在做串口驱动开发的时候，串口0和1都可以正常通信，但是换成串口2就无法从串口助手上接收到数据了。求前辈们指教可能是什么问题或者该怎么去查找问题的所在
驱动程序如下：
#include <linux/module.h>
#include <linux/kernel.h>
#include <asm/uaccess.h>
#include <linux/serial_core.h>
#include <asm/io.h>
#include <plat/regs-serial.h>
#define BUFSIZE 100
#define ttyS0_MAJOR 240
#define iobase S3C24XX_VA_UART2 //当宏定义为S3C24XX_VA_UART1和S3C24XX_VA_UART0的时候，串口1和串口0都可以正常工作
#define UART_ULCON0 iobase
#define UART_UCON0 (iobase+0x4)
#define UART_UFCON0 (iobase+0x8)
#define UART_UTRSTAT0 (iobase+0x10)
#define UART_UTXH0 (iobase+0x20)
#define UART_URXH0 (iobase+0x24)
#define UART_UBRDIV0 (iobase+0x28)
int s3c2440_open(struct inode * inode, struct file * filp)
{
writel(3, UART_ULCON0);
writel(5, UART_UCON0);
writel(26, UART_UBRDIV0);
printk("open OK\n");
return 0;
}
ssize_t s3c2440_write(struct file * filp, const char __user * buf, size_t count, loff_t * f_pos)
{
char wbuf[BUFSIZE] = {0};
int state;
int i = 0;
copy_from_user(wbuf, buf, count);
while(wbuf
!= '\0')
{
state = readl(UART_UTRSTAT0);
if(2 == (0x02 & state))
{
printk("%c", wbuf);
writeb(wbuf, UART_UTXH0);
i++;
}
}
printk("write OK\n");
return 0;
}
ssize_t s3c2440_read(struct file * filp, char __user * buf, size_t count, loff_t * f_ops)
{
char rbuf[1] = {0};
int state;
state = readl(UART_UTRSTAT0);
if(1 == (0x01 & state))
{
rbuf[0] = readb(UART_URXH0);
copy_to_user(buf, rbuf, 1);
}
else
{
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(10);
}
return 0;
}
int s3c2440_release(struct inode * inode, struct file * filp)
{
return 0;
}
struct file_operations ttyS0_fops =
{
.owner = THIS_MODULE,
.open = s3c2440_open,
.write = s3c2440_write,
.read = s3c2440_read,
.release = s3c2440_release,
};
int __init s3c2440_init(void)
{
int rc;
printk("s3c2440 serial module loaded!\n");
rc = register_chrdev(ttyS0_MAJOR, "ttyS0", &ttyS0_fops);
if(rc < 0)
{
printk("Error: register ttyS0 device error!\n");
return -1;
}
return 0;
}
void __exit s3c2440_exit(void)
{
unregister_chrdev(ttyS0_MAJOR, "ttyS0");
}
module_init(s3c2440_init);
module_exit(s3c2440_exit);
MODULE_AUTHOR("s3c2440");
MODULE_DESCRIPTION("s3c2440 serial driver");
MODULE_LICENSE("GPL");
运行该程序时，控制台可以看到输出：
open OK
send test 注：客户端待写入数据
write OK
但是连接串口2的串口助手并不能收到写入的数据，在连接串口2的串口助手界面输入开发板也接收不到数据。
检查过串口助手波特率是115200，根据串口2和串口1的波特率设置情况分析可以得出波特率正确
也分别用平行线和交叉线试过连接串口助手，都接收不到数据
文件arch/arm/mach-s3c2440/mach-mini2440.c中已经改成
static struct s3c2410_uartcfg mini2440_uartcfgs[] __initdata = {
[0] = {
.hwport = 0,
.flags = 0,
.ucon = 0x3c5,
.ulcon = 0x03,
.ufcon = 0x51,
},
[1] = {
.hwport = 1,
.flags = 0,
.ucon = 0x3c5,
.ulcon = 0x03,
.ufcon = 0x51,
},
[2] = {
.hwport = 2,
.flags = 0,
.ucon = 0x3c5,
.ulcon = 0x03,
.ufcon = 0x51,
}
};
并重新编译烧录，还是收不到数据。
有没有前辈遇到过这种问题？
