s3c2440串口驱动（二）

/*
* =====================================================================================
*
*       Filename:  app.c
*
*    Description:  可以在arm平台上运行的应用程序
*
*        Version:  1.0
*        Created:  2011年01月11日 00时13分58秒
*       Revision:  none
*       Compiler:  gcc
*
*         Author:  sunsea1026
*          Email:  sunsea1026@gmail.com
*
* =====================================================================================
*/
#include <stdio.h>
#include <string.h>
#include <fcntl.h>	//open(), read(), write()
#define BUFSIZE 100
int main(int argc, char* argv[])
{
int fd, ret;
char buf[BUFSIZE];
char *msg = "We have open ttyS0, we waited in the receiving data...";
fd = open("/dev/ttyS0", O_RDWR);
if(fd < 0)
{
printf("Error: open /dev/ttyS0 error!/n");
return 1;
}
ret = write(fd, msg, strlen(msg));
if(ret < 0)
{
printf("Error: write msg error!/n");
return 1;
}
while(1)
{
memset(buf, 0, sizeof(buf));
ret = read(fd, buf, BUFSIZE);
if(ret < 0)
{
printf("Error: read device error!/n");
return 1;
}
if(buf[0] != '/0')
{
printf("%s/n", buf);
}
}
return 0;
}

/*
* =====================================================================================
*
*       Filename:  s3c2440_serial.c
*
*    Description:  s3c2440 串口驱动程序
*
*        Version:  1.0
*        Created:  2011年01月11日 00时29分43秒
*       Revision:  none
*       Compiler:  linux 内核
*
*         Author:  sunsea1026
*          Email:  sunsea1026@gmail.com
*
* =====================================================================================
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <asm/uaccess.h>			//copy_to_use, copy_from_user
#include <linux/serial_core.h>
#include <asm/plat-s3c/regs-serial.h>		//寄存器宏
#include <asm/io.h>				//readl, readb, writel, writeb
#define BUFSIZE 100
#define ttyS0_MAJOR	240
#define iobase		S3C24XX_VA_UART1
#define UART_ULCON1	iobase
#define UART_UCON1	iobase + 0x4
#define UART_UFCON1	iobase + 0x8
#define UART_UTRSTAT1	iobase + 0x10
#define UART_UTXH1	iobase + 0x20
#define UART_URXH1	iobase + 0x24
#define UART_UBRDIV1	iobase + 0x28

MODULE_AUTHOR("sunsea");
MODULE_DESCRIPTION("s3c2440 serial driver");
MODULE_LICENSE("GPL");
int sunsea_open(struct inode *inode, struct file *filp)
{
/* 8N1 */
writel(3, UART_ULCON1);
/* poll mode */
writel(5, UART_UCON1);
/* 115200 */
writel(26, UART_UBRDIV1);
return 0;
}
ssize_t sunsea_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[i] != '/0')
{
state = readl(UART_UTRSTAT1);
if((0x02 & state) == 2)
{
writeb(wbuf[i], UART_UTXH1);
i++;
}
}
return 0;
}
ssize_t sunsea_read(struct file *filp, char __user *buf, size_t count, loff_t *f_ops)
{
char rbuf[1] = {0};
int state;
state = readl(UART_UTRSTAT1);
if((0x01 & state) == 1)
{
rbuf[0] = readb(UART_URXH1);
copy_to_user(buf, rbuf, 1);
}
else
{
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(10);
}
return 0;
}
int sunsea_release(struct inode *inode, struct file *filp)
{
return 0;
}
struct file_operations ttyS0_fops =
{
.owner = THIS_MODULE,
.open = sunsea_open,
.write = sunsea_write,
.read = sunsea_read,
.release = sunsea_release,
};
int __init
sunsea_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
sunsea_exit(void)
{
unregister_chrdev(ttyS0_MAJOR, "ttyS0");
printk("s3c2440 serial module exit!/n");
return;
}
module_init(sunsea_init);
module_exit(sunsea_exit);

ifneq ($(KERNELRELEASE),)
obj-m := s3c2440_serial.o
else
#在zsx-ubuntu下编译使用下面一行
#KERNELSRC := /home/zsx/study/term6/build-embedded/kernel-2.6.27-android_ok
#在aka-ubuntu下编译使用下面一行
KERNELSRC := /home/akaedu/build-embedded/kernel-2.6.27-android_ok
modules:
make -C $(KERNELSRC) SUBDIRS=$(PWD) $@
clean:
rm -f *.o *.ko *.mod *.mod.c *.order *.symvers
endif