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#include "char.h"
#include "linux/cdev.h"
#include "linux/device.h"
#include "linux/fs.h"
#include "util.h"
#define DOOMDEV_COUNT 256
#define DOOMDEV_NAME "doom"
dev_t first;
int major;
int next_minor = 0;
long doom_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
return -1;
}
int doom_open(struct inode *inode, struct file *filp)
{
return -1;
}
struct file_operations doomdev_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = doom_ioctl,
.compat_ioctl = doom_ioctl,
.open = doom_open
};
struct class *doom_class;
int new_doomdev(void)
{
int err = 0;
int minor;
dev_t devt;
struct cdev *doom_cdev;
struct device *doomdev;
if (next_minor >= DOOMDEV_COUNT) {
return -ENOMEM;
}
doom_cdev = cdev_alloc();
if (doom_cdev == NULL) {
return -ENOMEM;
}
doom_cdev->ops = &doomdev_fops;
ORFAIL(cdev_add(doom_cdev, first, 1), error_add);
minor = next_minor++;
devt = MKDEV(major, minor);
ORFAIL_PTR(device_create(doom_class, NULL, devt, NULL,
"doom%d", minor),
doomdev, error_create);
error_create:
cdev_del(doom_cdev);
error_add:
return err;
}
void destroy_doomdev(void)
{
device_destroy(doom_class, first);
}
int char_init(void)
{
int err = 0;
ORFAIL(alloc_chrdev_region(&first, 0, DOOMDEV_COUNT, DOOMDEV_NAME),
error_region);
major = MAJOR(first);
doom_class = class_create(THIS_MODULE, "doom");
if (IS_ERR(doom_class)) {
err = PTR_ERR(doom_class);
goto error_create;
}
error_create:
unregister_chrdev_region(first, DOOMDEV_COUNT);
error_region:
return err;
}
void char_cleanup(void)
{
unregister_chrdev_region(first, DOOMDEV_COUNT);
class_unregister(doom_class);
}
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