创建设备

#include
#include
#include
#include
#include
#include
#include
#include
#include

#define err(msg) printk(KERN_ALERT "%s\n", msg)

static struct class *ffclass;
static struct device *dev;

static int __init maininit(void)
{
        ffclass = class_create(THIS_MODULE, "ffclass");
        if (IS_ERR(ffclass)) {
                err("class_create");
                goto out;
        }

        dev = device_create(ffclass, NULL, MKDEV(22, 0), NULL, "ffclass");
        if (dev == NULL) {
                err("device_create");
                goto err;
        }

        printk(KERN_INFO "device create success.\n");

        return 0;
err:
        class_destroy(ffclass);
out:
        return -1;
}

static void __exit mainexit(void)
{
        device_destroy(ffclass, MKDEV(22, 0));
        class_destroy(ffclass);

        printk(KERN_INFO "device destroy success.\n");
}

module_init(maininit);
module_exit(mainexit);
MODULE_LICENSE("GPL");