USB(4)

NAME
usb - Universal Serial Bus

SYNOPSIS
To compile this driver into the kernel, place the following line in your kernel configuration file:

device usb

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

    usb_load="YES"

USERLAND PROGRAMMING
USB functions can be accessed from userland through the libusb library. See libusb(3) for more information.

DESCRIPTION
DragonFly provides machine-independent bus support and drivers for USB devices in host and device side mode.

The usb driver has three layers:

USB Controller (Bus)

USB Device

USB Driver

The controller attaches to a physical bus like pci(4). The USB bus attaches to the controller, and the root hub attaches to the controller. Any devices attached to the bus will attach to the root hub or another hub attached to the USB bus.

The uhub device will always be present as it is needed for the root hub.

DragonFly provides support for the following devices.

  Storage devices
umass(4)
    Mass Storage Devices, e.g., external disk drives
urio(4)
    Diamond Rio 500 MP3 player
usfs(4)
    Mass storage driver for device-side mode

  Wired network interfaces
aue(4)
    ADMtek AN986 Pegasus Ethernet driver
axe(4)
    ASIX Electronics AX88x7x/760 USB Ethernet driver
axge(4)
    ASIX Electronics AX88178A/AX88179 USB Gigabit Ethernet driver
cdce(4)
    USB Communication Device Class Ethernet driver
cue(4)
    CATC USB-EL1210A Ethernet driver
ipheth(4)
    USB Apple iPhone/iPad tethered Ethernet driver
kue(4)
    Kawasaki LSI KL5KUSB101B Ethernet driver
mos(4)
    Moschip MCS7730/MCS7830/MCS7832 USB Ethernet driver
udav(4)
    Davicom DM9601 USB Ethernet driver

  Wireless network interfaces
rum(4)
    Ralink Technology RT2501USB/RT2601USB IEEE 802.11 driver
run(4)
    Ralink Technology RT2700U/RT2800U/RT3000U IEEE 802.11 driver
urndis(4)
    RNDIS USB ethernet driver
urtwn(4)
    Realtek RTL8188CU/RTL8192CU IEEE 802.11 driver

  Serial and parallel interfaces
u3g(4)
    support for 3G datacards
uark(4)
    Arkmicro Technologies ARK3116 based serial adapters
ubsa(4)
    Belkin serial adapters
ubser(4)
    support for BWCT console serial adapters
uchcom(4)
    WinChipHead CH341/CH340 serial adapters
ucom(4)
    tty support
ucycom(4)
    Cypress CY7C63743 and CY7C64013 USB to RS232 bridges
ufoma(4)
    mobile phone support
uftdi(4)
    serial devices based on the FTDI chips
ugensa(4)
    generic serial device
uipaq(4)
    support for iPAQ units
ulpt(4)
    printer support
umcs(4)
    serial adapters based on the MCS7820 and MCS7840 chips
umct(4)
    Magic Control Technology USB-232 based serial adapters
umodem(4)
    modem support
umoscom(4)
    serial adapters based on the MCS7703 chip
uplcom(4)
    Prolific PL-2303/2303X/2303HX serial adapters
uslcom(4)
    Silicon Laboratories CP2101, CP2102 and CP2103 USB to serial bridge
uvisor(4)
    support for the Handspring Visor, a Palmpilot compatible PDA
uvscom(4)
    SUNTAC Slipper U VS-10U serial adapters

  Audio devices
uaudio(4)
    audio device driver

  Radio receiver devices
ufm(4)
    Cypress Semiconductor FM Radio

  Human Interface Devices
uep(4)
    eGalax touchscreen driver
uhid(4)
    generic driver for Human Interface Devices
ukbd(4)
    keyboards that follow the boot protocol
ums(4)
    mouse devices
wsp(4)
    Wellspring touchpad driver for Apple laptops

INTRODUCTION TO USB
The USB is a system where external devices can be connected to a PC. The most common USB speeds are:

Low Speed (1.5MBit/sec)

Full Speed (12MBit/sec)

High Speed (480MBit/sec)

Each USB has a USB controller that is the master of the bus. The physical communication is simplex which means the host controller only communicates with one USB device at a time.

There can be up to 127 devices connected to an USB HUB tree. The addresses are assigned dynamically by the host when each device is attached to the bus.

Within each device there can be up to 16 endpoints. Each endpoint is individually addressed and the addresses are static. Each of these endpoints will communicate in one of four different modes: control, isochronous, bulk, or interrupt. A device always has at least one endpoint. This endpoint has address 0 and is a control endpoint and is used to give commands to and extract basic data, such as descriptors, from the device. Each endpoint, except the control endpoint, is unidirectional.

The endpoints in a device are grouped into interfaces. An interface is a logical unit within a device; e.g. a compound device with both a keyboard and a trackball would present one interface for each. An interface can sometimes be set into different modes, called alternate settings, which affects how it operates. Different alternate settings can have different endpoints within it.

A device may operate in different configurations. Depending on the configuration, the device may present different sets of endpoints and interfaces.

The bus enumeration of the USB bus proceeds in several steps:

1.  Any interface specific driver can attach to the device.

2.  If none is found, generic interface class drivers can attach.

SEE ALSO
The USB specifications can be found at:

    http://www.usb.org/developers/docs/

usbhidaction(1), usbhidctl(1), libusb(3), libusb20(3), usbhid(3), aue(4), axe(4), axge(4), cdce(4), cue(4), ehci(4), ipheth(4), kue(4), mos(4), ohci(4), pci(4), rum(4), run(4), u3g(4), uark(4), uaudio(4), ubsa(4), ubser(4), uchcom(4), ucom(4), ucycom(4), udav(4), uep(4), ufm(4), ufoma(4), uftdi(4), ugen(4), ugensa(4), uhci(4), uhid(4), uipaq(4), ukbd(4), ulpt(4), umass(4), umcs(4), umct(4), umodem(4), umoscom(4), ums(4), uplcom(4), urio(4), urndis(4), urtwn(4), usb_template(4), usfs(4), uslcom(4), uvisor(4), uvscom(4), wsp(4), xhci(4), usbconfig(8), usbdi(9)

STANDARDS
The usb module complies with the USB 2.0 standard.

HISTORY
The usb module has been inspired by the NetBSD USB stack initially written by Lennart Augustsson. The usb module was written by Hans Petter Selasky <hselasky@FreeBSD.org>.