ch341usbserial

Ch341usbserial refers to the Linux kernel driver support for USB-to-serial adapters based on the CH341 family of bridge chips produced by WCH (Nanjing Qinheng Microelectronics). It is part of the usbserial subsystem and is used to provide a native serial interface to user space for devices that implement the CH341 USB-to-UART bridge.

Hardware background and scope: The CH341 family is widely used in inexpensive USB-to-serial adapters and embedded boards. The driver supports CH341-based devices that present a USB serial channel to the host. In most designs, the CH341 enables a single serial port, presented to Linux as a standard character device such as /dev/ttyUSB0. The CH341 acts as a USB-to-UART bridge; many boards output TTL-level serial signals, while RS-232 operation, when needed, typically requires external level-shifting hardware.

Driver role and behavior: The ch341usbserial driver integrates with the Linux usbserial core. When a CH341-based device is connected, the driver binds to the device and creates one or more /dev/ttyUSBx devices for user-space access. It implements the common serial port interface, exposing standard termios controls, data transfer, and basic modem signal handling (such as DTR and RTS) as appropriate to the hardware. Some variants may also expose additional GPIO lines via the driver interface.

Usage and compatibility: On modern Linux systems, CH341-based devices are usually detected automatically and work with no special configuration. If automatic loading fails, the ch341 (or ch341_usbserial) module can be loaded manually (for example, via modprobe). The driver is widely supported across mainline kernels and remains a common solution for USB-to-serial connectivity in both desktop and embedded environments.

Notes: The CH341 family is distinct from the CH340 line; both provide USB-to-serial functionality but use different chip IDs and drivers.