1 files changed, 70 insertions, 0 deletions
diff --git a/Documentation/driver-api/tty/tty_port.rst b/Documentation/driver-api/tty/tty_port.rst
new file mode 100644
index 0000000000..5cb90e954f
--- /dev/null
+++ b/Documentation/driver-api/tty/tty_port.rst
@@ -0,0 +1,70 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+========
+TTY Port
+========
+
+.. contents:: :local:
+
+The TTY drivers are advised to use struct tty_port helpers as much as possible.
+If the drivers implement :c:member:`tty_port.ops.activate()` and
+:c:member:`tty_port.ops.shutdown()`, they can use tty_port_open(),
+tty_port_close(), and tty_port_hangup() in respective
+:c:member:`tty_struct.ops` hooks.
+
+The reference and details are contained in the `TTY Port Reference`_ and `TTY
+Port Operations Reference`_ sections at the bottom.
+
+TTY Port Functions
+==================
+
+Init & Destroy
+--------------
+
+.. kernel-doc::  drivers/tty/tty_port.c
+   :identifiers: tty_port_init tty_port_destroy
+        tty_port_get tty_port_put
+
+Open/Close/Hangup Helpers
+-------------------------
+
+.. kernel-doc::  drivers/tty/tty_port.c
+   :identifiers: tty_port_install tty_port_open tty_port_block_til_ready
+        tty_port_close tty_port_close_start tty_port_close_end tty_port_hangup
+        tty_port_shutdown
+
+TTY Refcounting
+---------------
+
+.. kernel-doc::  drivers/tty/tty_port.c
+   :identifiers: tty_port_tty_get tty_port_tty_set
+
+TTY Helpers
+-----------
+
+.. kernel-doc::  drivers/tty/tty_port.c
+   :identifiers: tty_port_tty_hangup tty_port_tty_wakeup
+
+
+Modem Signals
+-------------
+
+.. kernel-doc::  drivers/tty/tty_port.c
+   :identifiers: tty_port_carrier_raised tty_port_raise_dtr_rts
+        tty_port_lower_dtr_rts
+
+----
+
+TTY Port Reference
+==================
+
+.. kernel-doc:: include/linux/tty_port.h
+   :identifiers: tty_port
+
+----
+
+TTY Port Operations Reference
+=============================
+
+.. kernel-doc:: include/linux/tty_port.h
+   :identifiers: tty_port_operations