2 files changed, 44 insertions, 13 deletions

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 690224483fa..098a7c72b64 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 80e72dc564a..3adc362f0bd 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)
 {