/*
 * Copyright (c) 2007-2015 Freescale Semiconductor, Inc.
 * Copyright 2018-2019 NXP
 *
 * License: NXP LA_OPT_NXP_Software_License
 *
 * NXP Confidential. This software is owned or controlled by NXP and may
 * only be used strictly in accordance with the applicable license terms.
 * By expressly accepting such terms or by downloading, installing,
 * activating and/or otherwise using the software, you are agreeing that
 * you have read, and that you agree to comply with and are bound by,
 * such license terms.  If you do not agree to be bound by the applicable
 * license terms, then you may not retain, install, activate or otherwise
 * use the software.  This code may only be used in a microprocessor,
 * microcontroller, sensor or digital signal processor ("NXP Product")
 * supplied directly or indirectly from NXP.  See the full NXP Software
 * License Agreement in license/LA_OPT_NXP_Software_License.pdf
 *
 * FreeMASTER Communication Driver - DSC FlexCAN low-level driver
 */

#include "freemaster.h"
#include "freemaster_private.h"

/* Numeric identifier to help pre-processor to identify whether our driver is used or not. */
#define FMSTR_CAN_MCUX_DSCFLEXCAN_ID 1

#if (FMSTR_MK_IDSTR(FMSTR_CAN_DRV) == FMSTR_CAN_MCUX_DSCFLEXCAN_ID)

#include "freemaster_flexcan_dsc.h"

#if (!(FMSTR_DISABLE))

#include "freemaster_can.h"
#include "fsl_flexcan.h"

/******************************************************************************
* Local macros
******************************************************************************/

/* FCAN: id to id-raw (idr) translation */
#define FMSTR_FCAN_ID2IDR(id) (((id)&FMSTR_CAN_EXTID) ? FLEXCAN_ID_EXT(id) : FLEXCAN_ID_STD(id))

/* user-selected MB as a 32bit or 64bit flag */
#if FMSTR_FLEXCAN_RXMB < 32
#define FMSTR_FLEXCAN_RXMB_FLAG (1UL << (FMSTR_FLEXCAN_RXMB))
#else
#define FMSTR_FLEXCAN_RXMB_FLAG (1ULL << (FMSTR_FLEXCAN_RXMB))
#endif
#if FMSTR_FLEXCAN_TXMB < 32
#define FMSTR_FLEXCAN_TXMB_FLAG (1UL << (FMSTR_FLEXCAN_TXMB))
#else
#define FMSTR_FLEXCAN_TXMB_FLAG (1ULL << (FMSTR_FLEXCAN_TXMB))
#endif

/* Using 64bit registers */
#if (defined(FSL_FEATURE_FLEXCAN_HAS_EXTENDED_FLAG_REGISTER)) && (FSL_FEATURE_FLEXCAN_HAS_EXTENDED_FLAG_REGISTER > 0)
#define FMSTR_FLEXCAN_REG_SIZE64
#define FMSTR_FLEXCAN_FLAG_ALL  0xFFFFFFFFFFFFFFFF
#else
#define FMSTR_FLEXCAN_FLAG_ALL  0xFFFFFFFF
#endif

/******************************************************************************
* Local functions
******************************************************************************/

static FMSTR_BOOL _FMSTR_FlexCAN_Init(FMSTR_U32 idRx, FMSTR_U32 idTx);  /* Initialize CAN module on a given base address. */
static void _FMSTR_FlexCAN_EnableTxInterrupt(FMSTR_BOOL enable);     /* Enable CAN Transmit interrupt. */
static void _FMSTR_FlexCAN_EnableRxInterrupt(FMSTR_BOOL enable);     /* Enable CAN Receive interrupt. */
static void _FMSTR_FlexCAN_EnableRx(void);                           /* Enable/re-initialize Receiver buffer. */
static FMSTR_SIZE8 _FMSTR_FlexCAN_GetRxFrameLen(void);               /* Return size of received CAN frame, or 0 if no Rx frame is available. */
static FMSTR_BCHR _FMSTR_FlexCAN_GetRxFrameByte(FMSTR_SIZE8 index);  /* Get data byte at index (0..8). */
static void _FMSTR_FlexCAN_AckRxFrame(void);                         /* Discard received frame and enable receiving a next one. */
static FMSTR_BOOL _FMSTR_FlexCAN_PrepareTxFrame(void);               /* Initialize transmit buffer; return false when Tx buffer is not available. */
static void _FMSTR_FlexCAN_PutTxFrameByte(FMSTR_SIZE8 index, FMSTR_BCHR data);   /* Fill one byte of transmit data. */
static void _FMSTR_FlexCAN_SendTxFrame(FMSTR_SIZE8 len);             /* Send the Tx buffer. */
/******************************************************************************
* Local variables
******************************************************************************/

/* Serial base address */
#ifdef FMSTR_CAN_BASE
    static CAN_Type *fmstr_canBaseAddr = FMSTR_CAN_BASE;
#else
    static CAN_Type *fmstr_canBaseAddr = NULL;
#endif

static flexcan_rx_mb_config_t fmstr_rxcfg; /* MB configuration with Raw ID */
static flexcan_frame_t fmstr_rxmsg;        /* Received frame buffer, valid when length>0 */
static flexcan_frame_t fmstr_txmsg;        /* Buffer to prepare transmission */
/******************************************************************************
* Driver interface
******************************************************************************/

const FMSTR_CAN_DRV_INTF FMSTR_CAN_MCUX_DSCFLEXCAN =
{
    FMSTR_C99_INIT(Init             ) _FMSTR_FlexCAN_Init,
    FMSTR_C99_INIT(EnableTxInterrupt) _FMSTR_FlexCAN_EnableTxInterrupt,
    FMSTR_C99_INIT(EnableRxInterrupt) _FMSTR_FlexCAN_EnableRxInterrupt,
    FMSTR_C99_INIT(EnableRx         ) _FMSTR_FlexCAN_EnableRx,
    FMSTR_C99_INIT(GetRxFrameLen    ) _FMSTR_FlexCAN_GetRxFrameLen,
    FMSTR_C99_INIT(GetRxFrameByte   ) _FMSTR_FlexCAN_GetRxFrameByte,
    FMSTR_C99_INIT(AckRxFrame       ) _FMSTR_FlexCAN_AckRxFrame,
    FMSTR_C99_INIT(PrepareTxFrame   ) _FMSTR_FlexCAN_PrepareTxFrame,
    FMSTR_C99_INIT(PutTxFrameByte   ) _FMSTR_FlexCAN_PutTxFrameByte,
    FMSTR_C99_INIT(SendTxFrame      ) _FMSTR_FlexCAN_SendTxFrame,
};

/******************************************************************************
* Implementation
******************************************************************************/

static FMSTR_BOOL _FMSTR_FlexCAN_Init(FMSTR_U32 idRx, FMSTR_U32 idTx)
{
    /* initialize Rx MB */
    FMSTR_MemSet(&fmstr_rxmsg, 0, sizeof(fmstr_rxmsg));
    FMSTR_MemSet(&fmstr_rxcfg, 0, sizeof(fmstr_rxcfg));
    fmstr_rxcfg.u32Id = FMSTR_FCAN_ID2IDR(idRx);
    fmstr_rxcfg.eFormat = (idRx & FMSTR_CAN_EXTID) ? kFLEXCAN_FrameFormatExtend : kFLEXCAN_FrameFormatStandard;
    fmstr_rxcfg.eType = kFLEXCAN_FrameTypeData;
    FLEXCAN_SetRxMbConfig(fmstr_canBaseAddr, FMSTR_FLEXCAN_RXMB, &fmstr_rxcfg, 0);

    /* initialize Tx MB */
    FMSTR_MemSet(&fmstr_txmsg, 0, sizeof(fmstr_txmsg));
    fmstr_txmsg.bitsId = FMSTR_FCAN_ID2IDR(idTx);
    fmstr_txmsg.bitFormat = (idTx & FMSTR_CAN_EXTID) ? kFLEXCAN_FrameFormatExtend : kFLEXCAN_FrameFormatStandard;
    fmstr_txmsg.bitType = kFLEXCAN_FrameTypeData;
    FLEXCAN_SetTxMbConfig(fmstr_canBaseAddr, FMSTR_FLEXCAN_TXMB, 1);

    { 
        /* Make sure the RX Message Buffer is unlocked. */
        volatile uint32_t dummy = fmstr_canBaseAddr->TIMER;
        FMSTR_UNUSED(dummy);
    }

    return FMSTR_TRUE;
}

static void _FMSTR_FlexCAN_EnableTxInterrupt(FMSTR_BOOL enable)
{
    if(enable)
        FLEXCAN_EnableMbInterrupts(fmstr_canBaseAddr, FMSTR_FLEXCAN_TXMB_FLAG);
    else
        FLEXCAN_DisableMbInterrupts(fmstr_canBaseAddr, FMSTR_FLEXCAN_TXMB_FLAG);
}

static void _FMSTR_FlexCAN_EnableRxInterrupt(FMSTR_BOOL enable)
{
    if(enable)
        FLEXCAN_EnableMbInterrupts(fmstr_canBaseAddr, FMSTR_FLEXCAN_RXMB_FLAG);
    else
        FLEXCAN_DisableMbInterrupts(fmstr_canBaseAddr, FMSTR_FLEXCAN_RXMB_FLAG);
}

static void _FMSTR_FlexCAN_EnableRx(void)
{
    /* enbale receiving into the MB */
    FLEXCAN_SetRxMbConfig(fmstr_canBaseAddr, FMSTR_FLEXCAN_RXMB, &fmstr_rxcfg, 1);
}

static FMSTR_SIZE8 _FMSTR_FlexCAN_GetRxFrameLen(void)
{
#if FMSTR_POLL_DRIVEN
    /* Is any data received? */
    if(FLEXCAN_GetMbStatusFlags(fmstr_canBaseAddr, FMSTR_FLEXCAN_RXMB_FLAG) == 0)
        return 0;

    /* Clear RX status flag */
    FLEXCAN_ClearMbStatusFlags(fmstr_canBaseAddr, FMSTR_FLEXCAN_RXMB_FLAG);
#endif /* FMSTR_POLL_DRIVEN */

    /* Current cache still valid? */
    if(!fmstr_rxmsg.bitsLength)
    {
        /* Try to read data, when successful, the MB is acknowledged and set for next receive */
        status_t s = FLEXCAN_ReadRxMb(fmstr_canBaseAddr, FMSTR_FLEXCAN_RXMB, &fmstr_rxmsg);

        /* Make sure the RX Message Buffer is unlocked. */
        volatile uint32_t dummy = fmstr_canBaseAddr->TIMER;
        FMSTR_UNUSED(dummy);

        if(s == kStatus_Fail)
            fmstr_rxmsg.bitsLength = 0; /* no frame available */
    }

    /* we have got some frame, return its length */
    return fmstr_rxmsg.bitsLength;
}

static FMSTR_BCHR _FMSTR_FlexCAN_GetRxFrameByte(FMSTR_SIZE8 index)
{
    FMSTR_BCHR data;

    /* need switch as data bytes are not necessarily ordered in the frame */
    switch(index)
    {
    case 0:  data = fmstr_rxmsg.u8DataByte0; break;
    case 1:  data = fmstr_rxmsg.u8DataByte1; break;
    case 2:  data = fmstr_rxmsg.u8DataByte2; break;
    case 3:  data = fmstr_rxmsg.u8DataByte3; break;
    case 4:  data = fmstr_rxmsg.u8DataByte4; break;
    case 5:  data = fmstr_rxmsg.u8DataByte5; break;
    case 6:  data = fmstr_rxmsg.u8DataByte6; break;
    default: data = fmstr_rxmsg.u8DataByte7; break;
    }

    return data;
}

static void _FMSTR_FlexCAN_AckRxFrame(void)
{
    /* The frame is already acknowledged in registers by calling FLEXCAN_ReadRxMb before. */
    /* We only clear the local cached buffer so it appears as if we have acknowledged it. */
    fmstr_rxmsg.bitsLength = 0;
}

static FMSTR_BOOL _FMSTR_FlexCAN_PrepareTxFrame(void)
{
#ifdef FMSTR_POLL_DRIVEN
    /* Was all data sent? */
    if(fmstr_txmsg.bitsLength && FLEXCAN_GetMbStatusFlags(fmstr_canBaseAddr, FMSTR_FLEXCAN_TXMB_FLAG) == 0)
        return FMSTR_FALSE;

    /* Clear TX status flag */
    FLEXCAN_ClearMbStatusFlags(fmstr_canBaseAddr, FMSTR_FLEXCAN_TXMB_FLAG);

    /* Acknowledge frame was transmitted */
    fmstr_txmsg.bitsLength = 0;
#else
    if(fmstr_txmsg.length)
        return FMSTR_FALSE;
#endif /* FMSTR_POLL_DRIVEN */

    /* set as transmit-emtpy MB */
    FLEXCAN_SetTxMbConfig(fmstr_canBaseAddr, FMSTR_FLEXCAN_TXMB, 1);

    return FMSTR_TRUE;
}

static void _FMSTR_FlexCAN_PutTxFrameByte(FMSTR_SIZE8 index, FMSTR_BCHR data)
{
    /* need switch as data bytes are not necessarily ordered in the frame */
    switch(index)
    {
    case 0:  fmstr_txmsg.u8DataByte0 = data; break;
    case 1:  fmstr_txmsg.u8DataByte1 = data; break;
    case 2:  fmstr_txmsg.u8DataByte2 = data; break;
    case 3:  fmstr_txmsg.u8DataByte3 = data; break;
    case 4:  fmstr_txmsg.u8DataByte4 = data; break;
    case 5:  fmstr_txmsg.u8DataByte5 = data; break;
    case 6:  fmstr_txmsg.u8DataByte6 = data; break;
    default: fmstr_txmsg.u8DataByte7 = data; break;
    }
}

static void _FMSTR_FlexCAN_SendTxFrame(FMSTR_SIZE8 len)
{
    fmstr_txmsg.bitsLength = len;
    FLEXCAN_WriteTxMb(fmstr_canBaseAddr, FMSTR_FLEXCAN_TXMB, &fmstr_txmsg);
}

/**************************************************************************//*!
*
* @brief    Assigning FreeMASTER communication module base address
*
******************************************************************************/
void FMSTR_CanSetBaseAddress(CAN_Type *base)
{
    fmstr_canBaseAddr = base;
}

#if FMSTR_LONG_INTR || FMSTR_SHORT_INTR
void FMSTR_CanIsr(void)
{
    uint32_t isrFlags = FLEXCAN_GetStatusFlags(fmstr_canBaseAddr);
#ifdef FMSTR_FLEXCAN_REG_SIZE64
    uint64_t isrFlagsMB;
#else
    uint32_t isrFlagsMB;
#endif

    isrFlagsMB = FLEXCAN_GetMbStatusFlags(fmstr_canBaseAddr, FMSTR_FLEXCAN_FLAG_ALL);

    /* Ignoring error and wake up flags */
    if(isrFlags)
        FLEXCAN_ClearStatusFlags(fmstr_canBaseAddr, isrFlags);

    if(isrFlagsMB)
    {
        /* Read or Write */
        if( (isrFlagsMB & FMSTR_FLEXCAN_RXMB_FLAG) )
        {
            FMSTR_ProcessCanRx();
        }
        if( (isrFlagsMB & FMSTR_FLEXCAN_TXMB_FLAG) )
        {
            /* Acknowledge frame transmission */
            fmstr_txmsg.bitsLength = 0;
            /* Send next frame, if needed */
            FMSTR_ProcessCanTx();
        }

        /* Clear all interrupt flags */
        FLEXCAN_ClearMbStatusFlags(fmstr_canBaseAddr, isrFlagsMB);
    }
}
#endif

#else /* (!(FMSTR_DISABLE)) */

void FMSTR_CanSetBaseAddress(CAN_Type *base)
{
    FMSTR_UNUSED(base);
}

#if FMSTR_LONG_INTR || FMSTR_SHORT_INTR
void FMSTR_CanIsr(void)
{
}
#endif /* FMSTR_LONG_INTR || FMSTR_SHORT_INTR */

#endif /* (!(FMSTR_DISABLE)) */
#endif /* (FMSTR_MK_IDSTR(FMSTR_CAN_DRV) == FMSTR_CAN_MCUX_DSCFLEXCAN_ID) */
