diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 690224483fab187e08e9cc0d030c698b4490ffa1..098a7c72b640460c58f62d9d9e5cc20bab1b526b 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -3061,21 +3061,37 @@ void tty_unregister_device(struct tty_driver *driver, unsigned index)
 }
 EXPORT_SYMBOL(tty_unregister_device);
 
-struct tty_driver *__alloc_tty_driver(int lines, struct module *owner)
+/**
+ * __tty_alloc_driver -- allocate tty driver
+ * @lines: count of lines this driver can handle at most
+ * @owner: module which is repsonsible for this driver
+ * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags
+ *
+ * This should not be called directly, some of the provided macros should be
+ * used instead. Use IS_ERR and friends on @retval.
+ */
+struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner,
+		unsigned long flags)
 {
 	struct tty_driver *driver;
 
+	if (!lines)
+		return ERR_PTR(-EINVAL);
+
 	driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL);
-	if (driver) {
-		kref_init(&driver->kref);
-		driver->magic = TTY_DRIVER_MAGIC;
-		driver->num = lines;
-		driver->owner = owner;
-		/* later we'll move allocation of tables here */
-	}
+	if (!driver)
+		return ERR_PTR(-ENOMEM);
+
+	kref_init(&driver->kref);
+	driver->magic = TTY_DRIVER_MAGIC;
+	driver->num = lines;
+	driver->owner = owner;
+	driver->flags = flags;
+	/* later we'll move allocation of tables here */
+
 	return driver;
 }
-EXPORT_SYMBOL(__alloc_tty_driver);
+EXPORT_SYMBOL(__tty_alloc_driver);
 
 static void destruct_tty_driver(struct kref *kref)
 {
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 80e72dc564a5b2de49f8c17c136adb0ace61682d..3adc362f0bd2bd8d886a10ae794cc6ce77284d9b 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -296,11 +296,11 @@ struct tty_driver {
 	int	name_base;	/* offset of printed name */
 	int	major;		/* major device number */
 	int	minor_start;	/* start of minor device number */
-	int	num;		/* number of devices allocated */
+	unsigned int	num;	/* number of devices allocated */
 	short	type;		/* type of tty driver */
 	short	subtype;	/* subtype of tty driver */
 	struct ktermios init_termios; /* Initial termios */
-	int	flags;		/* tty driver flags */
+	unsigned long	flags;		/* tty driver flags */
 	struct proc_dir_entry *proc_entry; /* /proc fs entry */
 	struct tty_driver *other; /* only used for the PTY driver */
 
@@ -322,7 +322,8 @@ struct tty_driver {
 
 extern struct list_head tty_drivers;
 
-extern struct tty_driver *__alloc_tty_driver(int lines, struct module *owner);
+extern struct tty_driver *__tty_alloc_driver(unsigned int lines,
+		struct module *owner, unsigned long flags);
 extern void put_tty_driver(struct tty_driver *driver);
 extern void tty_set_operations(struct tty_driver *driver,
 			const struct tty_operations *op);
@@ -330,7 +331,21 @@ extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
 
 extern void tty_driver_kref_put(struct tty_driver *driver);
 
-#define alloc_tty_driver(lines) __alloc_tty_driver(lines, THIS_MODULE)
+/* Use TTY_DRIVER_* flags below */
+#define tty_alloc_driver(lines, flags) \
+		__tty_alloc_driver(lines, THIS_MODULE, flags)
+
+/*
+ * DEPRECATED Do not use this in new code, use tty_alloc_driver instead.
+ * (And change the return value checks.)
+ */
+static inline struct tty_driver *alloc_tty_driver(unsigned int lines)
+{
+	struct tty_driver *ret = tty_alloc_driver(lines, 0);
+	if (IS_ERR(ret))
+		return NULL;
+	return ret;
+}
 
 static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d)
 {