/*
   * Copyright (c) 2010 Werner Fink, Jiri Slaby
   *
   * Licensed under GPLv2
   */
  
  #include <linux/console.h>
  #include <linux/kernel.h>
  #include <linux/proc_fs.h>
  #include <linux/seq_file.h>
  #include <linux/tty_driver.h>
  
  /*
   * This is handler for /proc/consoles
   */
  static int show_console_dev(struct seq_file *m, void *v)
  {
  	static const struct {
  		short flag;
  		char name;
  	} con_flags[] = {
  		{ CON_ENABLED,		'E' },
  		{ CON_CONSDEV,		'C' },
  		{ CON_BOOT,		'B' },
  		{ CON_PRINTBUFFER,	'p' },
  		{ CON_BRL,		'b' },
  		{ CON_ANYTIME,		'a' },
  	};
  	char flags[ARRAY_SIZE(con_flags) + 1];
  	struct console *con = v;
  	unsigned int a;
  	int len;
  	dev_t dev = 0;
  
  	if (con->device) {
  		const struct tty_driver *driver;
  		int index;
  		driver = con->device(con, &index);
  		if (driver) {
  			dev = MKDEV(driver->major, driver->minor_start);
  			dev += index;
  		}
  	}
  
  	for (a = 0; a < ARRAY_SIZE(con_flags); a++)
  		flags[a] = (con->flags & con_flags[a].flag) ?
  			con_flags[a].name : ' ';
  	flags[a] = 0;
  
  	seq_printf(m, "%s%d%n", con->name, con->index, &len);
  	len = 21 - len;
  	if (len < 1)
  		len = 1;
  	seq_printf(m, "%*c%c%c%c (%s)", len, ' ', con->read ? 'R' : '-',
  			con->write ? 'W' : '-', con->unblank ? 'U' : '-',
  			flags);
  	if (dev)
  		seq_printf(m, " %4d:%d", MAJOR(dev), MINOR(dev));
  
  	seq_printf(m, "
  ");
  
  	return 0;
  }
  
  static void *c_start(struct seq_file *m, loff_t *pos)
  {
  	struct console *con;
  	loff_t off = 0;

  	console_lock();

  	for_each_console(con)
  		if (off++ == *pos)
  			break;
  
  	return con;
  }
  
  static void *c_next(struct seq_file *m, void *v, loff_t *pos)
  {
  	struct console *con = v;
  	++*pos;
  	return con->next;
  }
  
  static void c_stop(struct seq_file *m, void *v)
  {

  	console_unlock();

  }
  
  static const struct seq_operations consoles_op = {
  	.start	= c_start,
  	.next	= c_next,
  	.stop	= c_stop,
  	.show	= show_console_dev
  };
  
  static int consoles_open(struct inode *inode, struct file *file)
  {
  	return seq_open(file, &consoles_op);
  }
  
  static const struct file_operations proc_consoles_operations = {
  	.open		= consoles_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= seq_release,
  };

  static int __init proc_consoles_init(void)

  {
  	proc_create("consoles", 0, NULL, &proc_consoles_operations);
  	return 0;
  }

  module_init(proc_consoles_init);