drivers/uart/fsl_uart_edma.c

/*
 * Copyright (c) 2015, Freescale Semiconductor, Inc.
 * Copyright 2016-2021 NXP
 * All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include "fsl_uart_edma.h"

/*******************************************************************************
 * Definitions
 ******************************************************************************/

/* Component ID definition, used by tools. */
#ifndef FSL_COMPONENT_ID
#define FSL_COMPONENT_ID "platform.drivers.uart_edma"
#endif

/* Array of UART handle. */
#if (defined(UART5))
#define UART_HANDLE_ARRAY_SIZE 6
#else /* UART5 */
#if (defined(UART4))
#define UART_HANDLE_ARRAY_SIZE 5
#else /* UART4 */
#if (defined(UART3))
#define UART_HANDLE_ARRAY_SIZE 4
#else /* UART3 */
#if (defined(UART2))
#define UART_HANDLE_ARRAY_SIZE 3
#else /* UART2 */
#if (defined(UART1))
#define UART_HANDLE_ARRAY_SIZE 2
#else /* UART1 */
#if (defined(UART0))
#define UART_HANDLE_ARRAY_SIZE 1
#else /* UART0 */
#error No UART instance.
#endif /* UART 0 */
#endif /* UART 1 */
#endif /* UART 2 */
#endif /* UART 3 */
#endif /* UART 4 */
#endif /* UART 5 */

/*<! Structure definition for uart_edma_private_handle_t. The structure is private. */
typedef struct _uart_edma_private_handle
{
    UART_Type *base;
    uart_edma_handle_t *handle;
} uart_edma_private_handle_t;

/* UART EDMA transfer handle. */
enum
{
    kUART_TxIdle, /* TX idle. */
    kUART_TxBusy, /* TX busy. */
    kUART_RxIdle, /* RX idle. */
    kUART_RxBusy  /* RX busy. */
};

/*******************************************************************************
 * Variables
 ******************************************************************************/

/*<! Private handle only used for internally. */
static uart_edma_private_handle_t s_edmaPrivateHandle[UART_HANDLE_ARRAY_SIZE];

/*******************************************************************************
 * Prototypes
 ******************************************************************************/

/*!
 * @brief UART EDMA send finished callback function.
 *
 * This function is called when UART EDMA send finished. It disables the UART
 * TX EDMA request and sends @ref kStatus_UART_TxIdle to UART callback.
 *
 * @param handle The EDMA handle.
 * @param param Callback function parameter.
 */
static void UART_SendEDMACallback(edma_handle_t *handle, void *param, bool transferDone, uint32_t tcds);

/*!
 * @brief UART EDMA receive finished callback function.
 *
 * This function is called when UART EDMA receive finished. It disables the UART
 * RX EDMA request and sends @ref kStatus_UART_RxIdle to UART callback.
 *
 * @param handle The EDMA handle.
 * @param param Callback function parameter.
 */
static void UART_ReceiveEDMACallback(edma_handle_t *handle, void *param, bool transferDone, uint32_t tcds);

/*******************************************************************************
 * Code
 ******************************************************************************/

static void UART_SendEDMACallback(edma_handle_t *handle, void *param, bool transferDone, uint32_t tcds)
{
    assert(param != NULL);

    uart_edma_private_handle_t *uartPrivateHandle = (uart_edma_private_handle_t *)param;

    /* Avoid the warning for unused variables. */
    handle = handle;
    tcds   = tcds;

    if (transferDone)
    {
        /* Disable UART TX EDMA. */
        UART_EnableTxDMA(uartPrivateHandle->base, false);
        /* Stop transfer. */
        EDMA_AbortTransfer(handle);

        /* Enable tx complete interrupt */
        UART_EnableInterrupts(uartPrivateHandle->base, (uint32_t)kUART_TransmissionCompleteInterruptEnable);
    }
}

static void UART_ReceiveEDMACallback(edma_handle_t *handle, void *param, bool transferDone, uint32_t tcds)
{
    assert(param != NULL);

    uart_edma_private_handle_t *uartPrivateHandle = (uart_edma_private_handle_t *)param;

    /* Avoid warning for unused parameters. */
    handle = handle;
    tcds   = tcds;

    if (transferDone)
    {
        /* Disable transfer. */
        UART_TransferAbortReceiveEDMA(uartPrivateHandle->base, uartPrivateHandle->handle);

        if (uartPrivateHandle->handle->callback != NULL)
        {
            uartPrivateHandle->handle->callback(uartPrivateHandle->base, uartPrivateHandle->handle, kStatus_UART_RxIdle,
                                                uartPrivateHandle->handle->userData);
        }
    }
}

/*!
 * brief Initializes the UART handle which is used in transactional functions.
 * param base UART peripheral base address.
 * param handle Pointer to the uart_edma_handle_t structure.
 * param callback UART callback, NULL means no callback.
 * param userData User callback function data.
 * param rxEdmaHandle User-requested DMA handle for RX DMA transfer.
 * param txEdmaHandle User-requested DMA handle for TX DMA transfer.
 */
void UART_TransferCreateHandleEDMA(UART_Type *base,
                                   uart_edma_handle_t *handle,
                                   uart_edma_transfer_callback_t callback,
                                   void *userData,
                                   edma_handle_t *txEdmaHandle,
                                   edma_handle_t *rxEdmaHandle)
{
    assert(handle != NULL);

    uint32_t instance = UART_GetInstance(base);

    s_edmaPrivateHandle[instance].base   = base;
    s_edmaPrivateHandle[instance].handle = handle;

    (void)memset(handle, 0, sizeof(*handle));

    handle->rxState = (uint8_t)kUART_RxIdle;
    handle->txState = (uint8_t)kUART_TxIdle;

    handle->rxEdmaHandle = rxEdmaHandle;
    handle->txEdmaHandle = txEdmaHandle;

    handle->callback = callback;
    handle->userData = userData;

#if defined(FSL_FEATURE_UART_HAS_FIFO) && FSL_FEATURE_UART_HAS_FIFO
    /* Note:
       Take care of the RX FIFO, EDMA request only assert when received bytes
       equal or more than RX water mark, there is potential issue if RX water
       mark larger than 1.
       For example, if RX FIFO water mark is 2, upper layer needs 5 bytes and
       5 bytes are received. the last byte will be saved in FIFO but not trigger
       EDMA transfer because the water mark is 2.
     */
    if (rxEdmaHandle != NULL)
    {
        base->RWFIFO = 1U;
    }
#endif

    /* Save the handle in global variables to support the double weak mechanism. */
    s_uartHandle[instance] = handle;
    /* Save IRQ handler into static ISR function pointer. */
    s_uartIsr = UART_TransferEdmaHandleIRQ;
    /* Disable internal IRQs and enable global IRQ. */
    UART_DisableInterrupts(base, (uint32_t)kUART_AllInterruptsEnable);
    (void)EnableIRQ(s_uartIRQ[instance]);

    /* Configure TX. */
    if (txEdmaHandle != NULL)
    {
        EDMA_SetCallback(handle->txEdmaHandle, UART_SendEDMACallback, &s_edmaPrivateHandle[instance]);
    }

    /* Configure RX. */
    if (rxEdmaHandle != NULL)
    {
        EDMA_SetCallback(handle->rxEdmaHandle, UART_ReceiveEDMACallback, &s_edmaPrivateHandle[instance]);
    }
}

/*!
 * brief Sends data using eDMA.
 *
 * This function sends data using eDMA. This is a non-blocking function, which returns
 * right away. When all data is sent, the send callback function is called.
 *
 * param base UART peripheral base address.
 * param handle UART handle pointer.
 * param xfer UART eDMA transfer structure. See #uart_transfer_t.
 * retval kStatus_Success if succeeded; otherwise failed.
 * retval kStatus_UART_TxBusy Previous transfer ongoing.
 * retval kStatus_InvalidArgument Invalid argument.
 */
status_t UART_SendEDMA(UART_Type *base, uart_edma_handle_t *handle, uart_transfer_t *xfer)
{
    assert(handle != NULL);
    assert(handle->txEdmaHandle != NULL);
    assert(xfer != NULL);
    assert(xfer->data != NULL);
    assert(xfer->dataSize != 0U);

    edma_transfer_config_t xferConfig;
    status_t status;

    /* If previous TX not finished. */
    if ((uint8_t)kUART_TxBusy == handle->txState)
    {
        status = kStatus_UART_TxBusy;
    }
    else
    {
        handle->txState       = (uint8_t)kUART_TxBusy;
        handle->txDataSizeAll = xfer->dataSize;

        /* Prepare transfer. */
        EDMA_PrepareTransfer(&xferConfig, xfer->data, sizeof(uint8_t), (uint32_t *)UART_GetDataRegisterAddress(base),
                             sizeof(uint8_t), sizeof(uint8_t), xfer->dataSize, kEDMA_MemoryToPeripheral);

        /* Store the initially configured eDMA minor byte transfer count into the UART handle */
        handle->nbytes = 1U;

        /* Submit transfer. */
        (void)EDMA_SubmitTransfer(handle->txEdmaHandle, &xferConfig);
        EDMA_StartTransfer(handle->txEdmaHandle);

        /* Enable UART TX EDMA. */
        UART_EnableTxDMA(base, true);

        status = kStatus_Success;
    }

    return status;
}

/*!
 * brief Receives data using eDMA.
 *
 * This function receives data using eDMA. This is a non-blocking function, which returns
 * right away. When all data is received, the receive callback function is called.
 *
 * param base UART peripheral base address.
 * param handle Pointer to the uart_edma_handle_t structure.
 * param xfer UART eDMA transfer structure. See #uart_transfer_t.
 * retval kStatus_Success if succeeded; otherwise failed.
 * retval kStatus_UART_RxBusy Previous transfer ongoing.
 * retval kStatus_InvalidArgument Invalid argument.
 */
status_t UART_ReceiveEDMA(UART_Type *base, uart_edma_handle_t *handle, uart_transfer_t *xfer)
{
    assert(handle != NULL);
    assert(handle->rxEdmaHandle != NULL);
    assert(xfer != NULL);
    assert(xfer->data != NULL);
    assert(xfer->dataSize != 0U);

    edma_transfer_config_t xferConfig;
    status_t status;

    /* If previous RX not finished. */
    if ((uint8_t)kUART_RxBusy == handle->rxState)
    {
        status = kStatus_UART_RxBusy;
    }
    else
    {
        handle->rxState       = (uint8_t)kUART_RxBusy;
        handle->rxDataSizeAll = xfer->dataSize;

        /* Prepare transfer. */
        EDMA_PrepareTransfer(&xferConfig, (uint32_t *)UART_GetDataRegisterAddress(base), sizeof(uint8_t), xfer->data,
                             sizeof(uint8_t), sizeof(uint8_t), xfer->dataSize, kEDMA_PeripheralToMemory);

        /* Store the initially configured eDMA minor byte transfer count into the UART handle */
        handle->nbytes = 1U;

        /* Submit transfer. */
        (void)EDMA_SubmitTransfer(handle->rxEdmaHandle, &xferConfig);
        EDMA_StartTransfer(handle->rxEdmaHandle);

        /* Enable UART RX EDMA. */
        UART_EnableRxDMA(base, true);

        status = kStatus_Success;
    }

    return status;
}

/*!
 * brief Aborts the sent data using eDMA.
 *
 * This function aborts sent data using eDMA.
 *
 * param base UART peripheral base address.
 * param handle Pointer to the uart_edma_handle_t structure.
 */
void UART_TransferAbortSendEDMA(UART_Type *base, uart_edma_handle_t *handle)
{
    assert(handle != NULL);
    assert(handle->txEdmaHandle != NULL);

    /* Disable UART TX EDMA. */
    UART_EnableTxDMA(base, false);

    /* Stop transfer. */
    EDMA_AbortTransfer(handle->txEdmaHandle);

    handle->txState = (uint8_t)kUART_TxIdle;
}

/*!
 * brief Aborts the receive data using eDMA.
 *
 * This function aborts receive data using eDMA.
 *
 * param base UART peripheral base address.
 * param handle Pointer to the uart_edma_handle_t structure.
 */
void UART_TransferAbortReceiveEDMA(UART_Type *base, uart_edma_handle_t *handle)
{
    assert(handle != NULL);
    assert(handle->rxEdmaHandle != NULL);

    /* Disable UART RX EDMA. */
    UART_EnableRxDMA(base, false);

    /* Stop transfer. */
    EDMA_AbortTransfer(handle->rxEdmaHandle);

    handle->rxState = (uint8_t)kUART_RxIdle;
}

/*!
 * brief Gets the number of received bytes.
 *
 * This function gets the number of received bytes.
 *
 * param base UART peripheral base address.
 * param handle UART handle pointer.
 * param count Receive bytes count.
 * retval kStatus_NoTransferInProgress No receive in progress.
 * retval kStatus_InvalidArgument Parameter is invalid.
 * retval kStatus_Success Get successfully through the parameter \p count;
 */
status_t UART_TransferGetReceiveCountEDMA(UART_Type *base, uart_edma_handle_t *handle, uint32_t *count)
{
    assert(handle != NULL);
    assert(handle->rxEdmaHandle != NULL);
    assert(count != NULL);

    if ((uint8_t)kUART_RxIdle == handle->rxState)
    {
        return kStatus_NoTransferInProgress;
    }

    *count = handle->rxDataSizeAll -
             (uint32_t)handle->nbytes *
                 EDMA_GetRemainingMajorLoopCount(handle->rxEdmaHandle->base, handle->rxEdmaHandle->channel);

    return kStatus_Success;
}

/*!
 * brief Gets the number of bytes that have been written to UART TX register.
 *
 * This function gets the number of bytes that have been written to UART TX
 * register by DMA.
 *
 * param base UART peripheral base address.
 * param handle UART handle pointer.
 * param count Send bytes count.
 * retval kStatus_NoTransferInProgress No send in progress.
 * retval kStatus_InvalidArgument Parameter is invalid.
 * retval kStatus_Success Get successfully through the parameter \p count;
 */
status_t UART_TransferGetSendCountEDMA(UART_Type *base, uart_edma_handle_t *handle, uint32_t *count)
{
    assert(handle != NULL);
    assert(handle->txEdmaHandle != NULL);
    assert(count != NULL);

    if ((uint8_t)kUART_TxIdle == handle->txState)
    {
        return kStatus_NoTransferInProgress;
    }

    *count = handle->txDataSizeAll -
             (uint32_t)handle->nbytes *
                 EDMA_GetRemainingMajorLoopCount(handle->txEdmaHandle->base, handle->txEdmaHandle->channel);

    return kStatus_Success;
}

/*!
 * brief UART eDMA IRQ handle function.
 *
 * This function handles the UART transmit complete IRQ request and invoke user callback.
 *
 * param base UART peripheral base address.
 * param uartEdmaHandle UART handle pointer.
 */
void UART_TransferEdmaHandleIRQ(UART_Type *base, void *uartEdmaHandle)
{
    assert(uartEdmaHandle != NULL);

    uart_edma_handle_t *handle = (uart_edma_handle_t *)uartEdmaHandle;

    handle->txState = (uint8_t)kUART_TxIdle;

    /* Disable tx complete interrupt */
    UART_DisableInterrupts(base, (uint32_t)kUART_TransmissionCompleteInterruptEnable);

    if (handle->callback != NULL)
    {
        handle->callback(base, handle, kStatus_UART_TxIdle, handle->userData);
    }
}