[PATCH] tty_register_driver

This patch reinstates the ability of tty devices to use dynamically
allocated major numbers yet specify the minor numbers statically.

The synclink drivers do this.

drivers/char/tty_io.c

@@ -2241,7 +2241,7 @@ int tty_register_driver(struct tty_driver *driver)
 		return 0;
 
 	if (!driver->major) {
-		error = alloc_chrdev_region(&dev, driver->num,
+		error = alloc_chrdev_region(&dev, driver->minor_start, driver->num,
 						(char*)driver->name);
 		if (!error) {
 			driver->major = MAJOR(dev);

fs/char_dev.c

@@ -179,10 +179,10 @@ int register_chrdev_region(dev_t from, unsigned count, char *name)
 	return PTR_ERR(cd);
 }
 
-int alloc_chrdev_region(dev_t *dev, unsigned count, char *name)
+int alloc_chrdev_region(dev_t *dev, unsigned baseminor, unsigned count, char *name)
 {
 	struct char_device_struct *cd;
-	cd = __register_chrdev_region(0, 0, count, name);
+	cd = __register_chrdev_region(0, baseminor, count, name);
 	if (IS_ERR(cd))
 		return PTR_ERR(cd);
 	*dev = MKDEV(cd->major, cd->baseminor);

include/linux/fs.h

@@ -1059,7 +1059,7 @@ extern void bd_release(struct block_device *);
 extern void blk_run_queues(void);
 
 /* fs/char_dev.c */
-extern int alloc_chrdev_region(dev_t *, unsigned, char *);
+extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, char *);
 extern int register_chrdev_region(dev_t, unsigned, char *);
 extern int register_chrdev(unsigned int, const char *,
 			   struct file_operations *);