iic* at alipm? # alpha amd64 i386 sparc64
iic* at amdpm? # amd64 i386
iic* at armadillo9iic? # evbarm
iic0 at at91twi? # evbarm
iic0 at ausmbus0 # evbmips
iic* at awiniic? # evbarm
iic* at bcmi2c? # evbarm
iic* at coram? # amd64 i386
iic* at cuda? # macppc
iic* at cxdtv? # amd64 i386
iic* at diic? # acorn32 evbppc
iic* at dwiic? # amd64 i386
iic* at exyoi2c? # evbarm
iic* at g2i2c? # evbarm
iic0 at gpiic? # evbppc
iic* at gpioiic? # amd64 i386
iic* at gttwsi? # evbarm evbppc
iic* at gxiic? # evbarm
iic* at i2cbus? # evbarm
iic* at ichsmb? # amd64 i386
iic* at imcsmb? # amd64 i386
iic* at imxi2c? # evbarm
iic0 at iomdiic? # acorn32
iic0 at iopiic? # evbarm iyonix
iic* at ismt? # amd64 i386
iic* at jziic? # evbmips
iic* at ki2c? # macppc
iic* at nbpiic? # hpcarm
iic* at nfsmb? # amd64 i386
iic* at ociic? # sandpoint
iic* at omapiic? # evbarm
iic* at pcfiic? # sparc64
iic* at piixpm? # amd64 i386
iic* at pmu? # macppc
iic* at ri2c? # evbmips
iic* at rtciic? # mmeye
iic0 at slugiic0 # evbarm
iic* at tegrai2c? # evbarm
iic* at tiiic? # evbarm
iic* at tsciic? # alpha
iic* at viapcib? # i386
iic* at voyager0 # evbmips
iic0 at ziic? # evbmips zaurus
I2C is a two-wire bus developed by Philips used for connecting integrated
circuits. It is commonly used for connecting devices such as EEPROMs,
temperature sensors, fan controllers, real-time clocks, tuners, and other
types of integrated circuits.
The iic
driver provides a uniform
programming interface layer between I2C master controllers and various I2C
slave devices. Each I2C master controller attaches an
iic
framework; several slave devices can then be
attached to the iic
bus.
All I2C slave devices are uniquely identified by the address on
the bus. The master accesses a particular slave device using its
address.
System Management Bus (SMBus) protocol is also supported by
emulating it with the I2C commands.
The following ioctl(2) calls apply
to IIC devices. They are defined in the header file
<dev/i2c/i2c_io.h>
:
I2C_IOCTL_EXEC
(i2c_ioctl_exec_t)
- User ioctl to execute an i2c operation.
typedef enum {
I2C_OP_READ,
I2C_OP_READ_WITH_STOP,
I2C_OP_WRITE,
I2C_OP_WRITE_WITH_STOP,
I2C_OP_READ_BLOCK,
I2C_OP_WRITE_BLOCK
} i2c_op_t;
typedef struct i2c_ioctl_exec {
i2c_op_t iie_op; /* operation to perform */
i2c_addr_t iie_addr; /* address of device */
const void *iie_cmd; /* pointer to command */
size_t iie_cmdlen; /* length of command */
void *iie_buf; /* pointer to data buffer */
size_t iie_buflen; /* length of data buffer */
} i2c_ioctl_exec_t;
A wide list of I2C masters are supported, among them are:
- acpismbus(4)
- ACPI SMBus Control Method Interface
- alipm(4)
- Acer Labs M7101 SMBus controller
- amdpm(4)
- AMD768 Power Management Controller and AMD8111 System Management
Controller
- coram(4)
- Digital video driver for Conexant CX23885 based cards
- cuda(4)
- Support for CUDA microcontrollers found in many Power Macintosh and
compatible computers
- cxdtv(4)
- Digital video driver for Conexant CX2388x based cards
- gpioiic(4)
- GPIO I2C controller
- ichsmb(4)
- Intel Chipset internal SMBus controller
- ismt(4)
- Intel Chipset internal SMBus 2.0 controller with DMA
- nfsmb(4)
- NVIDIA nForce 2/3/4 SMBus controller and SMBus driver
- piixpm(4)
- Intel PIIX and compatible Power Management controller
A wide list of slaves are supported, among them:
- adm1026hm(4)
- Analog Devices ADM1026 complete thermal system management controller
- admtemp(4)
- Analog Devices ADM1021 temperature sensor
- aht20temp(4)
- Aosong AHT20 humidity/temperature sensors
- am2315temp(4)
- Aosong AM2315 humidity/temperature sensors
- bmx280thp(4)
- Bosch BMP280/BME280 humidity/temperature/pressure sensors
- ddc(4)
- VESA Display Data Channel V2 devices
- dbcool(4)
- dbCool(tm) family of environmental monitors and fan controllers
- g760a(4)
- Global Mixed-mode Technology Inc. G760a fan speed controller
- hythygtemp(4)
- IST-AG HYT-221/271/939 humidity/temperature sensors
- ibmhawk(4)
- Temperature, voltage, and fan sensors present on IBM eServers
- ims(4)
- I2C mice and touch panels
- lm(4)
- National Semiconductor LM78, LM79, and compatible hardware monitors
- lmenv(4)
- National Semiconductor LM81, LM87, and compatible hardware monitors
- lmtemp(4)
- National Semiconductor LM75, LM77, and compatible hardware monitors
- mcp980x(4)
- Microchip 9800/1/2/3 I2C temperature sensor
- mpl115a(4)
- Freescale MPL115A2 absolute pressure sensor
- pcf8563rtc(4)
- NXP PCF8563 real-time clock
- rs5c372rtc(4)
- RICOH RS5C372A and RS5C372B real-time clock
- s390rtc(4)
- Seiko Instruments S-35390 real-time clock
- scmdi2c(4)
- I2C frontend for the Sparkfun Serial Controlled Motor Driver.
- sdtemp(4)
- JEDEC JC-42.4 compatible memory module temperature sensors
- seeprom(4)
- 24-series I2C EEPROM driver
- sgp40mox(4)
- Sensirion SGP40 MOx gas sensors
- sgsmix(4)
- SGS 7433 Basic Audio Processor found in some Apple machines
- sht3xtemp(4)
- Sensirion SHT30/SHT31/SHT35 temperature/humidity sensors
- sht4xtemp(4)
- Sensirion SHT40/SHT41/SHT45 temperature/humidity sensors
- si70xxtemp(4)
- Silicon Labs SI7013/SI7020/SI7021 humidity/temperature sensors
- smscmon(4)
- Standard Microsystems Corporation LPC47M192 and LPC47M997 sensors
- spdmem(4)
- Generic Memory Module Serial Presence Detect
- ssdfb(4)
- OLED/PLED framebuffer modules
- tea5767radio(4)
- Philips/NXP TEA5767 FM stereo radio
- tps65217pmic(4)
- Texas Instruments TPS65217 Power Management IC
- tsllux(4)
- Taos TSL256x Light-to-Digital Converter
- /dev/iicu
- I2C device unit u file.
The I2C framework first appeared in NetBSD 2.0.
OpenBSD support was added in OpenBSD
3.6. This manpage first appeared in NetBSD 6.0,
it was ported from OpenBSD.
The I2C framework was written by Steve C. Woodford and
Jason R. Thorpe for NetBSD and
then ported to OpenBSD by Alexander
Yurchenko
<grange@openbsd.org>.