rt-thread/bsp/nuvoton/libraries/m031/rtt_port/drv_pdma.c

/**************************************************************************//**
*
* @copyright (C) 2020 Nuvoton Technology Corp. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date            Author           Notes
* 2020-9-7        Philo            First version
*
******************************************************************************/

#include <rtconfig.h>

#if defined(BSP_USING_PDMA)

#include <rtdevice.h>
#include <rtthread.h>
#include <drv_pdma.h>
#include <nu_bitutil.h>

/* Private define ---------------------------------------------------------------*/
// RT_DEV_NAME_PREFIX pdma

#ifndef NU_PDMA_MEMFUN_ACTOR_MAX
    #define NU_PDMA_MEMFUN_ACTOR_MAX (4)
#endif

#define NU_PDMA_SG_TBL_MAXSIZE         (NU_PDMA_SG_LIMITED_DISTANCE/sizeof(DSCT_T))

#define NU_PDMA_CH_MAX (PDMA_CH_MAX)     /* Specify maximum channels of PDMA */
#define NU_PDMA_CH_Pos (0)               /* Specify first channel number of PDMA */
#define NU_PDMA_CH_Msk (((1 << NU_PDMA_CH_MAX) - 1) << NU_PDMA_CH_Pos)

/* Private typedef --------------------------------------------------------------*/
struct nu_pdma_periph_ctl
{
    uint32_t     m_u32Peripheral;
    nu_pdma_memctrl_t  m_eMemCtl;
};
typedef struct nu_pdma_periph_ctl nu_pdma_periph_ctl_t;

struct nu_pdma_chn
{
    nu_pdma_cb_handler_t   m_pfnCBHandler;
    void                  *m_pvUserData;
    uint32_t               m_u32EventFilter;
    uint32_t               m_u32IdleTimeout_us;
    nu_pdma_periph_ctl_t   m_spPeripCtl;
};
typedef struct nu_pdma_chn nu_pdma_chn_t;

struct nu_pdma_memfun_actor
{
    int         m_i32ChannID;
    uint32_t    m_u32Result;
    rt_sem_t    m_psSemMemFun;
} ;
typedef struct nu_pdma_memfun_actor *nu_pdma_memfun_actor_t;

/* Private functions ------------------------------------------------------------*/
static int nu_pdma_peripheral_set(uint32_t u32PeriphType);
static void nu_pdma_init(void);
static void nu_pdma_channel_enable(int i32ChannID);
static void nu_pdma_channel_disable(int i32ChannID);
static void nu_pdma_channel_reset(int i32ChannID);
static rt_err_t nu_pdma_timeout_set(int i32ChannID, int i32Timeout_us);
static void nu_pdma_periph_ctrl_fill(int i32ChannID, int i32CtlPoolIdx);
static rt_size_t nu_pdma_memfun(void *dest, void *src, uint32_t u32DataWidth, unsigned int count, nu_pdma_memctrl_t eMemCtl);
static void nu_pdma_memfun_cb(void *pvUserData, uint32_t u32Events);
static void nu_pdma_memfun_actor_init(void);
static int nu_pdma_memfun_employ(void);
static int nu_pdma_non_transfer_count_get(int32_t i32ChannID);

/* Public functions -------------------------------------------------------------*/


/* Private variables ------------------------------------------------------------*/
static volatile int nu_pdma_inited = 0;
static volatile uint32_t nu_pdma_chn_mask = 0;
static nu_pdma_chn_t nu_pdma_chn_arr[NU_PDMA_CH_MAX];
static rt_mutex_t g_mutex_res = RT_NULL;
static volatile uint32_t nu_pdma_memfun_actor_mask = 0;
static volatile uint32_t nu_pdma_memfun_actor_maxnum = 0;
static rt_sem_t nu_pdma_memfun_actor_pool_sem = RT_NULL;
static rt_mutex_t nu_pdma_memfun_actor_pool_lock = RT_NULL;

static const nu_pdma_periph_ctl_t g_nu_pdma_peripheral_ctl_pool[ ] =
{
    // M2M
    { PDMA_MEM, eMemCtl_SrcInc_DstInc },

    // M2P
    { PDMA_UART0_TX, eMemCtl_SrcInc_DstFix },
    { PDMA_UART1_TX, eMemCtl_SrcInc_DstFix },
    { PDMA_UART2_TX, eMemCtl_SrcInc_DstFix },
    { PDMA_UART3_TX, eMemCtl_SrcInc_DstFix },
    { PDMA_UART4_TX, eMemCtl_SrcInc_DstFix },
    { PDMA_UART5_TX, eMemCtl_SrcInc_DstFix },
    { PDMA_UART6_TX, eMemCtl_SrcInc_DstFix },
    { PDMA_UART7_TX, eMemCtl_SrcInc_DstFix },

    { PDMA_USCI0_TX, eMemCtl_SrcInc_DstFix },
    { PDMA_USCI1_TX, eMemCtl_SrcInc_DstFix },

    { PDMA_QSPI0_TX, eMemCtl_SrcInc_DstFix },

    { PDMA_SPI0_TX,  eMemCtl_SrcInc_DstFix },

    { PDMA_I2C0_TX,  eMemCtl_SrcInc_DstFix },
    { PDMA_I2C1_TX,  eMemCtl_SrcInc_DstFix },

    // P2M
    { PDMA_UART0_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_UART1_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_UART2_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_UART3_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_UART4_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_UART5_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_UART6_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_UART7_RX, eMemCtl_SrcFix_DstInc },

    { PDMA_USCI0_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_USCI1_RX, eMemCtl_SrcFix_DstInc },

    { PDMA_QSPI0_RX, eMemCtl_SrcFix_DstInc },

    { PDMA_SPI0_RX, eMemCtl_SrcFix_DstInc },

    { PDMA_PWM0_P1_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_PWM0_P2_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_PWM0_P3_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_PWM1_P1_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_PWM1_P2_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_PWM1_P3_RX, eMemCtl_SrcFix_DstInc },

    { PDMA_I2C0_RX, eMemCtl_SrcFix_DstInc },
    { PDMA_I2C1_RX, eMemCtl_SrcFix_DstInc },

    { PDMA_TMR0, eMemCtl_SrcFix_DstInc },
    { PDMA_TMR1, eMemCtl_SrcFix_DstInc },
    { PDMA_TMR2, eMemCtl_SrcFix_DstInc },
    { PDMA_TMR3, eMemCtl_SrcFix_DstInc },

    { PDMA_ADC_RX, eMemCtl_SrcFix_DstInc },
};
#define NU_PERIPHERAL_SIZE ( sizeof(g_nu_pdma_peripheral_ctl_pool) / sizeof(g_nu_pdma_peripheral_ctl_pool[0]) )

static struct nu_pdma_memfun_actor nu_pdma_memfun_actor_arr[NU_PDMA_MEMFUN_ACTOR_MAX];

/* SG table pool */
static DSCT_T nu_pdma_sgtbl_arr[NU_PDMA_SGTBL_POOL_SIZE] = { 0 };
static uint32_t nu_pdma_sgtbl_token[RT_ALIGN(NU_PDMA_SGTBL_POOL_SIZE, 32) / 32];
static rt_mutex_t g_mutex_sg = RT_NULL;

static int nu_pdma_peripheral_set(uint32_t u32PeriphType)
{
    int idx = 0;

    while (idx < NU_PERIPHERAL_SIZE)
    {
        if (g_nu_pdma_peripheral_ctl_pool[idx].m_u32Peripheral == u32PeriphType)
            return idx;
        idx++;
    }

    // Not such peripheral
    return -1;
}

static void nu_pdma_periph_ctrl_fill(int i32ChannID, int i32CtlPoolIdx)
{
    nu_pdma_chn_t *psPdmaChann = &nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos];
    psPdmaChann->m_spPeripCtl.m_u32Peripheral = g_nu_pdma_peripheral_ctl_pool[i32CtlPoolIdx].m_u32Peripheral;
    psPdmaChann->m_spPeripCtl.m_eMemCtl = g_nu_pdma_peripheral_ctl_pool[i32CtlPoolIdx].m_eMemCtl;
}

static void nu_pdma_init(void)
{
    int latest = 0;
    if (nu_pdma_inited)
        return;

    g_mutex_res = rt_mutex_create("pdmalock", RT_IPC_FLAG_PRIO);
    RT_ASSERT(g_mutex_res != RT_NULL);

    g_mutex_sg = rt_mutex_create("sgtbles", RT_IPC_FLAG_PRIO);
    RT_ASSERT(g_mutex_sg != RT_NULL);

    nu_pdma_chn_mask = ~NU_PDMA_CH_Msk;
    rt_memset(nu_pdma_chn_arr, 0x00, NU_PDMA_CH_MAX*sizeof(nu_pdma_chn_t));

    NVIC_EnableIRQ(PDMA_IRQn);

    /* Initialize PDMA setting */
    PDMA_Open(PDMA, NU_PDMA_CH_Msk);
    PDMA_Close(PDMA);

    rt_memset(&nu_pdma_sgtbl_arr[0], 0x00, sizeof(nu_pdma_sgtbl_arr));

    /* Assign first SG table address as PDMA SG table base address */
    PDMA->SCATBA = (uint32_t)&nu_pdma_sgtbl_arr[0];

    /* Initializa token pool. */
    rt_memset(&nu_pdma_sgtbl_token[0], 0xff, sizeof(nu_pdma_sgtbl_token));
    latest = NU_PDMA_SGTBL_POOL_SIZE / 32;
    nu_pdma_sgtbl_token[latest] ^= ~((1 << (NU_PDMA_SGTBL_POOL_SIZE % 32)) - 1) ;

    nu_pdma_inited = 1;
}

static void nu_pdma_channel_enable(int i32ChannID)
{
    PDMA_Open(PDMA, 1 << i32ChannID);
}

static inline void nu_pdma_channel_disable(int i32ChannID)
{
    PDMA->CHCTL &= ~(1 << i32ChannID);
}

static inline void nu_pdma_channel_reset(int i32ChannID)
{
    PDMA->CHRST = (1 << i32ChannID);
}

void nu_pdma_channel_terminate(int i32ChannID)
{
    int i;
    uint32_t u32EnabledChans;
    int ch_mask = 0;

    if (!(nu_pdma_chn_mask & (1 << i32ChannID)))
        goto exit_pdma_channel_terminate;

    rt_mutex_take(g_mutex_res, RT_WAITING_FOREVER);

    // Suspend all channels.
    u32EnabledChans = nu_pdma_chn_mask & NU_PDMA_CH_Msk;
    while ((i = nu_ctz(u32EnabledChans)) != 32)
    {
        ch_mask = (1 << i);
        if (i == i32ChannID)
        {
            u32EnabledChans &= ~ch_mask;
            continue;
        }

        // Pause the channel
        PDMA_PAUSE(PDMA, i);

        // Wait for channel to finish current transfer
        while (PDMA->TACTSTS & ch_mask) { }

        u32EnabledChans &= ~ch_mask;
    } //while

    // Reset specified channel ID
    nu_pdma_channel_reset(i32ChannID);

    // Clean descriptor table control register.
    PDMA->DSCT[i32ChannID].CTL = 0UL;

    // Resume all channels.
    u32EnabledChans = nu_pdma_chn_mask & NU_PDMA_CH_Msk;
    while ((i = nu_ctz(u32EnabledChans)) != 32)
    {
        ch_mask = (1 << i);

        PDMA->CHCTL |= ch_mask;
        PDMA_Trigger(PDMA, i);
        u32EnabledChans &= ~ch_mask;
    }

    rt_mutex_release(g_mutex_res);

exit_pdma_channel_terminate:

    return;
}

static rt_err_t nu_pdma_timeout_set(int i32ChannID, int i32Timeout_us)
{
    rt_err_t ret = RT_EINVAL;

    if (!(nu_pdma_chn_mask & (1 << i32ChannID)))
        goto exit_nu_pdma_timeout_set;

    nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_u32IdleTimeout_us = i32Timeout_us;

    if (i32Timeout_us && i32ChannID <= 1)   // M480 limit
    {
        uint32_t u32ToClk_Max = 1000000 / (CLK_GetHCLKFreq() / (1 << 8));
        uint32_t u32Divider     = (i32Timeout_us / u32ToClk_Max) / (1 << 16);
        uint32_t u32TOutCnt     = (i32Timeout_us / u32ToClk_Max) % (1 << 16);

        PDMA_DisableTimeout(PDMA,  1 << i32ChannID);
        PDMA_EnableInt(PDMA, i32ChannID, PDMA_INT_TIMEOUT);    // Interrupt type

        if (u32Divider > 7)
        {
            u32Divider = 7;
            u32TOutCnt = (1 << 16);
        }
        PDMA->TOUTPSC |= (u32Divider << (PDMA_TOUTPSC_TOUTPSC1_Pos * i32ChannID));
        PDMA_SetTimeOut(PDMA,  i32ChannID, 1, u32TOutCnt);

        ret = RT_EOK;
    }
    else
    {
        PDMA_DisableInt(PDMA, i32ChannID, PDMA_INT_TIMEOUT);    // Interrupt type
        PDMA_DisableTimeout(PDMA,  1 << i32ChannID);
    }

exit_nu_pdma_timeout_set:

    return -(ret);
}

int nu_pdma_channel_allocate(int32_t i32PeripType)
{
    int i, i32PeripCtlIdx;

    nu_pdma_init();

    if ((i32PeripCtlIdx = nu_pdma_peripheral_set(i32PeripType)) < 0)
        goto exit_nu_pdma_channel_allocate;

    /* Find the position of first '0' in nu_pdma_chn_mask. */
    i = nu_cto(nu_pdma_chn_mask);
    if (i != 32)
    {
        nu_pdma_chn_mask |= (1 << i);
        rt_memset(nu_pdma_chn_arr + i - NU_PDMA_CH_Pos, 0x00, sizeof(nu_pdma_chn_t));

        /* Set idx number of g_nu_pdma_peripheral_ctl_pool */
        nu_pdma_periph_ctrl_fill(i, i32PeripCtlIdx);

        /* Reset channel */
        nu_pdma_channel_reset(i);

        nu_pdma_channel_enable(i);

        return i;
    }

exit_nu_pdma_channel_allocate:
    // No channel available
    return -(RT_ERROR);
}

rt_err_t nu_pdma_channel_free(int i32ChannID)
{
    rt_err_t ret = RT_EINVAL;

    if (! nu_pdma_inited)
        goto exit_nu_pdma_channel_free;

    if (i32ChannID < NU_PDMA_CH_MAX && i32ChannID >= NU_PDMA_CH_Pos)
    {
        nu_pdma_chn_mask &= ~(1 << i32ChannID);
        nu_pdma_channel_disable(i32ChannID);
        ret =  RT_EOK;
    }
exit_nu_pdma_channel_free:

    return -(ret);
}

rt_err_t nu_pdma_callback_register(int i32ChannID, nu_pdma_cb_handler_t pfnHandler, void *pvUserData, uint32_t u32EventFilter)
{
    rt_err_t ret = RT_EINVAL;

    if (!(nu_pdma_chn_mask & (1 << i32ChannID)))
        goto exit_nu_pdma_callback_register;

    nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_pfnCBHandler = pfnHandler;
    nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_pvUserData = pvUserData;
    nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_u32EventFilter = u32EventFilter;

    ret = RT_EOK;

exit_nu_pdma_callback_register:

    return -(ret) ;
}

nu_pdma_cb_handler_t nu_pdma_callback_hijack(int i32ChannID, nu_pdma_cb_handler_t *ppfnHandler_Hijack,
        void **ppvUserData_Hijack, uint32_t *pu32Events_Hijack)
{
    nu_pdma_cb_handler_t pfnHandler_Org = NULL;
    void    *pvUserData_Org;
    uint32_t u32Events_Org;

    RT_ASSERT(ppfnHandler_Hijack != NULL);
    RT_ASSERT(ppvUserData_Hijack != NULL);
    RT_ASSERT(pu32Events_Hijack != NULL);

    if (!(nu_pdma_chn_mask & (1 << i32ChannID)))
        goto exit_nu_pdma_callback_hijack;

    pfnHandler_Org = nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_pfnCBHandler;
    pvUserData_Org = nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_pvUserData;
    u32Events_Org  = nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_u32EventFilter;

    nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_pfnCBHandler = *ppfnHandler_Hijack;
    nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_pvUserData = *ppvUserData_Hijack;
    nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_u32EventFilter = *pu32Events_Hijack;

    *ppfnHandler_Hijack = pfnHandler_Org;
    *ppvUserData_Hijack = pvUserData_Org;
    *pu32Events_Hijack  = u32Events_Org;

exit_nu_pdma_callback_hijack:

    return pfnHandler_Org;
}

static int nu_pdma_non_transfer_count_get(int32_t i32ChannID)
{
    return ((PDMA->DSCT[i32ChannID].CTL & PDMA_DSCT_CTL_TXCNT_Msk) >> PDMA_DSCT_CTL_TXCNT_Pos) + 1;
}

int nu_pdma_transferred_byte_get(int32_t i32ChannID, int32_t i32TriggerByteLen)
{
    int i32BitWidth = 0;
    int cur_txcnt = 0;

    if (!(nu_pdma_chn_mask & (1 << i32ChannID)))
        goto exit_nu_pdma_transferred_byte_get;

    i32BitWidth = PDMA->DSCT[i32ChannID].CTL & PDMA_DSCT_CTL_TXWIDTH_Msk;
    i32BitWidth = (i32BitWidth == PDMA_WIDTH_8) ? 1 : (i32BitWidth == PDMA_WIDTH_16) ? 2 : (i32BitWidth == PDMA_WIDTH_32) ? 4 : 0;

    cur_txcnt = nu_pdma_non_transfer_count_get(i32ChannID);

    return (i32TriggerByteLen - (cur_txcnt) * i32BitWidth);

exit_nu_pdma_transferred_byte_get:

    return -1;
}

nu_pdma_memctrl_t nu_pdma_channel_memctrl_get(int i32ChannID)
{
    nu_pdma_memctrl_t eMemCtrl = eMemCtl_Undefined;

    if (!(nu_pdma_chn_mask & (1 << i32ChannID)))
        goto exit_nu_pdma_channel_memctrl_get;

    eMemCtrl = nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_spPeripCtl.m_eMemCtl;

exit_nu_pdma_channel_memctrl_get:

    return eMemCtrl;
}

rt_err_t nu_pdma_channel_memctrl_set(int i32ChannID, nu_pdma_memctrl_t eMemCtrl)
{
    rt_err_t ret = RT_EINVAL;
    nu_pdma_chn_t *psPdmaChann = &nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos];


    if (!(nu_pdma_chn_mask & (1 << i32ChannID)))
        goto exit_nu_pdma_channel_memctrl_set;
    else if ((eMemCtrl < eMemCtl_SrcFix_DstFix) || (eMemCtrl > eMemCtl_SrcInc_DstInc))
        goto exit_nu_pdma_channel_memctrl_set;

    /* PDMA_MEM/SAR_FIX/BURST mode is not supported. */
    if ((psPdmaChann->m_spPeripCtl.m_u32Peripheral == PDMA_MEM) &&
            ((eMemCtrl == eMemCtl_SrcFix_DstInc) || (eMemCtrl == eMemCtl_SrcFix_DstFix)))
        goto exit_nu_pdma_channel_memctrl_set;

    nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_spPeripCtl.m_eMemCtl = eMemCtrl;

    ret = RT_EOK;

exit_nu_pdma_channel_memctrl_set:

    return -(ret);
}

static void nu_pdma_channel_memctrl_fill(nu_pdma_memctrl_t eMemCtl, uint32_t *pu32SrcCtl, uint32_t *pu32DstCtl)
{
    switch ((int)eMemCtl)
    {
    case eMemCtl_SrcFix_DstFix:
        *pu32SrcCtl = PDMA_SAR_FIX;
        *pu32DstCtl = PDMA_DAR_FIX;
        break;
    case eMemCtl_SrcFix_DstInc:
        *pu32SrcCtl = PDMA_SAR_FIX;
        *pu32DstCtl = PDMA_DAR_INC;
        break;
    case eMemCtl_SrcInc_DstFix:
        *pu32SrcCtl = PDMA_SAR_INC;
        *pu32DstCtl = PDMA_DAR_FIX;
        break;
    case eMemCtl_SrcInc_DstInc:
        *pu32SrcCtl = PDMA_SAR_INC;
        *pu32DstCtl = PDMA_DAR_INC;
        break;
    default:
        break;
    }
}

/* This is for Scatter-gather DMA. */
rt_err_t nu_pdma_desc_setup(int i32ChannID, nu_pdma_desc_t dma_desc, uint32_t u32DataWidth, uint32_t u32AddrSrc,
                            uint32_t u32AddrDst, int32_t i32TransferCnt, nu_pdma_desc_t next)
{
    nu_pdma_periph_ctl_t *psPeriphCtl = NULL;

    uint32_t u32SrcCtl = 0;
    uint32_t u32DstCtl = 0;

    rt_err_t ret = RT_EINVAL;

    if (!dma_desc)
        goto exit_nu_pdma_desc_setup;
    else if (!(nu_pdma_chn_mask & (1 << i32ChannID)))
        goto exit_nu_pdma_desc_setup;
    else if (!(u32DataWidth == 8 || u32DataWidth == 16 || u32DataWidth == 32))
        goto exit_nu_pdma_desc_setup;
    else if ((u32AddrSrc % (u32DataWidth / 8)) || (u32AddrDst % (u32DataWidth / 8)))
        goto exit_nu_pdma_desc_setup;
    else if (i32TransferCnt > NU_PDMA_MAX_TXCNT)
        goto exit_nu_pdma_desc_setup;

    psPeriphCtl = &nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_spPeripCtl;

    nu_pdma_channel_memctrl_fill(psPeriphCtl->m_eMemCtl, &u32SrcCtl, &u32DstCtl);

    dma_desc->CTL = ((i32TransferCnt - 1) << PDMA_DSCT_CTL_TXCNT_Pos) |
                    ((u32DataWidth == 8) ? PDMA_WIDTH_8 : (u32DataWidth == 16) ? PDMA_WIDTH_16 : PDMA_WIDTH_32) |
                    u32SrcCtl |
                    u32DstCtl |
                    PDMA_OP_BASIC;

    dma_desc->SA = u32AddrSrc;
    dma_desc->DA = u32AddrDst;
    dma_desc->NEXT = 0;  /* Terminating node by default. */

    if (psPeriphCtl->m_u32Peripheral == PDMA_MEM)
    {
        /* For M2M transfer */
        dma_desc->CTL |= (PDMA_REQ_BURST | PDMA_BURST_32);
    }
    else
    {
        /* For P2M and M2P transfer */
        dma_desc->CTL |= (PDMA_REQ_SINGLE);
    }

    if (next)
    {
        /* Link to Next and modify to scatter-gather DMA mode. */
        dma_desc->CTL = (dma_desc->CTL & ~PDMA_DSCT_CTL_OPMODE_Msk) | PDMA_OP_SCATTER;
        dma_desc->NEXT = (uint32_t)next - (PDMA->SCATBA);
    }

    ret = RT_EOK;

exit_nu_pdma_desc_setup:

    return -(ret);
}

static int nu_pdma_sgtbls_token_allocate(void)
{
    int idx, i;

    int pool_size = sizeof(nu_pdma_sgtbl_token) / sizeof(uint32_t);

    for (i = 0; i < pool_size; i++)
    {
        if ((idx = nu_ctz(nu_pdma_sgtbl_token[i])) != 32)
        {
            nu_pdma_sgtbl_token[i] &= ~(1 << idx);
            idx += i * 32;
            return idx;
        }
    }

    /* No available */
    return -1;
}

static void nu_pdma_sgtbls_token_free(nu_pdma_desc_t psSgtbls)
{
    int idx = (int)(psSgtbls - &nu_pdma_sgtbl_arr[0]);
    RT_ASSERT(idx >= 0);
    RT_ASSERT((idx + 1) <= NU_PDMA_SGTBL_POOL_SIZE);
    nu_pdma_sgtbl_token[idx / 32] |= (1 << (idx % 32));
}

rt_err_t nu_pdma_sgtbls_allocate(nu_pdma_desc_t *ppsSgtbls, int num)
{
    int i, j, idx;

    RT_ASSERT(ppsSgtbls != NULL);
    RT_ASSERT(num <= NU_PDMA_SG_TBL_MAXSIZE);

    rt_mutex_take(g_mutex_sg, RT_WAITING_FOREVER);

    for (i = 0; i < num; i++)
    {
        ppsSgtbls[i] = NULL;
        /* Get token. */
        if ((idx = nu_pdma_sgtbls_token_allocate()) < 0)
        {
            rt_kprintf("No available sgtbl.\n");
            goto fail_nu_pdma_sgtbls_allocate;
        }

        ppsSgtbls[i] = (nu_pdma_desc_t)&nu_pdma_sgtbl_arr[idx];
    }

    rt_mutex_release(g_mutex_sg);

    return RT_EOK;

fail_nu_pdma_sgtbls_allocate:

    /* Release allocated tables. */
    for (j = 0; j < i; j++)
    {
        if (ppsSgtbls[j] != NULL)
        {
            nu_pdma_sgtbls_token_free(ppsSgtbls[j]);
        }
        ppsSgtbls[j] = NULL;
    }

    rt_mutex_release(g_mutex_sg);
    return -RT_ERROR;
}

void nu_pdma_sgtbls_free(nu_pdma_desc_t *ppsSgtbls, int num)
{
    int i;

    RT_ASSERT(ppsSgtbls != NULL);
    RT_ASSERT(num <= NU_PDMA_SG_TBL_MAXSIZE);

    rt_mutex_take(g_mutex_sg, RT_WAITING_FOREVER);

    for (i = 0; i < num; i++)
    {
        if (ppsSgtbls[i] != NULL)
        {
            nu_pdma_sgtbls_token_free(ppsSgtbls[i]);
        }
        ppsSgtbls[i] = NULL;
    }

    rt_mutex_release(g_mutex_sg);
}

static rt_err_t nu_pdma_sgtbls_valid(nu_pdma_desc_t head)
{
    uint32_t node_addr;
    nu_pdma_desc_t node = head;

    do
    {
        node_addr = (uint32_t)node;
        if ((node_addr < PDMA->SCATBA) || (node_addr - PDMA->SCATBA) >= NU_PDMA_SG_LIMITED_DISTANCE)
        {
            rt_kprintf("The distance is over %d between 0x%08x and 0x%08x. \n", NU_PDMA_SG_LIMITED_DISTANCE, PDMA->SCATBA, node);
            rt_kprintf("Please use nu_pdma_sgtbl_allocate to allocate valid sg-table.\n");
            return RT_ERROR;
        }

        node = (nu_pdma_desc_t)(node->NEXT + PDMA->SCATBA);

    }
    while (((uint32_t)node != PDMA->SCATBA) && (node != head));

    return RT_EOK;
}

static void _nu_pdma_transfer(int i32ChannID, uint32_t u32Peripheral, nu_pdma_desc_t head, uint32_t u32IdleTimeout_us)
{
    PDMA_DisableTimeout(PDMA,  1 << i32ChannID);

    PDMA_EnableInt(PDMA, i32ChannID, PDMA_INT_TRANS_DONE);

    nu_pdma_timeout_set(i32ChannID, u32IdleTimeout_us);

    /* Set scatter-gather mode and head */
    PDMA_SetTransferMode(PDMA,
                         i32ChannID,
                         u32Peripheral,
                         (head->NEXT != 0) ? 1 : 0,
                         (uint32_t)head);

    /* If peripheral is M2M, trigger it. */
    if (u32Peripheral == PDMA_MEM)
        PDMA_Trigger(PDMA, i32ChannID);
}

rt_err_t nu_pdma_transfer(int i32ChannID, uint32_t u32DataWidth, uint32_t u32AddrSrc, uint32_t u32AddrDst, int32_t i32TransferCnt, uint32_t u32IdleTimeout_us)
{
    rt_err_t ret = RT_EINVAL;

    nu_pdma_periph_ctl_t *psPeriphCtl = NULL;

    if (!(nu_pdma_chn_mask & (1 << i32ChannID)))
        goto exit_nu_pdma_transfer;

    psPeriphCtl = &nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_spPeripCtl;

    ret = nu_pdma_desc_setup(i32ChannID,
                             &PDMA->DSCT[i32ChannID],
                             u32DataWidth,
                             u32AddrSrc,
                             u32AddrDst,
                             i32TransferCnt,
                             NULL);
    if (ret != RT_EOK)
        goto exit_nu_pdma_transfer;

    _nu_pdma_transfer(i32ChannID, psPeriphCtl->m_u32Peripheral,  &PDMA->DSCT[i32ChannID], u32IdleTimeout_us);

    ret = RT_EOK;

exit_nu_pdma_transfer:

    return -(ret);
}

rt_err_t nu_pdma_sg_transfer(int i32ChannID, nu_pdma_desc_t head, uint32_t u32IdleTimeout_us)
{
    rt_err_t ret = RT_EINVAL;
    nu_pdma_periph_ctl_t *psPeriphCtl = NULL;

    if (!head)
        goto exit_nu_pdma_sg_transfer;
    else if (!(nu_pdma_chn_mask & (1 << i32ChannID)))
        goto exit_nu_pdma_sg_transfer;
    else if ((ret = nu_pdma_sgtbls_valid(head)) != RT_EOK) /* Check SG-tbls. */
        goto exit_nu_pdma_sg_transfer;

    psPeriphCtl = &nu_pdma_chn_arr[i32ChannID - NU_PDMA_CH_Pos].m_spPeripCtl;

    _nu_pdma_transfer(i32ChannID, psPeriphCtl->m_u32Peripheral, head, u32IdleTimeout_us);

    ret = RT_EOK;

exit_nu_pdma_sg_transfer:

    return -(ret);
}

void PDMA_IRQHandler(void)
{
    int i;

    /* enter interrupt */
    rt_interrupt_enter();

    uint32_t intsts = PDMA_GET_INT_STATUS(PDMA);
    uint32_t abtsts = PDMA_GET_ABORT_STS(PDMA);
    uint32_t tdsts  = PDMA_GET_TD_STS(PDMA);
    uint32_t reqto  = intsts & (PDMA_INTSTS_REQTOF0_Msk | PDMA_INTSTS_REQTOF1_Msk);
    uint32_t reqto_ch = ((reqto & PDMA_INTSTS_REQTOF0_Msk) ? (1 << 0) : 0x0) | ((reqto & PDMA_INTSTS_REQTOF1_Msk) ? (1 << 1) : 0x0);

    int allch_sts = (reqto_ch | tdsts | abtsts);

    // Abort
    if (intsts & PDMA_INTSTS_ABTIF_Msk)
    {
        // Clear all Abort flags
        PDMA_CLR_ABORT_FLAG(PDMA, abtsts);
    }

    // Transfer done
    if (intsts & PDMA_INTSTS_TDIF_Msk)
    {
        // Clear all transfer done flags
        PDMA_CLR_TD_FLAG(PDMA, tdsts);
    }

    // Timeout
    if (reqto)
    {
        // Clear all Timeout flags
        PDMA->INTSTS = reqto;
    }

    // Find the position of first '1' in allch_sts.
    while ((i = nu_ctz(allch_sts)) != 32)
    {
        int ch_mask = (1 << i);

        if (nu_pdma_chn_mask & ch_mask)
        {
            int ch_event = 0;
            nu_pdma_chn_t *dma_chn = nu_pdma_chn_arr + i - NU_PDMA_CH_Pos;

            if (dma_chn->m_pfnCBHandler)
            {
                if (abtsts   & ch_mask)
                {
                    ch_event |= NU_PDMA_EVENT_ABORT;
                }

                if (tdsts    & ch_mask) ch_event |= NU_PDMA_EVENT_TRANSFER_DONE;

                if (reqto_ch & ch_mask)
                {
                    PDMA_DisableTimeout(PDMA,  ch_mask);
                    ch_event |= NU_PDMA_EVENT_TIMEOUT;
                }

                if (dma_chn->m_u32EventFilter & ch_event)
                    dma_chn->m_pfnCBHandler(dma_chn->m_pvUserData, ch_event);

                if (reqto_ch & ch_mask)
                    nu_pdma_timeout_set(i, nu_pdma_chn_arr[i - NU_PDMA_CH_Pos].m_u32IdleTimeout_us);

            }//if(dma_chn->handler)
        } //if (nu_pdma_chn_mask & ch_mask)

        // Clear the served bit.
        allch_sts &= ~ch_mask;

    } //while

    /* leave interrupt */
    rt_interrupt_leave();
}

static void nu_pdma_memfun_actor_init(void)
{
    int i = 0 ;
    nu_pdma_init();
    for (i = 0; i < NU_PDMA_MEMFUN_ACTOR_MAX; i++)
    {
        rt_memset(&nu_pdma_memfun_actor_arr[i], 0, sizeof(struct nu_pdma_memfun_actor));
        if (-(RT_ERROR) != (nu_pdma_memfun_actor_arr[i].m_i32ChannID = nu_pdma_channel_allocate(PDMA_MEM)))
        {
            nu_pdma_memfun_actor_arr[i].m_psSemMemFun = rt_sem_create("memactor_sem", 0, RT_IPC_FLAG_FIFO);
        }
        else
            break;
    }
    if (i)
    {
        nu_pdma_memfun_actor_maxnum = i;
        nu_pdma_memfun_actor_mask = ~(((1 << i) - 1));
        nu_pdma_memfun_actor_pool_sem = rt_sem_create("mempool_sem", nu_pdma_memfun_actor_maxnum, RT_IPC_FLAG_FIFO);
        nu_pdma_memfun_actor_pool_lock = rt_mutex_create("mempool_lock", RT_IPC_FLAG_PRIO);
    }
}

static void nu_pdma_memfun_cb(void *pvUserData, uint32_t u32Events)
{
    nu_pdma_memfun_actor_t psMemFunActor = (nu_pdma_memfun_actor_t)pvUserData;
    psMemFunActor->m_u32Result = u32Events;
    rt_sem_release(psMemFunActor->m_psSemMemFun);
}

static int nu_pdma_memfun_employ(void)
{
    int idx = -1 ;

    /* Headhunter */
    if (nu_pdma_memfun_actor_pool_sem && (rt_sem_take(nu_pdma_memfun_actor_pool_sem, RT_WAITING_FOREVER) == RT_EOK))
    {
        rt_mutex_take(nu_pdma_memfun_actor_pool_lock, RT_WAITING_FOREVER);
        /* Find the position of first '0' in nu_pdma_memfun_actor_mask. */
        idx = nu_cto(nu_pdma_memfun_actor_mask);
        if (idx != 32)
        {
            nu_pdma_memfun_actor_mask |= (1 << idx);
        }
        else
        {
            idx = -1;
        }
        rt_mutex_release(nu_pdma_memfun_actor_pool_lock);
    }

    return idx;
}

static rt_size_t nu_pdma_memfun(void *dest, void *src, uint32_t u32DataWidth, unsigned int u32TransferCnt, nu_pdma_memctrl_t eMemCtl)
{
    nu_pdma_memfun_actor_t psMemFunActor = NULL;
    int idx;
    rt_size_t ret = 0;
    rt_uint32_t u32Offset = 0;
    rt_uint32_t u32TxCnt = 0;

    while (1)
    {
        /* Employ actor */
        if ((idx = nu_pdma_memfun_employ()) < 0)
            continue;

        psMemFunActor = &nu_pdma_memfun_actor_arr[idx];

        do
        {

            u32TxCnt = (u32TransferCnt > NU_PDMA_MAX_TXCNT) ? NU_PDMA_MAX_TXCNT : u32TransferCnt;

            /* Set PDMA memory control to eMemCtl. */
            nu_pdma_channel_memctrl_set(psMemFunActor->m_i32ChannID, eMemCtl);

            /* Register ISR callback function */
            nu_pdma_callback_register(psMemFunActor->m_i32ChannID, nu_pdma_memfun_cb, (void *)psMemFunActor, NU_PDMA_EVENT_ABORT | NU_PDMA_EVENT_TRANSFER_DONE);

            psMemFunActor->m_u32Result = 0;

            /* Trigger it */
            nu_pdma_transfer(psMemFunActor->m_i32ChannID,
                             u32DataWidth,
                             (eMemCtl & 0x2ul) ? (uint32_t)src + u32Offset : (uint32_t)src, /* Src address is Inc or not. */
                             (eMemCtl & 0x1ul) ? (uint32_t)dest + u32Offset : (uint32_t)dest, /* Dst address is Inc or not. */
                             u32TxCnt,
                             0);

            /* Wait it done. */
            rt_sem_take(psMemFunActor->m_psSemMemFun, RT_WAITING_FOREVER);

            /* Give result if get NU_PDMA_EVENT_TRANSFER_DONE.*/
            if (psMemFunActor->m_u32Result & NU_PDMA_EVENT_TRANSFER_DONE)
            {
                ret +=  u32TxCnt;
            }
            else
            {
                ret += (u32TxCnt - nu_pdma_non_transfer_count_get(psMemFunActor->m_i32ChannID));
            }

            /* Terminate it if get ABORT event */
            if (psMemFunActor->m_u32Result & NU_PDMA_EVENT_ABORT)
            {
                nu_pdma_channel_terminate(psMemFunActor->m_i32ChannID);
                break;
            }

            u32TransferCnt -= u32TxCnt;
            u32Offset += u32TxCnt;
        }
        while (u32TransferCnt > 0);

        rt_mutex_take(nu_pdma_memfun_actor_pool_lock, RT_WAITING_FOREVER);
        nu_pdma_memfun_actor_mask &= ~(1 << idx);
        rt_mutex_release(nu_pdma_memfun_actor_pool_lock);

        /* Fire actor */
        rt_sem_release(nu_pdma_memfun_actor_pool_sem);

        break;
    }

    return ret;
}

rt_size_t nu_pdma_mempush(void *dest, void *src, uint32_t data_width, unsigned int transfer_count)
{
    if (data_width == 8 || data_width == 16 || data_width == 32)
        return nu_pdma_memfun(dest, src, data_width, transfer_count, eMemCtl_SrcInc_DstFix);
    return 0;
}

void *nu_pdma_memcpy(void *dest, void *src, unsigned int count)
{
    int i = 0;
    uint32_t u32Offset = 0;
    uint32_t u32Remaining = count;

    for (i = 4; (i > 0) && (u32Remaining > 0) ; i >>= 1)
    {
        uint32_t u32src   = (uint32_t)src + u32Offset;
        uint32_t u32dest  = (uint32_t)dest + u32Offset;

        if (((u32src % i) == (u32dest % i)) &&
                ((u32src % i) == 0) &&
                (RT_ALIGN_DOWN(u32Remaining, i) >= i))
        {
            uint32_t u32TXCnt = u32Remaining / i;
            if (u32TXCnt != nu_pdma_memfun((void *)u32dest, (void *)u32src, i * 8, u32TXCnt, eMemCtl_SrcInc_DstInc))
                goto exit_nu_pdma_memcpy;

            u32Offset += (u32TXCnt * i);
            u32Remaining -= (u32TXCnt * i);
        }
    }

    if (count == u32Offset)
        return dest;

exit_nu_pdma_memcpy:

    return NULL;
}

/**
 * PDMA memfun actor initialization
 */
int rt_hw_pdma_memfun_init(void)
{
    nu_pdma_memfun_actor_init();
    return 0;
}
INIT_DEVICE_EXPORT(rt_hw_pdma_memfun_init);
#endif // #if defined(BSP_USING_PDMA)