1.\" $NetBSD: iic.4,v 1.22 2018/02/26 08:23:44 wiz Exp $ 2.\" $OpenBSD: iic.4,v 1.74 2008/09/10 16:13:43 reyk Exp $ 3.\" 4.\" Copyright (c) 2004, 2006 Alexander Yurchenko <grange@openbsd.org> 5.\" Copyright (c) 2009 Hubert Feyrer <hubertf@NetBSD.org> 6.\" 7.\" Permission to use, copy, modify, and distribute this software for any 8.\" purpose with or without fee is hereby granted, provided that the above 9.\" copyright notice and this permission notice appear in all copies. 10.\" 11.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18.\" 19.Dd February 26, 2018 20.Dt IIC 4 21.Os 22.Sh NAME 23.Nm iic 24.Nd Inter IC (I2C) bus 25.Sh SYNOPSIS 26.\" 27.\" Use the following commands in (t)csh to output the list below (note 28.\" the first sed command includes a <space> and <tab> character in each 29.\" of the bracket expressions): 30.\" cd .../src/sys/arch 31.\" grep -h '^iic.*at' */conf/* | sort -u -k +3 | sed -e 's,[ ][ ]*, ,g' -e 's, *#.*,,' | sh -c 'while read iic at ic ; do printf ".Cd \"$iic $at %-20s # %s\"\n" "$ic" "`grep \"iic.*at.*$ic\" */conf/* | sed \"s,/.*,,\" | sort -u | tr \"\012\" \ `" ; done' | uniq | tee /tmp/x 32.\" cat /tmp/x 33.\" 34.Cd "iic* at alipm? # alpha amd64 i386 sparc64 " 35.Cd "iic* at amdpm? # amd64 i386 " 36.Cd "iic* at armadillo9iic? # evbarm " 37.Cd "iic0 at at91twi? # evbarm " 38.Cd "iic0 at ausmbus0 # evbmips " 39.Cd "iic* at awiniic? # evbarm " 40.Cd "iic* at bcmi2c? # evbarm " 41.Cd "iic* at coram? # amd64 i386 " 42.Cd "iic* at cuda? # macppc " 43.Cd "iic* at cxdtv? # amd64 i386 " 44.Cd "iic* at diic? # acorn32 evbppc " 45.Cd "iic* at dwiic? # amd64 i386 " 46.Cd "iic* at exyoi2c? # evbarm " 47.Cd "iic* at g2i2c? # evbarm " 48.Cd "iic0 at gpiic? # evbppc " 49.Cd "iic* at gpioiic? # amd64 i386 " 50.Cd "iic* at gttwsi? # evbarm evbppc " 51.Cd "iic* at gxiic? # evbarm " 52.Cd "iic* at i2cbus? # evbarm " 53.Cd "iic* at ichsmb? # amd64 i386 " 54.Cd "iic* at imcsmb? # amd64 i386 " 55.Cd "iic* at imxi2c? # evbarm " 56.Cd "iic0 at iomdiic? # acorn32 " 57.Cd "iic0 at iopiic? # evbarm iyonix " 58.Cd "iic* at ismt? # amd64 i386 " 59.Cd "iic* at jziic? # evbmips " 60.Cd "iic* at ki2c? # macppc " 61.Cd "iic* at nbpiic? # hpcarm " 62.Cd "iic* at nfsmb? # amd64 i386 " 63.Cd "iic* at ociic? # sandpoint " 64.Cd "iic* at omapiic? # evbarm " 65.Cd "iic* at pcfiic? # sparc64 " 66.Cd "iic* at piixpm? # amd64 i386 " 67.Cd "iic* at pmu? # macppc " 68.Cd "iic* at ri2c? # evbmips " 69.Cd "iic* at rtciic? # mmeye " 70.Cd "iic0 at slugiic0 # evbarm " 71.Cd "iic* at tegrai2c? # evbarm " 72.Cd "iic* at tiiic? # evbarm " 73.Cd "iic* at tsciic? # alpha " 74.Cd "iic* at viapcib? # i386 " 75.Cd "iic* at voyager0 # evbmips " 76.Cd "iic0 at ziic? # evbmips zaurus " 77.Sh DESCRIPTION 78I2C is a two-wire bus developed by Philips used for connecting 79integrated circuits. 80It is commonly used for connecting devices such as EEPROMs, 81temperature sensors, fan controllers, real-time clocks, tuners, 82and other types of integrated circuits. 83.Pp 84The 85.Nm 86driver provides a uniform programming interface layer between I2C 87master controllers and various I2C slave devices. 88Each I2C master controller attaches an 89.Nm 90framework; several slave devices can then be attached to the 91.Nm 92bus. 93.Pp 94All I2C slave devices are uniquely identified by the address on the bus. 95The master accesses a particular slave device using its address. 96.\" Devices are found on the bus using a sophisticated scanning routine 97.\" which attempts to identify commonly available devices. 98.\" On other machines (such as sparc64 and macppc) where the machine ROM 99.\" supplies a list of I2C devices, that list is used instead. 100.Pp 101System Management Bus (SMBus) protocol is also supported by emulating 102it with the I2C commands. 103.Sh SUPPORTED MASTERS 104A wide list of I2C masters are supported, among them are: 105.Pp 106.\" 107.\" Generate the following list with these (t)csh commands: 108.\" cd .../src/sys/arch 109.\" grep -h '^iic.*at' */conf/* | awk '{print $3}' | sed 's,.$,,' | sort -u | sh -c 'while read i ; do echo .It Xr $i 4; n=`grep -h ^.Nd ../../share/man/man4/$i* | sed "s,^.Nd ,,"`; if [ -n "$n" ]; then echo $n ; else echo "" ; fi ; done' | tee /tmp/x 110.\" cat /tmp/x 111.\" 112.Bl -tag -width 18n -compact -offset indent 113.It Xr acpismbus 4 114ACPI SMBus Control Method Interface 115.It Xr alipm 4 116Acer Labs M7101 SMBus controller 117.It Xr amdpm 4 118AMD768 Power Management Controller and AMD8111 System Management Controller 119.It Xr armadillo9iic 4 120.It Xr at91twi 4 121.It Xr ausmbus 4 122.It Xr awiniic 4 123.It Xr awinp2wi 4 124.It Xr bcmi2c 4 125.It Xr coram 4 126digital video driver for Conexant CX23885 based cards 127.It Xr cuda 4 128support for CUDA microcontrollers found in many Power Macintosh and 129compatible computers 130.It Xr cxdtv 4 131digital video driver for Conexant CX2388x based cards 132.It Xr diic 4 133.It Xr exyoiic 4 134.It Xr g2i2c 4 135.It Xr gpiic 4 136.It Xr gpioiic 4 137GPIO I2C controller 138.It Xr gttwsi 4 139.It Xr i2cbus 4 140.It Xr gxiic 4 141.It Xr ichsmb 4 142Intel Chipset internal SMBus controller 143.It Xr imxi2c 4 144.It Xr iociic 4 145.It Xr iomdiic 4 146.It Xr iopiic 4 147.It Xr ismt 4 148Intel Chipset internal SMBus 2.0 controller with DMA 149.It Xr jziic 4 150.It Xr ki2c 4 151.It Xr nbpiic 4 152.It Xr nfsmb 4 153NVIDIA nForce 2/3/4 SMBus controller and SMBus driver 154.It Xr ociic 4 155.It Xr omapiic 4 156.It Xr pcfiic 4 157.It Xr piixpm 4 158Intel PIIX and compatible Power Management controller 159.It Xr ri2c 4 160.It Xr rkiic 4 161.It Xr rtciic 4 162.It Xr slugiic 4 163.It Xr tegrai2c 4 164.It Xr tiiic 4 165.It Xr tsciic 4 166.It Xr viapcib 4 167.El 168.Sh SUPPORTED SLAVES 169A wide list of slaves are supported, among them: 170.Pp 171.\" 172.\" Create the following list with these commands: 173.\" cd .../src/sys/arch 174.\" grep -h '.* at iic.*' */conf/* | sed -e 's,^#,,' -e 's, .*,,' -e 's,.$,,' | sort -u | sh -c 'while read i ; do echo .It Xr $i 4 ; n=`grep ^.Nd ../../share/man/man4/$i* | sed "s,^.Nd ,,"` ; if [ -n "$n" ]; then echo $n ; else echo "" ; fi ; done' | tee /tmp/x 175.\" cat /tmp/x 176.\" 177.Bl -tag -width 13n -compact -offset indent 178.It Xr dbcool 4 179dbCool(tm) family of environmental monitors and fan controllers 180.It Xr dsrtc 4 181.It Xr ioexp 4 182.It Xr m41trtc 4 183.It Xr nbppcon 4 184.It Xr pcf8563rtc 4 185NXP PCF8563 real-time clock 186.It Xr r2025rtc 4 187.It Xr rs5c372rtc 4 188RICOH RS5C372A and RS5C372B real-time clock 189.It Xr s390rtc 4 190Seiko Instruments S-35390 real-time clock 191.It Xr sdtemp 4 192JEDEC JC-42.4 compatible memory module temperature sensors 193.It Xr seeprom 4 19424-series I2C EEPROM driver 195.It Xr sgsmix 4 196driver for SGS 7433 Basic Audio Processor found in some Apple machines 197.It Xr spdmem 4 198Generic Memory Module Serial Presence Detect 199.El 200.Sh SEE ALSO 201.Xr dtviic 4 , 202.Xr intro 4 , 203.Xr i2cscan 8 , 204.Xr iic 9 205.Sh HISTORY 206The I2C framework first appeared in 207.Nx 2.0 . 208.Ox 209support was added in 210.Ox 3.6 . 211This manpage first appeared in 212.Nx 6.0 , 213it was ported from 214.Ox . 215.Sh AUTHORS 216.An -nosplit 217The I2C framework was written by 218.An Steve C. Woodford 219and 220.An Jason R. Thorpe 221for 222.Nx 223and then ported to 224.Ox 225by 226.An Alexander Yurchenko Aq Mt grange@openbsd.org . 227