[字符设备]led驱动

--led.c

#include <linux/module.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/gpio.h>
#include <asm/io.h>
#include <asm/module.h>
#include <asm/uaccess.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>


#include "led.h"
#include "leddev.h"
#define DEVICE_NAME "ledss"
#define LEDDEV_MAJOR 0
#define LED_NR_DEVS  1
#define LEDON  0
#define LEDOFF 1

struct cdev dev;
struct class *my_class;

static int led_major = LEDDEV_MAJOR;

static unsigned long led_table[] =
{
    S3C2410_GPB(5),
    S3C2410_GPB(6),
    S3C2410_GPB(7),
    S3C2410_GPB(8),
};

static unsigned int led_cfg_table[] =
{
    S3C2410_GPIO_OUTPUT,
    S3C2410_GPIO_OUTPUT,
    S3C2410_GPIO_OUTPUT,
    S3C2410_GPIO_OUTPUT,
};
static int s3c2440_leds_open(struct inode *inode, struct file *filp)
{
    int i;
    for(i = 0; i < 4; ++i)
    {
        s3c2410_gpio_cfgpin(led_table[i], led_cfg_table[i]);
        s3c2410_gpio_setpin(led_table[i], 0);
    }
    return 0;
}
static int s3c2440_leds_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
    int i;
    struct status st;
    memset(&st, 0, sizeof(struct status));
    switch(cmd)
    {
        case LEDDEV_IOCON:
            for (i = 0; i < sizeof(led_table)/sizeof(led_table[0]); ++i)
                s3c2410_gpio_setpin(led_table[i], LEDON);
            break;
        case LEDDEV_IOCOFF:
            for (i = 0; i < sizeof(led_table)/sizeof(led_table[0]); ++i)
                s3c2410_gpio_setpin(led_table[i], LEDOFF);
            break;
        case LEDDEV_IOCROF:
            copy_from_user((void *)&st, (const void *)arg, sizeof(struct status));
            for (i = 0; i < sizeof(led_table)/sizeof(led_table[0]); ++i)
                s3c2410_gpio_setpin(led_table[i], LEDOFF);
            s3c2410_gpio_setpin(led_table[st.led_no - 1], !st.led_status);
            break;
        default:
            return -EINVAL;
    }
    return 0;
}

static struct file_operations dev_fops =
{
    .owner = THIS_MODULE,
    .ioctl = s3c2440_leds_ioctl,
    .open  = s3c2440_leds_open,
};


static int __init s3c2440_led_init(void)
{
    int result;
    struct device *devxx;
    dev_t devno = MKDEV(led_major, 0);

    if (led_major)
        result = register_chrdev_region(devno, 1, DEVICE_NAME);
    else
    {
        result = alloc_chrdev_region(&devno, 0, 1, DEVICE_NAME);
        led_major = MAJOR(devno);
        printk("Major-->%d\n", led_major);
    }

    if (result < 0)
        return result;

    cdev_init(&dev, &dev_fops);
    dev.owner = THIS_MODULE;
    dev.ops = &dev_fops;

    cdev_add(&dev, devno, LED_NR_DEVS);

    my_class = class_create(THIS_MODULE, "my_class");
    if (IS_ERR(my_class))
        return -1;
    devxx = device_create(my_class, NULL, devno, NULL, DEVICE_NAME);
    if (IS_ERR(devxx))
    {
        printk("create device node fail!\n");
        return -1;
    }
    printk("create device node sucess!\n");
    return result;
}

static void __exit s3c2440_led_exit(void)
{
    cdev_del(&dev);
    device_destroy(my_class, MKDEV(led_major, 0));
    class_destroy(my_class);
    unregister_chrdev_region(MKDEV(led_major, 0), LED_NR_DEVS);
}

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Domod");
module_init(s3c2440_led_init);
module_exit(s3c2440_led_exit);

--app-led.c

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

int main(int argc, char **argv)
{
    int on, led_no;
    int fd;
    struct status st;
    memset(&st, 0, sizeof(struct status));
    if (argc < 2 || argc > 3 )
    {
        fprintf(stderr, "Usage:%s 0|1\n\tOr %s led_no 0|1\n", argv[0], argv[0]);
        exit(1);
    }

    fd = open("/dev/ledss", 0);
    if (fd < 0)
    {
        perror("open device leds");
        exit(1);
    }

    if (argc == 2)
    {
        printf("argc=%d\nargv[1]=%s\n", argc, argv[1]);
        if (sscanf(argv[1], "%d", &on) != 1 || on < 0 || on > 1)
        {
            fprintf(stderr, "Usage:%s 0|1\n\tOr %s led_no 0|1\n", argv[0], argv[0]);
            exit(1);
        }
        if (on)
        {
            printf("turn on all leds!\n");
            ioctl(fd, LEDDEV_IOCON, 0);
        }
        else
        {
            printf("turn off all leds!\n");
            ioctl(fd, LEDDEV_IOCOFF, 0);
        }
    }
    else if (argc == 3)
    {
        if (sscanf(argv[1], "%d", &led_no) != 1 || led_no > 4 || led_no < 1 || sscanf(argv[2], "%d", &on) != 1 || on < 0 || on > 1)
        {
            fprintf(stderr, "Usage:%s 0|1\n\tOr %s led_no 0|1\n", argv[0], argv[0]);
            exit(1);
        }
        st.led_no = led_no;
        st.led_status = on;
        printf("select what you want!\n");
        ioctl(fd, LEDDEV_IOCROF, &st);
    }
}

--leddev.h

#ifndef __LEDDEV_H__
#define __LEDDEV_H__

#include <linux/ioctl.h>
#define LEDDEV_IOC_MAGIC 'l'

#define LEDDEV_IOCON  _IO(LEDDEV_IOC_MAGIC, 1)
#define LEDDEV_IOCOFF _IO(LEDDEV_IOC_MAGIC, 2)
#define LEDDEV_IOCROF _IO(LEDDEV_IOC_MAGIC, 3)

#define LEDDEV_IOC_MAXNR 3

struct status
{
    int led_no;
    int led_status;
};

#endif

--Makefile

CFILE=app-led.c
TFILE=led.ko
ifneq ($(KERNELRELEASE),)

obj-m := led.o

else

KDIR := /home/domod/arm/kernel/src/linux-2.6.32.2
all:
[tab]make -C $(KDIR) M=$(PWD) modules ARCH=arm CROSS_COMPILE=arm-linux-
app:
[tab]arm-linux-gcc $(CFILE) -o app
sub:
[tab]cp $(TFILE) app ../rootfs
clean:
[tab]rm -f *.ko *.o *.mod.o *.mod.c *.symvers  modul*

endif