Linux USB API

• The Linux-USB Host Side API
  • Introduction to USB on Linux
  • USB Host-Side API Model
  • USB-Standard Types
  • Host-Side Data Types and Macros
  • USB Core APIs
  • Host Controller APIs
  • The USB character device nodes
    • What files are in “devtmpfs”?
    • /dev/bus/usb/BBB/DDD
    • Life Cycle of User Mode Drivers
    • The ioctl() Requests
      • Management/Status Requests
      • Synchronous I/O Support
      • Asynchronous I/O Support
  • The USB devices
    • /sys/kernel/debug/usb/devices
      • /sys/kernel/debug/usb/devices output format
        • Topology info
        • Bandwidth info
        • Device descriptor info & Product ID info
        • String descriptor info
        • Configuration descriptor info
        • Interface descriptor info (can be multiple per Config)
        • Endpoint descriptor info (can be multiple per Interface)
      • Usage examples
• USB Gadget API for Linux
  • Introduction
  • Structure of Gadget Drivers
  • Kernel Mode Gadget API
    • Driver Life Cycle
    • USB 2.0 Chapter 9 Types and Constants
    • Core Objects and Methods
    • Optional Utilities
    • Composite Device Framework
    • Composite Device Functions
  • Peripheral Controller Drivers
  • Gadget Drivers
  • USB On-The-GO (OTG)
• USB Anchors
  • What is anchor?
  • Allocation and Initialisation
  • Deallocation
  • Association and disassociation of URBs with anchors
  • Operations on multitudes of URBs
    • usb_kill_anchored_urbs()
    • usb_unlink_anchored_urbs()
    • usb_scuttle_anchored_urbs()
    • usb_wait_anchor_empty_timeout()
    • usb_anchor_empty()
    • usb_get_from_anchor()
• USB bulk streams
  • Background
  • Device-side implications
  • Driver implications
  • Picking new Stream IDs to use
  • Clean up
• USB core callbacks
  • What callbacks will usbcore do?
  • Calling conventions
  • Hotplugging callbacks
    • The probe() callback
    • The disconnect() callback
  • Device level callbacks
    • pre_reset
    • post_reset
  • Call sequences
• USB DMA
  • API overview
  • Eliminating copies
  • Working with existing buffers
• USB Request Block (URB)
  • Basic concept or ‘What is an URB?’
  • The URB structure
  • How to get an URB?
  • What has to be filled in?
  • How to submit an URB?
  • How to cancel an already running URB?
  • What about the completion handler?
  • How to do isochronous (ISO) transfers?
  • How to start interrupt (INT) transfers?
• Power Management for USB
  • What is Power Management?
  • What is Remote Wakeup?
  • When is a USB device idle?
  • Forms of dynamic PM
  • The user interface for dynamic PM
  • Changing the default idle-delay time
  • Warnings
  • The driver interface for Power Management
  • The driver interface for autosuspend and autoresume
  • Other parts of the driver interface
  • Mutual exclusion
  • Interaction between dynamic PM and system PM
  • xHCI hardware link PM
  • USB Port Power Control
  • User Interface for Port Power Control
  • Suggested Userspace Port Power Policy
• USB hotplugging
  • Linux Hotplugging
  • Kernel Hotplug Helper (/sbin/hotplug)
  • USB Policy Agent
  • USB Modutils Support
• USB device persistence during system suspend
  • What is the problem?
  • What is the solution?
  • Is this the best solution?
  • WARNING: USB-persist can be dangerous!!
• USB Error codes
  • Error codes returned by usb_submit_urb()
  • Error codes returned by in urb->status or in iso_frame_desc[n].status (for ISO)
  • Error codes returned by usbcore-functions
• Writing USB Device Drivers
  • Introduction
  • Linux USB Basics
  • Device operation
  • Isochronous Data
  • Conclusion
  • Resources
• Synopsys DesignWare Core SuperSpeed USB 3.0 Controller
  • Introduction
  • Summary of Features
  • Driver Design
  • Known Limitations
    • OUT Transfer Size Requirements
    • TRB Ring Size Limitation
  • Reporting Bugs
    • Required Information
  • Debugging
    • DebugFS
      • link_state
      • regdump
      • testmode
      • ep[0..15]{in,out}
        • transfer_type
        • trb_ring
    • Trace Events
      • MMIO
      • Interrupt Events
      • Control Request
      • Lifetime of a struct usb_request
      • Generic Commands
      • Endpoint Commands
      • Lifetime of a TRB
      • Lifetime of an Endpoint
  • Structures, Methods and Definitions
• Writing a MUSB Glue Layer
  • Introduction
  • Linux MUSB Basics
  • Handling IRQs
  • Device Platform Data
  • Device Quirks
  • Conclusion
  • Acknowledgements
  • Resources
• USB Type-C connector class
  • Introduction
  • User space interface
  • Driver API
    • Registering the ports
    • Registering Partners
    • Registering Cables
    • Notifications
    • Alternate Modes
• USB3 debug port
  • GENERAL
  • INTRODUCTION
  • EARLY PRINTK