#include "main.h"

CAN_RXMessage canrx, cantx;
uint8_t CAN_error = 0;
uint8_t CANFrameReceiveFlag = 0, CANFrameSendFlag = 0;
/******************************************************************************************************************************************
* 函数名称: sameBits()
* 功能说明: 找到所有ID中相同位置值相同的位，比如所有ID的第10位都是0（或1）则返回值的第10位为1
* 输    入:
* 输    出:
* 注意事项: 无
******************************************************************************************************************************************/
uint32_t sameBits(uint32_t std_id[], uint32_t std_n, uint32_t ext_id[], uint32_t ext_n)
{
    uint32_t i, j;

    uint32_t mask = 0;

    for(i = 0; i < std_n; i++)
        std_id[i] = std_id[i] << 18;

    for(i = 0; i < std_n - 1; i++)
    {
        for(j = i + 1; j < std_n; j++)
        {
            mask |= std_id[i] ^ std_id[j];
        }
    }

    for(i = 0; i < ext_n - 1; i++)
    {
        for(j = i + 1; j < ext_n; j++)
        {
            mask |= ext_id[i] ^ ext_id[j];
        }
    }

    return ~mask;
}
void CANInit(void)
{
    CAN_InitStructure CAN_initStruct;

#if 0
    //for CAN1
    PORT_Init(PORTN, PIN16, FUNMUX0_CAN_RX, 1);	//GPION.16 配置为CAN输入引脚
    PORT_Init(PORTN, PIN15, FUNMUX1_CAN_TX, 0);	//GPION.15 配置为CAN输出引脚
#else
    //for CAN0
    PORT_Init(PORTN, PIN8, FUNMUX0_CAN_RX, 1);	//GPION.8 配置为CAN输入引脚
    PORT_Init(PORTN, PIN7, FUNMUX1_CAN_TX, 0);	//GPION.7 配置为CAN输出引脚
#endif

    CAN_initStruct.Mode = CAN_MODE_NORMAL;
    CAN_initStruct.CAN_BS1 = CAN_BS1_5tq;
    CAN_initStruct.CAN_BS2 = CAN_BS2_4tq;
    CAN_initStruct.CAN_SJW = CAN_SJW_2tq;
    CAN_initStruct.Baudrate = CAN_BPS;
    CAN_initStruct.FilterMode = CAN_FILTER_32b;
    CAN_initStruct.FilterMask32b = 0xFFFFFFFF;
    CAN_initStruct.FilterCheck32b = 0xFFFFFFFF;
    switch(0)
    {
    case 0:		// 接收ID为任意值的帧
        CAN_initStruct.FilterMask32b  = 0xFFFFFFFF;				// 0 must match    1 don't care
        CAN_initStruct.FilterCheck32b = 0xFFFFFFFF;
        break;

    case 1:		// 接收ID为0x122的标准帧
        CAN_initStruct.FilterMask32b = ~(0x7FFu << 21);
        CAN_initStruct.FilterCheck32b = (0x122  << 21);			// 标准帧ID在第21位到31位，详见手册
        break;

    case 2:		// 接收ID为0x122的扩展帧
        CAN_initStruct.FilterMask32b = ~(0x1FFFFFFFu << 3);
        CAN_initStruct.FilterCheck32b = (0x00000122  << 3);		// 扩展帧ID在第 3位到31位，详见手册
        break;

    case 3:		// 接收ID为0x12X的标准帧，X表示ID的低4位是什么值无所谓
        CAN_initStruct.FilterMask32b = ~(0x7F0u << 21);
        CAN_initStruct.FilterCheck32b = (0x122  << 21);
        break;

    case 4:		// 接收ID为0x122和0x101的标准帧
        CAN_initStruct.FilterMode = CAN_FILTER_16b;
        CAN_initStruct.FilterMask16b1 = (uint16_t)~(0x7FFu << 5);
        CAN_initStruct.FilterCheck16b1 = (0x122  << 5);
        CAN_initStruct.FilterMask16b2 = (uint16_t)~(0x7FFu << 5);
        CAN_initStruct.FilterCheck16b2 = (0x101  << 5);
        break;

    case 5:		// 即接收ID为0x122、0x235、0x450的标准帧，也接收ID为0x101, 0x235, 0x1780的扩展帧
    {
        // 并不是只接收ID为这6个值的帧，而是接收尽量最少的帧、且能保证ID为要求值的帧都能接收到
        uint32_t stdID[] = {0x122, 0x235, 0x450};
        uint32_t extID[] = {0x101, 0x235, 0x1780};

        CAN_initStruct.FilterMask32b = ~(sameBits(stdID, 3, extID, 3) << 3);
        CAN_initStruct.FilterCheck32b = (extID[0]  << 3);
        // 或者：
        // 		CAN_initStruct.FilterCheck32b = (stdID[0]  << 21);
    }
    break;
    }
    CAN_initStruct.RXNotEmptyIEn = 1;
    CAN_initStruct.RXOverflowIEn = 0;
    CAN_initStruct.ArbitrLostIEn = 0;
    CAN_initStruct.ErrPassiveIEn = 0;
    CAN_Init(CAN, &CAN_initStruct);
    NVIC_SetPriority(CAN_IRQn, 2);
    CAN_Open(CAN);
}

int CAN_SendMsg(CAN_RXMessage msg)
{
    while(CAN_TXBufferReady(CAN) == 0)
    {
        DelayMs(1);
    }
    //单次发送
    //	CAN_Transmit(CAN, CAN_FRAME_EXT, msg.id, msg.data, msg.size, 1);
    //	while(CAN_TXComplete(CAN) == 0){DelayMs(1);}
    //多次重发
    CAN_error = 0;
    CAN_Transmit(CAN, CAN_FRAME_EXT, msg.id, msg.data, msg.size, 0);
    for(uint16_t i = 0; CAN_TXComplete(CAN) == 0; i++)
    {
        if(i > 100)
        {
            CAN_AbortTransmit(CAN);    //超时，终止发送
            CAN_error = 1;
        }
        DelayMs(1);
    }
    return CAN_TXSuccess(CAN);
}

void CAN_Handler(void)
{
    uint32_t int_sr = CAN_INTStat(CAN);

    if(int_sr & CAN_IF_RXDA_Msk)
    {
        CAN_Receive(CAN, &canrx);
        CANFrameReceiveFlag = 1;
    }
}