rt-thread/bsp/lpc2478/drivers/serial.c

/*
 * File      : serial.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://openlab.rt-thread.com/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2006-08-23     Bernard      first version
 */

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

#include "LPC24xx.h"
#include "board.h"

/* serial hardware register */
#define REG8(d)			(*((volatile unsigned char *)(d)))
#define REG32(d)		(*((volatile unsigned long *)(d)))

#define UART_RBR(base)  REG8(base + 0x00)
#define UART_THR(base)  REG8(base + 0x00)
#define UART_IER(base)  REG32(base + 0x04)
#define UART_IIR(base)  REG32(base + 0x08)
#define UART_FCR(base)  REG8(base + 0x08)
#define UART_LCR(base)  REG8(base + 0x0C)
#define UART_MCR(base)  REG8(base + 0x10)
#define UART_LSR(base)  REG8(base + 0x14)
#define UART_MSR(base)  REG8(base + 0x18)
#define UART_SCR(base)  REG8(base + 0x1C)
#define UART_DLL(base)  REG8(base + 0x00)
#define UART_DLM(base)  REG8(base + 0x04)
#define UART_ACR(base)  REG32(base + 0x20)
#define UART_FDR(base)  REG32(base + 0x28)
#define UART_TER(base)  REG8(base + 0x30)

/* LPC serial device */
struct rt_lpcserial
{
	/* inherit from device */
	struct rt_device parent;

	rt_uint32_t hw_base;
	rt_uint32_t irqno;
	rt_uint32_t baudrate;

	/* reception field */
	rt_uint16_t save_index, read_index;
	rt_uint8_t  rx_buffer[RT_UART_RX_BUFFER_SIZE];
};

#ifdef RT_USING_UART1
struct rt_lpcserial serial1;
#endif
#ifdef RT_USING_UART2
struct rt_lpcserial serial2;
#endif

void rt_hw_serial_init(void);

#define U0PINS  	0x00000005

void rt_hw_uart_isr(int irqno, void *param)
{
	RT_UNUSED rt_uint32_t iir;
	struct rt_lpcserial* lpc_serial = (struct rt_lpcserial*)param;

	RT_ASSERT(lpc_serial != RT_NULL)
		
	if (UART_LSR(lpc_serial->hw_base) & 0x01)
	{
		rt_base_t level;

		while (UART_LSR(lpc_serial->hw_base) & 0x01)
		{
			/* disable interrupt */
			level = rt_hw_interrupt_disable();

			/* read character */
			lpc_serial->rx_buffer[lpc_serial->save_index] = 
				UART_RBR(lpc_serial->hw_base);
			lpc_serial->save_index ++;
			if (lpc_serial->save_index >= RT_UART_RX_BUFFER_SIZE)
				lpc_serial->save_index = 0;
			
			/* if the next position is read index, discard this 'read char' */
			if (lpc_serial->save_index == lpc_serial->read_index)
			{
				lpc_serial->read_index ++;
				if (lpc_serial->read_index >= RT_UART_RX_BUFFER_SIZE)
					lpc_serial->read_index = 0;
			}

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

		/* invoke callback */
		if(lpc_serial->parent.rx_indicate != RT_NULL)
		{
		  lpc_serial->parent.rx_indicate(&lpc_serial->parent, 1);
		}
	}

	/* clear interrupt source */
	iir = UART_IIR(lpc_serial->hw_base);

	/* acknowledge Interrupt */
	VICVectAddr = 0;
}


/**
 * @addtogroup LPC214x
 */
/*@{*/

static rt_err_t rt_serial_init (rt_device_t dev)
{
	return RT_EOK;
}

static rt_err_t rt_serial_open(rt_device_t dev, rt_uint16_t oflag)
{
	struct rt_lpcserial* lpc_serial;
	lpc_serial = (struct rt_lpcserial*) dev;
	
	RT_ASSERT(lpc_serial != RT_NULL);
	if (dev->flag & RT_DEVICE_FLAG_INT_RX)
	{
	    /* init UART rx interrupt */
    	UART_IER(lpc_serial->hw_base) = 0x01;

		/* install ISR */
	    rt_hw_interrupt_install(lpc_serial->irqno,
                                rt_hw_uart_isr, lpc_serial, RT_NULL);
	    rt_hw_interrupt_umask(lpc_serial->irqno);
	}

	return RT_EOK;
}

static rt_err_t rt_serial_close(rt_device_t dev)
{
	struct rt_lpcserial* lpc_serial;
	lpc_serial = (struct rt_lpcserial*) dev;
	
	RT_ASSERT(lpc_serial != RT_NULL);

	if (dev->flag & RT_DEVICE_FLAG_INT_RX)
	{
		/* disable UART rx interrupt */
		UART_IER(lpc_serial->hw_base) = 0x00;
	}

	return RT_EOK;
}

static rt_err_t rt_serial_control(rt_device_t dev, rt_uint8_t cmd, void *args)
{
	return RT_EOK;
}

static rt_size_t rt_serial_read(rt_device_t dev, rt_off_t pos, void* buffer, rt_size_t size)
{
	rt_uint8_t* ptr;
	struct rt_lpcserial *lpc_serial = (struct rt_lpcserial*)dev;
	RT_ASSERT(lpc_serial != 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 (lpc_serial->read_index != lpc_serial->save_index)
			{
				*ptr = lpc_serial->rx_buffer[lpc_serial->read_index];

				lpc_serial->read_index ++;
				if (lpc_serial->read_index >= RT_UART_RX_BUFFER_SIZE)
					lpc_serial->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;
	}
	else if (dev->flag & RT_DEVICE_FLAG_DMA_RX)
	{
		/* not support right now */
		RT_ASSERT(0);
	}

	/* polling mode */
	while (size && (UART_LSR(lpc_serial->hw_base) & 0x01))
	{
		/* Read Character */
		*ptr = UART_RBR(lpc_serial->hw_base);
		
		ptr  ++;
		size --;
	}

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

static rt_size_t rt_serial_write(rt_device_t dev, rt_off_t pos, const void* buffer, rt_size_t size)
{
	struct rt_lpcserial* lpc_serial;
	char *ptr;

	lpc_serial = (struct rt_lpcserial*) dev;
	if (dev->flag & RT_DEVICE_FLAG_INT_TX)
	{
		/* not support */
		RT_ASSERT(0);
	}
	else if (dev->flag & RT_DEVICE_FLAG_DMA_TX)
	{
		/* not support */
		RT_ASSERT(0);
	}

	/* polling write */
	ptr = (char *)buffer;
	
	if (dev->flag & RT_DEVICE_FLAG_STREAM)
	{
		/* stream mode */
		while (size)
		{
			if (*ptr == '\n')
			{
				while (!(UART_LSR(lpc_serial->hw_base) & 0x20));
				UART_THR(lpc_serial->hw_base) = '\r';
			}

			while (!(UART_LSR(lpc_serial->hw_base) & 0x20));
			UART_THR(lpc_serial->hw_base) = *ptr;
			
			ptr ++;
			size --;
		}
	}
	else
	{
		while (size)
		{
			while (!(UART_LSR(lpc_serial->hw_base) & 0x20));
			UART_THR(lpc_serial->hw_base) = *ptr;
			
			ptr ++;
			size --;
		}
	}
	
	return (rt_size_t) ptr - (rt_size_t) buffer;
}

void rt_hw_serial_init(void)
{
	struct rt_lpcserial* lpc_serial;
	
#ifdef RT_USING_UART1
	lpc_serial = &serial1;
	
	lpc_serial->parent.type = RT_Device_Class_Char;
	
	lpc_serial->hw_base = 0xE000C000;
	lpc_serial->baudrate = 115200;
	lpc_serial->irqno = UART0_INT;
	
	rt_memset(lpc_serial->rx_buffer, 0, sizeof(lpc_serial->rx_buffer));
	lpc_serial->read_index = lpc_serial->save_index = 0;

	/* Enable UART0 RxD and TxD pins */
  	PINSEL0 |= 0x50;

	/* 8 bits, no Parity, 1 Stop bit */
	UART_LCR(lpc_serial->hw_base) = 0x83;
	
	/* Setup Baudrate */
	UART_DLL(lpc_serial->hw_base) = (PCLK/16/lpc_serial->baudrate) & 0xFF;
	UART_DLM(lpc_serial->hw_base) = ((PCLK/16/lpc_serial->baudrate) >> 8) & 0xFF;

	/* DLAB = 0 */
	UART_LCR(lpc_serial->hw_base) = 0x03;

	lpc_serial->parent.type     = RT_Device_Class_Char;
	lpc_serial->parent.init 	= rt_serial_init;
	lpc_serial->parent.open 	= rt_serial_open;
	lpc_serial->parent.close    = rt_serial_close;
	lpc_serial->parent.read 	= rt_serial_read;
	lpc_serial->parent.write    = rt_serial_write;
	lpc_serial->parent.control  = rt_serial_control;
	lpc_serial->parent.user_data  = RT_NULL;

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

#ifdef RT_USING_UART2
	lpc_serial = &serial2;
	
	lpc_serial->parent.type = RT_Device_Class_Char;

	lpc_serial->hw_base = 0xE0010000;
	lpc_serial->baudrate = 115200;
	lpc_serial->irqno = UART1_INT;

	rt_memset(lpc_serial->rx_buffer, 0, sizeof(lpc_serial->rx_buffer));
	lpc_serial->read_index = lpc_serial->save_index = 0;

	/* Enable UART1 RxD and TxD pins */
  	PINSEL0 |= 0x05 << 16;

	/* 8 bits, no Parity, 1 Stop bit */
	UART_LCR(lpc_serial->hw_base) = 0x83;
	
	/* Setup Baudrate */
	UART_DLL(lpc_serial->hw_base) = (PCLK/16/lpc_serial->baudrate) & 0xFF;
	UART_DLM(lpc_serial->hw_base) = ((PCLK/16/lpc_serial->baudrate) >> 8) & 0xFF;

	/* DLAB = 0 */
	UART_LCR(lpc_serial->hw_base) = 0x03;

	lpc_serial->parent.type     = RT_Device_Class_Char;
	lpc_serial->parent.init 	= rt_serial_init;
	lpc_serial->parent.open 	= rt_serial_open;
	lpc_serial->parent.close    = rt_serial_close;
	lpc_serial->parent.read 	= rt_serial_read;
	lpc_serial->parent.write    = rt_serial_write;
	lpc_serial->parent.control  = rt_serial_control;
	lpc_serial->parent.user_data  = RT_NULL;

	rt_device_register(&lpc_serial->parent, 
		"uart2", RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX);
#endif
}

/*@}*/