110 строки
2.3 KiB
C
110 строки
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 2019 Axis Communications AB
|
|
*
|
|
* Based on ttyprintk.c:
|
|
* Copyright (C) 2010 Samo Pogacnik
|
|
*/
|
|
|
|
#include <linux/console.h>
|
|
#include <linux/module.h>
|
|
#include <linux/tty.h>
|
|
|
|
static const struct tty_port_operations ttynull_port_ops;
|
|
static struct tty_driver *ttynull_driver;
|
|
static struct tty_port ttynull_port;
|
|
|
|
static int ttynull_open(struct tty_struct *tty, struct file *filp)
|
|
{
|
|
return tty_port_open(&ttynull_port, tty, filp);
|
|
}
|
|
|
|
static void ttynull_close(struct tty_struct *tty, struct file *filp)
|
|
{
|
|
tty_port_close(&ttynull_port, tty, filp);
|
|
}
|
|
|
|
static void ttynull_hangup(struct tty_struct *tty)
|
|
{
|
|
tty_port_hangup(&ttynull_port);
|
|
}
|
|
|
|
static int ttynull_write(struct tty_struct *tty, const unsigned char *buf,
|
|
int count)
|
|
{
|
|
return count;
|
|
}
|
|
|
|
static unsigned int ttynull_write_room(struct tty_struct *tty)
|
|
{
|
|
return 65536;
|
|
}
|
|
|
|
static const struct tty_operations ttynull_ops = {
|
|
.open = ttynull_open,
|
|
.close = ttynull_close,
|
|
.hangup = ttynull_hangup,
|
|
.write = ttynull_write,
|
|
.write_room = ttynull_write_room,
|
|
};
|
|
|
|
static struct tty_driver *ttynull_device(struct console *c, int *index)
|
|
{
|
|
*index = 0;
|
|
return ttynull_driver;
|
|
}
|
|
|
|
static struct console ttynull_console = {
|
|
.name = "ttynull",
|
|
.device = ttynull_device,
|
|
};
|
|
|
|
static int __init ttynull_init(void)
|
|
{
|
|
struct tty_driver *driver;
|
|
int ret;
|
|
|
|
driver = tty_alloc_driver(1,
|
|
TTY_DRIVER_RESET_TERMIOS |
|
|
TTY_DRIVER_REAL_RAW |
|
|
TTY_DRIVER_UNNUMBERED_NODE);
|
|
if (IS_ERR(driver))
|
|
return PTR_ERR(driver);
|
|
|
|
tty_port_init(&ttynull_port);
|
|
ttynull_port.ops = &ttynull_port_ops;
|
|
|
|
driver->driver_name = "ttynull";
|
|
driver->name = "ttynull";
|
|
driver->type = TTY_DRIVER_TYPE_CONSOLE;
|
|
driver->init_termios = tty_std_termios;
|
|
driver->init_termios.c_oflag = OPOST | OCRNL | ONOCR | ONLRET;
|
|
tty_set_operations(driver, &ttynull_ops);
|
|
tty_port_link_device(&ttynull_port, driver, 0);
|
|
|
|
ret = tty_register_driver(driver);
|
|
if (ret < 0) {
|
|
put_tty_driver(driver);
|
|
tty_port_destroy(&ttynull_port);
|
|
return ret;
|
|
}
|
|
|
|
ttynull_driver = driver;
|
|
register_console(&ttynull_console);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit ttynull_exit(void)
|
|
{
|
|
unregister_console(&ttynull_console);
|
|
tty_unregister_driver(ttynull_driver);
|
|
put_tty_driver(ttynull_driver);
|
|
tty_port_destroy(&ttynull_port);
|
|
}
|
|
|
|
module_init(ttynull_init);
|
|
module_exit(ttynull_exit);
|
|
|
|
MODULE_LICENSE("GPL v2");
|