Re: [PATCH 00/11] net: wwan: t9xx: Add MediaTek T9XX WWAN driver

[Loic Poulain]

Hi Jack,

On Fri, May 29, 2026 at 12:31 PM Jack Wu via B4 Relay
<devnull+jackbb_wu.compal.com@xxxxxxxxxx> wrote:
>
> T9XX is the PCIe host device driver for MediaTek's
> t900 modem. The driver uses the WWAN framework
> infrastructure to create the following control ports
> and network interfaces for data transactions.
> * /dev/wwan0at0 - Interface that supports AT commands.
> * /dev/wwan0mbim0 - Interface conforming to the MBIM
>   protocol.
> * wwan0-X - Primary network interface for IP traffic.
>
> The main blocks in the T9XX driver are:
> * HW layer - Abstracts the hardware bus operations for
>    the device, and provides generic interfaces for the
>    transaction layer to get the device's information and
>    control the device's behavior. It includes:
>
>    * PCIe - Implements probe, removal and interrupt
>      handling.
>    * MHCCIF (Modem Host Cross-Core Interface) - Provides
>      interrupt channels for bidirectional event
>      notification such as handshake and port enumeration.
>
> * Transaction layer - Implements data transactions for
>    the control plane and the data plane. It includes:
>
>    * DPMAIF (Data Plane Modem AP Interface) - Controls
>      the hardware 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.
>    * CLDMA (Cross Layer DMA) - Manages the hardware
>      used by the port layer to send control messages to
>      the device using MediaTek's CCCI (Cross-Core
>      Communication Interface) protocol.
>    * TX Services - Dispatch packets from the port layer
>      to the device.
>    * RX Services - Dispatch packets to the port layer
>      when receiving packets from the device.
>
> * Port layer - Provides control plane and data plane
>    interfaces to userspace. It includes:
>
>    * Control Plane - Provides device node interfaces
>      for controlling data transactions.
>    * Data Plane - Provides network link interfaces
>      wwanX (0, 1, 2...) for IP data transactions.
>
> * Core logic - Contains the core logic to keep the
>    device working. It includes:
>
>    * FSM (Finite State Machine) - Monitors the state
>      of the device, and notifies each module when the
>      state changes.
>
> The compilation of the T9XX driver is enabled by the
> CONFIG_MTK_T9XX and CONFIG_MTK_T9XX_PCI config option
> which depends on CONFIG_WWAN.

Can you specify which userspace counterpart you need (e.g., a
ModemManager version or a link to the relevant patch series)?


>
> ---
> Jack Wu (11):
>       net: wwan: t9xx: Add PCIe core
>       net: wwan: t9xx: Add control plane transaction layer
>       net: wwan: t9xx: Add control DMA interface
>       net: wwan: t9xx: Add control port
>       net: wwan: t9xx: Add FSM thread
>       net: wwan: t9xx: Add AT & MBIM WWAN ports
>       net: wwan: t9xx: Introduce data plane hardware
>       net: wwan: t9xx: Add data plane transaction layer
>       net: wwan: t9xx: Introduce WWAN interface
>       net: wwan: t9xx: Add power management support
>       net: wwan: t9xx: Add maintainers and documentation
>
>  .../networking/device_drivers/wwan/t9xx.rst        |   48 +
>  MAINTAINERS                                        |   10 +
>  drivers/net/wwan/Kconfig                           |   17 +
>  drivers/net/wwan/Makefile                          |    1 +
>  drivers/net/wwan/t9xx/Makefile                     |   16 +
>  drivers/net/wwan/t9xx/mtk_ctrl_plane.c             |   95 +
>  drivers/net/wwan/t9xx/mtk_ctrl_plane.h             |   88 +
>  drivers/net/wwan/t9xx/mtk_data_plane.c             |  104 +
>  drivers/net/wwan/t9xx/mtk_data_plane.h             |  105 +
>  drivers/net/wwan/t9xx/mtk_dev.c                    |   55 +
>  drivers/net/wwan/t9xx/mtk_dev.h                    |  114 +
>  drivers/net/wwan/t9xx/mtk_fsm.c                    |  931 +++++++
>  drivers/net/wwan/t9xx/mtk_fsm.h                    |  140 +
>  drivers/net/wwan/t9xx/mtk_port.c                   |  967 +++++++
>  drivers/net/wwan/t9xx/mtk_port.h                   |  176 ++
>  drivers/net/wwan/t9xx/mtk_port_io.c                |  576 +++++
>  drivers/net/wwan/t9xx/mtk_port_io.h                |   41 +
>  drivers/net/wwan/t9xx/mtk_utility.h                |   33 +
>  drivers/net/wwan/t9xx/mtk_wwan.c                   |  475 ++++
>  drivers/net/wwan/t9xx/mtk_wwan.h                   |   17 +
>  drivers/net/wwan/t9xx/pcie/Makefile                |   19 +
>  drivers/net/wwan/t9xx/pcie/mtk_cldma.c             | 1527 +++++++++++
>  drivers/net/wwan/t9xx/pcie/mtk_cldma.h             |  176 ++
>  drivers/net/wwan/t9xx/pcie/mtk_cldma_drv.c         |  373 +++
>  drivers/net/wwan/t9xx/pcie/mtk_cldma_drv.h         |  174 ++
>  drivers/net/wwan/t9xx/pcie/mtk_cldma_drv_m9xx.c    |  177 ++
>  drivers/net/wwan/t9xx/pcie/mtk_cldma_drv_m9xx.h    |  101 +
>  drivers/net/wwan/t9xx/pcie/mtk_ctrl_cfg_m9xx.c     |   55 +
>  drivers/net/wwan/t9xx/pcie/mtk_dpmaif.c            | 2714 ++++++++++++++++++++
>  drivers/net/wwan/t9xx/pcie/mtk_dpmaif.h            |   16 +
>  drivers/net/wwan/t9xx/pcie/mtk_dpmaif_drv.c        | 1586 ++++++++++++
>  drivers/net/wwan/t9xx/pcie/mtk_dpmaif_drv.h        |  268 ++
>  drivers/net/wwan/t9xx/pcie/mtk_dpmaif_drv_m9xx.c   |  687 +++++
>  drivers/net/wwan/t9xx/pcie/mtk_dpmaif_reg.h        |  387 +++
>  drivers/net/wwan/t9xx/pcie/mtk_dpmaif_reg_m9xx.h   |   37 +
>  drivers/net/wwan/t9xx/pcie/mtk_dpmaif_ring.c       |  168 ++
>  drivers/net/wwan/t9xx/pcie/mtk_dpmaif_ring.h       |  161 ++
>  drivers/net/wwan/t9xx/pcie/mtk_pci.c               | 1067 ++++++++
>  drivers/net/wwan/t9xx/pcie/mtk_pci.h               |  219 ++
>  drivers/net/wwan/t9xx/pcie/mtk_pci_drv_m9xx.c      |   70 +
>  drivers/net/wwan/t9xx/pcie/mtk_pci_reg.h           |   72 +
>  drivers/net/wwan/t9xx/pcie/mtk_trans_ctrl.c        |  593 +++++
>  drivers/net/wwan/t9xx/pcie/mtk_trans_ctrl.h        |  105 +
>  43 files changed, 14761 insertions(+)
> ---
> base-commit: eb3f4b7426cfd2b79d65b7d37155480b32259a11
> change-id: 20260529-t9xx_driver_v1-1744f8af7739
>
> Best regards,
> --
> Jack Wu <jackbb_wu@xxxxxxxxxx>
>
>