Introduction to WinUSB for developers

As a driver developer, understanding WinUSB (Windows USB) can significantly streamline your development process, especially when you work with USB devices. WinUSB is a generic driver included with Windows. It allows you to communicate with USB devices without the need to write a custom driver. Using this driver can save you time, reduce complexity, and ensure compatibility across different Windows versions.

Key benefits of using WinUSB

• Simplified development

  • Ease of use: WinUSB abstracts much of the complexity involved in USB communication, which makes it easier for you to interact with USB devices.
  • No custom driver needed: For many USB devices, WinUSB can be used directly, which eliminates the need to write and maintain a custom driver.

• Cross-platform compatibility

  • Standardized interface: WinUSB provides a standardized interface for USB communication, which can help ensure compatibility across different Windows versions.

• Time and cost efficiency

  • Reduced development time: Using WinUSB can significantly reduce the time required to develop and test a USB driver.
  • Lower maintenance costs: Because Microsoft maintains WinUSB, you can rely on it being updated and supported, which reduces long-term maintenance costs.

• Access to USB features

  • Full USB functionality: WinUSB supports a wide range of USB features, including bulk transfers, control transfers, interrupt transfers, and isochronous transfers.

What you can accomplish with WinUSB

• Device communication

  • Data transfer: Send and receive data to and from a USB device using bulk, control, interrupt, or isochronous transfers.
  • Control requests: Send control requests to configure the device or retrieve information.

• Device configuration

  • Setting configuration: Select configurations, interfaces, and alternate settings to configure the USB device.
  • Endpoint management: Manage endpoints for data transfer.

• Device enumeration

  • Device identification: Enumerate and identify USB devices connected to the system.
  • Descriptor retrieval: Retrieve device descriptors, configuration descriptors, interface descriptors, and endpoint descriptors.

• Custom applications

  • User-mode applications: Develop user-mode applications that communicate with USB devices using the WinUSB API.
  • Firmware updates: Implement firmware update mechanisms for USB devices.

• Testing and debugging

  • Prototyping: Quickly prototype USB device communication to test hardware functionality.
  • Debugging: Use WinUSB to debug communication issues between the host and the USB device.

Components of WinUSB

WinUSB includes:

• A kernel-mode driver (winusb.sys)
• A user-mode dynamic link library (winusb.dll) that exposes WinUSB functions described in winusb.h. You can use these functions to manage USB devices with user-mode software.

By default, winusb.sys is installed in the device's kernel-mode stack as an upper filter driver. Apps communicate with the device's User-Mode Driver Framework (UMDF) function driver to issue read, write, or device I/O control requests. In this configuration, winusb.sys serves as the device stack's Plug and Play and power owner. You can also install winusb.sys as the function driver for a USB device.

Get started with WinUSB

This section includes information on:

• Selecting the correct driver for a device
• Using WinUSB to communicate with USB devices
• Installing winusb.sys as the function driver for a USB device

It also includes detailed code examples that show how apps and USB devices communicate.

Related content

• Microsoft-provided USB drivers