Updated: 2021/Apr/14

IIC(4)                       Device Drivers Manual                      IIC(4)

     iic - Inter IC (I2C) bus

     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_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
           cuda(4)             Support for CUDA microcontrollers found in many
                               Power Macintosh and compatible computers
           cxdtv(4)            Digital video driver for Conexant CX2388x based
           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
           piixpm(4)           Intel PIIX and compatible Power Management

     A wide list of slaves are supported, among them:

           dbcool(4)      dbCool(tm) family of environmental monitors and fan
           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
           sdtemp(4)      JEDEC JC-42.4 compatible memory module temperature
           seeprom(4)     24-series I2C EEPROM driver
           sgsmix(4)      SGS 7433 Basic Audio Processor found in some Apple
           spdmem(4)      Generic Memory Module Serial Presence Detect
           ssdfb(4)       OLED/PLED framebuffer modules

     /dev/iicu  I2C device unit u file.

     dtviic(4), intro(4), i2cscan(8), iic(9)

     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

NetBSD 9.99                    February 27, 2021                   NetBSD 9.99