[PATCH net-next v2 12/12] net: wwan: tmi: Add maintainers and documentation

[Yanchao Yang]

Adds maintainers and documentation for MediaTek TMI 5G WWAN modem
device driver.

Signed-off-by: Yanchao Yang <yanchao.yang@xxxxxxxxxxxx>
Signed-off-by: Felix Chen <felix.chen@xxxxxxxxxxxx>
---
 .../networking/device_drivers/wwan/index.rst  |  1 +
 .../networking/device_drivers/wwan/tmi.rst    | 48 +++++++++++++++++++
 MAINTAINERS                                   | 11 +++++
 3 files changed, 60 insertions(+)
 create mode 100644 Documentation/networking/device_drivers/wwan/tmi.rst

diff --git a/Documentation/networking/device_drivers/wwan/index.rst b/Documentation/networking/device_drivers/wwan/index.rst
index 370d8264d5dc..8298629b4d55 100644
--- a/Documentation/networking/device_drivers/wwan/index.rst
+++ b/Documentation/networking/device_drivers/wwan/index.rst
@@ -10,6 +10,7 @@ Contents:
 
    iosm
    t7xx
+   tmi
 
 .. only::  subproject and html
 
diff --git a/Documentation/networking/device_drivers/wwan/tmi.rst b/Documentation/networking/device_drivers/wwan/tmi.rst
new file mode 100644
index 000000000000..3655779bf692
--- /dev/null
+++ b/Documentation/networking/device_drivers/wwan/tmi.rst
@@ -0,0 +1,48 @@
+.. SPDX-License-Identifier: BSD-3-Clause-Clear
+
+.. Copyright (c) 2022, MediaTek Inc.
+
+.. _tmi_driver_doc:
+
+====================================================
+TMI driver for MTK PCIe based T-series 5G Modem
+====================================================
+The TMI(T-series Modem Interface) driver is a WWAN PCIe host driver developed
+for data exchange over PCIe interface between Host platform and MediaTek's
+T-series 5G modem. The driver exposes control plane and data plane interfaces
+to applications. The control plane provides device node interfaces for control
+data transactions. The data plane provides network link interfaces for IP data
+transactions.
+
+Control channel userspace ABI
+=============================
+/dev/wwan0at0 character device
+------------------------------
+The driver exposes an AT port by implementing AT WWAN Port.
+The userspace end of the control channel pipe is a /dev/wwan0at0 character
+device. Application shall use this interface to issue AT commands.
+
+/dev/wwan0mbim0 character device
+--------------------------------
+The driver exposes an MBIM interface to the MBIM function by implementing
+MBIM WWAN Port. The userspace end of the control channel pipe is a
+/dev/wwan0mbim0 character device. Applications shall use this interface
+for MBIM protocol communication.
+
+Data channel userspace ABI
+==========================
+wwan0-X network device
+----------------------
+The TMI driver exposes IP link interfaces "wwan0-X" of type "wwan" for IP
+traffic. Iproute network utility is used for creating "wwan0-X" network
+interfaces and for associating it with the MBIM IP session.
+
+The userspace management application is responsible for creating a new IP link
+prior to establishing an MBIM IP session where the SessionId is greater than 0.
+
+For example, creating a new IP link for an MBIM IP session with SessionId 1:
+
+  ip link add dev wwan0-1 parentdev wwan0 type wwan linkid 1
+
+The driver will automatically map the "wwan0-1" network device to MBIM IP
+session 1.
diff --git a/MAINTAINERS b/MAINTAINERS
index 7f0b7181e60a..30aa7d7c783e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13254,6 +13254,17 @@ L:	netdev@xxxxxxxxxxxxxxx
 S:	Supported
 F:	drivers/net/wwan/t7xx/
 
+MEDIATEK TMI 5G WWAN MODEM DRIVER
+M:	Yanchao Yang <yanchao.yang@xxxxxxxxxxxx>
+M:	Min Dong <min.dong@xxxxxxxxxxxx>
+M:	MediaTek Corporation <linuxwwan@xxxxxxxxxxxx>
+R:	Liang Lu <liang.lu@xxxxxxxxxxxx>
+R:	Haijun Liu <haijun.liu@xxxxxxxxxxxx>
+R:	Lambert Wang <lambert.wang@xxxxxxxxxxxx>
+L:	netdev@xxxxxxxxxxxxxxx
+S:	Supported
+F:	drivers/net/wwan/tmi/
+
 MEDIATEK USB3 DRD IP DRIVER
 M:	Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
 L:	linux-usb@xxxxxxxxxxxxxxx
-- 
2.32.0