rt-thread/bsp/lpc178x/drivers/uart.c

/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2010-03-08     Bernard      The first version for LPC17xx
 * 2010-05-02     Aozima       update CMSIS to 130
 */

#include <rthw.h>
#include <rtthread.h>

#include "board.h"
#include "LPC177x_8x.h"
#include "lpc177x_8x_uart.h"
#include "lpc177x_8x_pinsel.h"

/**
 * @addtogroup LPC11xx
 */

/*@{*/

struct rt_uart_lpc
{
    struct rt_device parent;

    LPC_UART_TypeDef * UART;
    IRQn_Type UART_IRQn;

    /* buffer for reception */
    rt_uint8_t read_index, save_index;
    rt_uint8_t rx_buffer[RT_UART_RX_BUFFER_SIZE];
};

#ifdef RT_USING_UART0
struct rt_uart_lpc uart0_device;
#endif
#ifdef RT_USING_UART1
struct rt_uart_lpc uart1_device;
#endif

#ifdef RT_USING_UART0
void UART0_IRQHandler(void)
{
    rt_ubase_t level, iir;
    struct rt_uart_lpc* uart = &uart0_device;

    /* enter interrupt */
    rt_interrupt_enter();

    /* read IIR and clear it */
    iir = uart->UART->IIR;

    if (iir == UART_IIR_INTID_RDA)      /* Receive Data Available */
    {
        /* Receive Data Available */
        uart->rx_buffer[uart->save_index] = uart->UART->RBR;

        level = rt_hw_interrupt_disable();
        uart->save_index ++;
        if (uart->save_index >= RT_UART_RX_BUFFER_SIZE)
            uart->save_index = 0;
        rt_hw_interrupt_enable(level);

        /* invoke callback */
        if(uart->parent.rx_indicate != RT_NULL)
        {
            rt_size_t length;
            if (uart->read_index > uart->save_index)
                length = RT_UART_RX_BUFFER_SIZE - uart->read_index + uart->save_index;
            else
                length = uart->save_index - uart->read_index;

            uart->parent.rx_indicate(&uart->parent, length);
        }
    }

    /* leave interrupt */
    rt_interrupt_leave();

    return;
}
#endif

#ifdef RT_USING_UART1
void UART1_IRQHandler(void)
{
    rt_ubase_t level, iir;
    struct rt_uart_lpc* uart = &uart1_device;

    /* enter interrupt */
    rt_interrupt_enter();

    /* read IIR and clear it */
    iir = uart->UART->IIR;

    if (iir == UART_IIR_INTID_RDA)      /* Receive Data Available */
    {
        /* Receive Data Available */
        uart->rx_buffer[uart->save_index] = uart->UART->RBR;

        level = rt_hw_interrupt_disable();
        uart->save_index ++;
        if (uart->save_index >= RT_UART_RX_BUFFER_SIZE)
            uart->save_index = 0;
        rt_hw_interrupt_enable(level);

        /* invoke callback */
        if(uart->parent.rx_indicate != RT_NULL)
        {
            rt_size_t length;
            if (uart->read_index > uart->save_index)
                length = RT_UART_RX_BUFFER_SIZE - uart->read_index + uart->save_index;
            else
                length = uart->save_index - uart->read_index;

            uart->parent.rx_indicate(&uart->parent, length);
        }
    }

    /* leave interrupt */
    rt_interrupt_leave();

    return;
}
#endif

static rt_err_t rt_uart_init (rt_device_t dev)
{
    struct rt_uart_lpc *uart = (struct rt_uart_lpc*)dev;
    UART_CFG_Type UART_ConfigStruct;

#ifdef RT_USING_UART0
    if( uart->UART == LPC_UART0 )
    {
        /*
         * Initialize UART0 pin connect
         * P0.2: TXD
         * P0.3: RXD
         */
        PINSEL_ConfigPin(0, 2, 1);
        PINSEL_ConfigPin(0, 3, 1);

        UART_ConfigStruct.Baud_rate = 115200;
        UART_ConfigStruct.Databits = UART_DATABIT_8;
        UART_ConfigStruct.Parity = UART_PARITY_NONE;
        UART_ConfigStruct.Stopbits = UART_STOPBIT_1;

        UART_Init( uart->UART, &UART_ConfigStruct);

        // Enable UART Transmit
        UART_TxCmd( uart->UART, ENABLE);

        UART_IntConfig( uart->UART, UART_INTCFG_RBR, ENABLE);
    }
#endif

#ifdef RT_USING_UART1
    if( ((LPC_UART1_TypeDef *)uart->UART) == LPC_UART1 )
    {
        /*
         * Initialize UART1 pin connect
         * P3.16: TXD
         * P3.17: RXD
         */
        PINSEL_ConfigPin(3, 16, 3);
        PINSEL_ConfigPin(3, 17, 3);

        UART_ConfigStruct.Baud_rate = 115200;
        UART_ConfigStruct.Databits = UART_DATABIT_8;
        UART_ConfigStruct.Parity = UART_PARITY_NONE;
        UART_ConfigStruct.Stopbits = UART_STOPBIT_1;

        UART_Init( uart->UART,&UART_ConfigStruct);

        // Enable UART Transmit
        UART_TxCmd( uart->UART, ENABLE);

        UART_IntConfig( uart->UART, UART_INTCFG_RBR, ENABLE);
    }
#endif

#ifdef RT_USING_UART2
    if( uart->UART == LPC_UART2 )
    {
    }
#endif

    return RT_EOK;
}

static rt_err_t rt_uart_open(rt_device_t dev, rt_uint16_t oflag)
{
    struct rt_uart_lpc *uart = (struct rt_uart_lpc*)dev;

    RT_ASSERT(dev != RT_NULL);
    if (dev->flag & RT_DEVICE_FLAG_INT_RX)
    {
        /* Enable the UART Interrupt */
        NVIC_EnableIRQ( uart->UART_IRQn );
    }

    return RT_EOK;
}

static rt_err_t rt_uart_close(rt_device_t dev)
{
    struct rt_uart_lpc *uart = (struct rt_uart_lpc*)dev;

    RT_ASSERT(dev != RT_NULL);
    if (dev->flag & RT_DEVICE_FLAG_INT_RX)
    {
        /* Disable the UART Interrupt */
        NVIC_DisableIRQ( uart->UART_IRQn );
    }

    return RT_EOK;
}

static rt_ssize_t rt_uart_read(rt_device_t dev, rt_off_t pos, void* buffer, rt_size_t size)
{
    rt_uint8_t* ptr;
    struct rt_uart_lpc *uart = (struct rt_uart_lpc*)dev;
    RT_ASSERT(uart != RT_NULL);

    /* point to buffer */
    ptr = (rt_uint8_t*) buffer;
    if (dev->flag & RT_DEVICE_FLAG_INT_RX)
    {
        while (size)
        {
            /* interrupt receive */
            rt_base_t level;

            /* disable interrupt */
            level = rt_hw_interrupt_disable();
            if (uart->read_index != uart->save_index)
            {
                *ptr = uart->rx_buffer[uart->read_index];

                uart->read_index ++;
                if (uart->read_index >= RT_UART_RX_BUFFER_SIZE)
                    uart->read_index = 0;
            }
            else
            {
                /* no data in rx buffer */

                /* enable interrupt */
                rt_hw_interrupt_enable(level);
                break;
            }

            /* enable interrupt */
            rt_hw_interrupt_enable(level);

            ptr ++;
            size --;
        }

        return (rt_uint32_t)ptr - (rt_uint32_t)buffer;
    }

    return 0;
}

static rt_ssize_t rt_uart_write(rt_device_t dev, rt_off_t pos, const void* buffer, rt_size_t size)
{
    struct rt_uart_lpc *uart = (struct rt_uart_lpc*)dev;
    char *ptr;
    ptr = (char*)buffer;

    if (dev->flag & RT_DEVICE_FLAG_STREAM)
    {
        /* stream mode */
        while (size)
        {
            if (*ptr == '\n')
            {
                while (!(uart->UART->LSR & UART_LSR_THRE));
                UART_SendByte( uart->UART,'\r');
            }

            while (!(uart->UART->LSR & UART_LSR_THRE));
            UART_SendByte( uart->UART,*ptr);
            ptr ++;
            size --;
        }
    }
    else
    {
        UART_Send( uart->UART, (uint8_t *)buffer, size, BLOCKING);
    }

    return (rt_size_t) ptr - (rt_size_t) buffer;
}

void rt_hw_uart_init(void)
{
    struct rt_uart_lpc* uart;

#ifdef RT_USING_UART0
    /* get uart device */
    uart = &uart0_device;
    uart0_device.UART = LPC_UART0;
    uart0_device.UART_IRQn = UART0_IRQn;

    /* device initialization */
    uart->parent.type = RT_Device_Class_Char;
    rt_memset(uart->rx_buffer, 0, sizeof(uart->rx_buffer));
    uart->read_index = uart->save_index = 0;

    /* device interface */
    uart->parent.init       = rt_uart_init;
    uart->parent.open       = rt_uart_open;
    uart->parent.close      = rt_uart_close;
    uart->parent.read       = rt_uart_read;
    uart->parent.write      = rt_uart_write;
    uart->parent.control    = RT_NULL;
    uart->parent.user_data  = RT_NULL;

    rt_device_register(&uart->parent,
        "uart0", RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_STREAM | RT_DEVICE_FLAG_INT_RX);
#endif

#ifdef RT_USING_UART1
    /* get uart device */
    uart = &uart1_device;
    uart1_device.UART = (LPC_UART_TypeDef *)LPC_UART1;
    uart1_device.UART_IRQn = UART1_IRQn;

    /* device initialization */
    uart->parent.type = RT_Device_Class_Char;
    rt_memset(uart->rx_buffer, 0, sizeof(uart->rx_buffer));
    uart->read_index = uart->save_index = 0;

    /* device interface */
    uart->parent.init       = rt_uart_init;
    uart->parent.open       = rt_uart_open;
    uart->parent.close      = rt_uart_close;
    uart->parent.read       = rt_uart_read;
    uart->parent.write      = rt_uart_write;
    uart->parent.control    = RT_NULL;
    uart->parent.user_data  = RT_NULL;

    rt_device_register(&uart->parent,
        "uart1", RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_STREAM | RT_DEVICE_FLAG_INT_RX);
#endif
}

/*@}*/