory also enters power 
          down mode when the device enters Stop mode. When the Flash memory 
          is in power down mode, an additional startup delay is incurred when 
          waking up from Stop mode.
          
@endverbatim
  * @{
  */

/**
  * @brief Enables the Backup Regulator.
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_PWREx_EnableBkUpReg(void)
{
  uint32_t tickstart = 0U;

  *(__IO uint32_t *) CSR_BRE_BB = (uint32_t)ENABLE;

  /* Get tick */
  tickstart = HAL_GetTick();

  /* Wait till Backup regulator ready flag is set */  
  while(__HAL_PWR_GET_FLAG(PWR_FLAG_BRR) == RESET)
  {
    if((HAL_GetTick() - tickstart ) > PWR_BKPREG_TIMEOUT_VALUE)
    {
      return HAL_TIMEOUT;
    } 
  }
  return HAL_OK;
}

/**
  * @brief Disables the Backup Regulator.
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_PWREx_DisableBkUpReg(void)
{
  uint32_t tickstart = 0U;

  *(__IO uint32_t *) CSR_BRE_BB = (uint32_t)DISABLE;

  /* Get tick */
  tickstart = HAL_GetTick();

  /* Wait till Backup regulator ready flag is set */  
  while(__HAL_PWR_GET_FLAG(PWR_FLAG_BRR) != RESET)
  {
    if((HAL_GetTick() - tickstart ) > PWR_BKPREG_TIMEOUT_VALUE)
    {
      return HAL_TIMEOUT;
    } 
  }
  return HAL_OK;
}

/**
  * @brief Enables the Flash Power Down in Stop mode.
  * @retval None
  */
void HAL_PWREx_EnableFlashPowerDown(void)
{
  *(__IO uint32_t *) CR_FPDS_BB = (uint32_t)ENABLE;
}

/**
  * @brief Disables the Flash Power Down in Stop mode.
  * @retval None
  */
void HAL_PWREx_DisableFlashPowerDown(void)
{
  *(__IO uint32_t *) CR_FPDS_BB = (uint32_t)DISABLE;
}

/**
  * @}
  */

/**
  * @}
  */
#endif /* HAL_PWR_MODULE_ENABLED */
/**
  * @}
  */

/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/