# SPDX-License-Identifier: GPL-2.0-only # # I2C subsystem configuration # menu "I2C support" config I2C tristate "I2C support" select RT_MUTEXES select IRQ_DOMAIN help I2C (pronounce: I-squared-C) is a slow serial bus protocol used in many micro controller applications and developed by Philips. SMBus, or System Management Bus is a subset of the I2C protocol. More information is contained in the directory <file:Documentation/i2c/>, especially in the file called "summary" there. Both I2C and SMBus are supported here. You will need this for hardware sensors support, and also for Video For Linux support. If you want I2C support, you should say Y here and also to the specific driver for your bus adapter(s) below. This I2C support can also be built as a module. If so, the module will be called i2c-core. config ACPI_I2C_OPREGION bool "ACPI I2C Operation region support" depends on I2C=y && ACPI default y help Say Y here if you want to enable ACPI I2C operation region support. Operation Regions allow firmware (BIOS) code to access I2C slave devices, such as smart batteries through an I2C host controller driver. if I2C config I2C_BOARDINFO bool default y config I2C_COMPAT bool "Enable compatibility bits for old user-space" default y help Say Y here if you intend to run lm-sensors 3.1.1 or older, or any other user-space package which expects i2c adapters to be class devices. If you don't know, say Y. config I2C_CHARDEV tristate "I2C device interface" help Say Y here to use i2c-* device files, usually found in the /dev directory on your system. They make it possible to have user-space programs use the I2C bus. Information on how to do this is contained in the file <file:Documentation/i2c/dev-interface.rst>. This support is also available as a module. If so, the module will be called i2c-dev. config I2C_MUX tristate "I2C bus multiplexing support" help Say Y here if you want the I2C core to support the ability to handle multiplexed I2C bus topologies, by presenting each multiplexed segment as a I2C adapter. This support is also available as a module. If so, the module will be called i2c-mux. source "drivers/i2c/muxes/Kconfig" config I2C_HELPER_AUTO bool "Autoselect pertinent helper modules" default y help Some I2C bus drivers require so-called "I2C algorithm" modules to work. These are basically software-only abstractions of generic I2C interfaces. This option will autoselect them so that you don't have to care. Unselect this only if you need to enable additional helper modules, for example for use with external I2C bus drivers. In doubt, say Y. config I2C_SMBUS tristate "SMBus-specific protocols" if !I2C_HELPER_AUTO help Say Y here if you want support for SMBus extensions to the I2C specification. At the moment, two extensions are supported: the SMBus Alert protocol and the SMBus Host Notify protocol. This support is also available as a module. If so, the module will be called i2c-smbus. source "drivers/i2c/algos/Kconfig" source "drivers/i2c/busses/Kconfig" config I2C_STUB tristate "I2C/SMBus Test Stub" depends on m help This module may be useful to developers of SMBus client drivers, especially for certain kinds of sensor chips. If you do build this module, be sure to read the notes and warnings in <file:Documentation/i2c/i2c-stub.rst>. If you don't know what to do here, definitely say N. config I2C_SLAVE bool "I2C slave support" help This enables Linux to act as an I2C slave device. Note that your I2C bus master driver also needs to support this functionality. Please read Documentation/i2c/slave-interface.rst for further details. if I2C_SLAVE config I2C_SLAVE_EEPROM tristate "I2C eeprom slave driver" help This backend makes Linux behave like an I2C EEPROM. Please read Documentation/i2c/slave-eeprom-backend.rst for further details. config I2C_SLAVE_TESTUNIT tristate "I2C eeprom testunit driver" help This backend can be used to trigger test cases for I2C bus masters which require a remote device with certain capabilities, e.g. multi-master, SMBus Host Notify, etc. Please read Documentation/i2c/slave-testunit-backend.rst for further details. endif config I2C_DEBUG_CORE bool "I2C Core debugging messages" help Say Y here if you want the I2C core to produce a bunch of debug messages to the system log. Select this if you are having a problem with I2C support and want to see more of what is going on. config I2C_DEBUG_ALGO bool "I2C Algorithm debugging messages" help Say Y here if you want the I2C algorithm drivers to produce a bunch of debug messages to the system log. Select this if you are having a problem with I2C support and want to see more of what is going on. config I2C_DEBUG_BUS bool "I2C Bus debugging messages" depends on HAS_IOMEM help Say Y here if you want the I2C bus drivers to produce a bunch of debug messages to the system log. Select this if you are having a problem with I2C support and want to see more of what is going on. endif # I2C endmenu