CODEWITHSUNDEEP
ckerneldriversioctl
anothertest
anothertest

Reputation: 979

Using ioctl to change value of autorepeat

How can I use ioctl to change the value of auto-repeat for a given device in C?

I know about

#define REP_DELAY               0x00
#define REP_PERIOD              0x01

source: http://lxr.free-electrons.com/source/include/uapi/linux/input.h#L931

I didn't find any tutorial or documentation about these things. This question is not vague, it is actually just about using ioctl with REP_DELAY and REP_PERIOD. How can I use them with ioctl?

Upvotes: 2

Views: 1320

Answers (2)

user2404501
user2404501

Reputation:

I think the ioctls you need are EVIOCGREP and EVIOCSREP. I can't find any documentation for them, but they are declared here as working on unsigned int[2] so I guess that REP_DELAY and REP_PERIOD are indexes in that array.

Something like this should work:

unsigned int rep[2];
ioctl(fd, EVIOCGREP, rep); /* get current values */
/* do something with rep[REP_DELAY] and/or rep[REP_PERIOD] */
ioctl(fd, EVIOCSREP, rep) /* write new values */

The KD ioctls predate evdev so the REP_ macros aren't be used with them. If you're operating directly on a virtual console (/dev/tty1 etc.) then KD and struct kbd_repeat are the way to go. On the newer input devices, EVIOC and REP_.

Upvotes: 1

Raunak Mukhia
Raunak Mukhia

Reputation: 388

You need to get the file descriptor for that particular device. The request is 

#define KDKBDREP        0x4B52

The parameters to pass are 

 struct kbd_repeat {
        int delay;      
        int period;     
 }

Source http://lxr.free-electrons.com/source/include/uapi/linux/kd.h?v=3.10#L153 .

Upvotes: 2

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