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 128endif 129 130config I2C_DEBUG_CORE 131 bool "I2C Core debugging messages" 132 help 133 Say Y here if you want the I2C core to produce a bunch of debug 134 messages to the system log. Select this if you are having a 135 problem with I2C support and want to see more of what is going on. 136 137config I2C_DEBUG_ALGO 138 bool "I2C Algorithm debugging messages" 139 help 140 Say Y here if you want the I2C algorithm drivers to produce a bunch 141 of debug messages to the system log. Select this if you are having 142 a problem with I2C support and want to see more of what is going 143 on. 144 145config I2C_DEBUG_BUS 146 bool "I2C Bus debugging messages" 147 depends on HAS_IOMEM 148 help 149 Say Y here if you want the I2C bus drivers to produce a bunch of 150 debug messages to the system log. Select this if you are having 151 a problem with I2C support and want to see more of what is going 152 on. 153 154endif # I2C 155 156endmenu 157