$OpenBSD: gpioiic.4,v 1.8 2013/07/16 16:05:48 schwarze Exp $
Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org>
Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.Dd $Mdocdate: October 3 2011 $ .Dt GPIOIIC 4 .Os .Sh NAME .Nm gpioiic .Nd GPIO I2C controller .Sh SYNOPSIS .Cd "gpioiic* at gpio? offset 0 mask 0x3 flag 0x0" .Cd "gpioiic* at gpio?" .Cd "iic* at gpioiic?" .Sh DESCRIPTION The .Nm driver allows bit-banging an I2C bus as a master using two GPIO pins. By default the first pin is used as a serial data (SDA) signal and the second as a serial clock (SCL). If the flag locator is set to 0x01, the order of the SDA and SCL signals is reversed. Both GPIO pins must be able to drive an output and the SDA pin must be also able to read an input.
Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org>
Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.Dd $Mdocdate: October 3 2011 $ .Dt GPIOIIC 4 .Os .Sh NAME .Nm gpioiic .Nd GPIO I2C controller .Sh SYNOPSIS .Cd "gpioiic* at gpio? offset 0 mask 0x3 flag 0x0" .Cd "gpioiic* at gpio?" .Cd "iic* at gpioiic?" .Sh DESCRIPTION The .Nm driver allows bit-banging an I2C bus as a master using two GPIO pins. By default the first pin is used as a serial data (SDA) signal and the second as a serial clock (SCL). If the flag locator is set to 0x01, the order of the SDA and SCL signals is reversed. Both GPIO pins must be able to drive an output and the SDA pin must be also able to read an input.
p The pins can be specified in the kernel configuration with the .Ar offset and the .Ar mask locators. The .Ar offset and .Ar mask can also be specified when .Nm is attached at runtime using the .Dv GPIOATTACH .Xr ioctl 2 on the .Xr gpio 4 device. Each bit in the .Ar mask locator defines one pin; the pin number is calculated as an addition of the bit position and the .Ar offset locator. For example, .Ar offset 17 and .Ar mask 0x5 defines pin numbers 17 and 19. .Sh SEE ALSO .Xr gpio 4 , .Xr iic 4 , .Xr intro 4 .Sh HISTORY The .Nm driver first appeared in .Ox 3.9 . .Sh AUTHORS .An -nosplit The .Nm driver was written by .An Alexander Yurchenko Aq Mt grange@openbsd.org .