1.\" $OpenBSD: usb.4,v 1.194 2019/05/12 06:09:59 jmc Exp $ 2.\" $NetBSD: usb.4,v 1.15 1999/07/29 14:20:32 augustss Exp $ 3.\" 4.\" Copyright (c) 1999 The NetBSD Foundation, Inc. 5.\" All rights reserved. 6.\" 7.\" This code is derived from software contributed to The NetBSD Foundation 8.\" by Lennart Augustsson. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29.\" POSSIBILITY OF SUCH DAMAGE. 30.\" 31.Dd $Mdocdate: May 12 2019 $ 32.Dt USB 4 33.Os 34.Sh NAME 35.Nm usb , 36.Nm uhub 37.Nd introduction to Universal Serial Bus support 38.Sh SYNOPSIS 39.Cd "# octeon specific" 40.Cd "dwctwo0 at iobus? irq 56" 41.Cd "# all architectures" 42.Cd "ehci* at cardbus?" 43.Cd "ohci* at cardbus?" 44.Cd "uhci* at cardbus?" 45.Cd "ehci* at pci?" 46.Cd "ohci* at pci?" 47.Cd "uhci* at pci?" 48.Cd "xhci* at pci?" 49.Cd "usb* at dwctwo?" 50.Cd "usb* at ehci? flags 0x00" 51.Cd "usb* at ohci? flags 0x00" 52.Cd "usb* at uhci? flags 0x00" 53.Cd "usb* at xhci? flags 0x00" 54.Cd "uhub* at usb?" 55.Cd "uhub* at uhub?" 56.Pp 57.Cd option USBVERBOSE 58.Pp 59.In dev/usb/usb.h 60.In dev/usb/usbhid.h 61.Sh DESCRIPTION 62.Ox 63provides machine-independent bus support and drivers for Universal 64Serial Bus (USB) devices. 65.Pp 66The 67.Ox 68.Nm 69driver has three layers (like 70.Xr scsi 4 71and 72.Xr pcmcia 4 ) : 73the controller, the bus, and the device layer. 74The controller attaches to a physical bus (like 75.Xr pci 4 76or 77.Xr cardbus 4 ) . 78The USB bus attaches to the controller and the root hub attaches 79to the USB bus. 80Devices, which may include further hubs, attach to the root hub. 81The attachment forms the same tree structure as the physical USB 82device tree. 83For each USB device there may be additional drivers attached to it. 84.Pp 85The 86.Cm uhub 87driver controls USB hubs and must always be present since there is 88at least one root hub in any USB system. 89.Pp 90The 91.Cm flags 92are used to specify if the devices on the USB bus should be probed 93early in the boot process. 94If the 95.Cm flags 96are specified with a value of 1, the USB bus will be probed when 97the USB host device is attached instead of waiting until kernel 98processes start running. 99.Pp 100.Ox 101provides support for the following devices. 102Note that not all architectures support all devices. 103.Ss Storage devices 104.Bl -tag -width 12n -offset ind -compact 105.It Xr umass 4 106USB Mass Storage Devices, e.g., external disk drives 107.El 108.Ss Wired network interfaces 109.Bl -tag -width 12n -offset ind -compact 110.It Xr aue 4 111ADMtek AN986/ADM8511 Pegasus family 10/100 USB Ethernet device 112.It Xr axe 4 113ASIX Electronics AX88172/AX88178/AX88772 10/100/Gigabit USB Ethernet device 114.It Xr axen 4 115ASIX Electronics AX88179 10/100/Gigabit USB Ethernet device 116.It Xr cdce 4 117USB Communication Device Class Ethernet device 118.It Xr cue 4 119CATC USB-EL1201A USB Ethernet device 120.It Xr kue 4 121Kawasaki LSI KL5KUSB101B USB Ethernet device 122.It Xr mos 4 123MosChip MCS7730/7830/7832 10/100 USB Ethernet device 124.It Xr mue 4 125Microchip LAN75xx/LAN78xx 10/100/Gigabit USB Ethernet device 126.It Xr smsc 4 127SMSC LAN95xx 10/100 USB Ethernet device 128.It Xr udav 4 129Davicom DM9601 10/100 USB Ethernet device 130.It Xr ure 4 131RealTek RTL8152/RTL8153 10/100/Gigabit USB Ethernet device 132.It Xr url 4 133Realtek RTL8150L 10/100 USB Ethernet device 134.It Xr urndis 4 135USB Remote NDIS Ethernet device 136.El 137.Ss Wireless network interfaces 138.Bl -tag -width 12n -offset ind -compact 139.It Xr athn 4 140Atheros IEEE 802.11a/b/g/n wireless network device 141.It Xr atu 4 142Atmel AT76C50x IEEE 802.11b wireless network device 143.It Xr bwfm 4 144Broadcom and Cypress IEEE 802.11a/ac/b/g/n wireless network device 145.It Xr otus 4 146Atheros USB IEEE 802.11a/b/g/n wireless network device 147.It Xr rsu 4 148Realtek RTL8188SU/RTL8192SU USB IEEE 802.11b/g/n wireless network device 149.It Xr rum 4 150Ralink Technology/MediaTek USB IEEE 802.11a/b/g wireless network device 151.It Xr run 4 152Ralink Technology/MediaTek USB IEEE 802.11a/b/g/n wireless network device 153.It Xr uath 4 154Atheros USB IEEE 802.11a/b/g wireless network device 155.It Xr upgt 4 156Conexant/Intersil PrismGT SoftMAC USB IEEE 802.11b/g wireless network device 157.It Xr ural 4 158Ralink Technology/MediaTek USB IEEE 802.11b/g wireless network device 159.It Xr urtw 4 160Realtek RTL8187L/RTL8187B USB IEEE 802.11b/g wireless network device 161.It Xr urtwn 4 162Realtek RTL8188CU/RTL8188EU/RTL8192CU/RTL8192EU USB IEEE 802.11b/g/n wireless 163network device 164.It Xr wi 4 165Intersil PRISM 2-3 IEEE 802.11b wireless network device 166.It Xr zyd 4 167ZyDAS ZD1211/ZD1211B USB IEEE 802.11b/g wireless network device 168.El 169.Ss Serial and parallel interfaces 170.Bl -tag -width 12n -offset ind -compact 171.It Xr moscom 4 172MosChip Semiconductor MCS7703 based USB serial adapter 173.It Xr uark 4 174Arkmicro Technologies ARK3116 based USB serial adapter 175.It Xr ubsa 4 176Belkin USB serial adapter 177.It Xr uchcom 4 178WinChipHead CH341/340 based USB serial adapter 179.It Xr ucom 4 180USB tty support 181.It Xr ucrcom 4 182Chromebook USB serial console 183.It Xr ucycom 4 184Cypress microcontroller based USB serial adapter 185.It Xr uftdi 4 186FTDI USB serial adapter 187.It Xr uipaq 4 188iPAQ USB units 189.It Xr ulpt 4 190USB printer support 191.It Xr umcs 4 192MosChip Semiconductor based USB multiport serial adapter 193.It Xr umct 4 194MCT USB-RS232 USB serial adapter 195.It Xr umodem 4 196USB modem support 197.It Xr umsm 4 198Qualcomm MSM modem device 199.It Xr uplcom 4 200Prolific PL-2303 USB serial adapter 201.It Xr uscom 4 202simple USB serial adapters 203.It Xr uslcom 4 204Silicon Laboratories CP210x based USB serial adapter 205.It Xr uslhcom 4 206Silicon Laboratories CP2110 based USB serial adapter 207.It Xr uticom 4 208Texas Instruments TUSB3410 USB serial adapter 209.It Xr uvisor 4 210USB Handspring Visor 211.It Xr uvscom 4 212SUNTAC Slipper U VS-10U USB serial adapter 213.It Xr uxrcom 4 214Exar XR21V1410 USB serial adapter 215.El 216.Ss Audio devices 217.Bl -tag -width 12n -offset ind -compact 218.It Xr uaudio 4 219USB audio devices 220.It Xr umidi 4 221USB MIDI devices 222.El 223.Ss Video devices 224.Bl -tag -width 12n -offset ind -compact 225.It Xr udl 4 226DisplayLink DL-120 / DL-160 USB display devices 227.It Xr utvfu 4 228USB Fushicai USBTV007 audio/video capture device 229.It Xr uvideo 4 230USB video devices 231.El 232.Ss Time receiver devices 233.Bl -tag -width 12n -offset ind -compact 234.It Xr udcf 4 235Gude ADS Expert mouseCLOCK USB timedelta sensor 236.It Xr umbg 4 237Meinberg Funkuhren USB5131 timedelta sensor 238.El 239.Ss Radio receiver devices 240.Bl -tag -width 12n -offset ind -compact 241.It Xr udsbr 4 242D-Link DSB-R100 USB radio device 243.El 244.Ss Human Interface Devices 245.Bl -tag -width 12n -offset ind -compact 246.It Xr ubcmtp 4 247Broadcom trackpad mouse 248.It Xr uhid 4 249Generic driver for Human Interface Devices 250.It Xr uhidev 4 251Base driver for all Human Interface Devices 252.It Xr ukbd 4 253USB keyboards that follow the boot protocol 254.It Xr ums 4 255USB HID mouse, touchscreen and digitiser devices 256.It Xr umt 4 257USB HID multitouch touchpad devices 258.It Xr uoaklux 4 259Toradex OAK USB illuminance sensor 260.It Xr uoakrh 4 261Toradex OAK USB temperature and relative humidity sensor 262.It Xr uoakv 4 263Toradex OAK USB +/-10V 8channel ADC interface 264.It Xr upd 4 265USB Power Devices sensor 266.It Xr uthum 4 267TEMPer HID thermometer and hygrometer 268.It Xr utpms 4 269Apple touchpad mouse 270.It Xr utrh 4 271USBRH temperature and humidity sensor 272.It Xr utwitch 4 273YUREX USB twitch/jiggle of knee sensor 274.It Xr uwacom 4 275Wacom USB tablets 276.El 277.Ss WAN network devices 278.Bl -tag -width 12n -offset ind -compact 279.It Xr umb 4 280USB Mobile Broadband Interface Model (MBIM) 281.El 282.Ss Miscellaneous devices 283.Bl -tag -width 12n -offset ind -compact 284.It Xr uberry 4 285Research In Motion BlackBerry 286.It Xr ugen 4 287USB generic device support 288.It Xr ugl 4 289Genesys Logic based host-to-host adapters 290.It Xr ugold 4 291TEMPer gold HID thermometer and hygrometer 292.It Xr uonerng 4 293Moonbase Otago OneRNG TRNG 294.It Xr uow 4 295Maxim/Dallas DS2490 USB 1-Wire adapter 296.It Xr upl 4 297Prolific based host-to-host adapters 298.It Xr urng 4 299USB Random Number Generator devices 300.It Xr usps 4 301USPS composite AC power and temperature sensor 302.It Xr uts 4 303USB touchscreen support 304.El 305.Sh INTRODUCTION TO USB 306There are different versions of the USB 307which provide different speeds. 308USB 3 can operate up to 5.0Gb/s. 309USB 2 operates at 480Mb/s, while USB versions 1 and 1.1 operate at 31012 Mb/s and 1.5 Mb/s for low speed devices. 311Each USB has a host controller that is the master of the bus; 312all other devices on the bus only speak when spoken to. 313.Pp 314There can be up to 127 devices (apart from the host controller) 315on a bus, each with its own address. 316The addresses are assigned 317dynamically by the host when each device is attached to the bus. 318.Pp 319Within each device there can be up to 16 endpoints. 320Each endpoint 321is individually addressed and the addresses are static. 322Each of these endpoints will communicate in one of four different modes: 323control, isochronous, bulk, or interrupt. 324A device always has at least one endpoint. 325This is a control endpoint at address 0 326and is used to give commands to the device and extract basic data, 327such as descriptors, from the device. 328Each endpoint, except the control endpoint, is unidirectional. 329.Pp 330The endpoints in a device are grouped into interfaces. 331An interface is a logical unit within a device; e.g., 332a compound device with both a keyboard and a trackball would present 333one interface for each. 334An interface can sometimes be set into different modes, 335called alternate settings, which affects how it operates. 336Different alternate settings can have different endpoints 337within it. 338.Pp 339A device may operate in different configurations. 340Depending on the 341configuration the device may present different sets of endpoints 342and interfaces. 343.Pp 344Each device located on a hub has several 345.Xr config 8 346locators: 347.Pp 348.Bl -tag -width configuration -compact 349.It Cd port 350Number of the port on closest upstream hub. 351.It Cd configuration 352Configuration the device must be in for this driver to attach. 353This locator does not set the configuration; it is iterated by the bus 354enumeration. 355.It Cd interface 356Interface number within a device that an interface driver attaches to. 357.It Cd vendor 35816-bit vendor ID of the device. 359.It Cd product 36016-bit product ID of the device. 361.It Cd release 36216-bit release (revision) number of the device. 363.El 364.Pp 365The first locator can be used to pin down a particular device 366according to its physical position in the device tree. 367The last three locators can be used to pin down a particular 368device according to what device it actually is. 369.Pp 370The bus enumeration of the USB bus proceeds in several steps: 371.Bl -enum 372.It 373Any device-specific driver can attach to the device. 374.It 375If none is found, any device class specific driver can attach. 376.It 377If none is found, all configurations are iterated over. 378For each configuration all the interfaces are iterated over and interface 379drivers can attach. 380If any interface driver attached in a certain 381configuration, the iteration over configurations is stopped. 382.It 383If still no drivers have been found, the generic USB driver can attach. 384.El 385.Sh USB CONTROLLER INTERFACE 386Use the following to get access to the USB specific structures 387and defines: 388.Bd -literal -offset indent 389#include <dev/usb/usb.h> 390.Ed 391.Pp 392The 393.Pa /dev/usbN 394device can be opened and a few operations can be performed on it. 395The following 396.Xr ioctl 2 397commands are supported on the controller device: 398.Bl -tag -width xxxxxx 399.It Dv USB_DEVICEINFO Fa "struct usb_device_info" 400This command can be used to retrieve some information about a device 401on the bus. 402The 403.Va udi_addr 404field should be filled before the call and the other fields will 405be filled by information about the device on that address. 406Should no such device exist, an error is reported. 407.Bd -literal 408#define USB_MAX_DEVNAMES 4 409#define USB_MAX_DEVNAMELEN 16 410struct usb_device_info { 411 u_int8_t udi_bus; 412 u_int8_t udi_addr; /* device address */ 413 char udi_product[USB_MAX_STRING_LEN]; 414 char udi_vendor[USB_MAX_STRING_LEN]; 415 char udi_release[8]; 416 u_int16_t udi_productNo; 417 u_int16_t udi_vendorNo; 418 u_int16_t udi_releaseNo; 419 u_int8_t udi_class; 420 u_int8_t udi_subclass; 421 u_int8_t udi_protocol; 422 u_int8_t udi_config; 423 u_int8_t udi_speed; 424#define USB_SPEED_LOW 1 425#define USB_SPEED_FULL 2 426#define USB_SPEED_HIGH 3 427 int udi_power; /* power consumption */ 428 int udi_nports; 429 char udi_devnames[USB_MAX_DEVNAMES] 430 [USB_MAX_DEVNAMELEN]; 431 u_int8_t udi_ports[16]; /* hub only */ 432#define USB_PORT_ENABLED 0xff 433#define USB_PORT_SUSPENDED 0xfe 434#define USB_PORT_POWERED 0xfd 435#define USB_PORT_DISABLED 0xfc 436 char udi_serial[USB_MAX_STRING_LEN]; 437}; 438.Ed 439.Pp 440The 441.Va udi_bus 442field contains the device unit number of the device. 443.Pp 444The 445.Va udi_product , 446.Va udi_vendor , 447and 448.Va udi_release 449fields contain self-explanatory descriptions of the device. 450The 451.Va udi_productNo , 452.Va udi_vendorNo , 453and 454.Va udi_releaseNo 455fields contain numeric identifiers for the device. 456.Pp 457The 458.Va udi_class 459and 460.Va udi_subclass 461fields contain the device class and subclass. 462.Pp 463The 464.Va udi_config 465field shows the current configuration of the device. 466.Pp 467The 468.Va udi_protocol 469field contains the device protocol as given from the device. 470.Pp 471The 472.Va udi_speed 473field 474contains the speed of the device. 475.Pp 476The 477.Va udi_power 478field shows the power consumption in milli-amps drawn at 5 volts 479or is zero if the device is self powered. 480.Pp 481The 482.Va udi_devnames 483field contains the names and instance numbers of the device drivers 484for the devices attached to this device. 485.Pp 486If the device is a hub, the 487.Va udi_nports 488field is non-zero and the 489.Va udi_ports 490field contains the addresses of the connected devices. 491If no device is connected to a port, one of the 492.Dv USB_PORT_* 493values indicates its status. 494.It Dv USB_DEVICESTATS Fa "struct usb_device_stats" 495This command retrieves statistics about the controller. 496.Bd -unfilled 497struct usb_device_stats { 498 u_long uds_requests[4]; 499}; 500.Ed 501.Pp 502The 503.Va uds_requests 504field is indexed by the transfer kind, i.e.\& 505.Dv UE_* , 506and indicates how many transfers of each kind have been completed 507by the controller. 508.It Dv USB_DEVICE_GET_DDESC Fa "struct usb_device_ddesc" 509This command can be used to retrieve the device descriptor 510of a device on the bus. 511The 512.Va udd_addr 513field needs to be filled with the bus device address: 514.Bd -literal 515struct usb_device_ddesc { 516 u_int8_t udd_bus; 517 u_int8_t udd_addr; /* device address */ 518 usb_device_descriptor_t udd_desc; 519}; 520.Ed 521.Pp 522The 523.Va udd_bus 524field contains the device unit number. 525.Pp 526The 527.Va udd_desc 528field contains the device descriptor structure. 529.It Dv USB_DEVICE_GET_CDESC Fa "struct usb_device_cdesc" 530This command can be used to retrieve the configuration descriptor for the 531given configuration of a device on the bus. 532The 533.Va udc_addr 534field needs to be filled with the bus device address. 535The 536.Va udc_config_index 537field needs to be filled with the configuration index for the 538relevant configuration descriptor. 539For convenience the current configuration can be specified by 540.Dv USB_CURRENT_CONFIG_INDEX : 541.Bd -literal 542struct usb_device_cdesc { 543 u_int8_t udc_bus; 544 u_int8_t udc_addr; /* device address */ 545 int udc_config_index; 546 usb_config_descriptor_t udc_desc; 547}; 548.Ed 549.Pp 550The 551.Va udc_bus 552field contains the device unit number. 553.Pp 554The 555.Va udc_desc 556field contains the configuration descriptor structure. 557.It Dv USB_DEVICE_GET_FDESC Fa "struct usb_device_fdesc" 558This command can be used to retrieve all descriptors for the 559given configuration of a device on the bus. 560The 561.Va udf_addr 562field needs to be filled with the bus device address. 563The 564.Va udf_config_index 565field needs to be filled with the configuration index for the 566relevant configuration descriptor. 567For convenience the current configuration can be specified by 568.Dv USB_CURRENT_CONFIG_INDEX . 569The 570.Va udf_data 571field needs to point to a memory area of the size given in the 572.Va udf_size 573field. 574The proper size can be determined by first issuing a 575.Dv USB_DEVICE_GET_CDESC 576command and inspecting the 577.Va wTotalLength 578field: 579.Bd -literal 580struct usb_device_fdesc { 581 u_int8_t udf_bus; 582 u_int8_t udf_addr; /* device address */ 583 int udf_config_index; 584 u_int udf_size; 585 u_char *udf_data; 586}; 587.Ed 588.Pp 589The 590.Va udf_bus 591field contains the device unit number. 592.Pp 593The 594.Va udf_data 595field contains all descriptors. 596.It Dv USB_REQUEST Fa "struct usb_ctl_request" 597This command can be used to execute arbitrary requests on the control pipe. 598This is 599.Em DANGEROUS 600and should be used with great care since it 601can destroy the bus integrity. 602.Pp 603The 604.Vt usb_ctl_request 605structure has the following definition: 606.Bd -literal 607typedef struct { 608 uByte bmRequestType; 609 uByte bRequest; 610 uWord wValue; 611 uWord wIndex; 612 uWord wLength; 613} __packed usb_device_request_t; 614 615struct usb_ctl_request { 616 int ucr_addr; 617 usb_device_request_t ucr_request; 618 void *ucr_data; 619 int ucr_flags; 620#define USBD_SHORT_XFER_OK 0x04 /* allow short reads */ 621 int ucr_actlen; /* actual length transferred */ 622}; 623.Ed 624.Pp 625The 626.Va ucr_addr 627field identifies the device on which to perform the request. 628The 629.Va ucr_request 630field identifies parameters of the request, such as length and type. 631The 632.Va ucr_data 633field contains the location where data will be read from or written to. 634The 635.Va ucr_flags 636field specifies options for the request, and the 637.Va ucr_actlen 638field contains the actual length transferred as the result of the request. 639.El 640.Pp 641The include file 642.In dev/usb/usb.h 643contains definitions for the types used by the various 644.Xr ioctl 2 645calls. 646The naming convention of the fields for the various USB descriptors 647exactly follows the naming in the USB specification. 648Byte sized fields can be accessed directly, but word (16-bit) 649sized fields must be accessed by the 650.Fn UGETW field 651and 652.Fn USETW field value 653macros and double word (32-bit) sized fields must be accessed by the 654.Fn UGETDW field 655and 656.Fn USETDW field value 657macros to handle byte order and alignment properly. 658.Pp 659The include file 660.In dev/usb/usbhid.h 661similarly contains the definitions for 662Human Interface Devices (HID). 663.Sh SEE ALSO 664.Xr usbhidaction 1 , 665.Xr usbhidctl 1 , 666.Xr ioctl 2 , 667.Xr dwctwo 4 , 668.Xr ehci 4 , 669.Xr ohci 4 , 670.Xr uhci 4 , 671.Xr xhci 4 , 672.Xr config 8 , 673.Xr usbdevs 8 674.Pp 675The USB specifications can be found at 676.Lk http://www.usb.org/developers/docs/ 677.Sh HISTORY 678The 679.Nm 680driver 681appeared in 682.Ox 2.6 . 683