1.\" $OpenBSD: usb.4,v 1.199 2019/12/17 13:08:54 reyk 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: December 17 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/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 umt 4 261USB HID multitouch touchpad devices 262.It Xr uoaklux 4 263Toradex OAK USB illuminance sensor 264.It Xr uoakrh 4 265Toradex OAK USB temperature and relative humidity sensor 266.It Xr uoakv 4 267Toradex OAK USB +/-10V 8channel ADC interface 268.It Xr upd 4 269USB Power Devices sensor 270.It Xr uthum 4 271TEMPer HID thermometer and hygrometer 272.It Xr utpms 4 273Apple touchpad mouse 274.It Xr utrh 4 275USBRH temperature and humidity sensor 276.It Xr utwitch 4 277YUREX USB twitch/jiggle of knee sensor 278.It Xr uwacom 4 279Wacom USB tablets 280.El 281.Ss WAN network devices 282.Bl -tag -width 12n -offset ind -compact 283.It Xr umb 4 284USB Mobile Broadband Interface Model (MBIM) 285.El 286.Ss Miscellaneous devices 287.Bl -tag -width 12n -offset ind -compact 288.It Xr uberry 4 289Research In Motion BlackBerry 290.It Xr ugen 4 291USB generic device support 292.It Xr ugl 4 293Genesys Logic based host-to-host adapters 294.It Xr ugold 4 295TEMPer gold HID thermometer and hygrometer 296.It Xr uonerng 4 297Moonbase Otago OneRNG TRNG 298.It Xr uow 4 299Maxim/Dallas DS2490 USB 1-Wire adapter 300.It Xr upl 4 301Prolific based host-to-host adapters 302.It Xr urng 4 303USB Random Number Generator devices 304.It Xr usps 4 305USPS composite AC power and temperature sensor 306.It Xr uts 4 307USB touchscreen support 308.El 309.Sh INTRODUCTION TO USB 310There are different versions of the USB 311which provide different speeds. 312USB 3 can operate up to 5.0Gb/s. 313USB 2 operates at 480Mb/s, while USB versions 1 and 1.1 operate at 31412 Mb/s and 1.5 Mb/s for low speed devices. 315Each USB has a host controller that is the master of the bus; 316all other devices on the bus only speak when spoken to. 317.Pp 318There can be up to 127 devices (apart from the host controller) 319on a bus, each with its own address. 320The addresses are assigned 321dynamically by the host when each device is attached to the bus. 322.Pp 323Within each device there can be up to 16 endpoints. 324Each endpoint 325is individually addressed and the addresses are static. 326Each of these endpoints will communicate in one of four different modes: 327control, isochronous, bulk, or interrupt. 328A device always has at least one endpoint. 329This is a control endpoint at address 0 330and is used to give commands to the device and extract basic data, 331such as descriptors, from the device. 332Each endpoint, except the control endpoint, is unidirectional. 333.Pp 334The endpoints in a device are grouped into interfaces. 335An interface is a logical unit within a device; e.g., 336a compound device with both a keyboard and a trackball would present 337one interface for each. 338An interface can sometimes be set into different modes, 339called alternate settings, which affects how it operates. 340Different alternate settings can have different endpoints 341within it. 342.Pp 343A device may operate in different configurations. 344Depending on the 345configuration the device may present different sets of endpoints 346and interfaces. 347.Pp 348Each device located on a hub has several 349.Xr config 8 350locators: 351.Pp 352.Bl -tag -width configuration -compact 353.It Cd port 354Number of the port on closest upstream hub. 355.It Cd configuration 356Configuration the device must be in for this driver to attach. 357This locator does not set the configuration; it is iterated by the bus 358enumeration. 359.It Cd interface 360Interface number within a device that an interface driver attaches to. 361.It Cd vendor 36216-bit vendor ID of the device. 363.It Cd product 36416-bit product ID of the device. 365.It Cd release 36616-bit release (revision) number of the device. 367.El 368.Pp 369The first locator can be used to pin down a particular device 370according to its physical position in the device tree. 371The last three locators can be used to pin down a particular 372device according to what device it actually is. 373.Pp 374The bus enumeration of the USB bus proceeds in several steps: 375.Bl -enum 376.It 377Any device-specific driver can attach to the device. 378.It 379If none is found, any device class specific driver can attach. 380.It 381If none is found, all configurations are iterated over. 382For each configuration all the interfaces are iterated over and interface 383drivers can attach. 384If any interface driver attached in a certain 385configuration, the iteration over configurations is stopped. 386.It 387If still no drivers have been found, the generic USB driver can attach. 388.El 389.Sh USB CONTROLLER INTERFACE 390Use the following to get access to the USB specific structures 391and defines: 392.Bd -literal -offset indent 393#include <dev/usb/usb.h> 394.Ed 395.Pp 396The 397.Pa /dev/usbN 398device can be opened and a few operations can be performed on it. 399The following 400.Xr ioctl 2 401commands are supported on the controller device: 402.Bl -tag -width xxxxxx 403.It Dv USB_DEVICEINFO Fa "struct usb_device_info" 404This command can be used to retrieve some information about a device 405on the bus. 406The 407.Va udi_addr 408field should be filled before the call and the other fields will 409be filled by information about the device on that address. 410Should no such device exist, an error is reported. 411.Bd -literal 412#define USB_MAX_DEVNAMES 4 413#define USB_MAX_DEVNAMELEN 16 414struct usb_device_info { 415 u_int8_t udi_bus; 416 u_int8_t udi_addr; /* device address */ 417 char udi_product[USB_MAX_STRING_LEN]; 418 char udi_vendor[USB_MAX_STRING_LEN]; 419 char udi_release[8]; 420 u_int16_t udi_productNo; 421 u_int16_t udi_vendorNo; 422 u_int16_t udi_releaseNo; 423 u_int8_t udi_class; 424 u_int8_t udi_subclass; 425 u_int8_t udi_protocol; 426 u_int8_t udi_config; 427 u_int8_t udi_speed; 428#define USB_SPEED_LOW 1 429#define USB_SPEED_FULL 2 430#define USB_SPEED_HIGH 3 431 int udi_power; /* power consumption */ 432 int udi_nports; 433 char udi_devnames[USB_MAX_DEVNAMES] 434 [USB_MAX_DEVNAMELEN]; 435 u_int8_t udi_ports[16]; /* hub only */ 436#define USB_PORT_ENABLED 0xff 437#define USB_PORT_SUSPENDED 0xfe 438#define USB_PORT_POWERED 0xfd 439#define USB_PORT_DISABLED 0xfc 440 char udi_serial[USB_MAX_STRING_LEN]; 441}; 442.Ed 443.Pp 444The 445.Va udi_bus 446field contains the device unit number of the device. 447.Pp 448The 449.Va udi_product , 450.Va udi_vendor , 451and 452.Va udi_release 453fields contain self-explanatory descriptions of the device. 454The 455.Va udi_productNo , 456.Va udi_vendorNo , 457and 458.Va udi_releaseNo 459fields contain numeric identifiers for the device. 460.Pp 461The 462.Va udi_class 463and 464.Va udi_subclass 465fields contain the device class and subclass. 466.Pp 467The 468.Va udi_config 469field shows the current configuration of the device. 470.Pp 471The 472.Va udi_protocol 473field contains the device protocol as given from the device. 474.Pp 475The 476.Va udi_speed 477field 478contains the speed of the device. 479.Pp 480The 481.Va udi_power 482field shows the power consumption in milli-amps drawn at 5 volts 483or is zero if the device is self powered. 484.Pp 485The 486.Va udi_devnames 487field contains the names and instance numbers of the device drivers 488for the devices attached to this device. 489.Pp 490If the device is a hub, the 491.Va udi_nports 492field is non-zero and the 493.Va udi_ports 494field contains the addresses of the connected devices. 495If no device is connected to a port, one of the 496.Dv USB_PORT_* 497values indicates its status. 498.It Dv USB_DEVICESTATS Fa "struct usb_device_stats" 499This command retrieves statistics about the controller. 500.Bd -unfilled 501struct usb_device_stats { 502 u_long uds_requests[4]; 503}; 504.Ed 505.Pp 506The 507.Va uds_requests 508field is indexed by the transfer kind, i.e.\& 509.Dv UE_* , 510and indicates how many transfers of each kind have been completed 511by the controller. 512.It Dv USB_DEVICE_GET_DDESC Fa "struct usb_device_ddesc" 513This command can be used to retrieve the device descriptor 514of a device on the bus. 515The 516.Va udd_addr 517field needs to be filled with the bus device address: 518.Bd -literal 519struct usb_device_ddesc { 520 u_int8_t udd_bus; 521 u_int8_t udd_addr; /* device address */ 522 usb_device_descriptor_t udd_desc; 523}; 524.Ed 525.Pp 526The 527.Va udd_bus 528field contains the device unit number. 529.Pp 530The 531.Va udd_desc 532field contains the device descriptor structure. 533.It Dv USB_DEVICE_GET_CDESC Fa "struct usb_device_cdesc" 534This command can be used to retrieve the configuration descriptor for the 535given configuration of a device on the bus. 536The 537.Va udc_addr 538field needs to be filled with the bus device address. 539The 540.Va udc_config_index 541field needs to be filled with the configuration index for the 542relevant configuration descriptor. 543For convenience the current configuration can be specified by 544.Dv USB_CURRENT_CONFIG_INDEX : 545.Bd -literal 546struct usb_device_cdesc { 547 u_int8_t udc_bus; 548 u_int8_t udc_addr; /* device address */ 549 int udc_config_index; 550 usb_config_descriptor_t udc_desc; 551}; 552.Ed 553.Pp 554The 555.Va udc_bus 556field contains the device unit number. 557.Pp 558The 559.Va udc_desc 560field contains the configuration descriptor structure. 561.It Dv USB_DEVICE_GET_FDESC Fa "struct usb_device_fdesc" 562This command can be used to retrieve all descriptors for the 563given configuration of a device on the bus. 564The 565.Va udf_addr 566field needs to be filled with the bus device address. 567The 568.Va udf_config_index 569field needs to be filled with the configuration index for the 570relevant configuration descriptor. 571For convenience the current configuration can be specified by 572.Dv USB_CURRENT_CONFIG_INDEX . 573The 574.Va udf_data 575field needs to point to a memory area of the size given in the 576.Va udf_size 577field. 578The proper size can be determined by first issuing a 579.Dv USB_DEVICE_GET_CDESC 580command and inspecting the 581.Va wTotalLength 582field: 583.Bd -literal 584struct usb_device_fdesc { 585 u_int8_t udf_bus; 586 u_int8_t udf_addr; /* device address */ 587 int udf_config_index; 588 u_int udf_size; 589 u_char *udf_data; 590}; 591.Ed 592.Pp 593The 594.Va udf_bus 595field contains the device unit number. 596.Pp 597The 598.Va udf_data 599field contains all descriptors. 600.It Dv USB_REQUEST Fa "struct usb_ctl_request" 601This command can be used to execute arbitrary requests on the control pipe. 602This is 603.Em DANGEROUS 604and should be used with great care since it 605can destroy the bus integrity. 606.Pp 607The 608.Vt usb_ctl_request 609structure has the following definition: 610.Bd -literal 611typedef struct { 612 uByte bmRequestType; 613 uByte bRequest; 614 uWord wValue; 615 uWord wIndex; 616 uWord wLength; 617} __packed usb_device_request_t; 618 619struct usb_ctl_request { 620 int ucr_addr; 621 usb_device_request_t ucr_request; 622 void *ucr_data; 623 int ucr_flags; 624#define USBD_SHORT_XFER_OK 0x04 /* allow short reads */ 625 int ucr_actlen; /* actual length transferred */ 626}; 627.Ed 628.Pp 629The 630.Va ucr_addr 631field identifies the device on which to perform the request. 632The 633.Va ucr_request 634field identifies parameters of the request, such as length and type. 635The 636.Va ucr_data 637field contains the location where data will be read from or written to. 638The 639.Va ucr_flags 640field specifies options for the request, and the 641.Va ucr_actlen 642field contains the actual length transferred as the result of the request. 643.El 644.Pp 645The include file 646.In dev/usb/usb.h 647contains definitions for the types used by the various 648.Xr ioctl 2 649calls. 650The naming convention of the fields for the various USB descriptors 651exactly follows the naming in the USB specification. 652Byte sized fields can be accessed directly, but word (16-bit) 653sized fields must be accessed by the 654.Fn UGETW field 655and 656.Fn USETW field value 657macros and double word (32-bit) sized fields must be accessed by the 658.Fn UGETDW field 659and 660.Fn USETDW field value 661macros to handle byte order and alignment properly. 662.Pp 663The include file 664.In dev/usb/usbhid.h 665similarly contains the definitions for 666Human Interface Devices (HID). 667.Sh SEE ALSO 668.Xr usbhidaction 1 , 669.Xr usbhidctl 1 , 670.Xr ioctl 2 , 671.Xr dwctwo 4 , 672.Xr ehci 4 , 673.Xr ohci 4 , 674.Xr uhci 4 , 675.Xr xhci 4 , 676.Xr config 8 , 677.Xr usbdevs 8 678.Pp 679The USB specifications can be found at 680.Lk http://www.usb.org/developers/docs/ 681.Sh HISTORY 682The 683.Nm 684driver 685appeared in 686.Ox 2.6 . 687