1 # SPDX-License-Identifier: GPL-2.0-only
3 # I2C subsystem configuration
13 I2C (pronounce: I-squared-C) is a slow serial bus protocol used in
14 many micro controller applications and developed by Philips. SMBus,
15 or System Management Bus is a subset of the I2C protocol. More
16 information is contained in the directory <file:Documentation/i2c/>,
17 especially in the file called "summary" there.
19 Both I2C and SMBus are supported here. You will need this for
20 hardware sensors support, and also for Video For Linux support.
22 If you want I2C support, you should say Y here and also to the
23 specific driver for your bus adapter(s) below.
25 This I2C support can also be built as a module. If so, the module
26 will be called i2c-core.
28 config ACPI_I2C_OPREGION
29 bool "ACPI I2C Operation region support"
30 depends on I2C=y && ACPI
33 Say Y here if you want to enable ACPI I2C operation region support.
34 Operation Regions allow firmware (BIOS) code to access I2C slave devices,
35 such as smart batteries through an I2C host controller driver.
44 bool "Enable compatibility bits for old user-space"
47 Say Y here if you intend to run lm-sensors 3.1.1 or older, or any
48 other user-space package which expects i2c adapters to be class
49 devices. If you don't know, say Y.
52 tristate "I2C device interface"
54 Say Y here to use i2c-* device files, usually found in the /dev
55 directory on your system. They make it possible to have user-space
56 programs use the I2C bus. Information on how to do this is
57 contained in the file <file:Documentation/i2c/dev-interface.rst>.
59 This support is also available as a module. If so, the module
60 will be called i2c-dev.
63 tristate "I2C bus multiplexing support"
65 Say Y here if you want the I2C core to support the ability to
66 handle multiplexed I2C bus topologies, by presenting each
67 multiplexed segment as a I2C adapter.
69 This support is also available as a module. If so, the module
70 will be called i2c-mux.
72 source "drivers/i2c/muxes/Kconfig"
75 tristate "I2C Address Translator (ATR) support" if COMPILE_TEST
77 Enable support for I2C Address Translator (ATR) chips.
79 An ATR allows accessing multiple I2C busses from a single
80 physical bus via address translation instead of bus selection as
83 config I2C_HELPER_AUTO
84 bool "Autoselect pertinent helper modules"
87 Some I2C bus drivers require so-called "I2C algorithm" modules
88 to work. These are basically software-only abstractions of generic
89 I2C interfaces. This option will autoselect them so that you don't
92 Unselect this only if you need to enable additional helper
93 modules, for example for use with external I2C bus drivers.
98 tristate "SMBus-specific protocols" if !I2C_HELPER_AUTO
100 Say Y here if you want support for SMBus extensions to the I2C
101 specification. At the moment, two extensions are supported:
102 the SMBus Alert protocol and the SMBus Host Notify protocol.
104 This support is also available as a module. If so, the module
105 will be called i2c-smbus.
107 source "drivers/i2c/algos/Kconfig"
108 source "drivers/i2c/busses/Kconfig"
111 tristate "I2C/SMBus Test Stub"
114 This module may be useful to developers of SMBus client drivers,
115 especially for certain kinds of sensor chips.
117 If you do build this module, be sure to read the notes and warnings
118 in <file:Documentation/i2c/i2c-stub.rst>.
120 If you don't know what to do here, definitely say N.
123 bool "I2C slave support"
125 This enables Linux to act as an I2C slave device. Note that your I2C
126 bus master driver also needs to support this functionality. Please
127 read Documentation/i2c/slave-interface.rst for further details.
131 config I2C_SLAVE_EEPROM
132 tristate "I2C eeprom slave driver"
134 This backend makes Linux behave like an I2C EEPROM. Please read
135 Documentation/i2c/slave-eeprom-backend.rst for further details.
137 config I2C_SLAVE_TESTUNIT
138 tristate "I2C eeprom testunit driver"
140 This backend can be used to trigger test cases for I2C bus masters
141 which require a remote device with certain capabilities, e.g.
142 multi-master, SMBus Host Notify, etc. Please read
143 Documentation/i2c/slave-testunit-backend.rst for further details.
147 config I2C_DEBUG_CORE
148 bool "I2C Core debugging messages"
150 Say Y here if you want the I2C core to produce a bunch of debug
151 messages to the system log. Select this if you are having a
152 problem with I2C support and want to see more of what is going on.
154 config I2C_DEBUG_ALGO
155 bool "I2C Algorithm debugging messages"
157 Say Y here if you want the I2C algorithm drivers to produce a bunch
158 of debug messages to the system log. Select this if you are having
159 a problem with I2C support and want to see more of what is going
163 bool "I2C Bus debugging messages"
166 Say Y here if you want the I2C bus drivers to produce a bunch of
167 debug messages to the system log. Select this if you are having
168 a problem with I2C support and want to see more of what is going