ARM-linux嵌入式驱动——LED的驱动

/************************************************

LED的驱动，在TX2440A开发板上做测试

维护记录：  2009-10-18  V1.0   

linux内核：2.6.31

 

硬件接法：

        LED1 --> GPF0

        LED2 --> GPF1

        LED3 --> GPF2

        LED4 --> GPF3

        低电平点亮

驱动用法：

        设备名称：TX2440-led

        点亮一个灯：LED_ON

        熄灭一个灯：LED_OFF

        点亮所有灯：ALL_LED_ON

        熄灭所有灯：ALL_LED_OFF

说明：

        内核源码里已经有LED的驱动，将它们注释掉

        在arch/arm/plat-s3c24xx/common-smdk.c中

        将GPF0-GPF3设为输出，全部输出低电平

*************************************************/

#include

#include

#include

#include

#include

#include

//#include

#include

//#include

#include

#include

#include

 

#define DEVICE_NAME  "TX2440-led"    /* 设备名称 */      

static int LED_Major = 0;           /* 主设备号 */

 

#define LED_OFF            0

#define LED_ON             1

#define ALL_LED_OFF      3

#define ALL_LED_ON       4

 

/* 用来指定LED所用的GPIO引脚 */

static unsigned long led_table [] =

{

    S3C2410_GPF(0),

    S3C2410_GPF(1),

    S3C2410_GPF(2),

    S3C2410_GPF(3),

};

 

static int TX2440_led_open(struct inode *inode, struct file *file)

{

//  MOD_INC_USE_COUNT;

    printk("TX2440-LED Driver Open Called!\n");

    return 0;

}

 

static int TX2440_led_release(struct inode *inode, struct file *file)

{

//  MOD_DEC_USE_COUNT;

    printk("TX2440-LED Driver Release Called!\n");

    return 0;

}

 

static int TX2440_led_ioctl( struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)

{

    int i;

    if (arg > 4)

    {

        return -EINVAL;

    }

    switch(cmd)

    {

        case LED_ON:  //set the pin

            s3c2410_gpio_setpin(led_table[arg], 0);

            break;

 

        case LED_OFF:  //clr the pin

            s3c2410_gpio_setpin(led_table[arg], 1);

            break;

           

        case ALL_LED_ON:  //set all pin

            for (i = 0; i < 4; i++)

                s3c2410_gpio_setpin(led_table[i], 0);

            break;

           

        case ALL_LED_OFF:  //clr all pin

            for (i = 0; i < 4; i++)

                s3c2410_gpio_setpin(led_table[i], 1);

            break;

 

        default:

            return -EINVAL;

    }

}

 

static struct file_operations TX2440_led_fops =

{

    .owner  =   THIS_MODULE,

    .open   =   TX2440_led_open,

    .release =  TX2440_led_release,

    .ioctl  =   TX2440_led_ioctl,

};

 

static struct class *led_class;

 

static int __init TX2440_led_init(void)

{

 

    printk("TX2440 LED DRIVER MODULE INIT\n");

 

    LED_Major = register_chrdev(0, DEVICE_NAME, &TX2440_led_fops);

    if (LED_Major < 0)

    {

        printk(DEVICE_NAME " can't register major number\n");

        return LED_Major;

    }

    printk("register TX2440-LED Driver OK! Major = %d\n", LED_Major);

 

    led_class = class_create(THIS_MODULE, DEVICE_NAME);

    if(IS_ERR(led_class))

    {

        printk("Err: failed in TX2440-LED class. \n");

        return -1;

    }

 

    device_create(led_class, NULL, MKDEV(LED_Major, 0), NULL, DEVICE_NAME);

 

    printk(DEVICE_NAME " initialized\n");

    return 0;

}

 

static void __exit TX2440_led_exit(void)

{

    printk("TX2440 LED DRIVER MODULE EXIT\n");

    unregister_chrdev(LED_Major, DEVICE_NAME);

    device_destroy(led_class, MKDEV(LED_Major, 0));

    class_destroy(led_class);

}

 

module_init(TX2440_led_init);

module_exit(TX2440_led_exit);

 

MODULE_AUTHOR("www.txmcu.com");    

MODULE_DESCRIPTION("TX2440 LED Driver"); 

MODULE_LICENSE("GPL");

 

 源代码： TX2440_led.rar   

测试代码： led.rar