1.\" $OpenBSD: usb.4,v 1.211 2021/09/08 20:29:21 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: September 8 2021 $ 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 10/100/1Gb USB Ethernet device 114.It Xr axen 4 115ASIX Electronics AX88179 10/100/1Gb 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 10/100/1Gb USB Ethernet device 126.It Xr smsc 4 127SMSC LAN95xx 10/100 USB Ethernet device 128.It Xr uaq 4 129Aquantia AQC111U/AQC112U 100/1Gb/2.5Gb/5Gb USB Ethernet device 130.It Xr udav 4 131Davicom DM9601 10/100 USB Ethernet device 132.It Xr ure 4 133Realtek RTL8152/RTL8153/RTL8153B/RTL8156 10/100/1Gb/2.5Gb USB Ethernet device 134.It Xr url 4 135Realtek RTL8150L 10/100 USB Ethernet device 136.It Xr urndis 4 137USB Remote NDIS Ethernet device 138.El 139.Ss Wireless network interfaces 140.Bl -tag -width 12n -offset ind -compact 141.It Xr athn 4 142Atheros IEEE 802.11a/b/g/n wireless network device 143.It Xr atu 4 144Atmel AT76C50x IEEE 802.11b wireless network device 145.It Xr bwfm 4 146Broadcom and Cypress IEEE 802.11a/ac/b/g/n wireless network device 147.It Xr otus 4 148Atheros USB IEEE 802.11a/b/g/n wireless network device 149.It Xr rsu 4 150Realtek RTL8188SU/RTL8192SU USB IEEE 802.11b/g/n wireless network device 151.It Xr rum 4 152Ralink Technology/MediaTek USB IEEE 802.11a/b/g wireless network device 153.It Xr run 4 154Ralink Technology/MediaTek USB IEEE 802.11a/b/g/n wireless network device 155.It Xr uath 4 156Atheros USB IEEE 802.11a/b/g wireless network device 157.It Xr upgt 4 158Conexant/Intersil PrismGT SoftMAC USB IEEE 802.11b/g wireless network device 159.It Xr ural 4 160Ralink Technology/MediaTek USB IEEE 802.11b/g wireless network device 161.It Xr urtw 4 162Realtek RTL8187L/RTL8187B USB IEEE 802.11b/g wireless network device 163.It Xr urtwn 4 164Realtek RTL8188CU/RTL8188EU/RTL8192CU/RTL8192EU USB IEEE 802.11b/g/n wireless 165network device 166.It Xr wi 4 167Intersil PRISM 2-3 IEEE 802.11b wireless network device 168.It Xr zyd 4 169ZyDAS ZD1211/ZD1211B USB IEEE 802.11b/g wireless network device 170.El 171.Ss Serial and parallel interfaces 172.Bl -tag -width 12n -offset ind -compact 173.It Xr moscom 4 174MosChip Semiconductor MCS7703 based USB serial adapter 175.It Xr uark 4 176Arkmicro Technologies ARK3116 based USB serial adapter 177.It Xr ubsa 4 178Belkin USB serial adapter 179.It Xr uchcom 4 180WinChipHead CH341/340 based USB serial adapter 181.It Xr ucom 4 182USB tty support 183.It Xr ucrcom 4 184Chromebook USB serial console 185.It Xr ucycom 4 186Cypress microcontroller based USB serial adapter 187.It Xr uftdi 4 188FTDI USB serial adapter 189.It Xr uipaq 4 190iPAQ USB units 191.It Xr ukspan 4 192Keyspan USB serial adapter 193.It Xr ulpt 4 194USB printer support 195.It Xr umcs 4 196MosChip Semiconductor based USB multiport serial adapter 197.It Xr umct 4 198MCT USB-RS232 USB serial adapter 199.It Xr umodem 4 200USB modem support 201.It Xr umsm 4 202Qualcomm MSM modem device 203.It Xr uplcom 4 204Prolific PL-2303 USB serial adapter 205.It Xr uscom 4 206simple USB serial adapters 207.It Xr uslcom 4 208Silicon Laboratories CP210x based USB serial adapter 209.It Xr uslhcom 4 210Silicon Laboratories CP2110 based USB serial adapter 211.It Xr uticom 4 212Texas Instruments TUSB3410 USB serial adapter 213.It Xr uvisor 4 214USB Handspring Visor 215.It Xr uvscom 4 216SUNTAC Slipper U VS-10U USB serial adapter 217.It Xr uxrcom 4 218Exar XR21V1410 USB serial adapter 219.El 220.Ss Audio devices 221.Bl -tag -width 12n -offset ind -compact 222.It Xr uaudio 4 223USB audio devices 224.It Xr umidi 4 225USB MIDI devices 226.El 227.Ss Video devices 228.Bl -tag -width 12n -offset ind -compact 229.It Xr udl 4 230DisplayLink DL-120 / DL-160 USB display devices 231.It Xr utvfu 4 232USB Fushicai USBTV007 audio/video capture device 233.It Xr uvideo 4 234USB video devices 235.El 236.Ss Time receiver devices 237.Bl -tag -width 12n -offset ind -compact 238.It Xr udcf 4 239Gude ADS Expert mouseCLOCK USB timedelta sensor 240.It Xr umbg 4 241Meinberg Funkuhren USB5131 timedelta sensor 242.El 243.Ss Radio receiver devices 244.Bl -tag -width 12n -offset ind -compact 245.It Xr udsbr 4 246D-Link DSB-R100 USB radio device 247.El 248.Ss Human Interface Devices 249.Bl -tag -width 12n -offset ind -compact 250.It Xr fido 4 251FIDO/U2F security keys 252.It Xr ubcmtp 4 253Broadcom trackpad mouse 254.It Xr ucc 4 255Consumer Control keyboards 256.It Xr ugold 4 257TEMPer gold HID thermometer and hygrometer 258.It Xr uhid 4 259Generic driver for Human Interface Devices 260.It Xr uhidev 4 261Base driver for all Human Interface Devices 262.It Xr uhidpp 4 263Logitech HID++ devices 264.It Xr ujoy 4 265USB joysticks/gamecontrollers 266.It Xr ukbd 4 267USB keyboards that follow the boot protocol 268.It Xr ums 4 269USB HID mouse, touchscreen and digitiser devices 270.It Xr umstc 4 271Microsoft Surface Type Cover keyboard 272.It Xr umt 4 273USB HID multitouch touchpad devices 274.It Xr uoaklux 4 275Toradex OAK USB illuminance sensor 276.It Xr uoakrh 4 277Toradex OAK USB temperature and relative humidity sensor 278.It Xr uoakv 4 279Toradex OAK USB +/-10V 8channel ADC interface 280.It Xr upd 4 281USB Power Devices sensor 282.It Xr uthum 4 283TEMPer HID thermometer and hygrometer 284.It Xr utpms 4 285Apple touchpad mouse 286.It Xr utrh 4 287USBRH temperature and humidity sensor 288.It Xr utwitch 4 289YUREX USB twitch/jiggle of knee sensor 290.It Xr uwacom 4 291Wacom USB tablets 292.El 293.Ss WAN network devices 294.Bl -tag -width 12n -offset ind -compact 295.It Xr umb 4 296USB Mobile Broadband Interface Model (MBIM) 297.El 298.Ss Miscellaneous devices 299.Bl -tag -width 12n -offset ind -compact 300.It Xr uberry 4 301Research In Motion BlackBerry 302.It Xr ugen 4 303USB generic device support 304.It Xr ugl 4 305Genesys Logic based host-to-host adapters 306.It Xr uonerng 4 307Moonbase Otago OneRNG TRNG 308.It Xr uow 4 309Maxim/Dallas DS2490 USB 1-Wire adapter 310.It Xr upl 4 311Prolific based host-to-host adapters 312.It Xr urng 4 313USB Random Number Generator devices 314.It Xr usps 4 315USPS composite AC power and temperature sensor 316.It Xr uts 4 317USB touchscreen support 318.El 319.Sh INTRODUCTION TO USB 320There are different versions of the USB 321which provide different speeds. 322USB 3 can operate up to 5.0Gb/s. 323USB 2 operates at 480Mb/s, while USB versions 1 and 1.1 operate at 32412 Mb/s and 1.5 Mb/s for low speed devices. 325Each USB has a host controller that is the master of the bus; 326all other devices on the bus only speak when spoken to. 327.Pp 328There can be up to 127 devices (apart from the host controller) 329on a bus, each with its own address. 330The addresses are assigned 331dynamically by the host when each device is attached to the bus. 332.Pp 333Within each device there can be up to 16 endpoints. 334Each endpoint 335is individually addressed and the addresses are static. 336Each of these endpoints will communicate in one of four different modes: 337control, isochronous, bulk, or interrupt. 338A device always has at least one endpoint. 339This is a control endpoint at address 0 340and is used to give commands to the device and extract basic data, 341such as descriptors, from the device. 342Each endpoint, except the control endpoint, is unidirectional. 343.Pp 344The endpoints in a device are grouped into interfaces. 345An interface is a logical unit within a device; e.g., 346a compound device with both a keyboard and a trackball would present 347one interface for each. 348An interface can sometimes be set into different modes, 349called alternate settings, which affects how it operates. 350Different alternate settings can have different endpoints 351within it. 352.Pp 353A device may operate in different configurations. 354Depending on the 355configuration the device may present different sets of endpoints 356and interfaces. 357.Pp 358Each device located on a hub has several 359.Xr config 8 360locators: 361.Pp 362.Bl -tag -width configuration -compact 363.It Cd port 364Number of the port on closest upstream hub. 365.It Cd configuration 366Configuration the device must be in for this driver to attach. 367This locator does not set the configuration; it is iterated by the bus 368enumeration. 369.It Cd interface 370Interface number within a device that an interface driver attaches to. 371.It Cd vendor 37216-bit vendor ID of the device. 373.It Cd product 37416-bit product ID of the device. 375.It Cd release 37616-bit release (revision) number of the device. 377.El 378.Pp 379The first locator can be used to pin down a particular device 380according to its physical position in the device tree. 381The last three locators can be used to pin down a particular 382device according to what device it actually is. 383.Pp 384The bus enumeration of the USB bus proceeds in several steps: 385.Bl -enum 386.It 387Any device-specific driver can attach to the device. 388.It 389If none is found, any device class specific driver can attach. 390.It 391If none is found, all configurations are iterated over. 392For each configuration all the interfaces are iterated over and interface 393drivers can attach. 394If any interface driver attached in a certain 395configuration, the iteration over configurations is stopped. 396.It 397If still no drivers have been found, the generic USB driver can attach. 398.El 399.Sh USB CONTROLLER INTERFACE 400Use the following to get access to the USB specific structures 401and defines: 402.Bd -literal -offset indent 403#include <dev/usb/usb.h> 404.Ed 405.Pp 406The 407.Pa /dev/usbN 408device can be opened and a few operations can be performed on it. 409The following 410.Xr ioctl 2 411commands are supported on the controller device: 412.Bl -tag -width xxxxxx 413.It Dv USB_DEVICEINFO Fa "struct usb_device_info" 414This command can be used to retrieve some information about a device 415on the bus. 416The 417.Va udi_addr 418field should be filled before the call and the other fields will 419be filled by information about the device on that address. 420Should no such device exist, an error is reported. 421.Bd -literal 422#define USB_MAX_DEVNAMES 4 423#define USB_MAX_DEVNAMELEN 16 424struct usb_device_info { 425 u_int8_t udi_bus; 426 u_int8_t udi_addr; /* device address */ 427 char udi_product[USB_MAX_STRING_LEN]; 428 char udi_vendor[USB_MAX_STRING_LEN]; 429 char udi_release[8]; 430 u_int16_t udi_productNo; 431 u_int16_t udi_vendorNo; 432 u_int16_t udi_releaseNo; 433 u_int8_t udi_class; 434 u_int8_t udi_subclass; 435 u_int8_t udi_protocol; 436 u_int8_t udi_config; 437 u_int8_t udi_speed; 438#define USB_SPEED_LOW 1 439#define USB_SPEED_FULL 2 440#define USB_SPEED_HIGH 3 441#define USB_SPEED_SUPER 4 442 u_int8_t udi_port; 443 int udi_power; /* power consumption */ 444 int udi_nports; 445 char udi_devnames[USB_MAX_DEVNAMES] 446 [USB_MAX_DEVNAMELEN]; 447 u_int32_t udi_ports[16]; /* hub only */ 448 char udi_serial[USB_MAX_STRING_LEN]; 449}; 450.Ed 451.Pp 452The 453.Va udi_bus 454field contains the device unit number of the device. 455.Pp 456The 457.Va udi_product , 458.Va udi_vendor , 459and 460.Va udi_release 461fields contain self-explanatory descriptions of the device. 462The 463.Va udi_productNo , 464.Va udi_vendorNo , 465and 466.Va udi_releaseNo 467fields contain numeric identifiers for the device. 468.Pp 469The 470.Va udi_class 471and 472.Va udi_subclass 473fields contain the device class and subclass. 474.Pp 475The 476.Va udi_config 477field shows the current configuration of the device. 478.Pp 479The 480.Va udi_protocol 481field contains the device protocol as given from the device. 482.Pp 483The 484.Va udi_speed 485field 486contains the speed of the device. 487.Pp 488The 489.Va udi_power 490field shows the power consumption in milli-amps drawn at 5 volts 491or is zero if the device is self powered. 492.Pp 493The 494.Va udi_devnames 495field contains the names and instance numbers of the device drivers 496for the devices attached to this device. 497.Pp 498If the device is a hub, the 499.Va udi_nports 500field is non-zero and the 501.Va udi_ports 502field contains the addresses of the connected devices. 503If no device is connected to a port, one of the 504.Dv USB_PORT_* 505values indicates its status. 506.It Dv USB_DEVICESTATS Fa "struct usb_device_stats" 507This command retrieves statistics about the controller. 508.Bd -unfilled 509struct usb_device_stats { 510 u_long uds_requests[4]; 511}; 512.Ed 513.Pp 514The 515.Va uds_requests 516field is indexed by the transfer kind, i.e.\& 517.Dv UE_* , 518and indicates how many transfers of each kind have been completed 519by the controller. 520.It Dv USB_DEVICE_GET_DDESC Fa "struct usb_device_ddesc" 521This command can be used to retrieve the device descriptor 522of a device on the bus. 523The 524.Va udd_addr 525field needs to be filled with the bus device address: 526.Bd -literal 527struct usb_device_ddesc { 528 u_int8_t udd_bus; 529 u_int8_t udd_addr; /* device address */ 530 usb_device_descriptor_t udd_desc; 531}; 532.Ed 533.Pp 534The 535.Va udd_bus 536field contains the device unit number. 537.Pp 538The 539.Va udd_desc 540field contains the device descriptor structure. 541.It Dv USB_DEVICE_GET_CDESC Fa "struct usb_device_cdesc" 542This command can be used to retrieve the configuration descriptor for the 543given configuration of a device on the bus. 544The 545.Va udc_addr 546field needs to be filled with the bus device address. 547The 548.Va udc_config_index 549field needs to be filled with the configuration index for the 550relevant configuration descriptor. 551For convenience the current configuration can be specified by 552.Dv USB_CURRENT_CONFIG_INDEX : 553.Bd -literal 554struct usb_device_cdesc { 555 u_int8_t udc_bus; 556 u_int8_t udc_addr; /* device address */ 557 int udc_config_index; 558 usb_config_descriptor_t udc_desc; 559}; 560.Ed 561.Pp 562The 563.Va udc_bus 564field contains the device unit number. 565.Pp 566The 567.Va udc_desc 568field contains the configuration descriptor structure. 569.It Dv USB_DEVICE_GET_FDESC Fa "struct usb_device_fdesc" 570This command can be used to retrieve all descriptors for the 571given configuration of a device on the bus. 572The 573.Va udf_addr 574field needs to be filled with the bus device address. 575The 576.Va udf_config_index 577field needs to be filled with the configuration index for the 578relevant configuration descriptor. 579For convenience the current configuration can be specified by 580.Dv USB_CURRENT_CONFIG_INDEX . 581The 582.Va udf_data 583field needs to point to a memory area of the size given in the 584.Va udf_size 585field. 586The proper size can be determined by first issuing a 587.Dv USB_DEVICE_GET_CDESC 588command and inspecting the 589.Va wTotalLength 590field: 591.Bd -literal 592struct usb_device_fdesc { 593 u_int8_t udf_bus; 594 u_int8_t udf_addr; /* device address */ 595 int udf_config_index; 596 u_int udf_size; 597 u_char *udf_data; 598}; 599.Ed 600.Pp 601The 602.Va udf_bus 603field contains the device unit number. 604.Pp 605The 606.Va udf_data 607field contains all descriptors. 608.It Dv USB_REQUEST Fa "struct usb_ctl_request" 609This command can be used to execute arbitrary requests on the control pipe. 610This is 611.Em DANGEROUS 612and should be used with great care since it 613can destroy the bus integrity. 614.Pp 615The 616.Vt usb_ctl_request 617structure has the following definition: 618.Bd -literal 619typedef struct { 620 uByte bmRequestType; 621 uByte bRequest; 622 uWord wValue; 623 uWord wIndex; 624 uWord wLength; 625} __packed usb_device_request_t; 626 627struct usb_ctl_request { 628 int ucr_addr; 629 usb_device_request_t ucr_request; 630 void *ucr_data; 631 int ucr_flags; 632#define USBD_SHORT_XFER_OK 0x04 /* allow short reads */ 633 int ucr_actlen; /* actual length transferred */ 634}; 635.Ed 636.Pp 637The 638.Va ucr_addr 639field identifies the device on which to perform the request. 640The 641.Va ucr_request 642field identifies parameters of the request, such as length and type. 643The 644.Va ucr_data 645field contains the location where data will be read from or written to. 646The 647.Va ucr_flags 648field specifies options for the request, and the 649.Va ucr_actlen 650field contains the actual length transferred as the result of the request. 651.El 652.Pp 653The include file 654.In dev/usb/usb.h 655contains definitions for the types used by the various 656.Xr ioctl 2 657calls. 658The naming convention of the fields for the various USB descriptors 659exactly follows the naming in the USB specification. 660Byte sized fields can be accessed directly, but word (16-bit) 661sized fields must be accessed by the 662.Fn UGETW field 663and 664.Fn USETW field value 665macros and double word (32-bit) sized fields must be accessed by the 666.Fn UGETDW field 667and 668.Fn USETDW field value 669macros to handle byte order and alignment properly. 670.Pp 671The include file 672.In dev/usb/usbhid.h 673similarly contains the definitions for 674Human Interface Devices (HID). 675.Sh SEE ALSO 676.Xr usbhidaction 1 , 677.Xr usbhidctl 1 , 678.Xr ioctl 2 , 679.Xr dwctwo 4 , 680.Xr ehci 4 , 681.Xr ohci 4 , 682.Xr uhci 4 , 683.Xr xhci 4 , 684.Xr config 8 , 685.Xr usbdevs 8 686.Pp 687The USB specifications can be found at: 688.Lk https://www.usb.org/documents 689.Sh HISTORY 690The 691.Nm 692driver 693appeared in 694.Ox 2.6 . 695