From 80fb91b164f3fdc7b2c54198d5fa7757b084c466 Mon Sep 17 00:00:00 2001
From: W_Y_CPP <383152993@qq.com>
Date: Wed, 9 Mar 2022 01:45:44 -0500
Subject: [PATCH] add tty driver missing function

---
 drivers/tty/tty_io.c       | 13 +++++++++++++
 include/linux/tty_driver.h | 15 +++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 6616d4a0d..79c6cc39e 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -3438,6 +3438,12 @@ void tty_driver_kref_put(struct tty_driver *driver)
 }
 EXPORT_SYMBOL(tty_driver_kref_put);
 
+void put_tty_driver(struct tty_driver *d)
+{
+	tty_driver_kref_put(d);
+}
+EXPORT_SYMBOL(put_tty_driver);
+
 /*
  * Called by a tty driver to register itself.
  */
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index c20431d8d..cc404cfdc 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -329,6 +329,7 @@ extern struct list_head tty_drivers;
 
 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 struct tty_driver *tty_find_polling_driver(char *name, int *line);
 
 extern void tty_driver_kref_put(struct tty_driver *driver);
@@ -337,6 +340,18 @@ extern void tty_driver_kref_put(struct tty_driver *driver);
 #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)
 {
 	kref_get(&d->kref);
-- 
2.17.1