mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-29 15:43:59 +08:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
63 lines
2.0 KiB
Plaintext
63 lines
2.0 KiB
Plaintext
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.
|