USB stack enhancements

This project is part of the Google Summer of Code 2009 project.

Roadmap

Phase 1 (50%):

• Implement a working HID class driver, replacing the charging-only driver
• Write a HID test application (control volume of the host)

Phase 2 (50%):

• Separate class driver from main binary, and implement infrastructure to dynamically load them

Currently working on: Phase 1

Remaining work for completing phase 1:

• Remove the charging-only USB class-driver in favour of the HID driver
• Configure keymaps for all platforms that uses the Rockbox USB stack (FS#10218)
• Implement a sample application that sends various key codes to the host, e.g. use Rockbox as a PowerPoint Presenter (but not cordless, of course)

Completed (and committed) tasks:

• Switch to git repository management, to ease development process
• Valid enumeration of the DAP as a Human-Interface Device
• Implement support for Interrupt transfers in Sansa e200
• Add debug menu items to control volume (VolUp/VolDown/Mute) on the host using HID messages
• Successfully send HID messages to host.

Other ideas for leveraging this work, which will not be implemented as part of this GSoC project:

• Implement Interrupt type endpoints in all other drivers
• Implement context menu to control the class driver, e.g. key-mappings (code pages), etc.
• Implement 'code-page' to configure key-mapping for controlling Power-Point presentations
• Make touch-screen enabled platforms identify as a tablet device, enabling the player to act as a touch-pad
• Use touchscreen platforms as a LCD keyboard
• Contol what is displayed on the DAP's LCD via a driver run on the host OS

Resources:

• HID data on Wikipedia: http://en.wikipedia.org/wiki/Human_interface_device
• HID Information: http://www.usb.org/developers/hidpage/
• The last HID 1.12 Specification: http://www.usb.org/developers/devclass_docs/Hut1_12.pdf/