GPIOIIC(4) OpenBSD Programmer's Manual GPIOIIC(4)NAMEgpioiic - 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 ALSOgpio(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 4.9 November 24, 2008 OpenBSD 4.9