29 Sep
2007
29 Sep
'07
9:47 a.m.
On Thu, 2007-09-27 at 07:53 +0200, Jens M Andreasen wrote:
Hi!
I am trying to create a userspace driver with module uinput and I am
getting into trouble when I terminate the program that creates the
device. After a while the machine will crash ...
Now I can laugh ... It is all in the details. For a uinput joystick
device, you will need to give min and max other than zero for the axes
in use as in:
--8<-------------------------------------------------------------------
void destroy_uinput()
{
fprintf(stderr,"\njoyLOOQ says: \"BYE!\" and winks knowingly
;-D\n");
if(uinp_fd > 0)
{
struct input_event event;
event.type = SYN_CONFIG;
event.code = 0;
event.value = 0;
write(uinp_fd,event,sizeof(event)); // Voodoo?
ioctl (uinp_fd, UI_DEV_DESTROY);
close (uinp_fd);
}
exit(0);
}
int create_uinput()
{
static struct uinput_user_dev uinp;
int fd = -1;
char buf[256];
sigset(SIGINT,destroy_uinput);
sigset(SIGTERM,destroy_uinput);
int i=0;
system("modprobe -v uinput");
while(++i < 3)
{
fprintf(stderr,"uinput? ... ");
fd = open ("/dev/input/uinput", O_WRONLY);
if (fd <= 0)
fd = open ("/dev/uinput", O_WRONLY);
if (fd <= 0)
sleep(i);
else
break;
}
if(fd < 0)
{
fprintf(stderr," Say, are you really root? \n");
exit(EXIT_FAILURE);
}
else
fprintf(stderr,"OK! ");
memset (&uinp, 0, sizeof (struct uinput_user_dev));
strncpy (uinp.name, "joyLOOQ from <ja(a)linux.nu>"u>",
UINPUT_MAX_NAME_SIZE);
uinp.id.version = 4;
uinp.id.bustype = BUS_USB;
uinp.id.vendor = 0x00046d; // Logitech
uinp.id.product = 0;
ioctl (fd, UI_SET_EVBIT, EV_SYN);
ioctl (fd, UI_SET_EVBIT, EV_ABS);
ioctl (fd, UI_SET_EVBIT, EV_KEY);
ioctl (fd, UI_SET_ABSBIT, ABS_X);
ioctl (fd, UI_SET_ABSBIT, ABS_Y);
ioctl (fd, UI_SET_ABSBIT, ABS_Z);
ioctl (fd, UI_SET_ABSBIT, ABS_RUDDER);
ioctl (fd, UI_SET_KEYBIT, BTN_TOP);
ioctl (fd, UI_SET_KEYBIT, BTN_TOP2);
ioctl (fd, UI_SET_KEYBIT, BTN_BASE);
ioctl (fd, UI_SET_KEYBIT, BTN_BASE2);
ioctl (fd, UI_SET_KEYBIT, BTN_BASE3);
ioctl (fd, UI_SET_KEYBIT, BTN_BASE4);
for(i = 0; i < ABS_MAX;++i)
{
uinp.absmax[i] = 511;
uinp.absmin[i] = -512;
}
// The jogwheel is different
uinp.absmax[ABS_Z] = 2047;
uinp.absmin[ABS_Z] =-2048;
// .. and rudder as well
uinp.absmax[ABS_RUDDER] = 255;
uinp.absmin[ABS_RUDDER] =-256;
// Create device
write (fd, &uinp, sizeof (uinp));
if (ioctl (fd, UI_DEV_CREATE))
{
fprintf (stderr,"Unable to create UINPUT device.\n");
exit(EXIT_FAILURE);
}
return fd;
}
--