add class/tty/console/real_dev symlink

Hollis Blanchard
IBM Linux Technology Center

===== drivers/char/tty_io.c 1.147 vs edited =====
--- 1.147/drivers/char/tty_io.c Sat Oct  2 17:45:19 2004
+++ edited/drivers/char/tty_io.c Wed Oct  6 17:08:27 2004
@@ -110,6 +110,8 @@
 #define TTY_PARANOIA_CHECK 1
 #define CHECK_TTY_COUNT 1
 
+static struct class_device *console_dev;
+
 struct termios tty_std_termios = { /* for the benefit of tty drivers  */
  .c_iflag = ICRNL | IXON,
  .c_oflag = OPOST | ONLCR,
@@ -2640,6 +2642,9 @@
 {
  char name[64];
  dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
+ struct class_device *tty_dev;
+ struct tty_driver *console_driver;
+ int console_index;
 
  if (index >= driver->num) {
   printk(KERN_ERR "Attempt to register invalid tty line number "
@@ -2654,7 +2659,12 @@
   pty_line_name(driver, index, name);
  else
   tty_line_name(driver, index, name);
- class_simple_device_add(tty_class, dev, device, name);
+ tty_dev = class_simple_device_add(tty_class, dev, device, name);
+
+ console_driver = console_device(&console_index);
+ if ((console_driver == driver) && (console_index == index)) {
+  sysfs_create_link(&console_dev->kobj, &tty_dev->kobj, "real_dev");
+ }
 }
 
 /**
@@ -2921,7 +2931,8 @@
      register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
   panic("Couldn't register /dev/console driver\n");
  devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 1), S_IFCHR|S_IRUSR|S_IWUSR, "console");
- class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 1), NULL, "console");
+ console_dev = class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 1),
+   NULL, "console");
 
 #ifdef CONFIG_UNIX98_PTYS
  cdev_init(&ptmx_cdev, &ptmx_fops);