#include <stdio.h>
#include <fcntl.h>
#include <linux/ioctl.h>
...
...
fptr = open("/dev/module", O_WRONLY);
retval = ioctl(fptr, cmd, param);
close(fptr);

#include <QtGui>
#include <QWidget>
#include <QGridLayout>
#include <QPushButton>

#include <stdio.h>
#include <fcntl.h>
#include <linux/ioctl.h>

int main(int argc, char **argv)
{
QApplication app(argc, argv);
QWidget *main_window = new QWidget;
QPushButton *button = new QPushButton("quit");
QGridLayout *layout = new QGridLayout;

QObject::connect(button, SIGNAL( clicked() ), &app, SLOT( quit() ));

layout->addWidget(button);
main_window->setLayout(layout);
main_window->show();

int fptr, cmd = 0, param = 0, retval = 0;
fptr = open("/dev/module", O_WRONLY);
retval = ioctl(fptr, cmd, param);
close(fptr);

return app.exec();
}