ref: 5622b0bbd878dbc34045cc6fd37cffa64461eabe
dir: /sys/man/4/nusb/
.TH NUSB 4 .SH NAME audio, disk, ether, kb, serial, ptp, usbd - Universal Serial Bus drivers .SH SYNOPSIS .B nusb/audio .I devid .PP .B nusb/cam [ .B -d ] .I devid .PP .B nusb/disk [ .B -d ] .I devid .PP .B nusb/ether [ .B -dD ] [ .B -t .I ethertype ] [ .B -a .I addr ] .I devid .PP .B nusb/kb [ .B -d ] .I devid .PP .B nusb/joy [ .B -d ] .I devid .PP .B nusb/serial [ .B -d ] .I devid .PP .B nusb/ptp [ .B -dD ] .I devid .PP .B nusb/usbd [ .B -dD ] .SH DESCRIPTION These programs drive USB devices of specific classes via .IR usb (3). Usually they are started by .IR nusbrc (8) upon attachment of the device to the bus. All drivers except .I usbd take the decimal usb .I devid of the device they should handle as their last argument. A driver's instance handles only one device at a time. .PP Drivers that provide file systems make them available as shares under .B /shr (see .IR shr (3)) or .BR /shr/usb (which is bound after .BR /dev by .IR nusbrc (8)). .PP Options .B \-d and .B \-D trigger debug diagnostics and file system debugging diagnostics for most drivers. Repeating any one of these may increase verbosity. .SS Hubs .I Usbd enumerates the tree of USB hubs and configures the device on attachment. It provides a filesystem with the file .B usbevent (usually seen as .BR /dev/usbevent ) which, when read, returns a 6-column, space-separated line of text, one for each event. The columns are: .B attach or .B detach followed by .I addr .I vid .I did .I csp and .IR hname . The .I addr is the decimal device address assigned. .I Vid and .I did are formatted as 4 digit hexadecimal. .I Csp is the device class, subclass, protocol indentifier formatted as 6 digit hexadecimal. .I Usbd assigns a stable device identifier based on the device descriptor for .IR hname . This information is read by .IR nusbrc (8) and the .I addr and .I hname are passed to a suitable driver as .I devid in the form \fIaddr\fB:\fIhname .SS Keyboards and mice .I Kb supports USB keyboards and mice either as separate USB devices or as a single combined USB device. Scan codes from the keyboard are sent to .B /dev/kbin to let .IR kbdfs (8) process them. Mouse events are sent to .B /dev/mousein in the same way. A file .BI /dev/hid N ctl supports setting keyboard repeat and delay setting, the unit is milliseconds. .SS Joysticks .I Joy parses data packets from a given endpoint and prints back any changes in the device's axes or buttons. Buttons are identified via an integer id. .PP Directional buttons are reported as axes with 3 positions: .IR 0 , .IR 128 , and .I 255 for left (or up), center and right (or down) respectively. Messages are in the form \fIaxis id position\fR. .PP On/off buttons are reported as either .I down or .I up respectively. Messages are in the form \fIdown\fB|\fIup id\fR. .SS Disks .I Disk configures and manages USB mass storage devices. It provides a file system (usually seen under .BR /dev ) that includes one directory per storage device, named .BI sdU N [. M ] in correspondence with the USB device identifier and the storage unit number (or LUN). The LUN is omited for single lun devices. .PP The storage device directory contains the usual files served by .IR sd (3): .BR data , .BR raw , and .BR ctl . .PP The .B ctl file supplies the device geometry and partitions when read. .I Ptp configures and exposes a camera's (and often a mobile device's) storage to allow transferring data via the Picture Transfer Protocol (PTP). .SS Ethernet .I Ether handles USB ethernet devices. The file system provided is compatible with .IR ether (3) and added to the share .B usbnet (see .IR shr (3)) which is bound after .B /net by .IR nusbrc (8) so the device will appear as .BI /net/etherU N . Without specifying the .B -t option, the device is assumed to be a CDC compliant ethernet communication device. Other devices might require setting an explicit .IR ethertype , such as .BR rndis , .BR smsc , .BR url , .BR lan78xx , .BR aue , .BR a88772, .BR a88178, or .BR a88179 (see .IR nusbrc (8)). On devices that support it, the mac address can be set using the .B -a .IR addr option. .SS Serial and JTAG ports .I Serial provides a file system (usually seen under .BR /dev ) that includes one directory per USB serial port, named .BI eiaU N or .BI eiaU N [. M ]. In this directory there are two files, .BR eiaU , similar to .BI eia N in .IR uart (3), and .BR eiaUctl , which admits writes in the same format as .BI eia N ctl in .IR uart (3). Reading from .B eiaUctl gives the serial port's settings in the same format as .BI eia N status in .IR uart (3). Options are similar to those of .IR disk . .PP JTAG ports are similar but the files are named .B jtag and .BR jtagctl . . .SS Audio devices .I Audio configures and manages a USB audio device. It implements a file system (normally seen under .BR /dev ), exporting .BN audioU N and .BI volumeU N files that have the same semantics as .IR audio (1)). .SS Camera devices .I Cam configures and exposes a USB camera device's capabilities, implementing a file system compatible with .IR camv (1), under a directory named .BI cam N [. M ]. It provides the following files: .BR desc , showing all of the device's internal descriptors and their values; .BR format , listing admissible image resolutions and framerates; .BR ctl , the picture settings control file; .BR frame , which captures and outputs a single video frame as an .IR image (6) file; and .IR video , streaming video in a preset format, resolution and framerate. In particular, reading from the .B ctl file yields a space-separated list of parameter settings, where the second and third columns correspond to key-value pairs, and an optional fourth column corresponds to the range of possible numerical values (formatted as .IR minimum / increment / maximum ). The same pairs can be written to the file to configure the camera. Currently, only the YUY2 video format is supported. .SH SOURCE .B /sys/src/cmd/nusb .SH "SEE ALSO" .IR camv (1), .IR joy (1), .IR audio (3), .IR ether (3), .IR mouse (3), .IR sd (3), .IR uart (3), .IR usb (3), .IR shr (3), .IR image (6), .IR nusbrc (8), .IR kbdfs (8) .SH HISTORY .I Joy first appeared in 9front (March, 2014). .br .I Cam first appeared in 9front (March, 2018). .SH BUGS The various device drivers are generic USB drivers and may work only for certain devices of each class. .PP USB ATA storage devices are not supported. .PP The serial driver works only for the Prolific chip and Ftdi, and control of the .B dcd and .B dsr signals and some of the extra features are not implemented. For Ftdi, only the Sheevaplug and Guruplug have been tried. There is support for the EHCI debug port, but it loses bytes. .PP USB video format settings cannot be changed while .IR camv (1) is running, and must be set manually by writing them to .IR cam (4)'s ctl file before starting the viewer.