| Kernel driver i2c-voodoo3 |
| |
| Supported adapters: |
| * 3dfx Voodoo3 based cards |
| * Voodoo Banshee based cards |
| |
| Authors: |
| Frodo Looijaard <frodol@dds.nl>, |
| Philip Edelbrock <phil@netroedge.com>, |
| Ralph Metzler <rjkm@thp.uni-koeln.de>, |
| Mark D. Studebaker <mdsxyz123@yahoo.com> |
| |
| Main contact: Philip Edelbrock <phil@netroedge.com> |
| |
| The code is based upon Ralph's test code (he did the hard stuff ;') |
| |
| Description |
| ----------- |
| |
| The 3dfx Voodoo3 chip contains two I2C interfaces (aka a I2C 'master' or |
| 'host'). |
| |
| The first interface is used for DDC (Data Display Channel) which is a |
| serial channel through the VGA monitor connector to a DDC-compliant |
| monitor. This interface is defined by the Video Electronics Standards |
| Association (VESA). The standards are available for purchase at |
| http://www.vesa.org . |
| |
| The second interface is a general-purpose I2C bus. The intent by 3dfx was |
| to allow manufacturers to add extra chips to the video card such as a |
| TV-out chip such as the BT869 or possibly even I2C based temperature |
| sensors like the ADM1021 or LM75. |
| |
| Stability |
| --------- |
| |
| Seems to be stable on the test machine, but needs more testing on other |
| machines. Simultaneous accesses of the DDC and I2C busses may cause errors. |
| |
| Supported Devices |
| ----------------- |
| |
| Specifically, this driver was written and tested on the '3dfx Voodoo3 AGP |
| 3000' which has a tv-out feature (s-video or composite). According to the |
| docs and discussions, this code should work for any Voodoo3 based cards as |
| well as Voodoo Banshee based cards. The DDC interface has been tested on a |
| Voodoo Banshee card. |
| |
| Issues |
| ------ |
| |
| Probably many, but it seems to work OK on my system. :') |
| |
| |
| External Device Connection |
| -------------------------- |
| |
| The digital video input jumpers give availability to the I2C bus. |
| Specifically, pins 13 and 25 (bottom row middle, and bottom right-end) are |
| the I2C clock and I2C data lines, respectively. +5V and GND are probably |
| also easily available making the addition of extra I2C/SMBus devices easy |
| to implement. |