STM32F10x_StdPeriph_Driver/src/stm32f10x_can.c

/**
  ******************************************************************************
  * @file    stm32f10x_can.c
  * @author  MCD Application Team
  * @version V3.4.0
  * @date    10/15/2010
  * @brief   This file provides all the CAN firmware functions.
  ******************************************************************************
  * @copy
  *
  * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
  * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
  * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
  * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
  * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
  * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
  *
  * <h2><center>&copy; COPYRIGHT 2010 STMicroelectronics</center></h2>
  */

/* Includes ------------------------------------------------------------------*/
#include "stm32f10x_can.h"
#include "stm32f10x_rcc.h"

/** @addtogroup STM32F10x_StdPeriph_Driver
  * @{
  */

/** @defgroup CAN
  * @brief CAN driver modules
  * @{
  */

/** @defgroup CAN_Private_TypesDefinitions
  * @{
  */

/**
  * @}
  */

/** @defgroup CAN_Private_Defines
  * @{
  */

/* CAN Master Control Register bits */

#define MCR_DBF      ((uint32_t)0x00010000) /* software master reset */

/* CAN Mailbox Transmit Request */
#define TMIDxR_TXRQ  ((uint32_t)0x00000001) /* Transmit mailbox request */

/* CAN Filter Master Register bits */
#define FMR_FINIT    ((uint32_t)0x00000001) /* Filter init mode */

/* Time out for INAK bit */
#define INAK_TIMEOUT        ((uint32_t)0x0000FFFF)
/* Time out for SLAK bit */
#define SLAK_TIMEOUT        ((uint32_t)0x0000FFFF)


/* Flags in TSR register */
#define CAN_FLAGS_TSR              ((uint32_t)0x08000000)
/* Flags in RF1R register */
#define CAN_FLAGS_RF1R             ((uint32_t)0x04000000)
/* Flags in RF0R register */
#define CAN_FLAGS_RF0R             ((uint32_t)0x02000000)
/* Flags in MSR register */
#define CAN_FLAGS_MSR              ((uint32_t)0x01000000)
/* Flags in ESR register */
#define CAN_FLAGS_ESR              ((uint32_t)0x00F00000)


/**
  * @}
  */

/** @defgroup CAN_Private_Macros
  * @{
  */

/**
  * @}
  */

/** @defgroup CAN_Private_Variables
  * @{
  */

/**
  * @}
  */

/** @defgroup CAN_Private_FunctionPrototypes
  * @{
  */

static ITStatus CheckITStatus(uint32_t CAN_Reg, uint32_t It_Bit);

/**
  * @}
  */

/** @defgroup CAN_Private_Functions
  * @{
  */

/**
  * @brief  Deinitializes the CAN peripheral registers to their default reset values.
  * @param  CANx: where x can be 1 or 2 to select the CAN peripheral.
  * @retval None.
  */
void CAN_DeInit(CAN_TypeDef* CANx)
{
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));

  if (CANx == CAN1)
  {
    /* Enable CAN1 reset state */
    RCC_APB1PeriphResetCmd(RCC_APB1Periph_CAN1, ENABLE);
    /* Release CAN1 from reset state */
    RCC_APB1PeriphResetCmd(RCC_APB1Periph_CAN1, DISABLE);
  }
  else
  {
    /* Enable CAN2 reset state */
    RCC_APB1PeriphResetCmd(RCC_APB1Periph_CAN2, ENABLE);
    /* Release CAN2 from reset state */
    RCC_APB1PeriphResetCmd(RCC_APB1Periph_CAN2, DISABLE);
  }
}

/**
  * @brief  Initializes the CAN peripheral according to the specified
  *   parameters in the CAN_InitStruct.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  CAN_InitStruct: pointer to a CAN_InitTypeDef structure that
  *   contains the configuration information for the CAN peripheral.
  * @retval Constant indicates initialization succeed which will be
  *   CANINITFAILED or CANINITOK.
  */
uint8_t CAN_Init(CAN_TypeDef* CANx, CAN_InitTypeDef* CAN_InitStruct)
{
  uint8_t InitStatus = CANINITFAILED;
  uint32_t wait_ack = 0x00000000;
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_FUNCTIONAL_STATE(CAN_InitStruct->CAN_TTCM));
  assert_param(IS_FUNCTIONAL_STATE(CAN_InitStruct->CAN_ABOM));
  assert_param(IS_FUNCTIONAL_STATE(CAN_InitStruct->CAN_AWUM));
  assert_param(IS_FUNCTIONAL_STATE(CAN_InitStruct->CAN_NART));
  assert_param(IS_FUNCTIONAL_STATE(CAN_InitStruct->CAN_RFLM));
  assert_param(IS_FUNCTIONAL_STATE(CAN_InitStruct->CAN_TXFP));
  assert_param(IS_CAN_MODE(CAN_InitStruct->CAN_Mode));
  assert_param(IS_CAN_SJW(CAN_InitStruct->CAN_SJW));
  assert_param(IS_CAN_BS1(CAN_InitStruct->CAN_BS1));
  assert_param(IS_CAN_BS2(CAN_InitStruct->CAN_BS2));
  assert_param(IS_CAN_PRESCALER(CAN_InitStruct->CAN_Prescaler));

  /* exit from sleep mode */
  CANx->MCR &= (~(uint32_t)CAN_MCR_SLEEP);

  /* Request initialisation */
  CANx->MCR |= CAN_MCR_INRQ ;

  /* Wait the acknowledge */
  while (((CANx->MSR & CAN_MSR_INAK) != CAN_MSR_INAK) && (wait_ack != INAK_TIMEOUT))
  {
    wait_ack++;
  }

  /* ...and check acknowledged */
  if ((CANx->MSR & CAN_MSR_INAK) != CAN_MSR_INAK)
  {
    InitStatus = CANINITFAILED;
  }
  else
  {
    /* Set the time triggered communication mode */
    if (CAN_InitStruct->CAN_TTCM == ENABLE)
    {
      CANx->MCR |= CAN_MCR_TTCM;
    }
    else
    {
      CANx->MCR &= ~(uint32_t)CAN_MCR_TTCM;
    }

    /* Set the automatic bus-off management */
    if (CAN_InitStruct->CAN_ABOM == ENABLE)
    {
      CANx->MCR |= CAN_MCR_ABOM;
    }
    else
    {
      CANx->MCR &= ~(uint32_t)CAN_MCR_ABOM;
    }

    /* Set the automatic wake-up mode */
    if (CAN_InitStruct->CAN_AWUM == ENABLE)
    {
      CANx->MCR |= CAN_MCR_AWUM;
    }
    else
    {
      CANx->MCR &= ~(uint32_t)CAN_MCR_AWUM;
    }

    /* Set the no automatic retransmission */
    if (CAN_InitStruct->CAN_NART == ENABLE)
    {
      CANx->MCR |= CAN_MCR_NART;
    }
    else
    {
      CANx->MCR &= ~(uint32_t)CAN_MCR_NART;
    }

    /* Set the receive FIFO locked mode */
    if (CAN_InitStruct->CAN_RFLM == ENABLE)
    {
      CANx->MCR |= CAN_MCR_RFLM;
    }
    else
    {
      CANx->MCR &= ~(uint32_t)CAN_MCR_RFLM;
    }

    /* Set the transmit FIFO priority */
    if (CAN_InitStruct->CAN_TXFP == ENABLE)
    {
      CANx->MCR |= CAN_MCR_TXFP;
    }
    else
    {
      CANx->MCR &= ~(uint32_t)CAN_MCR_TXFP;
    }

    /* Set the bit timing register */
    CANx->BTR = (uint32_t)((uint32_t)CAN_InitStruct->CAN_Mode << 30) | ((uint32_t)CAN_InitStruct->CAN_SJW << 24) |
               ((uint32_t)CAN_InitStruct->CAN_BS1 << 16) | ((uint32_t)CAN_InitStruct->CAN_BS2 << 20) |
               ((uint32_t)CAN_InitStruct->CAN_Prescaler - 1);

    /* Request leave initialisation */
    CANx->MCR &= ~(uint32_t)CAN_MCR_INRQ;

   /* Wait the acknowledge */
   wait_ack = 0x00;

   while (((CANx->MSR & CAN_MSR_INAK) == CAN_MSR_INAK) && (wait_ack != INAK_TIMEOUT))
   {
     wait_ack++;
   }

    /* ...and check acknowledged */
    if ((CANx->MSR & CAN_MSR_INAK) == CAN_MSR_INAK)
    {
      InitStatus = CANINITFAILED;
    }
    else
    {
      InitStatus = CANINITOK ;
    }
  }

  /* At this step, return the status of initialization */
  return InitStatus;
}

/**
  * @brief  Initializes the CAN peripheral according to the specified
  *   parameters in the CAN_FilterInitStruct.
  * @param  CAN_FilterInitStruct: pointer to a CAN_FilterInitTypeDef
  *   structure that contains the configuration information.
  * @retval None.
  */
void CAN_FilterInit(CAN_FilterInitTypeDef* CAN_FilterInitStruct)
{
  uint32_t filter_number_bit_pos = 0;
  /* Check the parameters */
  assert_param(IS_CAN_FILTER_NUMBER(CAN_FilterInitStruct->CAN_FilterNumber));
  assert_param(IS_CAN_FILTER_MODE(CAN_FilterInitStruct->CAN_FilterMode));
  assert_param(IS_CAN_FILTER_SCALE(CAN_FilterInitStruct->CAN_FilterScale));
  assert_param(IS_CAN_FILTER_FIFO(CAN_FilterInitStruct->CAN_FilterFIFOAssignment));
  assert_param(IS_FUNCTIONAL_STATE(CAN_FilterInitStruct->CAN_FilterActivation));

  filter_number_bit_pos = ((uint32_t)0x00000001) << CAN_FilterInitStruct->CAN_FilterNumber;

  /* Initialisation mode for the filter */
  CAN1->FMR |= FMR_FINIT;

  /* Filter Deactivation */
  CAN1->FA1R &= ~(uint32_t)filter_number_bit_pos;

  /* Filter Scale */
  if (CAN_FilterInitStruct->CAN_FilterScale == CAN_FilterScale_16bit)
  {
    /* 16-bit scale for the filter */
    CAN1->FS1R &= ~(uint32_t)filter_number_bit_pos;

    /* First 16-bit identifier and First 16-bit mask */
    /* Or First 16-bit identifier and Second 16-bit identifier */
    CAN1->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR1 =
    ((0x0000FFFF & (uint32_t)CAN_FilterInitStruct->CAN_FilterMaskIdLow) << 16) |
        (0x0000FFFF & (uint32_t)CAN_FilterInitStruct->CAN_FilterIdLow);

    /* Second 16-bit identifier and Second 16-bit mask */
    /* Or Third 16-bit identifier and Fourth 16-bit identifier */
    CAN1->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR2 =
    ((0x0000FFFF & (uint32_t)CAN_FilterInitStruct->CAN_FilterMaskIdHigh) << 16) |
        (0x0000FFFF & (uint32_t)CAN_FilterInitStruct->CAN_FilterIdHigh);
  }

  if (CAN_FilterInitStruct->CAN_FilterScale == CAN_FilterScale_32bit)
  {
    /* 32-bit scale for the filter */
    CAN1->FS1R |= filter_number_bit_pos;
    /* 32-bit identifier or First 32-bit identifier */
    CAN1->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR1 =
    ((0x0000FFFF & (uint32_t)CAN_FilterInitStruct->CAN_FilterIdHigh) << 16) |
        (0x0000FFFF & (uint32_t)CAN_FilterInitStruct->CAN_FilterIdLow);
    /* 32-bit mask or Second 32-bit identifier */
    CAN1->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR2 =
    ((0x0000FFFF & (uint32_t)CAN_FilterInitStruct->CAN_FilterMaskIdHigh) << 16) |
        (0x0000FFFF & (uint32_t)CAN_FilterInitStruct->CAN_FilterMaskIdLow);
  }

  /* Filter Mode */
  if (CAN_FilterInitStruct->CAN_FilterMode == CAN_FilterMode_IdMask)
  {
    /*Id/Mask mode for the filter*/
    CAN1->FM1R &= ~(uint32_t)filter_number_bit_pos;
  }
  else /* CAN_FilterInitStruct->CAN_FilterMode == CAN_FilterMode_IdList */
  {
    /*Identifier list mode for the filter*/
    CAN1->FM1R |= (uint32_t)filter_number_bit_pos;
  }

  /* Filter FIFO assignment */
  if (CAN_FilterInitStruct->CAN_FilterFIFOAssignment == CAN_FilterFIFO0)
  {
    /* FIFO 0 assignation for the filter */
    CAN1->FFA1R &= ~(uint32_t)filter_number_bit_pos;
  }

  if (CAN_FilterInitStruct->CAN_FilterFIFOAssignment == CAN_FilterFIFO1)
  {
    /* FIFO 1 assignation for the filter */
    CAN1->FFA1R |= (uint32_t)filter_number_bit_pos;
  }

  /* Filter activation */
  if (CAN_FilterInitStruct->CAN_FilterActivation == ENABLE)
  {
    CAN1->FA1R |= filter_number_bit_pos;
  }

  /* Leave the initialisation mode for the filter */
  CAN1->FMR &= ~FMR_FINIT;
}

/**
  * @brief  Fills each CAN_InitStruct member with its default value.
  * @param  CAN_InitStruct: pointer to a CAN_InitTypeDef structure which
  *   will be initialized.
  * @retval None.
  */
void CAN_StructInit(CAN_InitTypeDef* CAN_InitStruct)
{
  /* Reset CAN init structure parameters values */
  /* Initialize the time triggered communication mode */
  CAN_InitStruct->CAN_TTCM = DISABLE;
  /* Initialize the automatic bus-off management */
  CAN_InitStruct->CAN_ABOM = DISABLE;
  /* Initialize the automatic wake-up mode */
  CAN_InitStruct->CAN_AWUM = DISABLE;
  /* Initialize the no automatic retransmission */
  CAN_InitStruct->CAN_NART = DISABLE;
  /* Initialize the receive FIFO locked mode */
  CAN_InitStruct->CAN_RFLM = DISABLE;
  /* Initialize the transmit FIFO priority */
  CAN_InitStruct->CAN_TXFP = DISABLE;
  /* Initialize the CAN_Mode member */
  CAN_InitStruct->CAN_Mode = CAN_Mode_Normal;
  /* Initialize the CAN_SJW member */
  CAN_InitStruct->CAN_SJW = CAN_SJW_1tq;
  /* Initialize the CAN_BS1 member */
  CAN_InitStruct->CAN_BS1 = CAN_BS1_4tq;
  /* Initialize the CAN_BS2 member */
  CAN_InitStruct->CAN_BS2 = CAN_BS2_3tq;
  /* Initialize the CAN_Prescaler member */
  CAN_InitStruct->CAN_Prescaler = 1;
}

/**
  * @brief  Select the start bank filter for slave CAN.
  * @note   This function applies only to STM32 Connectivity line devices.
  * @param  CAN_BankNumber: Select the start slave bank filter from 1..27.
  * @retval None.
  */
void CAN_SlaveStartBank(uint8_t CAN_BankNumber)
{
  /* Check the parameters */
  assert_param(IS_CAN_BANKNUMBER(CAN_BankNumber));
  /* enter Initialisation mode for the filter */
  CAN1->FMR |= FMR_FINIT;
  /* Select the start slave bank */
  CAN1->FMR &= (uint32_t)0xFFFFC0F1 ;
  CAN1->FMR |= (uint32_t)(CAN_BankNumber)<<8;
  /* Leave Initialisation mode for the filter */
  CAN1->FMR &= ~FMR_FINIT;
}

/**
  * @brief  Enables or disables the specified CANx interrupts.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  CAN_IT: specifies the CAN interrupt sources to be enabled or disabled.
  *   This parameter can be:
  *        -CAN_IT_TME,
  *        -CAN_IT_FMP0,
  *        -CAN_IT_FF0,
  *        -CAN_IT_FOV0,
  *        -CAN_IT_FMP1,
  *        -CAN_IT_FF1,
  *        -CAN_IT_FOV1,
  *        -CAN_IT_EWG,
  *        -CAN_IT_EPV,
  *        -CAN_IT_LEC,
  *        -CAN_IT_ERR,
  *        -CAN_IT_WKU or
  *        -CAN_IT_SLK.
  * @param  NewState: new state of the CAN interrupts.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None.
  */
void CAN_ITConfig(CAN_TypeDef* CANx, uint32_t CAN_IT, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_IT(CAN_IT));
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable the selected CANx interrupt */
    CANx->IER |= CAN_IT;
  }
  else
  {
    /* Disable the selected CANx interrupt */
    CANx->IER &= ~CAN_IT;
  }
}

/**
  * @brief  Initiates the transmission of a message.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  TxMessage: pointer to a structure which contains CAN Id, CAN
  *   DLC and CAN datas.
  * @retval The number of the mailbox that is used for transmission
  *   or CAN_NO_MB if there is no empty mailbox.
  */
uint8_t CAN_Transmit(CAN_TypeDef* CANx, CanTxMsg* TxMessage)
{
  uint8_t transmit_mailbox = 0;
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_IDTYPE(TxMessage->IDE));
  assert_param(IS_CAN_RTR(TxMessage->RTR));
  assert_param(IS_CAN_DLC(TxMessage->DLC));

  /* Select one empty transmit mailbox */
  if ((CANx->TSR&CAN_TSR_TME0) == CAN_TSR_TME0)
  {
    transmit_mailbox = 0;
  }
  else if ((CANx->TSR&CAN_TSR_TME1) == CAN_TSR_TME1)
  {
    transmit_mailbox = 1;
  }
  else if ((CANx->TSR&CAN_TSR_TME2) == CAN_TSR_TME2)
  {
    transmit_mailbox = 2;
  }
  else
  {
    transmit_mailbox = CAN_NO_MB;
  }

  if (transmit_mailbox != CAN_NO_MB)
  {
    /* Set up the Id */
    CANx->sTxMailBox[transmit_mailbox].TIR &= TMIDxR_TXRQ;
    if (TxMessage->IDE == CAN_ID_STD)
    {
      assert_param(IS_CAN_STDID(TxMessage->StdId));
      CANx->sTxMailBox[transmit_mailbox].TIR |= ((TxMessage->StdId << 21) | TxMessage->RTR);
    }
    else
    {
      assert_param(IS_CAN_EXTID(TxMessage->ExtId));
      CANx->sTxMailBox[transmit_mailbox].TIR |= ((TxMessage->ExtId<<3) | TxMessage->IDE |
                                               TxMessage->RTR);
    }


    /* Set up the DLC */
    TxMessage->DLC &= (uint8_t)0x0000000F;
    CANx->sTxMailBox[transmit_mailbox].TDTR &= (uint32_t)0xFFFFFFF0;
    CANx->sTxMailBox[transmit_mailbox].TDTR |= TxMessage->DLC;

    /* Set up the data field */
    CANx->sTxMailBox[transmit_mailbox].TDLR = (((uint32_t)TxMessage->Data[3] << 24) |
                                             ((uint32_t)TxMessage->Data[2] << 16) |
                                             ((uint32_t)TxMessage->Data[1] << 8) |
                                             ((uint32_t)TxMessage->Data[0]));
    CANx->sTxMailBox[transmit_mailbox].TDHR = (((uint32_t)TxMessage->Data[7] << 24) |
                                             ((uint32_t)TxMessage->Data[6] << 16) |
                                             ((uint32_t)TxMessage->Data[5] << 8) |
                                             ((uint32_t)TxMessage->Data[4]));
    /* Request transmission */
    CANx->sTxMailBox[transmit_mailbox].TIR |= TMIDxR_TXRQ;
  }
  return transmit_mailbox;
}

/**
  * @brief  Checks the transmission of a message.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  TransmitMailbox: the number of the mailbox that is used for transmission.
  * @retval CANTXOK if the CAN driver transmits the message, CANTXFAILED in an other case.
  */
uint8_t CAN_TransmitStatus(CAN_TypeDef* CANx, uint8_t TransmitMailbox)
{
  /* RQCP, TXOK and TME bits */
  uint8_t state = 0;
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_TRANSMITMAILBOX(TransmitMailbox));
  switch (TransmitMailbox)
  {
    case (0): state |= (uint8_t)((CANx->TSR & CAN_TSR_RQCP0) << 2);
      state |= (uint8_t)((CANx->TSR & CAN_TSR_TXOK0) >> 0);
      state |= (uint8_t)((CANx->TSR & CAN_TSR_TME0) >> 26);
      break;
    case (1): state |= (uint8_t)((CANx->TSR & CAN_TSR_RQCP1) >> 6);
      state |= (uint8_t)((CANx->TSR & CAN_TSR_TXOK1) >> 8);
      state |= (uint8_t)((CANx->TSR & CAN_TSR_TME1) >> 27);
      break;
    case (2): state |= (uint8_t)((CANx->TSR & CAN_TSR_RQCP2) >> 14);
      state |= (uint8_t)((CANx->TSR & CAN_TSR_TXOK2) >> 16);
      state |= (uint8_t)((CANx->TSR & CAN_TSR_TME2) >> 28);
      break;
    default:
      state = CANTXFAILED;
      break;
  }
  switch (state)
  {
      /* transmit pending  */
    case (0x0): state = CANTXPENDING;
      break;
      /* transmit failed  */
    case (0x5): state = CANTXFAILED;
      break;
      /* transmit succedeed  */
    case (0x7): state = CANTXOK;
      break;
    default:
      state = CANTXFAILED;
      break;
  }
  return state;
}

/**
  * @brief  Cancels a transmit request.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  Mailbox: Mailbox number.
  * @retval None.
  */
void CAN_CancelTransmit(CAN_TypeDef* CANx, uint8_t Mailbox)
{
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_TRANSMITMAILBOX(Mailbox));
  /* abort transmission */
  switch (Mailbox)
  {
    case (0): CANx->TSR |= CAN_TSR_ABRQ0;
      break;
    case (1): CANx->TSR |= CAN_TSR_ABRQ1;
      break;
    case (2): CANx->TSR |= CAN_TSR_ABRQ2;
      break;
    default:
      break;
  }
}

/**
  * @brief  Releases a FIFO.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  FIFONumber: FIFO to release, CAN_FIFO0 or CAN_FIFO1.
  * @retval None.
  */
void CAN_FIFORelease(CAN_TypeDef* CANx, uint8_t FIFONumber)
{
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_FIFO(FIFONumber));
  /* Release FIFO0 */
  if (FIFONumber == CAN_FIFO0)
  {
    CANx->RF0R |= CAN_RF0R_RFOM0;
  }
  /* Release FIFO1 */
  else /* FIFONumber == CAN_FIFO1 */
  {
    CANx->RF1R |= CAN_RF1R_RFOM1;
  }
}

/**
  * @brief  Returns the number of pending messages.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  FIFONumber: Receive FIFO number, CAN_FIFO0 or CAN_FIFO1.
  * @retval NbMessage which is the number of pending message.
  */
uint8_t CAN_MessagePending(CAN_TypeDef* CANx, uint8_t FIFONumber)
{
  uint8_t message_pending=0;
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_FIFO(FIFONumber));
  if (FIFONumber == CAN_FIFO0)
  {
    message_pending = (uint8_t)(CANx->RF0R&(uint32_t)0x03);
  }
  else if (FIFONumber == CAN_FIFO1)
  {
    message_pending = (uint8_t)(CANx->RF1R&(uint32_t)0x03);
  }
  else
  {
    message_pending = 0;
  }
  return message_pending;
}

/**
  * @brief  Receives a message.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  FIFONumber: Receive FIFO number, CAN_FIFO0 or CAN_FIFO1.
  * @param  RxMessage: pointer to a structure receive message which
  *   contains CAN Id, CAN DLC, CAN datas and FMI number.
  * @retval None.
  */
void CAN_Receive(CAN_TypeDef* CANx, uint8_t FIFONumber, CanRxMsg* RxMessage)
{
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_FIFO(FIFONumber));
  /* Get the Id */
  RxMessage->IDE = (uint8_t)0x04 & CANx->sFIFOMailBox[FIFONumber].RIR;
  if (RxMessage->IDE == CAN_ID_STD)
  {
    RxMessage->StdId = (uint32_t)0x000007FF & (CANx->sFIFOMailBox[FIFONumber].RIR >> 21);
  }
  else
  {
    RxMessage->ExtId = (uint32_t)0x1FFFFFFF & (CANx->sFIFOMailBox[FIFONumber].RIR >> 3);
  }

  RxMessage->RTR = (uint8_t)0x02 & CANx->sFIFOMailBox[FIFONumber].RIR;
  /* Get the DLC */
  RxMessage->DLC = (uint8_t)0x0F & CANx->sFIFOMailBox[FIFONumber].RDTR;
  /* Get the FMI */
  RxMessage->FMI = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDTR >> 8);
  /* Get the data field */
  RxMessage->Data[0] = (uint8_t)0xFF & CANx->sFIFOMailBox[FIFONumber].RDLR;
  RxMessage->Data[1] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDLR >> 8);
  RxMessage->Data[2] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDLR >> 16);
  RxMessage->Data[3] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDLR >> 24);
  RxMessage->Data[4] = (uint8_t)0xFF & CANx->sFIFOMailBox[FIFONumber].RDHR;
  RxMessage->Data[5] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDHR >> 8);
  RxMessage->Data[6] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDHR >> 16);
  RxMessage->Data[7] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDHR >> 24);
  /* Release the FIFO */
  CAN_FIFORelease(CANx, FIFONumber);
}

/**
  * @brief  Enables or disables the DBG Freeze for CAN.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  NewState: new state of the CAN peripheral.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None.
  */
void CAN_DBGFreeze(CAN_TypeDef* CANx, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable Debug Freeze  */
    CANx->MCR |= MCR_DBF;
  }
  else
  {
    /* Disable Debug Freeze */
    CANx->MCR &= ~MCR_DBF;
  }
}

/**
  * @brief  Enters the low power mode.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @retval CANSLEEPOK if sleep entered, CANSLEEPFAILED in an other case.
  */
uint8_t CAN_Sleep(CAN_TypeDef* CANx)
{
  uint8_t sleepstatus = CANSLEEPFAILED;

  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));

  /* Request Sleep mode */
   CANx->MCR = (((CANx->MCR) & (uint32_t)(~(uint32_t)CAN_MCR_INRQ)) | CAN_MCR_SLEEP);

  /* Sleep mode status */
  if ((CANx->MSR & (CAN_MSR_SLAK|CAN_MSR_INAK)) == CAN_MSR_SLAK)
  {
    /* Sleep mode not entered */
    sleepstatus =  CANSLEEPOK;
  }
  /* At this step, sleep mode status */
   return (uint8_t)sleepstatus;
}

/**
  * @brief  Wakes the CAN up.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @retval CANWAKEUPOK if sleep mode left, CANWAKEUPFAILED in an other case.
  */
uint8_t CAN_WakeUp(CAN_TypeDef* CANx)
{
  uint32_t wait_slak = SLAK_TIMEOUT;
  uint8_t wakeupstatus = CANWAKEUPFAILED;

  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));

  /* Wake up request */
  CANx->MCR &= ~(uint32_t)CAN_MCR_SLEEP;

  /* Sleep mode status */
  while(((CANx->MSR & CAN_MSR_SLAK) == CAN_MSR_SLAK)&&(wait_slak!=0x00))
  {
   wait_slak--;
  }
  if((CANx->MSR & CAN_MSR_SLAK) != CAN_MSR_SLAK)
  {
   /* Sleep mode exited */
    wakeupstatus = CANWAKEUPOK;
  }
  /* At this step, sleep mode status */
  return (uint8_t)wakeupstatus;
}

/**
  * @brief  Checks whether the specified CAN flag is set or not.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  CAN_FLAG: specifies the flag to check.
  *   This parameter can be one of the following flags:
  *         - CAN_FLAG_EWG
  *         - CAN_FLAG_EPV
  *         - CAN_FLAG_BOF
  *         - CAN_FLAG_RQCP0
  *         - CAN_FLAG_RQCP1
  *         - CAN_FLAG_RQCP2
  *         - CAN_FLAG_FMP1
  *         - CAN_FLAG_FF1
  *         - CAN_FLAG_FOV1
  *         - CAN_FLAG_FMP0
  *         - CAN_FLAG_FF0
  *         - CAN_FLAG_FOV0
  *         - CAN_FLAG_WKU
  *         - CAN_FLAG_SLAK
  *         - CAN_FLAG_LEC
  * @retval The new state of CAN_FLAG (SET or RESET).
  */
FlagStatus CAN_GetFlagStatus(CAN_TypeDef* CANx, uint32_t CAN_FLAG)
{
  FlagStatus bitstatus = RESET;

  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_GET_FLAG(CAN_FLAG));


  if((CAN_FLAG & CAN_FLAGS_ESR) != (uint32_t)RESET)
  {
    /* Check the status of the specified CAN flag */
    if ((CANx->ESR & (CAN_FLAG & 0x000FFFFF)) != (uint32_t)RESET)
    {
      /* CAN_FLAG is set */
      bitstatus = SET;
    }
    else
    {
      /* CAN_FLAG is reset */
      bitstatus = RESET;
    }
  }
  else if((CAN_FLAG & CAN_FLAGS_MSR) != (uint32_t)RESET)
  {
    /* Check the status of the specified CAN flag */
    if ((CANx->MSR & (CAN_FLAG & 0x000FFFFF)) != (uint32_t)RESET)
    {
      /* CAN_FLAG is set */
      bitstatus = SET;
    }
    else
    {
      /* CAN_FLAG is reset */
      bitstatus = RESET;
    }
  }
  else if((CAN_FLAG & CAN_FLAGS_TSR) != (uint32_t)RESET)
  {
    /* Check the status of the specified CAN flag */
    if ((CANx->TSR & (CAN_FLAG & 0x000FFFFF)) != (uint32_t)RESET)
    {
      /* CAN_FLAG is set */
      bitstatus = SET;
    }
    else
    {
      /* CAN_FLAG is reset */
      bitstatus = RESET;
    }
  }
  else if((CAN_FLAG & CAN_FLAGS_RF0R) != (uint32_t)RESET)
  {
    /* Check the status of the specified CAN flag */
    if ((CANx->RF0R & (CAN_FLAG & 0x000FFFFF)) != (uint32_t)RESET)
    {
      /* CAN_FLAG is set */
      bitstatus = SET;
    }
    else
    {
      /* CAN_FLAG is reset */
      bitstatus = RESET;
    }
  }
  else /* If(CAN_FLAG & CAN_FLAGS_RF1R != (uint32_t)RESET) */
  {
    /* Check the status of the specified CAN flag */
    if ((uint32_t)(CANx->RF1R & (CAN_FLAG & 0x000FFFFF)) != (uint32_t)RESET)
    {
      /* CAN_FLAG is set */
      bitstatus = SET;
    }
    else
    {
      /* CAN_FLAG is reset */
      bitstatus = RESET;
    }
  }
  /* Return the CAN_FLAG status */
  return  bitstatus;
}

/**
  * @brief  Clears the CAN's pending flags.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  CAN_FLAG: specifies the flag to clear.
  *   This parameter can be one of the following flags:
  *         - CAN_FLAG_RQCP0
  *         - CAN_FLAG_RQCP1
  *         - CAN_FLAG_RQCP2
  *         - CAN_FLAG_FF1
  *         - CAN_FLAG_FOV1
  *         - CAN_FLAG_FF0
  *         - CAN_FLAG_FOV0
  *         - CAN_FLAG_WKU
  *         - CAN_FLAG_SLAK
  *         - CAN_FLAG_LEC
  * @retval None.
  */
void CAN_ClearFlag(CAN_TypeDef* CANx, uint32_t CAN_FLAG)
{
  uint32_t flagtmp=0;
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_CLEAR_FLAG(CAN_FLAG));

  if (CAN_FLAG == CAN_FLAG_LEC) /* ESR register */
  {
    /* Clear the selected CAN flags */
    CANx->ESR = (uint32_t)RESET;
  }
  else /* MSR or TSR or RF0R or RF1R */
  {
    flagtmp = CAN_FLAG & 0x000FFFFF;

    if ((CAN_FLAG & CAN_FLAGS_RF0R)!=(uint32_t)RESET)
    {
      /* Receive Flags */
      CANx->RF0R = (uint32_t)(flagtmp);
    }
    else if ((CAN_FLAG & CAN_FLAGS_RF1R)!=(uint32_t)RESET)
    {
      /* Receive Flags */
      CANx->RF1R = (uint32_t)(flagtmp);
    }
    else if ((CAN_FLAG & CAN_FLAGS_TSR)!=(uint32_t)RESET)
    {
      /* Transmit Flags */
      CANx->TSR = (uint32_t)(flagtmp);
    }
    else /* If((CAN_FLAG & CAN_FLAGS_MSR)!=(uint32_t)RESET) */
    {
      /* Operating mode Flags */
      CANx->MSR = (uint32_t)(flagtmp);
    }
  }
}

/**
  * @brief  Checks whether the specified CANx interrupt has occurred or not.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  CAN_IT: specifies the CAN interrupt source to check.
  *   This parameter can be one of the following flags:
  *         -  CAN_IT_TME
  *         -  CAN_IT_FMP0
  *         -  CAN_IT_FF0
  *         -  CAN_IT_FOV0
  *         -  CAN_IT_FMP1
  *         -  CAN_IT_FF1
  *         -  CAN_IT_FOV1
  *         -  CAN_IT_WKU
  *         -  CAN_IT_SLK
  *         -  CAN_IT_EWG
  *         -  CAN_IT_EPV
  *         -  CAN_IT_BOF
  *         -  CAN_IT_LEC
  *         -  CAN_IT_ERR
  * @retval The current  state of CAN_IT (SET or RESET).
  */
ITStatus CAN_GetITStatus(CAN_TypeDef* CANx, uint32_t CAN_IT)
{
  ITStatus itstatus = RESET;
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_IT(CAN_IT));

  /* check the enable interrupt bit */
 if((CANx->IER & CAN_IT) != RESET)
 {
   /* in case the Interrupt is enabled, .... */
    switch (CAN_IT)
    {
      case CAN_IT_TME:
               /* Check CAN_TSR_RQCPx bits */
	      itstatus = CheckITStatus(CANx->TSR, CAN_TSR_RQCP0|CAN_TSR_RQCP1|CAN_TSR_RQCP2);
	      break;
      case CAN_IT_FMP0:
               /* Check CAN_RF0R_FMP0 bit */
	      itstatus = CheckITStatus(CANx->RF0R, CAN_RF0R_FMP0);
	      break;
      case CAN_IT_FF0:
               /* Check CAN_RF0R_FULL0 bit */
              itstatus = CheckITStatus(CANx->RF0R, CAN_RF0R_FULL0);
	      break;
      case CAN_IT_FOV0:
               /* Check CAN_RF0R_FOVR0 bit */
              itstatus = CheckITStatus(CANx->RF0R, CAN_RF0R_FOVR0);
	      break;
      case CAN_IT_FMP1:
               /* Check CAN_RF1R_FMP1 bit */
              itstatus = CheckITStatus(CANx->RF1R, CAN_RF1R_FMP1);
	      break;
      case CAN_IT_FF1:
               /* Check CAN_RF1R_FULL1 bit */
	      itstatus = CheckITStatus(CANx->RF1R, CAN_RF1R_FULL1);
	      break;
      case CAN_IT_FOV1:
               /* Check CAN_RF1R_FOVR1 bit */
	      itstatus = CheckITStatus(CANx->RF1R, CAN_RF1R_FOVR1);
	      break;
      case CAN_IT_WKU:
               /* Check CAN_MSR_WKUI bit */
              itstatus = CheckITStatus(CANx->MSR, CAN_MSR_WKUI);
	      break;
      case CAN_IT_SLK:
               /* Check CAN_MSR_SLAKI bit */
	      itstatus = CheckITStatus(CANx->MSR, CAN_MSR_SLAKI);
	      break;
      case CAN_IT_EWG:
               /* Check CAN_ESR_EWGF bit */
	      itstatus = CheckITStatus(CANx->ESR, CAN_ESR_EWGF);
	      break;
      case CAN_IT_EPV:
               /* Check CAN_ESR_EPVF bit */
	     itstatus = CheckITStatus(CANx->ESR, CAN_ESR_EPVF);
	      break;
      case CAN_IT_BOF:
               /* Check CAN_ESR_BOFF bit */
	     itstatus = CheckITStatus(CANx->ESR, CAN_ESR_BOFF);
	      break;
      case CAN_IT_LEC:
               /* Check CAN_ESR_LEC bit */
	     itstatus = CheckITStatus(CANx->ESR, CAN_ESR_LEC);
	      break;
      case CAN_IT_ERR:
               /* Check CAN_MSR_ERRI, CAN_ESR_EWGF, CAN_ESR_EPVF, CAN_ESR_BOFF and CAN_ESR_LEC  bits */
	      itstatus = CheckITStatus(CANx->ESR, CAN_ESR_EWGF|CAN_ESR_EPVF|CAN_ESR_BOFF|CAN_ESR_LEC);
              itstatus |= CheckITStatus(CANx->MSR, CAN_MSR_ERRI);
	      break;
      default :
               /* in case of error, return RESET */
              itstatus = RESET;
              break;
    }
  }
  else
  {
   /* in case the Interrupt is not enabled, return RESET */
    itstatus  = RESET;
  }

  /* Return the CAN_IT status */
  return  itstatus;
}

/**
  * @brief  Clears the CANx�s interrupt pending bits.
  * @param  CANx: where x can be 1 or 2 to to select the CAN peripheral.
  * @param  CAN_IT: specifies the interrupt pending bit to clear.
  *         -  CAN_IT_TME
  *         -  CAN_IT_FF0
  *         -  CAN_IT_FOV0
  *         -  CAN_IT_FF1
  *         -  CAN_IT_FOV1
  *         -  CAN_IT_WKU
  *         -  CAN_IT_SLK
  *         -  CAN_IT_EWG
  *         -  CAN_IT_EPV
  *         -  CAN_IT_BOF
  *         -  CAN_IT_LEC
  *         -  CAN_IT_ERR
  * @retval None.
  */
void CAN_ClearITPendingBit(CAN_TypeDef* CANx, uint32_t CAN_IT)
{
  /* Check the parameters */
  assert_param(IS_CAN_ALL_PERIPH(CANx));
  assert_param(IS_CAN_CLEAR_IT(CAN_IT));

  switch (CAN_IT)
  {
      case CAN_IT_TME:
              /* Clear CAN_TSR_RQCPx (rc_w1)*/
	      CANx->TSR = CAN_TSR_RQCP0|CAN_TSR_RQCP1|CAN_TSR_RQCP2;
	      break;
      case CAN_IT_FF0:
              /* Clear CAN_RF0R_FULL0 (rc_w1)*/
	      CANx->RF0R = CAN_RF0R_FULL0;
	      break;
      case CAN_IT_FOV0:
              /* Clear CAN_RF0R_FOVR0 (rc_w1)*/
	      CANx->RF0R = CAN_RF0R_FOVR0;
	      break;
      case CAN_IT_FF1:
              /* Clear CAN_RF1R_FULL1 (rc_w1)*/
	      CANx->RF1R = CAN_RF1R_FULL1;
	      break;
      case CAN_IT_FOV1:
              /* Clear CAN_RF1R_FOVR1 (rc_w1)*/
	      CANx->RF1R = CAN_RF1R_FOVR1;
	      break;
      case CAN_IT_WKU:
              /* Clear CAN_MSR_WKUI (rc_w1)*/
	      CANx->MSR = CAN_MSR_WKUI;
	      break;
      case CAN_IT_SLK:
              /* Clear CAN_MSR_SLAKI (rc_w1)*/
	      CANx->MSR = CAN_MSR_SLAKI;
	      break;
      case CAN_IT_EWG:
              /* Clear CAN_MSR_ERRI (rc_w1) */
	      CANx->MSR = CAN_MSR_ERRI;
              /* Note : the corresponding Flag is cleared by hardware depending of the CAN Bus status*/
	      break;
      case CAN_IT_EPV:
              /* Clear CAN_MSR_ERRI (rc_w1) */
	      CANx->MSR = CAN_MSR_ERRI;
              /* Note : the corresponding Flag is cleared by hardware depending of the CAN Bus status*/
	      break;
      case CAN_IT_BOF:
              /* Clear CAN_MSR_ERRI (rc_w1) */
	      CANx->MSR = CAN_MSR_ERRI;
              /* Note : the corresponding Flag is cleared by hardware depending of the CAN Bus status*/
	      break;
      case CAN_IT_LEC:
              /*  Clear LEC bits */
	      CANx->ESR = RESET;
              /* Clear CAN_MSR_ERRI (rc_w1) */
	      CANx->MSR = CAN_MSR_ERRI;
	      break;
      case CAN_IT_ERR:
              /*Clear LEC bits */
	      CANx->ESR = RESET;
              /* Clear CAN_MSR_ERRI (rc_w1) */
	      CANx->MSR = CAN_MSR_ERRI;
	      /* Note : BOFF, EPVF and EWGF Flags are cleared by hardware depending of the CAN Bus status*/
	      break;
      default :
	      break;
   }
}

/**
  * @brief  Checks whether the CAN interrupt has occurred or not.
  * @param  CAN_Reg: specifies the CAN interrupt register to check.
  * @param  It_Bit: specifies the interrupt source bit to check.
  * @retval The new state of the CAN Interrupt (SET or RESET).
  */
static ITStatus CheckITStatus(uint32_t CAN_Reg, uint32_t It_Bit)
{
  ITStatus pendingbitstatus = RESET;

  if ((CAN_Reg & It_Bit) != (uint32_t)RESET)
  {
    /* CAN_IT is set */
    pendingbitstatus = SET;
  }
  else
  {
    /* CAN_IT is reset */
    pendingbitstatus = RESET;
  }
  return pendingbitstatus;
}

/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */

/******************* (C) COPYRIGHT 2010 STMicroelectronics *****END OF FILE****/