s3c2440串口驱动（二）

s3c2440串口驱动（二）

 

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arm平台上的应用程序

app.c源代码 

/* * ===================================================================================== * * 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: [e-mail] * * ===================================================================================== */#include <stdio.h>#include <string.h>#include <fcntl.h>//open(), read(), write()#define BUFSIZE 100int 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; } 

编译方法

arm-linux-gcc app.c -o app

 

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驱动部分

s3c2440_seial.c源代码  

/* * ===================================================================================== * * 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: [e-mail] * * ===================================================================================== */#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_MAJOR240#define iobaseS3C24XX_VA_UART1#define UART_ULCON1iobase#define UART_UCON1iobase + 0x4#define UART_UFCON1iobase + 0x8#define UART_UTRSTAT1iobase + 0x10#define UART_UTXH1iobase + 0x20#define UART_URXH1iobase + 0x24#define UART_UBRDIV1iobase + 0x28MODULE_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 __initsunsea_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 __exitsunsea_exit(void){unregister_chrdev(ttyS0_MAJOR, "ttyS0");printk("s3c2440 serial module exit!/n"); return;}module_init(sunsea_init);module_exit(sunsea_exit); 

Makefile源代码  

ifneq ($(KERNELRELEASE),)obj-m := s3c2440_serial.oelse#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_okmodules:make -C $(KERNELSRC) SUBDIRS=$(PWD) $@clean:rm -f *.o *.ko *.mod *.mod.c *.order *.symversendif