/******************** (C) COPYRIGHT 2006 STMicroelectronics ********************
* File Name          : stm32f10x_can.c
* Author             : MCD Application Team
* Date First Issued  : 09/29/2006
* Description        : This file provides all the CAN firmware functions.
********************************************************************************
* History:
* 02/05/2007: V0.1
* 09/29/2006: V0.01
********************************************************************************
* THE PRESENT SOFTWARE 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 SOFTWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING
* INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*******************************************************************************/

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

/* Private typedef -----------------------------------------------------------*/

/* Private define ------------------------------------------------------------*/
/* CAN Master Control Register bits */
#define CAN_MCR_INRQ     ((u32)0x00000001) /* Initialization request */
#define CAN_MCR_SLEEP    ((u32)0x00000002) /* Sleep mode request */
#define CAN_MCR_TXFP     ((u32)0x00000004) /* Transmit FIFO priority */
#define CAN_MCR_RFLM     ((u32)0x00000008) /* Receive FIFO locked mode */
#define CAN_MCR_NART     ((u32)0x00000010) /* No automatic retransmission */
#define CAN_MCR_AWUM     ((u32)0x00000020) /* Automatic wake up mode */
#define CAN_MCR_ABOM     ((u32)0x00000040) /* Automatic bus-off management */
#define CAN_MCR_TTCM     ((u32)0x00000080) /* time triggered communication */
#define CAN_MCR_Reset    ((u32)0x00008000) /* bxCAN master reset */
#define CAN_MCR_DbF      ((u32)0x00010000) /* Debug freeze */

/* CAN Master Status Register bits */
#define CAN_MSR_INAK     ((u32)0x00000001)    /* Initialization acknowledge */
#define CAN_MSR_SLAK     ((u32)0x00000002)    /* Sleep acknowledge */
#define CAN_MSR_ERRI     ((u32)0x00000004)    /* Error interrupt */
#define CAN_MSR_WKUI     ((u32)0x00000008)    /* Wake-up interrupt */
#define CAN_MSR_SLAKI    ((u32)0x00000010)    /* Sleep acknowledge interrupt */
#define CAN_MSR_TXM      ((u32)0x00000100)    /* Transmit mode */
#define CAN_MSR_RXM      ((u32)0x00000200)    /* Receive mode */
#define CAN_MSR_SAMP     ((u32)0x00000400)    /* Last sample point */
#define CAN_MSR_RX       ((u32)0x00000800)    /* CAN Rx signal */

/* CAN Transmit Status Register bits */
#define CAN_TSR_RQCP0    ((u32)0x00000001)    /* Request completed mailbox0 */
#define CAN_TSR_TXOK0    ((u32)0x00000002)    /* Transmission OK of mailbox0 */
#define CAN_TSR_ALST0    ((u32)0x00000004)    /* Arbitration lost for mailbox0 */
#define CAN_TSR_TERR0    ((u32)0x00000008)    /* Transmission error of mailbox0 */
#define CAN_TSR_ABRQ0    ((u32)0x00000080)    /* Abort request for mailbox0 */
#define CAN_TSR_RQCP1    ((u32)0x00000100)    /* Request completed mailbox1 */
#define CAN_TSR_TXOK1    ((u32)0x00000200)    /* Transmission OK of mailbox1 */
#define CAN_TSR_ALST1    ((u32)0x00000400)    /* Arbitration lost for mailbox1 */
#define CAN_TSR_TERR1    ((u32)0x00000800)    /* Transmission error of mailbox1 */
#define CAN_TSR_ABRQ1    ((u32)0x00008000)    /* Abort request for mailbox1 */
#define CAN_TSR_RQCP2    ((u32)0x00010000)    /* Request completed mailbox2 */
#define CAN_TSR_TXOK2    ((u32)0x00020000)    /* Transmission OK of mailbox2 */
#define CAN_TSR_ALST2    ((u32)0x00040000)    /* Arbitration lost for mailbox2 */
#define CAN_TSR_TERR2    ((u32)0x00080000)    /* Transmission error of mailbox2 */
#define CAN_TSR_ABRQ2    ((u32)0x00800000)    /* Abort request for mailbox2 */
#define CAN_TSR_CODE0    ((u32)0x01000000)    /* Mailbox code bit 0 */
#define CAN_TSR_CODE1    ((u32)0x02000000)    /* Mailbox code bit 1 */
#define CAN_TSR_TME0     ((u32)0x04000000)    /* Transmit mailbox 0 empty */
#define CAN_TSR_TME1     ((u32)0x08000000)    /* Transmit mailbox 1 empty */
#define CAN_TSR_TME2     ((u32)0x10000000)    /* Transmit mailbox 2 empty */
#define CAN_TSR_LOW0     ((u32)0x20000000)    /* Lowest priority flag for mailbox 0 */
#define CAN_TSR_LOW1     ((u32)0x40000000)    /* Lowest priority flag for mailbox 1 */
#define CAN_TSR_LOW2     ((u32)0x80000000)    /* Lowest priority flag for mailbox 2 */

/* CAN Receive FIFO 0 Register bits */
#define CAN_RF0R_FMP00   ((u32)0x00000001)    /* FIFO 0 message pending bit 0 */
#define CAN_RF0R_FMP01   ((u32)0x00000002)    /* FIFO 0 message pending bit 1 */
#define CAN_RF0R_FULL0   ((u32)0x00000008)    /* FIFO 0 full */
#define CAN_RF0R_FOVR0   ((u32)0x00000010)    /* FIFO 0 overrun */
#define CAN_RF0R_RFOM0   ((u32)0x00000020)    /* Release FIFO 0 output mailbox */

/* CAN Receive FIFO 1 Register bits */
#define CAN_RF1R_FMP10   ((u32)0x00000001)    /* FIFO 1 message pending bit 0 */
#define CAN_RF1R_FMP11   ((u32)0x00000002)    /* FIFO 1 message pending bit 1 */
#define CAN_RF1R_FULL1   ((u32)0x00000008)    /* FIFO 1 full */
#define CAN_RF1R_FOVR1   ((u32)0x00000010)    /* FIFO 1 overrun */
#define CAN_RF1R_RFOM1   ((u32)0x00000020)    /* Release FIFO 1 output mailbox */

/* CAN Error Status Register bits */
#define CAN_ESR_EWGF     ((u32)0x00000001)    /* Error warning flag */
#define CAN_ESR_EPVF     ((u32)0x00000002)    /* Error passive flag */
#define CAN_ESR_BOFF     ((u32)0x00000004)    /* Bus-off flag */

/* CAN Bit Timing Register bits */
#define CAN_BTR_CLK8     ((u32)0x00008000) /* CLK8 8Mhz clock input */
#define CAN_BTR_LBKM     ((u32)0x40000000) /* Loop back mode */
#define CAN_BTR_SILM     ((u32)0x80000000) /* Silent mode */

/* CAN Mailbox Transmit Request */
#define CAN_TMIDxR_TXRQ    ((u32)0x00000001) /* Transmit mailbox request */

/* CAN Filter Master Register bits */
#define CAN_FMR_FINIT ((u32)0x00000001) /* Filter init mode */


/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
ITStatus CheckITStatus(u32 CAN_Reg, u32 It_Bit);

/* Private functions ---------------------------------------------------------*/
/*******************************************************************************
* Function Name  : CAN_DeInit
* Description    : Deinitializes the CAN peripheral registers to their default
*                  reset values.
* Input          : None.
* Output         : None.
* Return         : None.
*******************************************************************************/
void CAN_DeInit(void)
{
  /* Enable CAN reset state */
  RCC_APB1PeriphResetCmd(RCC_APB1Periph_CAN, ENABLE);
  /* Release CAN from reset state */
  RCC_APB1PeriphResetCmd(RCC_APB1Periph_CAN, DISABLE);
}

/*******************************************************************************
* Function Name  : CAN_Init
* Description    : Initializes the CAN peripheral according to the specified
*                  parameters in the CAN_InitStruct.
* Input          : CAN_InitStruct: pointer to a CAN_InitTypeDef structure that
                   contains the configuration information for the CAN peripheral.
* Output         : None.
* Return         : Constant indicates initialization succeed which will be 
*                  CANINITFAILED or CANINITOK.
*******************************************************************************/
u8 CAN_Init(CAN_InitTypeDef* CAN_InitStruct)
{
  u8 InitStatus = 0;

  /* Request initialisation */
  CAN->MCR = CAN_MCR_INRQ;

  /* ...and check acknowledged */
  if ((CAN->MSR & CAN_MSR_INAK) == 0)
  {
    InitStatus = CANINITFAILED;
  }
  else
  {
    /* Set the time triggered communication mode */
    if (CAN_InitStruct->CAN_TTCM == ENABLE)
    {
      CAN->MCR |= CAN_MCR_TTCM;
    }
    else
    {
      CAN->MCR &= ~CAN_MCR_TTCM;
    }

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

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

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

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

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

    /* Set the bit timing register */
    CAN->BTR = (u32)(CAN_InitStruct->CAN_Mode << 30) | (CAN_InitStruct->CAN_SJW << 24) |
               (CAN_InitStruct->CAN_BS1 << 16) | (CAN_InitStruct->CAN_BS2 << 20) |
               (CAN_InitStruct->CAN_Clock << 15) | (CAN_InitStruct->CAN_Prescaler - 1);

    InitStatus = CANINITOK;

    /* Request leave initialisation */
    CAN->MCR &= ~CAN_MCR_INRQ;

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

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

/*******************************************************************************
* Function Name  : CAN_FilterInit
* Description    : Initializes the CAN peripheral according to the specified
*                  parameters in the CAN_FilterInitStruct.
* Input          : CAN_FilterInitStruct: pointer to a CAN_FilterInitTypeDef
*                  structure that contains the configuration information.
* Output         : None.
* Return         : None.
*******************************************************************************/
void CAN_FilterInit(CAN_FilterInitTypeDef* CAN_FilterInitStruct)
{
  u16 FilterNumber_BitPos = 0;

  FilterNumber_BitPos = (0x0001 << (CAN_FilterInitStruct->CAN_FilterNumber));

  /* Initialisation mode for the filter */
  CAN->FMR |= CAN_FMR_FINIT;

  /* Filter Deactivation */
  CAN->FA0R &= ~FilterNumber_BitPos;

  /* Filter Scale */
  if (CAN_FilterInitStruct->CAN_FilterScale == CAN_FilterScale_16bit)
  {
    /* 16-bit scale for the filter */
    CAN->FS0R &= ~FilterNumber_BitPos;

    /* First 16-bit identifier and First 16-bit mask */
    /* Or First 16-bit identifier and Second 16-bit identifier */
    CAN->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR0 = ((u32)(0x0000FFFF & CAN_FilterInitStruct->CAN_FilterMaskIdLow) << 16) |
        (0x0000FFFF & CAN_FilterInitStruct->CAN_FilterIdLow);

    /* Second 16-bit identifier and Second 16-bit mask */
    /* Or Third 16-bit identifier and Fourth 16-bit identifier */
    CAN->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR1 = ((u32)(0x0000FFFF & CAN_FilterInitStruct->CAN_FilterMaskIdHigh) << 16) |
        (0x0000FFFF & CAN_FilterInitStruct->CAN_FilterIdHigh);
  }
  if (CAN_FilterInitStruct->CAN_FilterScale == CAN_FilterScale_32bit)
  {
    /* 32-bit scale for the filter */
    CAN->FS0R |= FilterNumber_BitPos;

    /* 32-bit identifier or First 32-bit identifier */
    CAN->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR0 = ((u32)(0x0000FFFF & CAN_FilterInitStruct->CAN_FilterIdHigh) << 16) |
        (0x0000FFFF & CAN_FilterInitStruct->CAN_FilterIdLow);

    /* 32-bit mask or Second 32-bit identifier */
    CAN->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR1 = ((u32)(0x0000FFFF & CAN_FilterInitStruct->CAN_FilterMaskIdHigh) << 16) |
        (0x0000FFFF & CAN_FilterInitStruct->CAN_FilterMaskIdLow);

  }

  /* Filter Mode */
  if (CAN_FilterInitStruct->CAN_FilterMode == CAN_FilterMode_IdMask)
  {
    /*Id/Mask mode for the filter*/
    CAN->FM0R &= ~FilterNumber_BitPos;
  }
  else /* CAN_FilterInitStruct->CAN_FilterMode == CAN_FilterMode_IdList */
  {
    /*Identifier list mode for the filter*/
    CAN->FM0R |= FilterNumber_BitPos;
  }

  /* Filter FIFO assignment */
  if (CAN_FilterInitStruct->CAN_FilterFIFOAssignment == CAN_FilterFIFO0)
  {
    /* FIFO 0 assignation for the filter */
    CAN->FFA0R &= ~FilterNumber_BitPos;
  }
  if (CAN_FilterInitStruct->CAN_FilterFIFOAssignment == CAN_FilterFIFO1)
  {
    /* FIFO 1 assignation for the filter */
    CAN->FFA0R |= FilterNumber_BitPos;
  }
  
  /* Filter activation */
  if (CAN_FilterInitStruct->CAN_FilterActivation == ENABLE)
  {
    CAN->FA0R |= FilterNumber_BitPos;
  }

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

/*******************************************************************************
* Function Name  : CAN_StructInit
* Description    : Fills each CAN_InitStruct member with its default value.
* Input          : CAN_InitStruct: pointer to a CAN_InitTypeDef structure which
*                  will be initialized.
* Output         : None.
* Return         : 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_0tq;

  /* 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_Clock member */
  CAN_InitStruct->CAN_Clock = CAN_Clock_APB;

  /* Initialize the CAN_Prescaler member */
  CAN_InitStruct->CAN_Prescaler = 1;
}

/*******************************************************************************
* Function Name  : CAN_ITConfig
* Description    : Enables or disables the CAN interrupts.
* Input          : - CAN_IT: specifies the CAN interrupt sources to be enabled or
*                    disabled.
*                  - NewState: new state of the CAN interrupts.
*                    This parameter can be: ENABLE or DISABLE.
* Output         : None.
* Return         : None.
*******************************************************************************/
void CAN_ITConfig(u32 CAN_IT, FunctionalState NewState)
{
  if (NewState != DISABLE)
  {
    /* Enable the selected CAN interrupt */
    CAN->IER |= CAN_IT;
  }
  else
  {
    /* Disable the selected CAN interrupt */
    CAN->IER &= ~CAN_IT;
  }
}

/*******************************************************************************
* Function Name  : CAN_Transmit
* Description    : Initiates the transmission of a message.
* Input          : TxMessage: pointer to a structure which contains CAN Id, CAN
*                  DLC and CAN datas.
* Output         : None.
* Return         : The number of the mailbox that is used for transmission
*                  or CAN_NO_MB if there is no empty mailbox.
*******************************************************************************/
u8 CAN_Transmit(CanTxMsg* TxMessage)
{
  u8 TransmitMailbox = 0;

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