mirror of
https://github.com/sysprog21/lkmpg.git
synced 2024-11-28 19:33:38 +08:00
faf3aa7c22
It is vital to denote the file name and summary for each source, otherwise readers could not figure out the corresponding files.
67 lines
1.5 KiB
C
67 lines
1.5 KiB
C
/*
|
|
* chardev.h - the header file with the ioctl definitions.
|
|
*
|
|
* The declarations here have to be in a header file, because
|
|
* they need to be known both to the kernel module
|
|
* (in chardev.c) and the process calling ioctl (ioctl.c)
|
|
*/
|
|
|
|
#ifndef CHARDEV_H
|
|
#define CHARDEV_H
|
|
|
|
#include <linux/ioctl.h>
|
|
|
|
/*
|
|
* The major device number. We can't rely on dynamic
|
|
* registration any more, because ioctls need to know
|
|
* it.
|
|
*/
|
|
#define MAJOR_NUM 100
|
|
|
|
/*
|
|
* Set the message of the device driver
|
|
*/
|
|
#define IOCTL_SET_MSG _IOW(MAJOR_NUM, 0, char *)
|
|
/*
|
|
* _IOW means that we're creating an ioctl command
|
|
* number for passing information from a user process
|
|
* to the kernel module.
|
|
*
|
|
* The first arguments, MAJOR_NUM, is the major device
|
|
* number we're using.
|
|
*
|
|
* The second argument is the number of the command
|
|
* (there could be several with different meanings).
|
|
*
|
|
* The third argument is the type we want to get from
|
|
* the process to the kernel.
|
|
*/
|
|
|
|
/*
|
|
* Get the message of the device driver
|
|
*/
|
|
#define IOCTL_GET_MSG _IOR(MAJOR_NUM, 1, char *)
|
|
/*
|
|
* This IOCTL is used for output, to get the message
|
|
* of the device driver. However, we still need the
|
|
* buffer to place the message in to be input,
|
|
* as it is allocated by the process.
|
|
*/
|
|
|
|
/*
|
|
* Get the n'th byte of the message
|
|
*/
|
|
#define IOCTL_GET_NTH_BYTE _IOWR(MAJOR_NUM, 2, int)
|
|
/*
|
|
* The IOCTL is used for both input and output. It
|
|
* receives from the user a number, n, and returns
|
|
* Message[n].
|
|
*/
|
|
|
|
/*
|
|
* The name of the device file
|
|
*/
|
|
#define DEVICE_FILE_NAME "char_dev"
|
|
|
|
#endif
|