Changing default line discipline at kernel level/ any way other than( user space) IOCTL TCIOCSETD

Changing default line discipline at kernel level/ any way other than( user
space) IOCTL TCIOCSETD

I am implementing a custom line discipline in order to communicate with
the peripheral connected to the serial port. So during kernel boot itself
i want to assign the custom line discipline to serial port which is
connected to the peripheral. When i walk through the kernel source, i come
to know that by default all the serial port will be assigned n_tty line
discipline with this function tty_ldisc_init(struct tty_struct *tty). Now
how can i identify the particular serial port and assign custom line
discipline? I searched a lot , i am getting all the refernce from user
spcae. I have a dependency, because two component will be using this line
discipline. i component can access from user space while the other is in
kernel space. So if user space component is not up, kernel space module
cannot communicate