// SPDX-License-Identifier: GPL-2.0-only

  /*
   * Copyright (c) 2010 Werner Fink, Jiri Slaby

   */
  
  #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;

  	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_setwidth(m, 21 - 1);
  	seq_printf(m, "%s%d", con->name, con->index);
  	seq_pad(m, ' ');
  	seq_printf(m, "%c%c%c (%s)", con->read ? 'R' : '-',

  			con->write ? 'W' : '-', con->unblank ? 'U' : '-',
  			flags);
  	if (dev)
  		seq_printf(m, " %4d:%d", MAJOR(dev), MINOR(dev));

  	seq_putc(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 __init proc_consoles_init(void)

  {

  	proc_create_seq("consoles", 0, NULL, &consoles_op);

  	return 0;
  }

  fs_initcall(proc_consoles_init);