1.\" $OpenBSD: usb.4,v 1.207 2021/05/07 09:13:19 jsg 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 7 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/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 ugold 4 253TEMPer gold HID thermometer and hygrometer 254.It Xr uhid 4 255Generic driver for Human Interface Devices 256.It Xr uhidev 4 257Base driver for all Human Interface Devices 258.It Xr uhidpp 4 259Logitech HID++ devices 260.It Xr ujoy 4 261USB joysticks/gamecontrollers 262.It Xr ukbd 4 263USB keyboards that follow the boot protocol 264.It Xr ums 4 265USB HID mouse, touchscreen and digitiser devices 266.It Xr umstc 4 267Microsoft Surface Type Cover keyboard 268.It Xr umt 4 269USB HID multitouch touchpad devices 270.It Xr uoaklux 4 271Toradex OAK USB illuminance sensor 272.It Xr uoakrh 4 273Toradex OAK USB temperature and relative humidity sensor 274.It Xr uoakv 4 275Toradex OAK USB +/-10V 8channel ADC interface 276.It Xr upd 4 277USB Power Devices sensor 278.It Xr uthum 4 279TEMPer HID thermometer and hygrometer 280.It Xr utpms 4 281Apple touchpad mouse 282.It Xr utrh 4 283USBRH temperature and humidity sensor 284.It Xr utwitch 4 285YUREX USB twitch/jiggle of knee sensor 286.It Xr uwacom 4 287Wacom USB tablets 288.El 289.Ss WAN network devices 290.Bl -tag -width 12n -offset ind -compact 291.It Xr umb 4 292USB Mobile Broadband Interface Model (MBIM) 293.El 294.Ss Miscellaneous devices 295.Bl -tag -width 12n -offset ind -compact 296.It Xr uberry 4 297Research In Motion BlackBerry 298.It Xr ugen 4 299USB generic device support 300.It Xr ugl 4 301Genesys Logic based host-to-host adapters 302.It Xr uonerng 4 303Moonbase Otago OneRNG TRNG 304.It Xr uow 4 305Maxim/Dallas DS2490 USB 1-Wire adapter 306.It Xr upl 4 307Prolific based host-to-host adapters 308.It Xr urng 4 309USB Random Number Generator devices 310.It Xr usps 4 311USPS composite AC power and temperature sensor 312.It Xr uts 4 313USB touchscreen support 314.El 315.Sh INTRODUCTION TO USB 316There are different versions of the USB 317which provide different speeds. 318USB 3 can operate up to 5.0Gb/s. 319USB 2 operates at 480Mb/s, while USB versions 1 and 1.1 operate at 32012 Mb/s and 1.5 Mb/s for low speed devices. 321Each USB has a host controller that is the master of the bus; 322all other devices on the bus only speak when spoken to. 323.Pp 324There can be up to 127 devices (apart from the host controller) 325on a bus, each with its own address. 326The addresses are assigned 327dynamically by the host when each device is attached to the bus. 328.Pp 329Within each device there can be up to 16 endpoints. 330Each endpoint 331is individually addressed and the addresses are static. 332Each of these endpoints will communicate in one of four different modes: 333control, isochronous, bulk, or interrupt. 334A device always has at least one endpoint. 335This is a control endpoint at address 0 336and is used to give commands to the device and extract basic data, 337such as descriptors, from the device. 338Each endpoint, except the control endpoint, is unidirectional. 339.Pp 340The endpoints in a device are grouped into interfaces. 341An interface is a logical unit within a device; e.g., 342a compound device with both a keyboard and a trackball would present 343one interface for each. 344An interface can sometimes be set into different modes, 345called alternate settings, which affects how it operates. 346Different alternate settings can have different endpoints 347within it. 348.Pp 349A device may operate in different configurations. 350Depending on the 351configuration the device may present different sets of endpoints 352and interfaces. 353.Pp 354Each device located on a hub has several 355.Xr config 8 356locators: 357.Pp 358.Bl -tag -width configuration -compact 359.It Cd port 360Number of the port on closest upstream hub. 361.It Cd configuration 362Configuration the device must be in for this driver to attach. 363This locator does not set the configuration; it is iterated by the bus 364enumeration. 365.It Cd interface 366Interface number within a device that an interface driver attaches to. 367.It Cd vendor 36816-bit vendor ID of the device. 369.It Cd product 37016-bit product ID of the device. 371.It Cd release 37216-bit release (revision) number of the device. 373.El 374.Pp 375The first locator can be used to pin down a particular device 376according to its physical position in the device tree. 377The last three locators can be used to pin down a particular 378device according to what device it actually is. 379.Pp 380The bus enumeration of the USB bus proceeds in several steps: 381.Bl -enum 382.It 383Any device-specific driver can attach to the device. 384.It 385If none is found, any device class specific driver can attach. 386.It 387If none is found, all configurations are iterated over. 388For each configuration all the interfaces are iterated over and interface 389drivers can attach. 390If any interface driver attached in a certain 391configuration, the iteration over configurations is stopped. 392.It 393If still no drivers have been found, the generic USB driver can attach. 394.El 395.Sh USB CONTROLLER INTERFACE 396Use the following to get access to the USB specific structures 397and defines: 398.Bd -literal -offset indent 399#include <dev/usb/usb.h> 400.Ed 401.Pp 402The 403.Pa /dev/usbN 404device can be opened and a few operations can be performed on it. 405The following 406.Xr ioctl 2 407commands are supported on the controller device: 408.Bl -tag -width xxxxxx 409.It Dv USB_DEVICEINFO Fa "struct usb_device_info" 410This command can be used to retrieve some information about a device 411on the bus. 412The 413.Va udi_addr 414field should be filled before the call and the other fields will 415be filled by information about the device on that address. 416Should no such device exist, an error is reported. 417.Bd -literal 418#define USB_MAX_DEVNAMES 4 419#define USB_MAX_DEVNAMELEN 16 420struct usb_device_info { 421 u_int8_t udi_bus; 422 u_int8_t udi_addr; /* device address */ 423 char udi_product[USB_MAX_STRING_LEN]; 424 char udi_vendor[USB_MAX_STRING_LEN]; 425 char udi_release[8]; 426 u_int16_t udi_productNo; 427 u_int16_t udi_vendorNo; 428 u_int16_t udi_releaseNo; 429 u_int8_t udi_class; 430 u_int8_t udi_subclass; 431 u_int8_t udi_protocol; 432 u_int8_t udi_config; 433 u_int8_t udi_speed; 434#define USB_SPEED_LOW 1 435#define USB_SPEED_FULL 2 436#define USB_SPEED_HIGH 3 437#define USB_SPEED_SUPER 4 438 u_int8_t udi_port; 439 int udi_power; /* power consumption */ 440 int udi_nports; 441 char udi_devnames[USB_MAX_DEVNAMES] 442 [USB_MAX_DEVNAMELEN]; 443 u_int32_t udi_ports[16]; /* hub only */ 444 char udi_serial[USB_MAX_STRING_LEN]; 445}; 446.Ed 447.Pp 448The 449.Va udi_bus 450field contains the device unit number of the device. 451.Pp 452The 453.Va udi_product , 454.Va udi_vendor , 455and 456.Va udi_release 457fields contain self-explanatory descriptions of the device. 458The 459.Va udi_productNo , 460.Va udi_vendorNo , 461and 462.Va udi_releaseNo 463fields contain numeric identifiers for the device. 464.Pp 465The 466.Va udi_class 467and 468.Va udi_subclass 469fields contain the device class and subclass. 470.Pp 471The 472.Va udi_config 473field shows the current configuration of the device. 474.Pp 475The 476.Va udi_protocol 477field contains the device protocol as given from the device. 478.Pp 479The 480.Va udi_speed 481field 482contains the speed of the device. 483.Pp 484The 485.Va udi_power 486field shows the power consumption in milli-amps drawn at 5 volts 487or is zero if the device is self powered. 488.Pp 489The 490.Va udi_devnames 491field contains the names and instance numbers of the device drivers 492for the devices attached to this device. 493.Pp 494If the device is a hub, the 495.Va udi_nports 496field is non-zero and the 497.Va udi_ports 498field contains the addresses of the connected devices. 499If no device is connected to a port, one of the 500.Dv USB_PORT_* 501values indicates its status. 502.It Dv USB_DEVICESTATS Fa "struct usb_device_stats" 503This command retrieves statistics about the controller. 504.Bd -unfilled 505struct usb_device_stats { 506 u_long uds_requests[4]; 507}; 508.Ed 509.Pp 510The 511.Va uds_requests 512field is indexed by the transfer kind, i.e.\& 513.Dv UE_* , 514and indicates how many transfers of each kind have been completed 515by the controller. 516.It Dv USB_DEVICE_GET_DDESC Fa "struct usb_device_ddesc" 517This command can be used to retrieve the device descriptor 518of a device on the bus. 519The 520.Va udd_addr 521field needs to be filled with the bus device address: 522.Bd -literal 523struct usb_device_ddesc { 524 u_int8_t udd_bus; 525 u_int8_t udd_addr; /* device address */ 526 usb_device_descriptor_t udd_desc; 527}; 528.Ed 529.Pp 530The 531.Va udd_bus 532field contains the device unit number. 533.Pp 534The 535.Va udd_desc 536field contains the device descriptor structure. 537.It Dv USB_DEVICE_GET_CDESC Fa "struct usb_device_cdesc" 538This command can be used to retrieve the configuration descriptor for the 539given configuration of a device on the bus. 540The 541.Va udc_addr 542field needs to be filled with the bus device address. 543The 544.Va udc_config_index 545field needs to be filled with the configuration index for the 546relevant configuration descriptor. 547For convenience the current configuration can be specified by 548.Dv USB_CURRENT_CONFIG_INDEX : 549.Bd -literal 550struct usb_device_cdesc { 551 u_int8_t udc_bus; 552 u_int8_t udc_addr; /* device address */ 553 int udc_config_index; 554 usb_config_descriptor_t udc_desc; 555}; 556.Ed 557.Pp 558The 559.Va udc_bus 560field contains the device unit number. 561.Pp 562The 563.Va udc_desc 564field contains the configuration descriptor structure. 565.It Dv USB_DEVICE_GET_FDESC Fa "struct usb_device_fdesc" 566This command can be used to retrieve all descriptors for the 567given configuration of a device on the bus. 568The 569.Va udf_addr 570field needs to be filled with the bus device address. 571The 572.Va udf_config_index 573field needs to be filled with the configuration index for the 574relevant configuration descriptor. 575For convenience the current configuration can be specified by 576.Dv USB_CURRENT_CONFIG_INDEX . 577The 578.Va udf_data 579field needs to point to a memory area of the size given in the 580.Va udf_size 581field. 582The proper size can be determined by first issuing a 583.Dv USB_DEVICE_GET_CDESC 584command and inspecting the 585.Va wTotalLength 586field: 587.Bd -literal 588struct usb_device_fdesc { 589 u_int8_t udf_bus; 590 u_int8_t udf_addr; /* device address */ 591 int udf_config_index; 592 u_int udf_size; 593 u_char *udf_data; 594}; 595.Ed 596.Pp 597The 598.Va udf_bus 599field contains the device unit number. 600.Pp 601The 602.Va udf_data 603field contains all descriptors. 604.It Dv USB_REQUEST Fa "struct usb_ctl_request" 605This command can be used to execute arbitrary requests on the control pipe. 606This is 607.Em DANGEROUS 608and should be used with great care since it 609can destroy the bus integrity. 610.Pp 611The 612.Vt usb_ctl_request 613structure has the following definition: 614.Bd -literal 615typedef struct { 616 uByte bmRequestType; 617 uByte bRequest; 618 uWord wValue; 619 uWord wIndex; 620 uWord wLength; 621} __packed usb_device_request_t; 622 623struct usb_ctl_request { 624 int ucr_addr; 625 usb_device_request_t ucr_request; 626 void *ucr_data; 627 int ucr_flags; 628#define USBD_SHORT_XFER_OK 0x04 /* allow short reads */ 629 int ucr_actlen; /* actual length transferred */ 630}; 631.Ed 632.Pp 633The 634.Va ucr_addr 635field identifies the device on which to perform the request. 636The 637.Va ucr_request 638field identifies parameters of the request, such as length and type. 639The 640.Va ucr_data 641field contains the location where data will be read from or written to. 642The 643.Va ucr_flags 644field specifies options for the request, and the 645.Va ucr_actlen 646field contains the actual length transferred as the result of the request. 647.El 648.Pp 649The include file 650.In dev/usb/usb.h 651contains definitions for the types used by the various 652.Xr ioctl 2 653calls. 654The naming convention of the fields for the various USB descriptors 655exactly follows the naming in the USB specification. 656Byte sized fields can be accessed directly, but word (16-bit) 657sized fields must be accessed by the 658.Fn UGETW field 659and 660.Fn USETW field value 661macros and double word (32-bit) sized fields must be accessed by the 662.Fn UGETDW field 663and 664.Fn USETDW field value 665macros to handle byte order and alignment properly. 666.Pp 667The include file 668.In dev/usb/usbhid.h 669similarly contains the definitions for 670Human Interface Devices (HID). 671.Sh SEE ALSO 672.Xr usbhidaction 1 , 673.Xr usbhidctl 1 , 674.Xr ioctl 2 , 675.Xr dwctwo 4 , 676.Xr ehci 4 , 677.Xr ohci 4 , 678.Xr uhci 4 , 679.Xr xhci 4 , 680.Xr config 8 , 681.Xr usbdevs 8 682.Pp 683The USB specifications can be found at: 684.Lk https://www.usb.org/documents 685.Sh HISTORY 686The 687.Nm 688driver 689appeared in 690.Ox 2.6 . 691