[...]
keycode  59 = F1               F13              Console_13       F25
        alt     keycode  59 = Console_1
        control alt     keycode  59 = Console_1
keycode  60 = F2               F14              Console_14       F26
        alt     keycode  60 = Console_2
        control alt     keycode  60 = Console_2
keycode  61 = F3               F15              Console_15       F27
        alt     keycode  61 = Console_3
        control alt     keycode  61 = Console_3
[...]

» grep set_console *.c
keyboard.c:     set_console(last_console);
keyboard.c:     set_console(i);
keyboard.c:     set_console(i);
keyboard.c:     set_console(value);
vt.c:int set_console(int nr)
vt_ioctl.c:                     set_console(arg);

MODULE_DEVICE_TABLE(input, kbd_ids);

static struct input_handler kbd_handler = {
    .event      = kbd_event,   <--- function pointer HERE
    .match      = kbd_match,
    .connect    = kbd_connect,
    .disconnect = kbd_disconnect,
    .start      = kbd_start,
    .name       = "kbd",
    .id_table   = kbd_ids,
};

int __init kbd_init(void)
{

[...]

    error = input_register_handler(&kbd_handler);