1ec8f24b7SThomas Gleixner# SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds# 3be53f9b2SArthur Othieno# I2C subsystem configuration 41da177e4SLinus Torvalds# 51da177e4SLinus Torvalds 6da3c6647SLan Tianyumenu "I2C support" 7da3c6647SLan Tianyu 8da3c6647SLan Tianyuconfig I2C 91da177e4SLinus Torvalds tristate "I2C support" 10194684e5SMika Kuoppala select RT_MUTEXES 114d5538f5SBenjamin Tissoires select IRQ_DOMAIN 12a7f7f624SMasahiro Yamada help 13622e040dSMichael Witten I2C (pronounce: I-squared-C) is a slow serial bus protocol used in 141da177e4SLinus Torvalds many micro controller applications and developed by Philips. SMBus, 151da177e4SLinus Torvalds or System Management Bus is a subset of the I2C protocol. More 161da177e4SLinus Torvalds information is contained in the directory <file:Documentation/i2c/>, 171da177e4SLinus Torvalds especially in the file called "summary" there. 181da177e4SLinus Torvalds 191da177e4SLinus Torvalds Both I2C and SMBus are supported here. You will need this for 201da177e4SLinus Torvalds hardware sensors support, and also for Video For Linux support. 211da177e4SLinus Torvalds 221da177e4SLinus Torvalds If you want I2C support, you should say Y here and also to the 231da177e4SLinus Torvalds specific driver for your bus adapter(s) below. 241da177e4SLinus Torvalds 251da177e4SLinus Torvalds This I2C support can also be built as a module. If so, the module 261da177e4SLinus Torvalds will be called i2c-core. 271da177e4SLinus Torvalds 2836604751SLan Tianyuconfig ACPI_I2C_OPREGION 2936604751SLan Tianyu bool "ACPI I2C Operation region support" 3036604751SLan Tianyu depends on I2C=y && ACPI 31da3c6647SLan Tianyu default y 32da3c6647SLan Tianyu help 3336604751SLan Tianyu Say Y here if you want to enable ACPI I2C operation region support. 3436604751SLan Tianyu Operation Regions allow firmware (BIOS) code to access I2C slave devices, 3536604751SLan Tianyu such as smart batteries through an I2C host controller driver. 36da3c6647SLan Tianyu 3716538e6bSJan Engelhardtif I2C 3816538e6bSJan Engelhardt 399c1600edSDavid Brownellconfig I2C_BOARDINFO 406341e62bSChristoph Jaeger bool 419c1600edSDavid Brownell default y 429c1600edSDavid Brownell 432bb5095aSJean Delvareconfig I2C_COMPAT 446341e62bSChristoph Jaeger bool "Enable compatibility bits for old user-space" 452bb5095aSJean Delvare default y 462bb5095aSJean Delvare help 472bb5095aSJean Delvare Say Y here if you intend to run lm-sensors 3.1.1 or older, or any 482bb5095aSJean Delvare other user-space package which expects i2c adapters to be class 492bb5095aSJean Delvare devices. If you don't know, say Y. 502bb5095aSJean Delvare 511da177e4SLinus Torvaldsconfig I2C_CHARDEV 521da177e4SLinus Torvalds tristate "I2C device interface" 531da177e4SLinus Torvalds help 541da177e4SLinus Torvalds Say Y here to use i2c-* device files, usually found in the /dev 551da177e4SLinus Torvalds directory on your system. They make it possible to have user-space 561da177e4SLinus Torvalds programs use the I2C bus. Information on how to do this is 57ccf988b6SMauro Carvalho Chehab contained in the file <file:Documentation/i2c/dev-interface.rst>. 581da177e4SLinus Torvalds 591da177e4SLinus Torvalds This support is also available as a module. If so, the module 601da177e4SLinus Torvalds will be called i2c-dev. 611da177e4SLinus Torvalds 620826374bSMichael Lawnickconfig I2C_MUX 630826374bSMichael Lawnick tristate "I2C bus multiplexing support" 640826374bSMichael Lawnick help 650826374bSMichael Lawnick Say Y here if you want the I2C core to support the ability to 660826374bSMichael Lawnick handle multiplexed I2C bus topologies, by presenting each 670826374bSMichael Lawnick multiplexed segment as a I2C adapter. 680826374bSMichael Lawnick 690826374bSMichael Lawnick This support is also available as a module. If so, the module 700826374bSMichael Lawnick will be called i2c-mux. 710826374bSMichael Lawnick 728636a1f9SMasahiro Yamadasource "drivers/i2c/muxes/Kconfig" 737f528135SMichael Lawnick 748d24f8dcSJean Delvareconfig I2C_HELPER_AUTO 758d24f8dcSJean Delvare bool "Autoselect pertinent helper modules" 768d24f8dcSJean Delvare default y 778d24f8dcSJean Delvare help 788d24f8dcSJean Delvare Some I2C bus drivers require so-called "I2C algorithm" modules 798d24f8dcSJean Delvare to work. These are basically software-only abstractions of generic 808d24f8dcSJean Delvare I2C interfaces. This option will autoselect them so that you don't 818d24f8dcSJean Delvare have to care. 828d24f8dcSJean Delvare 838d24f8dcSJean Delvare Unselect this only if you need to enable additional helper 848d24f8dcSJean Delvare modules, for example for use with external I2C bus drivers. 858d24f8dcSJean Delvare 868d24f8dcSJean Delvare In doubt, say Y. 878d24f8dcSJean Delvare 88e2ca3074SJean Delvareconfig I2C_SMBUS 89dfc518ddSArnaud Lacombe tristate "SMBus-specific protocols" if !I2C_HELPER_AUTO 90e2ca3074SJean Delvare help 91e2ca3074SJean Delvare Say Y here if you want support for SMBus extensions to the I2C 92d380a204SJean Delvare specification. At the moment, two extensions are supported: 93d380a204SJean Delvare the SMBus Alert protocol and the SMBus Host Notify protocol. 94e2ca3074SJean Delvare 95e2ca3074SJean Delvare This support is also available as a module. If so, the module 96e2ca3074SJean Delvare will be called i2c-smbus. 97e2ca3074SJean Delvare 988636a1f9SMasahiro Yamadasource "drivers/i2c/algos/Kconfig" 998636a1f9SMasahiro Yamadasource "drivers/i2c/busses/Kconfig" 1001da177e4SLinus Torvalds 1013ddb59d4SPeter Hueweconfig I2C_STUB 1023ddb59d4SPeter Huewe tristate "I2C/SMBus Test Stub" 103417e86ceSKees Cook depends on m 1043ddb59d4SPeter Huewe help 1053ddb59d4SPeter Huewe This module may be useful to developers of SMBus client drivers, 1063ddb59d4SPeter Huewe especially for certain kinds of sensor chips. 1073ddb59d4SPeter Huewe 1083ddb59d4SPeter Huewe If you do build this module, be sure to read the notes and warnings 109ccf988b6SMauro Carvalho Chehab in <file:Documentation/i2c/i2c-stub.rst>. 1103ddb59d4SPeter Huewe 1113ddb59d4SPeter Huewe If you don't know what to do here, definitely say N. 1123ddb59d4SPeter Huewe 113389be323SWolfram Sangconfig I2C_SLAVE 114389be323SWolfram Sang bool "I2C slave support" 11558e64b05SWolfram Sang help 11658e64b05SWolfram Sang This enables Linux to act as an I2C slave device. Note that your I2C 11758e64b05SWolfram Sang bus master driver also needs to support this functionality. Please 11858e64b05SWolfram Sang read Documentation/i2c/slave-interface.rst for further details. 119389be323SWolfram Sang 120389be323SWolfram Sangif I2C_SLAVE 121389be323SWolfram Sang 122389be323SWolfram Sangconfig I2C_SLAVE_EEPROM 123389be323SWolfram Sang tristate "I2C eeprom slave driver" 12459d3d604SWolfram Sang help 12559d3d604SWolfram Sang This backend makes Linux behave like an I2C EEPROM. Please read 12659d3d604SWolfram Sang Documentation/i2c/slave-eeprom-backend.rst for further details. 127389be323SWolfram Sang 128a8335c64SWolfram Sangconfig I2C_SLAVE_TESTUNIT 129a8335c64SWolfram Sang tristate "I2C eeprom testunit driver" 130a8335c64SWolfram Sang help 131a8335c64SWolfram Sang This backend can be used to trigger test cases for I2C bus masters 132a8335c64SWolfram Sang which require a remote device with certain capabilities, e.g. 133a8335c64SWolfram Sang multi-master, SMBus Host Notify, etc. Please read 134a8335c64SWolfram Sang Documentation/i2c/slave-testunit-backend.rst for further details. 135a8335c64SWolfram Sang 136389be323SWolfram Sangendif 137389be323SWolfram Sang 1381da177e4SLinus Torvaldsconfig I2C_DEBUG_CORE 1391da177e4SLinus Torvalds bool "I2C Core debugging messages" 1401da177e4SLinus Torvalds help 1411da177e4SLinus Torvalds Say Y here if you want the I2C core to produce a bunch of debug 1421da177e4SLinus Torvalds messages to the system log. Select this if you are having a 1431da177e4SLinus Torvalds problem with I2C support and want to see more of what is going on. 1441da177e4SLinus Torvalds 1451da177e4SLinus Torvaldsconfig I2C_DEBUG_ALGO 1461da177e4SLinus Torvalds bool "I2C Algorithm debugging messages" 1471da177e4SLinus Torvalds help 1481da177e4SLinus Torvalds Say Y here if you want the I2C algorithm drivers to produce a bunch 1491da177e4SLinus Torvalds of debug messages to the system log. Select this if you are having 1501da177e4SLinus Torvalds a problem with I2C support and want to see more of what is going 1511da177e4SLinus Torvalds on. 1521da177e4SLinus Torvalds 1531da177e4SLinus Torvaldsconfig I2C_DEBUG_BUS 1541da177e4SLinus Torvalds bool "I2C Bus debugging messages" 1553ddb59d4SPeter Huewe depends on HAS_IOMEM 1561da177e4SLinus Torvalds help 1571da177e4SLinus Torvalds Say Y here if you want the I2C bus drivers to produce a bunch of 1581da177e4SLinus Torvalds debug messages to the system log. Select this if you are having 1591da177e4SLinus Torvalds a problem with I2C support and want to see more of what is going 1601da177e4SLinus Torvalds on. 1611da177e4SLinus Torvalds 16216538e6bSJan Engelhardtendif # I2C 163da3c6647SLan Tianyu 164da3c6647SLan Tianyuendmenu 165