linux--LED设备驱动1

开发环境：红帽企业版5，mini2440-2.6.29版本

交叉编译器4.3.2

我是用mini2440板子运行的，适合没有驱动基础的同学的。

源代码如下：

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>
#include <linux/gpio.h>
//#include <mach/gpio-nrs.h>

#define LED_MAJOR 234
#define DEVICE_NAME "leds"

static unsigned long led_table[]={
S3C2410_GPF3,
S3C2410_GPF4,
S3C2410_GPF5,
S3C2410_GPF6,
};

static unsigned long led_cfg_table[]={
S3C2410_GPF3_OUTP,
S3C2410_GPF4_OUTP,
S3C2410_GPF5_OUTP,
S3C2410_GPF6_OUTP,
};

int led_ioctl(struct inode *inode, struct file *file, unsigned int cmd , unsigned long arg){
switch(cmd){
case 0:
s3c2410_gpio_setpin(led_table[0],0);
s3c2410_gpio_setpin(led_table[1],1);
s3c2410_gpio_setpin(led_table[2],1);
s3c2410_gpio_setpin(led_table[3],1);
break;
case 1:
s3c2410_gpio_setpin(led_table[0],1);
s3c2410_gpio_setpin(led_table[1],0);
s3c2410_gpio_setpin(led_table[2],1);
s3c2410_gpio_setpin(led_table[3],1);
break;
case 2:
s3c2410_gpio_setpin(led_table[0],1);
s3c2410_gpio_setpin(led_table[1],1);
s3c2410_gpio_setpin(led_table[2],0);
s3c2410_gpio_setpin(led_table[3],1);
break;
case 3:
s3c2410_gpio_setpin(led_table[0],1);
s3c2410_gpio_setpin(led_table[1],1);
s3c2410_gpio_setpin(led_table[2],1);
s3c2410_gpio_setpin(led_table[3],0);
break;
default:
return -EINVAL;
break;
}
return 0;
}

struct file_operations led_ops = {
.owner = THIS_MODULE,
.ioctl = led_ioctl,
};

static int __init init_led(void)
{
int i, ret;
ret = register_chrdev(LED_MAJOR,DEVICE_NAME,&led_ops);
if(ret < 0){
printk(DEVICE_NAME, "can't register major number/n");
}
for(i = 0; i < 4; i++){
s3c2410_gpio_cfgpin(led_table[i],led_cfg_table[i]);
s3c2410_gpio_setpin(led_table[i],1);
}
printk(DEVICE_NAME "initialized/n");
return 0;
}

static void __exit exit_led(void)
{
unregister_chrdev(LED_MAJOR,DEVICE_NAME);
}

module_init(init_led);
module_exit(exit_led);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("linwei");

makefile如下：

ifneq ($(KERNELRELEASE),)

obj-m := led2.o

else

KDIR := /home/smb/kernel/linux-2.6.29
all:
make -C $(KDIR) M=$(PWD) modules ARCH=arm CROSS_COMPILE=arm-linux-
clean:
rm -f *.ko *.o *.mod.o *.mod.c *.symvers  modul*

endif

测试程序如下：

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>

int main(int argc, char **argv)
{
int on;
int led_no;
int fd;
if (argc != 3 || sscanf(argv[1], "%d", &led_no) != 1 || sscanf(argv[2],"%d", &on) != 1 ||
on < 0 || on > 1 || led_no < 0 || led_no > 3) {
fprintf(stderr, "Usage: leds led_no 0|1\n");
exit(1);
}
fd = open("/dev/leds", 0);
if (fd < 0) {
fd = open("/dev/leds", 0);
}
if (fd < 0) {
perror("open device leds");
exit(1);
}
ioctl(fd, on, led_no);
close(fd);
return 0;
}

虚拟机运行图：



开发板运行图



本人弄了一上午才弄出来 让大家见笑了，一次记录我的驱动人生。