GPIOIIC(4)                OpenBSD Programmer's Manual               GPIOIIC(4)

NAME
     gpioiic - GPIO I2C controller

SYNOPSIS
     gpioiic* at gpio? offset 0 mask 0x3
     gpioiic* at gpio?
     iic* at gpioiic?

DESCRIPTION
     The gpioiic driver allows bit-banging an I2C bus as a master using two
     GPIO pins.  The first pin is used as a serial data (SDA) signal and the
     second as a serial clock (SCL).  Both GPIO pins must be able to drive an
     output and the SDA pin must be also able to read an input.

     The pins can be specified in the kernel configuration with the offset and
     the mask locators.  The offset and mask can also be specified when
     gpioiic is attached at runtime using the GPIOATTACH ioctl(2) on the
     gpio(4) device.  Each bit in the mask locator defines one pin; the pin
     number is calculated as an addition of the bit position and the offset
     locator.  For example, offset 17 and mask 0x5 defines pin numbers 17 and
     19.

SEE ALSO
     gpio(4), iic(4), intro(4)

HISTORY
     The gpioiic driver first appeared in OpenBSD 3.9.

AUTHORS
     The gpioiic driver was written by Alexander Yurchenko
     <grange@openbsd.org>.

OpenBSD 4.7                    November 24, 2008                             1
