usbhid

usbhid refers to the Linux kernel driver that implements the USB Human Interface Device (HID) class for devices connected over USB. The USB HID class, defined by the USB Implementers Forum, standardizes how devices describe their capabilities and exchange data with the host. Devices provide a HID report descriptor that defines the format of reports, which can be input, output, or feature, and data is transferred over an interrupt endpoint. The host uses the HID class driver to parse reports and translate them into input events.

In Linux, the usbhid driver binds to USB devices that advertise the HID class. It exposes input devices in the kernel input subsystem and, for raw access, a hidraw character device. It cooperates with the HID core and the user-space input stack to deliver events to applications and desktop environments through interfaces such as evdev, libinput, or other input handlers. Many HID devices—such as keyboards, mice, and game controllers—work with usbhid without requiring device-specific drivers; some devices may rely on quirks or vendor-specific features described by their HID reports or feature reports.

Cross-platform context: while usbhid is the Linux implementation of the USB HID class, other operating systems implement their own HID stacks. HID devices expose their functionality through standard report formats and usage pages, enabling broad interoperability. Developers interact with HID devices via standard APIs and, when needed, via raw access through hidraw or higher-level input frameworks to implement custom input handling or device-specific features.