LP-AM263: LP-AM263 MCAN1 Signal Question

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/* This example demonstrates the CAN message transmission and reception in
 * digital loop back mode with the following configuration.
 *
 * CAN FD Message Format.
 * Message ID Type is Standard, Msg Id 0xC0.
 * MCAN is configured in Interrupt Mode.
 * MCAN Interrupt Line Number 0.
 * Arbitration Bit Rate 1Mbps.
 * Data Bit Rate 5Mbps.
 * Buffer mode is used for Tx and RX to store message in message RAM.
 *
 * Message is transmitted and received back internally using internal loopback
 * mode. When the received message id and the data matches with the transmitted
 * one, then the example is completed.
 *
 */

#include <stdio.h>
#include <kernel/dpl/DebugP.h>
#include <kernel/dpl/AddrTranslateP.h>
#include <kernel/dpl/SemaphoreP.h>
#include <drivers/mcan.h>
#include "ti_drivers_config.h"
#include "ti_drivers_open_close.h"
#include "ti_board_open_close.h"

#define APP_MCAN_BASE_ADDR                       (CONFIG_MCAN1_BASE_ADDR)
#define APP_MCAN_INTR_NUM                        (CONFIG_MCAN1_INTR)
#define APP_MCAN_MSG_LOOP_COUNT                  (10U)

/* Allocate Message RAM memory section to filter elements, buffers, FIFO */
/* Maximum STD Filter Element can be configured is 128 */
#define APP_MCAN_STD_ID_FILTER_CNT               (1U)
/* Maximum EXT Filter Element can be configured is 64 */
#define APP_MCAN_EXT_ID_FILTER_CNT               (0U)
/* Maximum TX Buffer + TX FIFO, combined can be configured is 32 */
#define APP_MCAN_TX_BUFF_CNT                     (1U)
#define APP_MCAN_TX_FIFO_CNT                     (0U)
/* Maximum TX Event FIFO can be configured is 32 */
#define APP_MCAN_TX_EVENT_FIFO_CNT               (0U)
/* Maximum RX FIFO 0 can be configured is 64 */
#define APP_MCAN_FIFO_0_CNT                      (0U)
/* Maximum RX FIFO 1 can be configured is 64 and
 * rest of the memory is allocated to RX buffer which is again of max size 64 */
#define APP_MCAN_FIFO_1_CNT                      (0U)

/* Standard Id configured in this app */
#define APP_MCAN_STD_ID                          (0xC0U)
#define APP_MCAN_STD_ID_MASK                     (0x7FFU)
#define APP_MCAN_STD_ID_SHIFT                    (18U)

#define APP_MCAN_EXT_ID_MASK                     (0x1FFFFFFFU)

/* In the CAN FD format, the Data length coding differs from the standard CAN.
 * In case of standard CAN it is 8 bytes */
static const uint8_t gMcanDataSize[16U] = {0U,  1U,  2U,  3U,
                                           4U,  5U,  6U,  7U,
                                           8U,  12U, 16U, 20U,
                                           24U, 32U, 48U, 64U};

/* Semaphore to indicate transfer completion */
static SemaphoreP_Object gMcanTxDoneSem, gMcanRxDoneSem;
static HwiP_Object       gMcanHwiObject;
static uint32_t          gMcanBaseAddr;

/* Static Function Declarations */

static void    App_mcanMuxSelect(void);
static void    App_mcanEnableTransceiver(void);
static void    App_mcanIntrISR(void *arg);
static void    App_mcanConfig(Bool enableInternalLpbk);
static void    App_mcanInitMsgRamConfigParams(
               MCAN_MsgRAMConfigParams *msgRAMConfigParams);
static void    App_mcanEnableIntr(void);
static void    APP_MCAN_initSetBitTimeParams(MCAN_BitTimingParams *bitTimes);
static void    App_mcanConfigTxMsg(MCAN_TxBufElement *txMsg);
static void    App_mcanCompareMsg(MCAN_TxBufElement *txMsg,
                                  MCAN_RxBufElement *rxMsg);
static void    App_mcanInitStdFilterElemParams(
                                  MCAN_StdMsgIDFilterElement *stdFiltElem,
                                  uint32_t bufNum);

void mcan_loopback_interrupt_main(void *args)
{
    int32_t                 status = SystemP_SUCCESS;
    HwiP_Params             hwiPrms;
    MCAN_TxBufElement       txMsg;
    MCAN_ProtocolStatus     protStatus;
    MCAN_RxBufElement       rxMsg;
    MCAN_RxNewDataStatus    newDataStatus;
    MCAN_ErrCntStatus       errCounter;
    uint32_t                i, bufNum, fifoNum, bitPos = 0U;

    /* Open drivers to open the UART driver for console */
    Drivers_open();
    Board_driversOpen();

    App_mcanMuxSelect();
    App_mcanEnableTransceiver();

    DebugP_log("[MCAN] Loopback Interrupt mode, application started ...\r\n");

    /* Construct Tx/Rx Semaphore objects */
    status = SemaphoreP_constructBinary(&gMcanTxDoneSem, 0);
    DebugP_assert(SystemP_SUCCESS == status);
    status = SemaphoreP_constructBinary(&gMcanRxDoneSem, 0);
    DebugP_assert(SystemP_SUCCESS == status);

    /* Register interrupt */
    HwiP_Params_init(&hwiPrms);
    hwiPrms.intNum      = APP_MCAN_INTR_NUM;
    hwiPrms.callback    = &App_mcanIntrISR;
    status              = HwiP_construct(&gMcanHwiObject, &hwiPrms);
    DebugP_assert(status == SystemP_SUCCESS);

    /* Assign MCAN instance address */
    gMcanBaseAddr = (uint32_t) AddrTranslateP_getLocalAddr(APP_MCAN_BASE_ADDR);

    /* Configure MCAN module, Enable LoopBack Mode */
    App_mcanConfig(TRUE);

    /* Enable Interrupts */
    App_mcanEnableIntr();

    /* Transmit And Receive Message */
    for (i = 0U; i < APP_MCAN_MSG_LOOP_COUNT; i++)
    {
        /* Configure Tx Msg to transmit */
        App_mcanConfigTxMsg(&txMsg);

        /* Select buffer number, 32 buffers available */
        bufNum = 0U;
        /* Enable Transmission interrupt for the selected buf num,
         * If FIFO is used, then need to send FIFO start index until FIFO count */
        status = MCAN_txBufTransIntrEnable(gMcanBaseAddr, bufNum, (uint32_t)TRUE);
        DebugP_assert(status == CSL_PASS);

        /* Write message to Msg RAM */
        MCAN_writeMsgRam(gMcanBaseAddr, MCAN_MEM_TYPE_BUF, bufNum, &txMsg);

        /* Add request for transmission, This function will trigger transmission */
        status = MCAN_txBufAddReq(gMcanBaseAddr, bufNum);
        DebugP_assert(status == CSL_PASS);

        /* Wait for Tx completion */
        SemaphoreP_pend(&gMcanTxDoneSem, SystemP_WAIT_FOREVER);

        MCAN_getProtocolStatus(gMcanBaseAddr, &protStatus);
        /* Checking for Tx Errors */
        if (((MCAN_ERR_CODE_NO_ERROR != protStatus.lastErrCode) ||
             (MCAN_ERR_CODE_NO_CHANGE != protStatus.lastErrCode)) &&
            ((MCAN_ERR_CODE_NO_ERROR != protStatus.dlec) ||
             (MCAN_ERR_CODE_NO_CHANGE != protStatus.dlec)) &&
            (0U != protStatus.pxe))
        {
             DebugP_assert(FALSE);
        }

        /* Wait for Rx completion */
        SemaphoreP_pend(&gMcanRxDoneSem, SystemP_WAIT_FOREVER);

        /* Checking for Rx Errors */
        MCAN_getErrCounters(gMcanBaseAddr, &errCounter);
        DebugP_assert((0U == errCounter.recErrCnt) &&
                      (0U == errCounter.canErrLogCnt));

        /* Get the new data staus, indicates buffer num which received message */
        MCAN_getNewDataStatus(gMcanBaseAddr, &newDataStatus);
        MCAN_clearNewDataStatus(gMcanBaseAddr, &newDataStatus);

        /* Select buffer and fifo number, Buffer is used in this app */
        bufNum = 0U;
        fifoNum = MCAN_RX_FIFO_NUM_0;

        bitPos = (1U << bufNum);
        if (bitPos == (newDataStatus.statusLow & bitPos))
        {
            MCAN_readMsgRam(gMcanBaseAddr, MCAN_MEM_TYPE_BUF, bufNum, fifoNum, &rxMsg);
        }
        else
        {
            DebugP_assert(FALSE);
        }

        /* Compare Tx/Rx data */
        App_mcanCompareMsg(&txMsg, &rxMsg);
    }
    /* De-Construct Tx/Rx Semaphore objects */
    HwiP_destruct(&gMcanHwiObject);
    SemaphoreP_destruct(&gMcanTxDoneSem);
    SemaphoreP_destruct(&gMcanRxDoneSem);

    DebugP_log("All tests have passed!!\r\n");

    Board_driversClose();
    Drivers_close();

    return;
}

static void App_mcanConfig(Bool enableInternalLpbk)
{
    MCAN_StdMsgIDFilterElement stdFiltElem[APP_MCAN_STD_ID_FILTER_CNT] = {0U};
    MCAN_InitParams            initParams = {0U};
    MCAN_ConfigParams          configParams = {0U};
    MCAN_MsgRAMConfigParams    msgRAMConfigParams = {0U};
    MCAN_BitTimingParams       bitTimes = {0U};
    uint32_t                   i;

    /* Initialize MCAN module initParams */
    MCAN_initOperModeParams(&initParams);
    /* CAN FD Mode and Bit Rate Switch Enabled */
    initParams.fdMode          = TRUE;
    initParams.brsEnable       = TRUE;

    /* Initialize MCAN module Global Filter Params */
    MCAN_initGlobalFilterConfigParams(&configParams);

    /* Initialize MCAN module Bit Time Params */
    /* Configuring default 1Mbps and 5Mbps as nominal and data bit-rate resp */
    APP_MCAN_initSetBitTimeParams(&bitTimes);

    /* Initialize MCAN module Message Ram Params */
    App_mcanInitMsgRamConfigParams(&msgRAMConfigParams);

    /* Initialize Filter element to receive msg, should be same as tx msg id */
    for (i = 0U; i < APP_MCAN_STD_ID_FILTER_CNT; i++)
    {
        App_mcanInitStdFilterElemParams(&stdFiltElem[i], i);
    }
    /* wait for memory initialization to happen */
    while (FALSE == MCAN_isMemInitDone(gMcanBaseAddr))
    {}

    /* Put MCAN in SW initialization mode */
    MCAN_setOpMode(gMcanBaseAddr, MCAN_OPERATION_MODE_SW_INIT);
    while (MCAN_OPERATION_MODE_SW_INIT != MCAN_getOpMode(gMcanBaseAddr))
    {}

    /* Initialize MCAN module */
    MCAN_init(gMcanBaseAddr, &initParams);
    /* Configure MCAN module Gloabal Filter */
    MCAN_config(gMcanBaseAddr, &configParams);
    /* Configure Bit timings */
    MCAN_setBitTime(gMcanBaseAddr, &bitTimes);
    /* Configure Message RAM Sections */
    MCAN_msgRAMConfig(gMcanBaseAddr, &msgRAMConfigParams);
    /* Set Extended ID Mask */
    MCAN_setExtIDAndMask(gMcanBaseAddr, APP_MCAN_EXT_ID_MASK);

    /* Configure Standard ID filter element */
    for (i = 0U; i < APP_MCAN_STD_ID_FILTER_CNT; i++)
    {
        MCAN_addStdMsgIDFilter(gMcanBaseAddr, i, &stdFiltElem[i]);
    }
    if (TRUE == enableInternalLpbk)
    {
        MCAN_lpbkModeEnable(gMcanBaseAddr, MCAN_LPBK_MODE_EXTERNAL, TRUE);
    }

    /* Take MCAN out of the SW initialization mode */
    MCAN_setOpMode(gMcanBaseAddr, MCAN_OPERATION_MODE_NORMAL);
    while (MCAN_OPERATION_MODE_NORMAL != MCAN_getOpMode(gMcanBaseAddr))
    {}

    return;
}

static void App_mcanConfigTxMsg(MCAN_TxBufElement *txMsg)
{
    uint32_t i;

    /* Initialize message to transmit */
    MCAN_initTxBufElement(txMsg);
    /* Standard message identifier 11 bit, stored into ID[28-18] */
    txMsg->id  = ((APP_MCAN_STD_ID & MCAN_STD_ID_MASK) << MCAN_STD_ID_SHIFT);
    txMsg->dlc = MCAN_DATA_SIZE_64BYTES; /* Payload size is 64 bytes */
    txMsg->fdf = TRUE; /* CAN FD Frame Format */
    txMsg->xtd = FALSE; /* Extended id not configured */
    for (i = 0U; i < gMcanDataSize[MCAN_DATA_SIZE_64BYTES]; i++)
    {
        txMsg->data[i] = i;
    }

    return;
}

static void App_mcanInitStdFilterElemParams(MCAN_StdMsgIDFilterElement *stdFiltElem,
                                            uint32_t bufNum)
{
    /* sfid1 defines the ID of the standard message to be stored. */
    stdFiltElem->sfid1 = APP_MCAN_STD_ID;
    /* As buffer mode is selected, sfid2 should be bufNum[0 - 63] */
    stdFiltElem->sfid2 = bufNum;
    /* Store message in buffer */
    stdFiltElem->sfec  = MCAN_STD_FILT_ELEM_BUFFER;
    /* Below configuration is ignored if message is stored in buffer */
    stdFiltElem->sft   = MCAN_STD_FILT_TYPE_RANGE;

    return;
}

static void App_mcanEnableIntr(void)
{
    MCAN_enableIntr(gMcanBaseAddr, MCAN_INTR_MASK_ALL, (uint32_t)TRUE);
    MCAN_enableIntr(gMcanBaseAddr,
                    MCAN_INTR_SRC_RES_ADDR_ACCESS, (uint32_t)FALSE);
    /* Select Interrupt Line 0 */
    MCAN_selectIntrLine(gMcanBaseAddr, MCAN_INTR_MASK_ALL, MCAN_INTR_LINE_NUM_0);
    /* Enable Interrupt Line */
    MCAN_enableIntrLine(gMcanBaseAddr, MCAN_INTR_LINE_NUM_0, (uint32_t)TRUE);

    return;
}

static void App_mcanInitMsgRamConfigParams(MCAN_MsgRAMConfigParams
                                           *msgRAMConfigParams)
{
    int32_t status;

    MCAN_initMsgRamConfigParams(msgRAMConfigParams);

    /* Configure the user required msg ram params */
    msgRAMConfigParams->lss = APP_MCAN_STD_ID_FILTER_CNT;
    msgRAMConfigParams->lse = APP_MCAN_EXT_ID_FILTER_CNT;
    msgRAMConfigParams->txBufCnt = APP_MCAN_TX_BUFF_CNT;
    msgRAMConfigParams->txFIFOCnt = APP_MCAN_TX_FIFO_CNT;
    /* Buffer/FIFO mode is selected */
    msgRAMConfigParams->txBufMode = MCAN_TX_MEM_TYPE_BUF;
    msgRAMConfigParams->txEventFIFOCnt = APP_MCAN_TX_EVENT_FIFO_CNT;
    msgRAMConfigParams->rxFIFO0Cnt = APP_MCAN_FIFO_0_CNT;
    msgRAMConfigParams->rxFIFO1Cnt = APP_MCAN_FIFO_1_CNT;
    /* FIFO blocking mode is selected */
    msgRAMConfigParams->rxFIFO0OpMode = MCAN_RX_FIFO_OPERATION_MODE_BLOCKING;
    msgRAMConfigParams->rxFIFO1OpMode = MCAN_RX_FIFO_OPERATION_MODE_BLOCKING;

    status = MCAN_calcMsgRamParamsStartAddr(msgRAMConfigParams);
    DebugP_assert(status == CSL_PASS);

    return;
}

static void App_mcanCompareMsg(MCAN_TxBufElement *txMsg,
                               MCAN_RxBufElement *rxMsg)
{
    uint32_t i;

    if (((txMsg->id >> APP_MCAN_STD_ID_SHIFT) & APP_MCAN_STD_ID_MASK) ==
            ((rxMsg->id >> APP_MCAN_STD_ID_SHIFT) & APP_MCAN_STD_ID_MASK))
    {
        for (i = 0U; i < gMcanDataSize[MCAN_DATA_SIZE_64BYTES]; i++)
        {
            if (txMsg->data[i] != rxMsg->data[i])
            {
                DebugP_logError("Data mismatch !!!\r\n");
                DebugP_assert(FALSE);
            }
        }
    }
    else
    {
        DebugP_logError("Message ID mismatch !!!\r\n");
        DebugP_assert(FALSE);
    }

    return;
}

static void App_mcanIntrISR(void *arg)
{
    uint32_t intrStatus;

    intrStatus = MCAN_getIntrStatus(gMcanBaseAddr);
    MCAN_clearIntrStatus(gMcanBaseAddr, intrStatus);

    if (MCAN_INTR_SRC_TRANS_COMPLETE ==
        (intrStatus & MCAN_INTR_SRC_TRANS_COMPLETE))
    {
        SemaphoreP_post(&gMcanTxDoneSem);
    }

    /* If FIFO0/FIFO1 is used, then MCAN_INTR_SRC_DEDICATED_RX_BUFF_MSG macro
     * needs to be replaced by MCAN_INTR_SRC_RX_FIFO0_NEW_MSG/
     * MCAN_INTR_SRC_RX_FIFO1_NEW_MSG respectively */
    if (MCAN_INTR_SRC_DEDICATED_RX_BUFF_MSG ==
        (intrStatus & MCAN_INTR_SRC_DEDICATED_RX_BUFF_MSG))
    {
        SemaphoreP_post(&gMcanRxDoneSem);
    }

    return;
}

static void App_mcanMuxSelect(void)
{
    uint32_t    gpioBaseAddr_en, pinNum_en;
    uint32_t    gpioBaseAddr_sel, pinNum_sel;
    /* Get address after translation translate */
    gpioBaseAddr_en = (uint32_t) AddrTranslateP_getLocalAddr(AM263_U52_MUX_EN_GPIO58_BASE_ADDR);
    pinNum_en      = AM263_U52_MUX_EN_GPIO58_PIN;

    GPIO_setDirMode(gpioBaseAddr_en, pinNum_en, AM263_U52_MUX_EN_GPIO58_DIR);
    GPIO_pinWriteHigh(gpioBaseAddr_en, pinNum_en);
    ClockP_sleep(1); /* just make sure MUX route is stable */

    gpioBaseAddr_sel = (uint32_t) AddrTranslateP_getLocalAddr(AM263_U52_MUX_SEL_GPIO63_BASE_ADDR);
    pinNum_sel      = AM263_U52_MUX_SEL_GPIO63_PIN;

    GPIO_setDirMode(gpioBaseAddr_sel, pinNum_sel,AM263_U52_MUX_SEL_GPIO63_DIR);
    GPIO_pinWriteHigh(gpioBaseAddr_sel, pinNum_sel);


}


static void App_mcanEnableTransceiver(void)
{
 /*
  * Do nothing
  * We use HW setting to pull low STB directly
  */

}


static void APP_MCAN_initSetBitTimeParams(MCAN_BitTimingParams *bitTimes)
{
    /* Arbitrary bitrate to 1Mbps, sample point @75%
     * Data bit rate to 5Mbps sample point @75%
     *
     * ip link set can0 up type can tq 125 prop-seg 33 phase-seg1 26 phase-seg2 20 sjw 20 \
     * dtq 125 dprop-seg 6 dphase-seg1 5 dphase-seg2 4 dsjw 4 restart-ms 1000 berr-reporting on fd on
     *
     */

    if (bitTimes != NULL)
    {
        /* Initialize bit timings */
        bitTimes->nomRatePrescalar   = 0;
        bitTimes->nomTimeSeg1        = 58;
        bitTimes->nomTimeSeg2        = 19;
        bitTimes->nomSynchJumpWidth  = 19;
        bitTimes->dataRatePrescalar  = 0;
        bitTimes->dataTimeSeg1       = 10;
        bitTimes->dataTimeSeg2       = 3;
        bitTimes->dataSynchJumpWidth = 3;
    }

    return;
}