pios_iap.c

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/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, see <http://www.gnu.org/licenses/>
 */

/****************************************************************************************
 *  Header files
 ****************************************************************************************/
#include <pios.h>

/****************************************************************************************
 *  Private Definitions/Macros
 ****************************************************************************************/

/* these definitions reside here for protection and privacy. */
#define IAP_MAGIC_WORD_1        0x1122
#define IAP_MAGIC_WORD_2        0xAA55
#define IAP_MAGIC_WORD_3        0xBB11

#define UPPERWORD16(lw) (uint16_t)((uint32_t)(lw)>>16)
#define LOWERWORD16(lw) (uint16_t)((uint32_t)(lw)&0x0000ffff)
#define UPPERBYTE(w)    (uint8_t)((w)>>8)
#define LOWERBYTE(w)    (uint8_t)((w)&0x00ff)

/****************************************************************************************
 *  Private Functions
 ****************************************************************************************/

/****************************************************************************************
 *  Private (static) Data
 ****************************************************************************************/

/****************************************************************************************
 *  Public/Global Data
 ****************************************************************************************/

void PIOS_IAP_Init( void )
{
        /* Enable CRC clock */
        RCC_AHBPeriphClockCmd(RCC_AHBPeriph_CRC, ENABLE);

        /* Enable PWR and BKP clock */
        RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);

        /* Enable write access to Backup domain */
        PWR_BackupAccessCmd(ENABLE);

        /* Clear Tamper pin Event(TE) pending flag */
        BKP_ClearFlag();

}

uint32_t        PIOS_IAP_CheckRequest( void )
{
        uint32_t        retval = false;
        uint16_t        reg1;
        uint16_t        reg2;

        reg1 = BKP_ReadBackupRegister( MAGIC_REG_1 );
        reg2 = BKP_ReadBackupRegister( MAGIC_REG_2 );

        if( reg1 == IAP_MAGIC_WORD_1 && reg2 == IAP_MAGIC_WORD_2 ) {
                // We have a match.
                retval = true;
        } else {
                retval = false;
        }
        return retval;
}

uint32_t        PIOS_Boot_CheckRequest( void )
{
        uint32_t        retval = false;
        uint16_t        reg1;
        uint16_t        reg2;

        reg1 = BKP_ReadBackupRegister( MAGIC_REG_1 );
        reg2 = BKP_ReadBackupRegister( MAGIC_REG_2 );

        if( reg1 == IAP_MAGIC_WORD_1 && reg2 == IAP_MAGIC_WORD_3 ) {
                // We have a match.
                retval = true;
        } else {
                retval = false;
        }
        return retval;
}

void    PIOS_IAP_SetRequest1(void)
{
        BKP_WriteBackupRegister( MAGIC_REG_1, IAP_MAGIC_WORD_1);
}

void    PIOS_IAP_SetRequest2(void)
{
        BKP_WriteBackupRegister( MAGIC_REG_2, IAP_MAGIC_WORD_2);
}

void    PIOS_IAP_SetRequest3(void)
{
        BKP_WriteBackupRegister( MAGIC_REG_2, IAP_MAGIC_WORD_3);
}

void    PIOS_IAP_ClearRequest(void)
{
        BKP_WriteBackupRegister( MAGIC_REG_1, 0);
        BKP_WriteBackupRegister( MAGIC_REG_2, 0);
}

uint16_t PIOS_IAP_ReadBootCount(void)
{
        return BKP_ReadBackupRegister ( IAP_BOOTCOUNT );
}

void PIOS_IAP_WriteBootCount (uint16_t boot_count)
{
        BKP_WriteBackupRegister ( IAP_BOOTCOUNT, boot_count );
}