arch/um/drivers/stdio_console.c

#include "linux/posix_types.h"
#include "linux/tty.h"
#include "linux/types.h"
#include "linux/major.h"
#include "linux/kdev_t.h"
#include "linux/console.h"
#include "linux/string.h"
#include "linux/sched.h"
#include "linux/init.h"
#include "linux/interrupt.h"
#include "asm/current.h"
#include "asm/softirq.h"
#include "stdio_console.h"
#include "user_util.h"
#include "kern_util.h"

#define MAX_TTYS (8)

static struct tty_driver console_driver;
static struct tty_struct *console_table[MAX_TTYS];
static struct termios *console_termios[MAX_TTYS];
static struct termios *console_termios_locked[MAX_TTYS];
static int console_refcount;

static struct vt {
  int fd;
  int count;
  int xterm_pid;
} vts[MAX_TTYS] = { { 0, 0, -1 }, [ 1 ... MAX_TTYS - 1 ] = { -1, 0, -1 } };

DECLARE_MUTEX(stdio_sem);

static int con_open(struct tty_struct * tty, struct file * filp)
{
  int line;

  line = MINOR(tty->device) - tty->driver.minor_start;
  vts[line].count++;
  if(line != 0){
    down(&stdio_sem);
    if(vts[line].fd == -1){
      vts[line].fd = open_vt(line, &vts[line].xterm_pid);
      input_new_fd(stdio_rcv_proc, vts[line].fd);
    }
    up(&stdio_sem);
  }
  return(0);
}

static void con_close(struct tty_struct * tty, struct file * filp)
{
  int line;

  line = MINOR(tty->device) - tty->driver.minor_start;
  vts[line].count--;
  if(vts[line].count == 0){
    if(vts[line].xterm_pid != -1) kill_pid(vts[line].xterm_pid);
    if(line == 0) vts[line] = ((struct vt) { 0, 0, -1});
    else vts[line] = ((struct vt) { -1, 0, -1});
  }
}

static int con_write(struct tty_struct * tty, int from_user, 
		     const unsigned char *buf, int count)
{
  int line;

  line = MINOR(tty->device) - tty->driver.minor_start;
  stdio_write(vts[line].fd, buf, count);
  return(count);
}

static int write_room(struct tty_struct * tty)
{
  return(1024);
}

static void set_termios(struct tty_struct *tty, struct termios * old)
{
}

static int chars_in_buffer(struct tty_struct *tty)
{
  return(0);
}

DECLARE_TASKLET_DISABLED(input_tasklet, input_handler, 0);

extern void tty_register_devfs  (struct tty_driver *driver, unsigned int flags,
				 unsigned int minor);
extern void tty_unregister_devfs (struct tty_driver *driver, unsigned minor);

int stdio_init(void)
{
  int i;

  printk("Initializing stdio console driver\n");
  memset(&console_driver, 0, sizeof(struct tty_driver));
  console_driver.magic = TTY_DRIVER_MAGIC;
  console_driver.driver_name = "stdio console";
  console_driver.name = "ttys/%d";
  console_driver.major = TTY_MAJOR;
  console_driver.minor_start = 0;
  console_driver.num = 8;
  console_driver.type = TTY_DRIVER_TYPE_CONSOLE;
  console_driver.subtype = SYSTEM_TYPE_CONSOLE;
  console_driver.init_termios = tty_std_termios;
  console_driver.init_termios.c_oflag |= OCRNL;
  console_driver.flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
  console_driver.refcount = &console_refcount;
  console_driver.table = console_table;
  console_driver.termios = console_termios;
  console_driver.termios_locked = console_termios_locked;

  console_driver.open = con_open;
  console_driver.close = con_close;
  console_driver.write = con_write;
  console_driver.put_char = NULL;
  console_driver.flush_chars = NULL;
  console_driver.write_room = write_room;
  console_driver.chars_in_buffer = chars_in_buffer;
  console_driver.flush_buffer = NULL;
  console_driver.ioctl = NULL;
  console_driver.throttle = NULL;
  console_driver.unthrottle = NULL;
  console_driver.send_xchar = NULL;
  console_driver.set_termios = set_termios;
  console_driver.stop = NULL;
  console_driver.start = NULL;
  console_driver.hangup = NULL;
  console_driver.break_ctl = NULL;
  console_driver.wait_until_sent = NULL;
  console_driver.read_proc = NULL;
  if (tty_register_driver(&console_driver))
    panic("Couldn't register console driver\n");
  for(i=0;i<MAX_TTYS;i++){
    tty_register_devfs(&console_driver, 0, i);
  }
  setup_fd(0);
  tasklet_enable(&input_tasklet);
  input_new_fd(stdio_rcv_proc, 0);
  return(0);
}

__initcall(stdio_init);

static void console_write(struct console *console, const char *string, 
			  unsigned len)
{
  stdio_write(console->index, string, len);
}

static kdev_t console_device(struct console *c)
{
  return MKDEV(TTY_MAJOR, c->index);
}

static int console_setup(struct console *co, char *options)
{
  return(0);
}

static struct console stdiocons = {
	"tty",
	console_write,
	NULL,
	console_device,
	NULL,
	NULL,
	console_setup,
	CON_PRINTBUFFER,
	-1,
	0,
	NULL
};

void stdio_console_init(void)
{
	register_console(&stdiocons);
}

void stdio_receive_char(int fd, char ch)
{
  struct tty_struct *tty;
  int i;

  for(i=0;i<MAX_TTYS;i++){
    if(vts[i].fd == fd) break;
  }
  if(i == MAX_TTYS){
    printk("Input received on unknown terminal - fd = %d\n", fd);
    return;
  }
  tty = console_table[i];
  if(tty == NULL) return;
  if(tty->flip.count >= TTY_FLIPBUF_SIZE) return;
  tty->flip.count++;
  *tty->flip.flag_buf_ptr++ = 0;
  *tty->flip.char_buf_ptr++ = ch;
  tty_flip_buffer_push(tty);
}