1# SPDX-License-Identifier: GPL-2.0-only
2#
3# I2C subsystem configuration
4#
5
6menu "I2C support"
7
8config I2C
9	tristate "I2C support"
10	select RT_MUTEXES
11	select IRQ_DOMAIN
12	help
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.
18
19	  Both I2C and SMBus are supported here. You will need this for
20	  hardware sensors support, and also for Video For Linux support.
21
22	  If you want I2C support, you should say Y here and also to the
23	  specific driver for your bus adapter(s) below.
24
25	  This I2C support can also be built as a module.  If so, the module
26	  will be called i2c-core.
27
28config ACPI_I2C_OPREGION
29	bool "ACPI I2C Operation region support"
30	depends on I2C=y && ACPI
31	default y
32	help
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.
36
37if I2C
38
39config I2C_BOARDINFO
40	bool
41	default y
42
43config I2C_COMPAT
44	bool "Enable compatibility bits for old user-space"
45	default y
46	help
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.
50
51config I2C_CHARDEV
52	tristate "I2C device interface"
53	help
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>.
58
59	  This support is also available as a module.  If so, the module
60	  will be called i2c-dev.
61
62config I2C_MUX
63	tristate "I2C bus multiplexing support"
64	help
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.
68
69	  This support is also available as a module.  If so, the module
70	  will be called i2c-mux.
71
72source "drivers/i2c/muxes/Kconfig"
73
74config I2C_HELPER_AUTO
75	bool "Autoselect pertinent helper modules"
76	default y
77	help
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
81	  have to care.
82
83	  Unselect this only if you need to enable additional helper
84	  modules, for example for use with external I2C bus drivers.
85
86	  In doubt, say Y.
87
88config I2C_SMBUS
89	tristate "SMBus-specific protocols" if !I2C_HELPER_AUTO
90	help
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.
94
95	  This support is also available as a module.  If so, the module
96	  will be called i2c-smbus.
97
98source "drivers/i2c/algos/Kconfig"
99source "drivers/i2c/busses/Kconfig"
100
101config I2C_STUB
102	tristate "I2C/SMBus Test Stub"
103	depends on m
104	help
105	  This module may be useful to developers of SMBus client drivers,
106	  especially for certain kinds of sensor chips.
107
108	  If you do build this module, be sure to read the notes and warnings
109	  in <file:Documentation/i2c/i2c-stub.rst>.
110
111	  If you don't know what to do here, definitely say N.
112
113config I2C_SLAVE
114	bool "I2C slave support"
115	help
116	  This enables Linux to act as an I2C slave device. Note that your I2C
117	  bus master driver also needs to support this functionality. Please
118	  read Documentation/i2c/slave-interface.rst for further details.
119
120if I2C_SLAVE
121
122config I2C_SLAVE_EEPROM
123	tristate "I2C eeprom slave driver"
124	help
125	  This backend makes Linux behave like an I2C EEPROM. Please read
126	  Documentation/i2c/slave-eeprom-backend.rst for further details.
127
128config I2C_SLAVE_TESTUNIT
129	tristate "I2C eeprom testunit driver"
130	help
131	  This backend can be used to trigger test cases for I2C bus masters
132	  which require a remote device with certain capabilities, e.g.
133	  multi-master, SMBus Host Notify, etc. Please read
134	  Documentation/i2c/slave-testunit-backend.rst for further details.
135
136endif
137
138config I2C_DEBUG_CORE
139	bool "I2C Core debugging messages"
140	help
141	  Say Y here if you want the I2C core to produce a bunch of debug
142	  messages to the system log.  Select this if you are having a
143	  problem with I2C support and want to see more of what is going on.
144
145config I2C_DEBUG_ALGO
146	bool "I2C Algorithm debugging messages"
147	help
148	  Say Y here if you want the I2C algorithm drivers to produce a bunch
149	  of debug messages to the system log.  Select this if you are having
150	  a problem with I2C support and want to see more of what is going
151	  on.
152
153config I2C_DEBUG_BUS
154	bool "I2C Bus debugging messages"
155	depends on HAS_IOMEM
156	help
157	  Say Y here if you want the I2C bus drivers to produce a bunch of
158	  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
160	  on.
161
162endif # I2C
163
164endmenu
165