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

/*
 * File      : board.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2009 RT-Thread Develop Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rt-thread.org/license/LICENSE
 *
 * 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"

#define IER_RBR		0x01
#define IER_THRE	0x02
#define IER_RLS		0x04

#define IIR_PEND	0x01
#define IIR_RLS		0x03
#define IIR_RDA		0x02
#define IIR_CTI		0x06
#define IIR_THRE	0x01

#define LSR_RDR		0x01
#define LSR_OE		0x02
#define LSR_PE		0x04
#define LSR_FE		0x08
#define LSR_BI		0x10
#define LSR_THRE	0x20
#define LSR_TEMT	0x40
#define LSR_RXFE	0x80

/**
 * @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

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;

	iir >>= 1;			    /* skip pending bit in IIR */
	iir &= 0x07;			/* check bit 1~3, interrupt identification */

	if (iir == IIR_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;
}

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;

//	iir >>= 1;			    /* skip pending bit in IIR */
//	iir &= 0x07;			/* check bit 1~3, interrupt identification */

	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;
}

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, 2, 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_RLS, 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_RLS, 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_size_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_size_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
}

/*@}*/