| 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. |