device number(dev_t)
linux driver 2009-08-21 10:08:03 阅读26 评论0 字号：大中小
dev_t
description:
the dev_t type in is used to hold device numbers—both the major and minor
parts.
header:
#include
constructor:
MKDEV(int major, int minor);
method:
MAJOR(dev_t dev); //obtain the major part of a dev_t
MINOR(dev_t dev); //obtain the minor part of a dev_t
register_chrdev_region(); //manually obtain(register) device numbers
from the system
alloc_chrdev_region(); //allocate a major number by kernel
unregister_chrdev_region(); //free the device number back to kernel
int print_dev_t(char *buffer, dev_t dev); //encode the device number into the given buffer;
char *format_dev_t(char *buffer, dev_t dev); //encode the device number into the given buffer;
转载自：http://leewez.blog.163.com/blog/static/2958954620097211083517/