1.\" $OpenBSD: usb.4,v 1.202 2020/06/01 01:52:21 jcs 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: June 1 2020 $ 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/RTL8153B/RTL8156 10/100/Gigabit/2.5Gb 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 ukspan 4 190Keyspan USB serial adapter 191.It Xr ulpt 4 192USB printer support 193.It Xr umcs 4 194MosChip Semiconductor based USB multiport serial adapter 195.It Xr umct 4 196MCT USB-RS232 USB serial adapter 197.It Xr umodem 4 198USB modem support 199.It Xr umsm 4 200Qualcomm MSM modem device 201.It Xr uplcom 4 202Prolific PL-2303 USB serial adapter 203.It Xr uscom 4 204simple USB serial adapters 205.It Xr uslcom 4 206Silicon Laboratories CP210x based USB serial adapter 207.It Xr uslhcom 4 208Silicon Laboratories CP2110 based USB serial adapter 209.It Xr uticom 4 210Texas Instruments TUSB3410 USB serial adapter 211.It Xr uvisor 4 212USB Handspring Visor 213.It Xr uvscom 4 214SUNTAC Slipper U VS-10U USB serial adapter 215.It Xr uxrcom 4 216Exar XR21V1410 USB serial adapter 217.El 218.Ss Audio devices 219.Bl -tag -width 12n -offset ind -compact 220.It Xr uaudio 4 221USB audio devices 222.It Xr umidi 4 223USB MIDI devices 224.El 225.Ss Video devices 226.Bl -tag -width 12n -offset ind -compact 227.It Xr udl 4 228DisplayLink DL-120 / DL-160 USB display devices 229.It Xr utvfu 4 230USB Fushicai USBTV007 audio/video capture device 231.It Xr uvideo 4 232USB video devices 233.El 234.Ss Time receiver devices 235.Bl -tag -width 12n -offset ind -compact 236.It Xr udcf 4 237Gude ADS Expert mouseCLOCK USB timedelta sensor 238.It Xr umbg 4 239Meinberg Funkuhren USB5131 timedelta sensor 240.El 241.Ss Radio receiver devices 242.Bl -tag -width 12n -offset ind -compact 243.It Xr udsbr 4 244D-Link DSB-R100 USB radio device 245.El 246.Ss Human Interface Devices 247.Bl -tag -width 12n -offset ind -compact 248.It Xr fido 4 249FIDO/U2F security keys 250.It Xr ubcmtp 4 251Broadcom trackpad mouse 252.It Xr uhid 4 253Generic driver for Human Interface Devices 254.It Xr uhidev 4 255Base driver for all Human Interface Devices 256.It Xr ukbd 4 257USB keyboards that follow the boot protocol 258.It Xr ums 4 259USB HID mouse, touchscreen and digitiser devices 260.It Xr umstc 4 261Microsoft Surface Type Cover keyboard 262.It Xr umt 4 263USB HID multitouch touchpad devices 264.It Xr uoaklux 4 265Toradex OAK USB illuminance sensor 266.It Xr uoakrh 4 267Toradex OAK USB temperature and relative humidity sensor 268.It Xr uoakv 4 269Toradex OAK USB +/-10V 8channel ADC interface 270.It Xr upd 4 271USB Power Devices sensor 272.It Xr uthum 4 273TEMPer HID thermometer and hygrometer 274.It Xr utpms 4 275Apple touchpad mouse 276.It Xr utrh 4 277USBRH temperature and humidity sensor 278.It Xr utwitch 4 279YUREX USB twitch/jiggle of knee sensor 280.It Xr uwacom 4 281Wacom USB tablets 282.El 283.Ss WAN network devices 284.Bl -tag -width 12n -offset ind -compact 285.It Xr umb 4 286USB Mobile Broadband Interface Model (MBIM) 287.El 288.Ss Miscellaneous devices 289.Bl -tag -width 12n -offset ind -compact 290.It Xr uberry 4 291Research In Motion BlackBerry 292.It Xr ugen 4 293USB generic device support 294.It Xr ugl 4 295Genesys Logic based host-to-host adapters 296.It Xr ugold 4 297TEMPer gold HID thermometer and hygrometer 298.It Xr uonerng 4 299Moonbase Otago OneRNG TRNG 300.It Xr uow 4 301Maxim/Dallas DS2490 USB 1-Wire adapter 302.It Xr upl 4 303Prolific based host-to-host adapters 304.It Xr urng 4 305USB Random Number Generator devices 306.It Xr usps 4 307USPS composite AC power and temperature sensor 308.It Xr uts 4 309USB touchscreen support 310.El 311.Sh INTRODUCTION TO USB 312There are different versions of the USB 313which provide different speeds. 314USB 3 can operate up to 5.0Gb/s. 315USB 2 operates at 480Mb/s, while USB versions 1 and 1.1 operate at 31612 Mb/s and 1.5 Mb/s for low speed devices. 317Each USB has a host controller that is the master of the bus; 318all other devices on the bus only speak when spoken to. 319.Pp 320There can be up to 127 devices (apart from the host controller) 321on a bus, each with its own address. 322The addresses are assigned 323dynamically by the host when each device is attached to the bus. 324.Pp 325Within each device there can be up to 16 endpoints. 326Each endpoint 327is individually addressed and the addresses are static. 328Each of these endpoints will communicate in one of four different modes: 329control, isochronous, bulk, or interrupt. 330A device always has at least one endpoint. 331This is a control endpoint at address 0 332and is used to give commands to the device and extract basic data, 333such as descriptors, from the device. 334Each endpoint, except the control endpoint, is unidirectional. 335.Pp 336The endpoints in a device are grouped into interfaces. 337An interface is a logical unit within a device; e.g., 338a compound device with both a keyboard and a trackball would present 339one interface for each. 340An interface can sometimes be set into different modes, 341called alternate settings, which affects how it operates. 342Different alternate settings can have different endpoints 343within it. 344.Pp 345A device may operate in different configurations. 346Depending on the 347configuration the device may present different sets of endpoints 348and interfaces. 349.Pp 350Each device located on a hub has several 351.Xr config 8 352locators: 353.Pp 354.Bl -tag -width configuration -compact 355.It Cd port 356Number of the port on closest upstream hub. 357.It Cd configuration 358Configuration the device must be in for this driver to attach. 359This locator does not set the configuration; it is iterated by the bus 360enumeration. 361.It Cd interface 362Interface number within a device that an interface driver attaches to. 363.It Cd vendor 36416-bit vendor ID of the device. 365.It Cd product 36616-bit product ID of the device. 367.It Cd release 36816-bit release (revision) number of the device. 369.El 370.Pp 371The first locator can be used to pin down a particular device 372according to its physical position in the device tree. 373The last three locators can be used to pin down a particular 374device according to what device it actually is. 375.Pp 376The bus enumeration of the USB bus proceeds in several steps: 377.Bl -enum 378.It 379Any device-specific driver can attach to the device. 380.It 381If none is found, any device class specific driver can attach. 382.It 383If none is found, all configurations are iterated over. 384For each configuration all the interfaces are iterated over and interface 385drivers can attach. 386If any interface driver attached in a certain 387configuration, the iteration over configurations is stopped. 388.It 389If still no drivers have been found, the generic USB driver can attach. 390.El 391.Sh USB CONTROLLER INTERFACE 392Use the following to get access to the USB specific structures 393and defines: 394.Bd -literal -offset indent 395#include <dev/usb/usb.h> 396.Ed 397.Pp 398The 399.Pa /dev/usbN 400device can be opened and a few operations can be performed on it. 401The following 402.Xr ioctl 2 403commands are supported on the controller device: 404.Bl -tag -width xxxxxx 405.It Dv USB_DEVICEINFO Fa "struct usb_device_info" 406This command can be used to retrieve some information about a device 407on the bus. 408The 409.Va udi_addr 410field should be filled before the call and the other fields will 411be filled by information about the device on that address. 412Should no such device exist, an error is reported. 413.Bd -literal 414#define USB_MAX_DEVNAMES 4 415#define USB_MAX_DEVNAMELEN 16 416struct usb_device_info { 417 u_int8_t udi_bus; 418 u_int8_t udi_addr; /* device address */ 419 char udi_product[USB_MAX_STRING_LEN]; 420 char udi_vendor[USB_MAX_STRING_LEN]; 421 char udi_release[8]; 422 u_int16_t udi_productNo; 423 u_int16_t udi_vendorNo; 424 u_int16_t udi_releaseNo; 425 u_int8_t udi_class; 426 u_int8_t udi_subclass; 427 u_int8_t udi_protocol; 428 u_int8_t udi_config; 429 u_int8_t udi_speed; 430#define USB_SPEED_LOW 1 431#define USB_SPEED_FULL 2 432#define USB_SPEED_HIGH 3 433 int udi_power; /* power consumption */ 434 int udi_nports; 435 char udi_devnames[USB_MAX_DEVNAMES] 436 [USB_MAX_DEVNAMELEN]; 437 u_int8_t udi_ports[16]; /* hub only */ 438#define USB_PORT_ENABLED 0xff 439#define USB_PORT_SUSPENDED 0xfe 440#define USB_PORT_POWERED 0xfd 441#define USB_PORT_DISABLED 0xfc 442 char udi_serial[USB_MAX_STRING_LEN]; 443}; 444.Ed 445.Pp 446The 447.Va udi_bus 448field contains the device unit number of the device. 449.Pp 450The 451.Va udi_product , 452.Va udi_vendor , 453and 454.Va udi_release 455fields contain self-explanatory descriptions of the device. 456The 457.Va udi_productNo , 458.Va udi_vendorNo , 459and 460.Va udi_releaseNo 461fields contain numeric identifiers for the device. 462.Pp 463The 464.Va udi_class 465and 466.Va udi_subclass 467fields contain the device class and subclass. 468.Pp 469The 470.Va udi_config 471field shows the current configuration of the device. 472.Pp 473The 474.Va udi_protocol 475field contains the device protocol as given from the device. 476.Pp 477The 478.Va udi_speed 479field 480contains the speed of the device. 481.Pp 482The 483.Va udi_power 484field shows the power consumption in milli-amps drawn at 5 volts 485or is zero if the device is self powered. 486.Pp 487The 488.Va udi_devnames 489field contains the names and instance numbers of the device drivers 490for the devices attached to this device. 491.Pp 492If the device is a hub, the 493.Va udi_nports 494field is non-zero and the 495.Va udi_ports 496field contains the addresses of the connected devices. 497If no device is connected to a port, one of the 498.Dv USB_PORT_* 499values indicates its status. 500.It Dv USB_DEVICESTATS Fa "struct usb_device_stats" 501This command retrieves statistics about the controller. 502.Bd -unfilled 503struct usb_device_stats { 504 u_long uds_requests[4]; 505}; 506.Ed 507.Pp 508The 509.Va uds_requests 510field is indexed by the transfer kind, i.e.\& 511.Dv UE_* , 512and indicates how many transfers of each kind have been completed 513by the controller. 514.It Dv USB_DEVICE_GET_DDESC Fa "struct usb_device_ddesc" 515This command can be used to retrieve the device descriptor 516of a device on the bus. 517The 518.Va udd_addr 519field needs to be filled with the bus device address: 520.Bd -literal 521struct usb_device_ddesc { 522 u_int8_t udd_bus; 523 u_int8_t udd_addr; /* device address */ 524 usb_device_descriptor_t udd_desc; 525}; 526.Ed 527.Pp 528The 529.Va udd_bus 530field contains the device unit number. 531.Pp 532The 533.Va udd_desc 534field contains the device descriptor structure. 535.It Dv USB_DEVICE_GET_CDESC Fa "struct usb_device_cdesc" 536This command can be used to retrieve the configuration descriptor for the 537given configuration of a device on the bus. 538The 539.Va udc_addr 540field needs to be filled with the bus device address. 541The 542.Va udc_config_index 543field needs to be filled with the configuration index for the 544relevant configuration descriptor. 545For convenience the current configuration can be specified by 546.Dv USB_CURRENT_CONFIG_INDEX : 547.Bd -literal 548struct usb_device_cdesc { 549 u_int8_t udc_bus; 550 u_int8_t udc_addr; /* device address */ 551 int udc_config_index; 552 usb_config_descriptor_t udc_desc; 553}; 554.Ed 555.Pp 556The 557.Va udc_bus 558field contains the device unit number. 559.Pp 560The 561.Va udc_desc 562field contains the configuration descriptor structure. 563.It Dv USB_DEVICE_GET_FDESC Fa "struct usb_device_fdesc" 564This command can be used to retrieve all descriptors for the 565given configuration of a device on the bus. 566The 567.Va udf_addr 568field needs to be filled with the bus device address. 569The 570.Va udf_config_index 571field needs to be filled with the configuration index for the 572relevant configuration descriptor. 573For convenience the current configuration can be specified by 574.Dv USB_CURRENT_CONFIG_INDEX . 575The 576.Va udf_data 577field needs to point to a memory area of the size given in the 578.Va udf_size 579field. 580The proper size can be determined by first issuing a 581.Dv USB_DEVICE_GET_CDESC 582command and inspecting the 583.Va wTotalLength 584field: 585.Bd -literal 586struct usb_device_fdesc { 587 u_int8_t udf_bus; 588 u_int8_t udf_addr; /* device address */ 589 int udf_config_index; 590 u_int udf_size; 591 u_char *udf_data; 592}; 593.Ed 594.Pp 595The 596.Va udf_bus 597field contains the device unit number. 598.Pp 599The 600.Va udf_data 601field contains all descriptors. 602.It Dv USB_REQUEST Fa "struct usb_ctl_request" 603This command can be used to execute arbitrary requests on the control pipe. 604This is 605.Em DANGEROUS 606and should be used with great care since it 607can destroy the bus integrity. 608.Pp 609The 610.Vt usb_ctl_request 611structure has the following definition: 612.Bd -literal 613typedef struct { 614 uByte bmRequestType; 615 uByte bRequest; 616 uWord wValue; 617 uWord wIndex; 618 uWord wLength; 619} __packed usb_device_request_t; 620 621struct usb_ctl_request { 622 int ucr_addr; 623 usb_device_request_t ucr_request; 624 void *ucr_data; 625 int ucr_flags; 626#define USBD_SHORT_XFER_OK 0x04 /* allow short reads */ 627 int ucr_actlen; /* actual length transferred */ 628}; 629.Ed 630.Pp 631The 632.Va ucr_addr 633field identifies the device on which to perform the request. 634The 635.Va ucr_request 636field identifies parameters of the request, such as length and type. 637The 638.Va ucr_data 639field contains the location where data will be read from or written to. 640The 641.Va ucr_flags 642field specifies options for the request, and the 643.Va ucr_actlen 644field contains the actual length transferred as the result of the request. 645.El 646.Pp 647The include file 648.In dev/usb/usb.h 649contains definitions for the types used by the various 650.Xr ioctl 2 651calls. 652The naming convention of the fields for the various USB descriptors 653exactly follows the naming in the USB specification. 654Byte sized fields can be accessed directly, but word (16-bit) 655sized fields must be accessed by the 656.Fn UGETW field 657and 658.Fn USETW field value 659macros and double word (32-bit) sized fields must be accessed by the 660.Fn UGETDW field 661and 662.Fn USETDW field value 663macros to handle byte order and alignment properly. 664.Pp 665The include file 666.In dev/usb/usbhid.h 667similarly contains the definitions for 668Human Interface Devices (HID). 669.Sh SEE ALSO 670.Xr usbhidaction 1 , 671.Xr usbhidctl 1 , 672.Xr ioctl 2 , 673.Xr dwctwo 4 , 674.Xr ehci 4 , 675.Xr ohci 4 , 676.Xr uhci 4 , 677.Xr xhci 4 , 678.Xr config 8 , 679.Xr usbdevs 8 680.Pp 681The USB specifications can be found at: 682.Lk https://www.usb.org/documents 683.Sh HISTORY 684The 685.Nm 686driver 687appeared in 688.Ox 2.6 . 689