led驱动_使用次设备号来区别设备

#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 <asm/arch/regs-gpio.h>
#include <asm/hardware.h>

#define DEVICE_NAME     "leds"  /* 加载模式后，执行”cat /proc/devices”命令看到的设备名称 */
#define LED_MAJOR       231     /* 主设备号 */

static struct class *leds_class;
static struct class_device  *leds_class_devs[4];

/*  bit0<=>D10, 0:亮, 1:灭
*  bit1<=>D11, 0:亮, 1:灭
*  bit2<=>D12, 0:亮, 1:灭
*/
static char leds_status = 0x0;
static DECLARE_MUTEX(leds_lock); // 定义赋值

//static int minor;
static unsigned long gpio_va;

#define GPIO_OFT(x) ((x) - 0x56000000)
#define GPFCON  (*(volatile unsigned long *)(gpio_va + GPIO_OFT(0x56000050)))
#define GPFDAT  (*(volatile unsigned long *)(gpio_va + GPIO_OFT(0x56000054)))

/* 应用程序对设备文件/dev/leds执行open(...)时，
* 就会调用s3c24xx_leds_open函数
*/
static int s3c24xx_leds_open(struct inode *inode, struct file *file)
{
int minor = MINOR(inode->i_rdev); //MINOR(inode->i_cdev);

switch(minor)
{
case 0: /* /dev/leds */
{
// 配置3引脚为输出
//s3c2410_gpio_cfgpin(S3C2410_GPF4, S3C2410_GPF4_OUTP);
GPFCON &= ~(0x3<<(4*2));
GPFCON |= (1<<(4*2));

//s3c2410_gpio_cfgpin(S3C2410_GPF5, S3C2410_GPF5_OUTP);
GPFCON &= ~(0x3<<(5*2));
GPFCON |= (1<<(5*2));

//s3c2410_gpio_cfgpin(S3C2410_GPF6, S3C2410_GPF6_OUTP);
GPFCON &= ~(0x3<<(6*2));
GPFCON |= (1<<(6*2));

// 都输出0
//s3c2410_gpio_setpin(S3C2410_GPF4, 0);
GPFDAT &= ~(1<<4);

//s3c2410_gpio_setpin(S3C2410_GPF5, 0);
GPFDAT &= ~(1<<5);
//s3c2410_gpio_setpin(S3C2410_GPF6, 0);
GPFDAT &= ~(1<<6);

down(&leds_lock);
leds_status = 0x0;
up(&leds_lock);

break;
}

case 1: /* /dev/led1 */
{
s3c2410_gpio_cfgpin(S3C2410_GPF4, S3C2410_GPF4_OUTP);
s3c2410_gpio_setpin(S3C2410_GPF4, 0);

down(&leds_lock);
leds_status &= ~(1<<0);
up(&leds_lock);

break;
}

case 2: /* /dev/led2 */
{
s3c2410_gpio_cfgpin(S3C2410_GPF5, S3C2410_GPF5_OUTP);
s3c2410_gpio_setpin(S3C2410_GPF5, 0);
leds_status &= ~(1<<1);
break;
}

case 3: /* /dev/led3 */
{
s3c2410_gpio_cfgpin(S3C2410_GPF6, S3C2410_GPF6_OUTP);
s3c2410_gpio_setpin(S3C2410_GPF6, 0);

down(&leds_lock);
leds_status &= ~(1<<2);
up(&leds_lock);

break;
}

}

return 0;
}

static int s3c24xx_leds_read(struct file *filp, char __user *buff, <span style="font-family: Arial, Helvetica, sans-serif;">size_t count, loff_t *offp)</span>
{
int minor = MINOR(filp->f_dentry->d_inode->i_rdev);
char val;

switch (minor)
{
case 0: /* /dev/leds */
{

copy_to_user(buff, (const void *)&leds_status, 1);
break;
}

case 1: /* /dev/led1 */
{
down(&leds_lock);
val = leds_status & 0x1;
up(&leds_lock);
copy_to_user(buff, (const void *)&val, 1);
break;
}

case 2: /* /dev/led2 */
{
down(&leds_lock);
val = (leds_status>>1) & 0x1;
up(&leds_lock);
copy_to_user(buff, (const void *)&val, 1);
break;
}

case 3: /* /dev/led3 */
{
down(&leds_lock);
val = (leds_status>>2) & 0x1;
up(&leds_lock);
copy_to_user(buff, (const void *)&val, 1);
break;
}

}

return 1;
}

static ssize_t s3c24xx_leds_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos)
{
//int minor = MINOR(inode->i_rdev); //MINOR(inode->i_cdev);
int minor = MINOR(file->f_dentry->d_inode->i_rdev);
char val;

copy_from_user(&val, buf, 1);

switch (minor)
{
case 0: /* /dev/leds */
{
s3c2410_gpio_setpin(S3C2410_GPF4, (val & 0x1));
s3c2410_gpio_setpin(S3C2410_GPF5, (val & 0x1));
s3c2410_gpio_setpin(S3C2410_GPF6, (val & 0x1));
down(&leds_lock);
leds_status = val;
up(&leds_lock);
break;
}

case 1: /* /dev/led1 */
{
s3c2410_gpio_setpin(S3C2410_GPF4, val);

if (val == 0)
{
down(&leds_lock);
leds_status &= ~(1<<0);
up(&leds_lock);
}
else
{
down(&leds_lock);
leds_status |= (1<<0);
up(&leds_lock);
}
break;
}

case 2: /* /dev/led2 */
{
s3c2410_gpio_setpin(S3C2410_GPF5, val);
if (val == 0)
{
down(&leds_lock);
leds_status &= ~(1<<1);
up(&leds_lock);
}
else
{
down(&leds_lock);
leds_status |= (1<<1);
up(&leds_lock);
}
break;
}

case 3: /* /dev/led3 */
{
s3c2410_gpio_setpin(S3C2410_GPF6, val);
if (val == 0)
{
down(&leds_lock);
leds_status &= ~(1<<2);
up(&leds_lock);
}
else
{
down(&leds_lock);
leds_status |= (1<<2);
up(&leds_lock);
}
break;
}

}

return 1;
}

/* 这个结构是字符设备驱动程序的核心
* 当应用程序操作设备文件时所调用的open、read、write等函数，
* 最终会调用这个结构中指定的对应函数
*/
static struct file_operations s3c24xx_leds_fops = {
.owner  =   THIS_MODULE,    /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */
.open   =   s3c24xx_leds_open,
.read   =   s3c24xx_leds_read,
.write  =   s3c24xx_leds_write,
};

/*
* 执行insmod命令时就会调用这个函数
*/
static int __init s3c24xx_leds_init(void)
//static int __init init_module(void)
{
int ret;
int minor = 0;

gpio_va = ioremap(0x56000000, 0x100000);
if (!gpio_va) {
return -EIO;
}

/* 注册字符设备
* 参数为主设备号、设备名字、file_operations结构；
* 这样，主设备号就和具体的file_operations结构联系起来了，
* 操作主设备为LED_MAJOR的设备文件时，就会调用s3c24xx_leds_fops中的相关成员函数
* LED_MAJOR可以设为0，表示由内核自动分配主设备号
*/
ret = register_chrdev(LED_MAJOR, DEVICE_NAME, &s3c24xx_leds_fops);
if (ret < 0) {
printk(DEVICE_NAME " can't register major number\n");
return ret;
}

//创建设备, 然后在类下创建设备
leds_class = class_create(THIS_MODULE, "leds");
if (IS_ERR(leds_class))
return PTR_ERR(leds_class);

//这里创建了 /dev/leds,  /dev/led1,  /dev/led2, /dev/led3 四个设备
leds_class_devs[0] = class_device_create(leds_class, NULL, MKDEV(LED_MAJOR, 0), NULL, "leds"); /* /dev/leds */

for (minor = 1; minor < 4; minor++)  /* /dev/led1,2,3 */
{
leds_class_devs[minor] = class_device_create(leds_class, NULL, MKDEV(LED_MAJOR, minor), NULL, "led%d", minor);
if (unlikely(IS_ERR(leds_class_devs[minor])))
return PTR_ERR(leds_class_devs[minor]);
}

printk(DEVICE_NAME " initialized\n");
return 0;
}

/*
* 执行rmmod命令时就会调用这个函数
*/
static void __exit s3c24xx_leds_exit(void)
{
int minor;
/* 卸载驱动程序 */
unregister_chrdev(LED_MAJOR, DEVICE_NAME);

for (minor = 0; minor < 4; minor++)
{
class_device_unregister(leds_class_devs[minor]);
}
class_destroy(leds_class);
iounmap(gpio_va);
}

/* 这两行指定驱动程序的初始化函数和卸载函数 */
module_init(s3c24xx_leds_init);
module_exit(s3c24xx_leds_exit);

/* 描述驱动程序的一些信息，不是必须的 */
MODULE_AUTHOR("http://www.100ask.net");
MODULE_VERSION("0.1.0");
MODULE_DESCRIPTION("S3C2410/S3C2440 LED Driver");
MODULE_LICENSE("GPL");