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"
74 config I2C_HELPER_AUTO
75 bool "Autoselect pertinent helper modules"
78 Some I2C bus drivers require so-called "I2C algorithm" modules
79 to work. These are basically software-only abstractions of generic
80 I2C interfaces. This option will autoselect them so that you don't
83 Unselect this only if you need to enable additional helper
84 modules, for example for use with external I2C bus drivers.
89 tristate "SMBus-specific protocols" if !I2C_HELPER_AUTO
91 Say Y here if you want support for SMBus extensions to the I2C
92 specification. At the moment, two extensions are supported:
93 the SMBus Alert protocol and the SMBus Host Notify protocol.
95 This support is also available as a module. If so, the module
96 will be called i2c-smbus.
98 source "drivers/i2c/algos/Kconfig"
99 source "drivers/i2c/busses/Kconfig"
102 tristate "I2C/SMBus Test Stub"
106 This module may be useful to developers of SMBus client drivers,
107 especially for certain kinds of sensor chips.
109 If you do build this module, be sure to read the notes and warnings
110 in <file:Documentation/i2c/i2c-stub.rst>.
112 If you don't know what to do here, definitely say N.
115 bool "I2C slave support"
117 This enables Linux to act as an I2C slave device. Note that your I2C
118 bus master driver also needs to support this functionality. Please
119 read Documentation/i2c/slave-interface.rst for further details.
123 config I2C_SLAVE_EEPROM
124 tristate "I2C eeprom slave driver"
126 This backend makes Linux behave like an I2C EEPROM. Please read
127 Documentation/i2c/slave-eeprom-backend.rst for further details.
131 config I2C_DEBUG_CORE
132 bool "I2C Core debugging messages"
134 Say Y here if you want the I2C core to produce a bunch of debug
135 messages to the system log. Select this if you are having a
136 problem with I2C support and want to see more of what is going on.
138 config I2C_DEBUG_ALGO
139 bool "I2C Algorithm debugging messages"
141 Say Y here if you want the I2C algorithm drivers to produce a bunch
142 of debug messages to the system log. Select this if you are having
143 a problem with I2C support and want to see more of what is going
147 bool "I2C Bus debugging messages"
150 Say Y here if you want the I2C bus drivers to produce a bunch of
151 debug messages to the system log. Select this if you are having
152 a problem with I2C support and want to see more of what is going