1.\" $OpenBSD: usb.4,v 1.219 2024/05/15 01:41:18 kevlo 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 15 2024 $ 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/AX88179A 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/RTL8153D/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/ax/b/g/n wireless network device 147.It Xr mtw 4 148MediaTek USB IEEE 802.11b/g/n wireless network device 149.It Xr otus 4 150Atheros USB IEEE 802.11a/b/g/n wireless network device 151.It Xr rsu 4 152Realtek RTL8188SU/RTL8192SU USB IEEE 802.11b/g/n wireless network device 153.It Xr rum 4 154Ralink Technology/MediaTek USB IEEE 802.11a/b/g wireless network device 155.It Xr run 4 156Ralink Technology/MediaTek USB IEEE 802.11a/b/g/n wireless network device 157.It Xr uath 4 158Atheros USB IEEE 802.11a/b/g wireless network device 159.It Xr upgt 4 160Conexant/Intersil PrismGT SoftMAC USB IEEE 802.11b/g wireless network device 161.It Xr ural 4 162Ralink Technology/MediaTek USB IEEE 802.11b/g wireless network device 163.It Xr urtw 4 164Realtek RTL8187L/RTL8187B USB IEEE 802.11b/g wireless network device 165.It Xr urtwn 4 166Realtek RTL8188CU/RTL8188EU/RTL8188FTV/RTL8192CU/RTL8192EU USB IEEE 802.11b/g/n wireless 167network device 168.It Xr wi 4 169Intersil PRISM 2-3 IEEE 802.11b wireless network device 170.It Xr zyd 4 171ZyDAS ZD1211/ZD1211B USB IEEE 802.11b/g wireless network device 172.El 173.Ss Serial and parallel interfaces 174.Bl -tag -width 12n -offset ind -compact 175.It Xr moscom 4 176MosChip Semiconductor MCS7703 based USB serial adapter 177.It Xr uark 4 178Arkmicro Technologies ARK3116 based USB serial adapter 179.It Xr ubsa 4 180Belkin USB serial adapter 181.It Xr uchcom 4 182WinChipHead CH9102/343/341/340 based USB serial adapter 183.It Xr ucom 4 184USB tty support 185.It Xr ucrcom 4 186Chromebook USB serial console 187.It Xr ucycom 4 188Cypress microcontroller based USB serial adapter 189.It Xr uftdi 4 190FTDI USB serial adapter 191.It Xr uipaq 4 192iPAQ USB units 193.It Xr ukspan 4 194Keyspan USB serial adapter 195.It Xr ulpt 4 196USB printer support 197.It Xr umcs 4 198MosChip Semiconductor based USB multiport serial adapter 199.It Xr umct 4 200MCT USB-RS232 USB serial adapter 201.It Xr umodem 4 202USB modem support 203.It Xr umsm 4 204Qualcomm MSM modem device 205.It Xr uplcom 4 206Prolific PL-2303 USB serial adapter 207.It Xr uscom 4 208simple USB serial adapters 209.It Xr uslcom 4 210Silicon Laboratories CP210x based USB serial adapter 211.It Xr uslhcom 4 212Silicon Laboratories CP2110 based USB serial adapter 213.It Xr uticom 4 214Texas Instruments TUSB3410 USB serial adapter 215.It Xr uvisor 4 216USB Handspring Visor 217.It Xr uvscom 4 218SUNTAC Slipper U VS-10U USB serial adapter 219.It Xr uxrcom 4 220Exar XR21V1410 USB serial adapter 221.El 222.Ss Audio devices 223.Bl -tag -width 12n -offset ind -compact 224.It Xr uaudio 4 225USB audio devices 226.It Xr umidi 4 227USB MIDI devices 228.El 229.Ss Video devices 230.Bl -tag -width 12n -offset ind -compact 231.It Xr udl 4 232DisplayLink DL-120/DL-160 USB display devices 233.It Xr utvfu 4 234USB Fushicai USBTV007 audio/video capture device 235.It Xr uvideo 4 236USB video devices 237.El 238.Ss Time receiver devices 239.Bl -tag -width 12n -offset ind -compact 240.It Xr udcf 4 241Gude ADS Expert mouseCLOCK USB timedelta sensor 242.It Xr umbg 4 243Meinberg Funkuhren USB5131 timedelta sensor 244.El 245.Ss Radio receiver devices 246.Bl -tag -width 12n -offset ind -compact 247.It Xr udsbr 4 248D-Link DSB-R100 USB radio device 249.El 250.Ss Human Interface Devices 251.Bl -tag -width 12n -offset ind -compact 252.It Xr fido 4 253FIDO/U2F security keys 254.It Xr ubcmtp 4 255Broadcom trackpad mouse 256.It Xr ucc 4 257Consumer Control keyboards 258.It Xr ugold 4 259TEMPer gold HID thermometer and hygrometer 260.It Xr uhid 4 261Generic driver for Human Interface Devices 262.It Xr uhidev 4 263Base driver for all Human Interface Devices 264.It Xr uhidpp 4 265Logitech HID++ devices 266.It Xr ujoy 4 267USB joysticks/gamecontrollers 268.It Xr ukbd 4 269USB keyboards that follow the boot protocol 270.It Xr ums 4 271USB HID mouse, touchscreen and digitiser devices 272.It Xr umstc 4 273Microsoft Surface Type Cover keyboard 274.It Xr umt 4 275USB HID multitouch touchpad devices 276.It Xr uoaklux 4 277Toradex OAK USB illuminance sensor 278.It Xr uoakrh 4 279Toradex OAK USB temperature and relative humidity sensor 280.It Xr uoakv 4 281Toradex OAK USB +/-10V 8channel ADC interface 282.It Xr upd 4 283USB Power Devices sensor 284.It Xr uthum 4 285TEMPer HID thermometer and hygrometer 286.It Xr utpms 4 287Apple touchpad mouse 288.It Xr utrh 4 289USBRH temperature and humidity sensor 290.It Xr utwitch 4 291YUREX USB twitch/jiggle of knee sensor 292.It Xr uwacom 4 293Wacom USB tablets 294.El 295.Ss WAN network devices 296.Bl -tag -width 12n -offset ind -compact 297.It Xr umb 4 298USB Mobile Broadband Interface Model (MBIM) 299.El 300.Ss Miscellaneous devices 301.Bl -tag -width 12n -offset ind -compact 302.It Xr uberry 4 303Research In Motion BlackBerry 304.It Xr ugen 4 305USB generic device support 306.It Xr ugl 4 307Genesys Logic based host-to-host adapters 308.It Xr uonerng 4 309Moonbase Otago OneRNG TRNG 310.It Xr uow 4 311Maxim/Dallas DS2490 USB 1-Wire adapter 312.It Xr upl 4 313Prolific based host-to-host adapters 314.It Xr urng 4 315USB Random Number Generator devices 316.It Xr usps 4 317USPS composite AC power and temperature sensor 318.It Xr uts 4 319USB touchscreen support 320.El 321.Sh INTRODUCTION TO USB 322There are different versions of the USB 323which provide different speeds. 324USB 3 can operate up to 5.0Gb/s. 325USB 2 operates at 480Mb/s, while USB versions 1 and 1.1 operate at 32612 Mb/s and 1.5 Mb/s for low speed devices. 327Each USB has a host controller that is the master of the bus; 328all other devices on the bus only speak when spoken to. 329.Pp 330There can be up to 127 devices (apart from the host controller) 331on a bus, each with its own address. 332The addresses are assigned 333dynamically by the host when each device is attached to the bus. 334.Pp 335Within each device there can be up to 16 endpoints. 336Each endpoint 337is individually addressed and the addresses are static. 338Each of these endpoints will communicate in one of four different modes: 339control, isochronous, bulk, or interrupt. 340A device always has at least one endpoint. 341This is a control endpoint at address 0 342and is used to give commands to the device and extract basic data, 343such as descriptors, from the device. 344Each endpoint, except the control endpoint, is unidirectional. 345.Pp 346The endpoints in a device are grouped into interfaces. 347An interface is a logical unit within a device; e.g., 348a compound device with both a keyboard and a trackball would present 349one interface for each. 350An interface can sometimes be set into different modes, 351called alternate settings, which affects how it operates. 352Different alternate settings can have different endpoints 353within it. 354.Pp 355A device may operate in different configurations. 356Depending on the 357configuration the device may present different sets of endpoints 358and interfaces. 359.Pp 360Each device located on a hub has several 361.Xr config 8 362locators: 363.Pp 364.Bl -tag -width configuration -compact 365.It Cd port 366Number of the port on closest upstream hub. 367.It Cd configuration 368Configuration the device must be in for this driver to attach. 369This locator does not set the configuration; it is iterated by the bus 370enumeration. 371.It Cd interface 372Interface number within a device that an interface driver attaches to. 373.It Cd vendor 37416-bit vendor ID of the device. 375.It Cd product 37616-bit product ID of the device. 377.It Cd release 37816-bit release (revision) number of the device. 379.El 380.Pp 381The first locator can be used to pin down a particular device 382according to its physical position in the device tree. 383The last three locators can be used to pin down a particular 384device according to what device it actually is. 385.Pp 386The bus enumeration of the USB bus proceeds in several steps: 387.Bl -enum 388.It 389Any device-specific driver can attach to the device. 390.It 391If none is found, any device class specific driver can attach. 392.It 393If none is found, all configurations are iterated over. 394For each configuration all the interfaces are iterated over and interface 395drivers can attach. 396If any interface driver attached in a certain 397configuration, the iteration over configurations is stopped. 398.It 399If still no drivers have been found, the generic USB driver can attach. 400.El 401.Sh USB CONTROLLER INTERFACE 402Use the following to get access to the USB specific structures 403and defines: 404.Bd -literal -offset indent 405#include <dev/usb/usb.h> 406.Ed 407.Pp 408The 409.Pa /dev/usbN 410device can be opened and a few operations can be performed on it. 411The following 412.Xr ioctl 2 413commands are supported on the controller device: 414.Bl -tag -width xxxxxx 415.It Dv USB_DEVICEINFO Fa "struct usb_device_info" 416This command can be used to retrieve some information about a device 417on the bus. 418The 419.Va udi_addr 420field should be filled before the call and the other fields will 421be filled by information about the device on that address. 422Should no such device exist, an error is reported. 423.Bd -literal 424#define USB_MAX_DEVNAMES 4 425#define USB_MAX_DEVNAMELEN 16 426struct usb_device_info { 427 u_int8_t udi_bus; 428 u_int8_t udi_addr; /* device address */ 429 char udi_product[USB_MAX_STRING_LEN]; 430 char udi_vendor[USB_MAX_STRING_LEN]; 431 char udi_release[8]; 432 u_int16_t udi_productNo; 433 u_int16_t udi_vendorNo; 434 u_int16_t udi_releaseNo; 435 u_int8_t udi_class; 436 u_int8_t udi_subclass; 437 u_int8_t udi_protocol; 438 u_int8_t udi_config; 439 u_int8_t udi_speed; 440#define USB_SPEED_LOW 1 441#define USB_SPEED_FULL 2 442#define USB_SPEED_HIGH 3 443#define USB_SPEED_SUPER 4 444 u_int8_t udi_port; 445 int udi_power; /* power consumption */ 446 int udi_nports; 447 char udi_devnames[USB_MAX_DEVNAMES] 448 [USB_MAX_DEVNAMELEN]; 449 u_int32_t udi_ports[16]; /* hub only */ 450 char udi_serial[USB_MAX_STRING_LEN]; 451}; 452.Ed 453.Pp 454The 455.Va udi_bus 456field contains the device unit number of the device. 457.Pp 458The 459.Va udi_product , 460.Va udi_vendor , 461and 462.Va udi_release 463fields contain self-explanatory descriptions of the device. 464The 465.Va udi_productNo , 466.Va udi_vendorNo , 467and 468.Va udi_releaseNo 469fields contain numeric identifiers for the device. 470.Pp 471The 472.Va udi_class 473and 474.Va udi_subclass 475fields contain the device class and subclass. 476.Pp 477The 478.Va udi_config 479field shows the current configuration of the device. 480.Pp 481The 482.Va udi_protocol 483field contains the device protocol as given from the device. 484.Pp 485The 486.Va udi_speed 487field 488contains the speed of the device. 489.Pp 490The 491.Va udi_power 492field shows the power consumption in milli-amps drawn at 5 volts 493or is zero if the device is self powered. 494.Pp 495The 496.Va udi_devnames 497field contains the names and instance numbers of the device drivers 498for the devices attached to this device. 499.Pp 500If the device is a hub, the 501.Va udi_nports 502field is non-zero and the 503.Va udi_ports 504field contains the addresses of the connected devices. 505If no device is connected to a port, one of the 506.Dv USB_PORT_* 507values indicates its status. 508.It Dv USB_DEVICESTATS Fa "struct usb_device_stats" 509This command retrieves statistics about the controller. 510.Bd -unfilled 511struct usb_device_stats { 512 u_long uds_requests[4]; 513}; 514.Ed 515.Pp 516The 517.Va uds_requests 518field is indexed by the transfer kind, i.e.\& 519.Dv UE_* , 520and indicates how many transfers of each kind have been completed 521by the controller. 522.It Dv USB_DEVICE_GET_DDESC Fa "struct usb_device_ddesc" 523This command can be used to retrieve the device descriptor 524of a device on the bus. 525The 526.Va udd_addr 527field needs to be filled with the bus device address: 528.Bd -literal 529struct usb_device_ddesc { 530 u_int8_t udd_bus; 531 u_int8_t udd_addr; /* device address */ 532 usb_device_descriptor_t udd_desc; 533}; 534.Ed 535.Pp 536The 537.Va udd_bus 538field contains the device unit number. 539.Pp 540The 541.Va udd_desc 542field contains the device descriptor structure. 543.It Dv USB_DEVICE_GET_CDESC Fa "struct usb_device_cdesc" 544This command can be used to retrieve the configuration descriptor for the 545given configuration of a device on the bus. 546The 547.Va udc_addr 548field needs to be filled with the bus device address. 549The 550.Va udc_config_index 551field needs to be filled with the configuration index for the 552relevant configuration descriptor. 553For convenience the current configuration can be specified by 554.Dv USB_CURRENT_CONFIG_INDEX : 555.Bd -literal 556struct usb_device_cdesc { 557 u_int8_t udc_bus; 558 u_int8_t udc_addr; /* device address */ 559 int udc_config_index; 560 usb_config_descriptor_t udc_desc; 561}; 562.Ed 563.Pp 564The 565.Va udc_bus 566field contains the device unit number. 567.Pp 568The 569.Va udc_desc 570field contains the configuration descriptor structure. 571.It Dv USB_DEVICE_GET_FDESC Fa "struct usb_device_fdesc" 572This command can be used to retrieve all descriptors for the 573given configuration of a device on the bus. 574The 575.Va udf_addr 576field needs to be filled with the bus device address. 577The 578.Va udf_config_index 579field needs to be filled with the configuration index for the 580relevant configuration descriptor. 581For convenience the current configuration can be specified by 582.Dv USB_CURRENT_CONFIG_INDEX . 583The 584.Va udf_data 585field needs to point to a memory area of the size given in the 586.Va udf_size 587field. 588The proper size can be determined by first issuing a 589.Dv USB_DEVICE_GET_CDESC 590command and inspecting the 591.Va wTotalLength 592field: 593.Bd -literal 594struct usb_device_fdesc { 595 u_int8_t udf_bus; 596 u_int8_t udf_addr; /* device address */ 597 int udf_config_index; 598 u_int udf_size; 599 u_char *udf_data; 600}; 601.Ed 602.Pp 603The 604.Va udf_bus 605field contains the device unit number. 606.Pp 607The 608.Va udf_data 609field contains all descriptors. 610.It Dv USB_REQUEST Fa "struct usb_ctl_request" 611This command can be used to execute arbitrary requests on the control pipe. 612This is 613.Em DANGEROUS 614and should be used with great care since it 615can destroy the bus integrity. 616.Pp 617The 618.Vt usb_ctl_request 619structure has the following definition: 620.Bd -literal 621typedef struct { 622 uByte bmRequestType; 623 uByte bRequest; 624 uWord wValue; 625 uWord wIndex; 626 uWord wLength; 627} __packed usb_device_request_t; 628 629struct usb_ctl_request { 630 int ucr_addr; 631 usb_device_request_t ucr_request; 632 void *ucr_data; 633 int ucr_flags; 634#define USBD_SHORT_XFER_OK 0x04 /* allow short reads */ 635 int ucr_actlen; /* actual length transferred */ 636}; 637.Ed 638.Pp 639The 640.Va ucr_addr 641field identifies the device on which to perform the request. 642The 643.Va ucr_request 644field identifies parameters of the request, such as length and type. 645The 646.Va ucr_data 647field contains the location where data will be read from or written to. 648The 649.Va ucr_flags 650field specifies options for the request, and the 651.Va ucr_actlen 652field contains the actual length transferred as the result of the request. 653.El 654.Pp 655The include file 656.In dev/usb/usb.h 657contains definitions for the types used by the various 658.Xr ioctl 2 659calls. 660The naming convention of the fields for the various USB descriptors 661exactly follows the naming in the USB specification. 662Byte sized fields can be accessed directly, but word (16-bit) 663sized fields must be accessed by the 664.Fn UGETW field 665and 666.Fn USETW field value 667macros and double word (32-bit) sized fields must be accessed by the 668.Fn UGETDW field 669and 670.Fn USETDW field value 671macros to handle byte order and alignment properly. 672.Pp 673The include file 674.In dev/usb/usbhid.h 675similarly contains the definitions for 676Human Interface Devices (HID). 677.Sh SEE ALSO 678.Xr usbhidaction 1 , 679.Xr usbhidctl 1 , 680.Xr ioctl 2 , 681.Xr dwctwo 4 , 682.Xr ehci 4 , 683.Xr ohci 4 , 684.Xr uhci 4 , 685.Xr xhci 4 , 686.Xr config 8 , 687.Xr usbdevs 8 688.Pp 689The USB specifications can be found at: 690.Lk https://www.usb.org/documents 691.Sh HISTORY 692The 693.Nm 694driver 695appeared in 696.Ox 2.6 . 697