在别人的程序的基础上修改得来的。
开发环境
• 主 机：virtualBox--Fedora 9
• 开发板：Mini2440--128MB Nand
• 编译器：arm-linux-gcc-4.4.3
linux内核代码树版本为2.6.32.2
1、LED驱动的源代码
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/serio.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/miscdevice.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <mach/regs-clock.h>
#include <plat/regs-timer.h>
#include <mach/regs-gpio.h>
#include <mach/gpio.h>//我用的是友善之臂的内核代码树，可能跟代码树的配置有关，必须要加这个头文件才行
#include <linux/cdev.h>
#define DEVICE_NAME "my2440_leds" //device name
#define DEVICE_MAJOR 211 //device major
#define LED_ON 1 //led light status
#define LED_OFF 0 //led black status
static unsigned long led_table[] = //LED IO
{
S3C2410_GPB(5),
S3C2410_GPB(6),
S3C2410_GPB(7),
S3C2410_GPB(8),
};
static unsigned int led_cfg_table[] = //LED IO MODE
{
S3C2410_GPIO_OUTPUT,
S3C2410_GPIO_OUTPUT,
S3C2410_GPIO_OUTPUT,
S3C2410_GPIO_OUTPUT,
};
static int leds_open(struct inode *inode, struct file *file)
{
return 0;
}
static int leds_ioctl(struct inode *inode,struct file *file, unsigned int cmd, unsigned long arg)
{
//detect which led
if(arg<0||arg>3)
return -EINVAL;
switch(cmd)
{
case LED_ON:
{
s3c2410_gpio_setpin(led_table[arg], !(LED_ON)); //cannot use ~LED_ON
break;
}
case LED_OFF:
{
s3c2410_gpio_setpin(led_table[arg], !(LED_OFF)); //cannot use ~LED_OFF
break;
}
default:
{
return -EINVAL;
}
}
return 0;
}
static struct file_operations leds_fops =
{
.owner = THIS_MODULE,
.open = leds_open,
.ioctl = leds_ioctl,
};
static int __init led_init(void)
{
int ret,i;
//initial led and set led status high
for(i=0;i<4;i++)
{
s3c2410_gpio_cfgpin(led_table[i],led_cfg_table[i]);
s3c2410_gpio_setpin(led_table[i], ~(LED_OFF));
}
ret = register_chrdev(LED_MAJOR, DEVICE_NAME, &leds_fops);
if(ret < 0)
{
printk(DEVICE_NAME " register falid!\n");
return ret;
}
}
static void __exit led_exit(void)
{
unregister_chrdev(DEVICE_MAJOR, DEVICE_NAME);
}
module_init(led_init);
module_exit(led_exit);
MODULE_LICENSE("GPL");
2、LED驱动的测试程序
测试程序：
#include<stdio.h>
#include<stdlib.h>
#include<sys/ioctl.h>
#include<fcntl.h>
int main(int argc,char **argv)
{
int turn,index;
int fd;
//test paramter is currest
if(argc!=3||sscanf(argv[2], "%d", &index) != 1 || index < 1 || index > 4)
{
printf("Usage:led_test on|off 1|2|3|4 \n ");
exit(1);
}
//judge the input paramter
if(strcmp(argv[1],"on")==0)
{
turn=1;
}
else if(strcmp(argv[1],"off")==0)
{
turn=0;
}
else
{
printf("Usage:led_test on|off 1|2|3|4 \n ");
exit(1);
}
//open blacklight device
fd=open("/dev/my2440_leds", O_RDWR);
if(fd<0)
{
printf("Open Backlight Device Faild!\n");
exit(1);
}
//ioctl
ioctl(fd,turn,index-1);
close(fd);
return 0;
}