Re: [PATCH net-next v7 00/14] net: wwan: t7xx: PCIe driver for MediaTek M.2 modem

On 5/6/2022 6:43 AM, Sergey Ryazanov wrote:

Hello Ricardo,

On Fri, May 6, 2022 at 4:16 AM Ricardo Martinez
[off-list ref] wrote:

quoted

t7xx is the PCIe host device driver for Intel 5G 5000 M.2 solution which
is based on MediaTek's T700 modem to provide WWAN connectivity.
The driver uses the WWAN framework infrastructure to create the following
control ports and network interfaces:
* /dev/wwan0mbim0 - Interface conforming to the MBIM protocol.
   Applications like libmbim [1] or Modem Manager [2] from v1.16 onwards
   with [3][4] can use it to enable data communication towards WWAN.
* /dev/wwan0at0 - Interface that supports AT commands.
* wwan0 - Primary network interface for IP traffic.

The main blocks in t7xx driver are:
* PCIe layer - Implements probe, removal, and power management callbacks.
* Port-proxy - Provides a common interface to interact with different types
   of ports such as WWAN ports.
* Modem control & status monitor - Implements the entry point for modem
   initialization, reset and exit, as well as exception handling.
* CLDMA (Control Layer DMA) - Manages the HW used by the port layer to send
   control messages to the modem using MediaTek's CCCI (Cross-Core
   Communication Interface) protocol.
* DPMAIF (Data Plane Modem AP Interface) - Controls the HW that provides
   uplink and downlink queues for the data path. The data exchange takes
   place using circular buffers to share data buffer addresses and metadata
   to describe the packets.
* MHCCIF (Modem Host Cross-Core Interface) - Provides interrupt channels
   for bidirectional event notification such as handshake, exception, PM and
   port enumeration.

The compilation of the t7xx driver is enabled by the CONFIG_MTK_T7XX config
option which depends on CONFIG_WWAN.
This driver was originally developed by MediaTek. Intel adapted t7xx to
the WWAN framework, optimized and refactored the driver source code in close
collaboration with MediaTek. This will enable getting the t7xx driver on the
Approved Vendor List for interested OEM's and ODM's productization plans
with Intel 5G 5000 M.2 solution.

List of contributors:
Amir Hanania [off-list ref]
Andriy Shevchenko [off-list ref]
Chandrashekar Devegowda [off-list ref]
Dinesh Sharma [off-list ref]
Eliot Lee [off-list ref]
Haijun Liu [off-list ref]
M Chetan Kumar [off-list ref]
Mika Westerberg [off-list ref]
Moises Veleta [off-list ref]
Pierre-louis Bossart [off-list ref]
Chiranjeevi Rapolu [off-list ref]
Ricardo Martinez [off-list ref]
Madhusmita Sahu [off-list ref]
Muralidharan Sethuraman [off-list ref]
Soumya Prakash Mishra [off-list ref]
Sreehari Kancharla [off-list ref]
Suresh Nagaraj [off-list ref]

[1] https://www.freedesktop.org/software/libmbim/
[2] https://www.freedesktop.org/software/ModemManager/
[3] https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/merge_requests/582
[4] https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/merge_requests/523

Now the driver looks really nice. Good job!

Thanks Sergey.