[PATCH v1 0/4] usb: serial: mxuport: extend MXU50U support and runtime controls

From: Crescent Hsieh

Date: Mon Mar 23 2026 - 23:53:59 EST


This series extends the mxuport driver for additional MXU50U-based devices
and adds runtime configuration support for interface mode and UART FIFO
control.

The first patch adds support for additional 3-, 5-, 6-, and 7-port MXU50U
devices and updates the firmware selection logic accordingly.

The second patch implements TX flow control based on the device SEND_NEXT
event so the driver stops queueing bulk-out data once the device buffer is
full and resumes when the device is ready again.

The third patch adds serial interface mode configuration through
TIOCSRS485/TIOCGRS485, allowing userspace to switch between RS232, RS422,
2-wire RS485, and 4-wire RS485 modes.

The final patch adds a per-port sysfs attribute for controlling the UART
FIFO state at runtime.

Together these changes improve hardware coverage and expose the runtime
controls supported by the device firmware.

Crescent Hsieh (4):
usb: serial: mxuport: add support for more MXU50U UART devices
usb: serial: mxuport: handle SEND_NEXT tx flow control
usb: serial: mxuport: support serial interface mode configuration
usb: serial: mxuport: add sysfs control for UART FIFO

drivers/usb/serial/mxuport.c | 319 +++++++++++++++++++++++++++++++++--
1 file changed, 305 insertions(+), 14 deletions(-)

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2.43.0