serial.c

基于arm s3c2410下的串口设备驱动

#include <linux/module.h>
#include <linux/kernel.h>
#include <asm/uaccess.h>
#include <asm/arch-s3c2410/regs-serial.h>
#include <asm/io.h>

MODULE_AUTHOR("akae");
MODULE_DESCRIPTION("serial module test");
MODULE_LICENSE("GPL");

#define iobase           S3C24XX_VA_UART1 

#define UART_ULCON	 (iobase + 0x00)
#define UART_UCON	 (iobase + 0x04)
#define UART_UTRSTAT  	 (iobase + 0x10)
#define UART_UTXH	 (iobase + 0x20)
#define UART_URXH	 (iobase + 0x24)
#define UART_UBRDIV	 (iobase + 0x28)

void serial_write (void);
void serial_read (void);



int __init
serial_init(void)
{
	/*8N1*/
	writel(3, UART_ULCON);	// 00000011

	/*poll mode */
	writel(5, UART_UCON);	// 00000101

	/*115200*/
	writel(26, UART_UBRDIV);	
	
	serial_write ();
	serial_read ();

	return 0;
}

void
serial_write (void)
{
	int state;
	char *str="akae serial write test\r\n";

	
	while('\0' != *str)
	{
		state = readl(UART_UTRSTAT);
		if((state & 2)  ==  0x02)
		{
			writel(*str, UART_UTXH);
			str++;
		}
	}
	
}

void
serial_read (void)
{
	int state;
	int read_count = 15;

	while(read_count)
	 {
		state = readl(UART_UTRSTAT);
		
		if((state & 1)  ==  0x01)	
		{
			char ch;
			ch = readl(UART_URXH);
			printk("%c", ch);
			read_count --;
		}
		else
		{		
	        	set_current_state(TASK_INTERRUPTIBLE);
	        	schedule_timeout(1);
		}
	 } 
	printk("\n");
}


void __exit
serial_exit(void)
{
	printk("module exit\n");
	return;
}

module_init(serial_init);
module_exit(serial_exit);