mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 20:53:53 +08:00
68 lines
4.3 KiB
Plaintext
68 lines
4.3 KiB
Plaintext
|
===============================================================
|
||
|
|
== BT8XXGPIO driver ==
|
||
|
|
== ==
|
||
|
|
== A driver for a selfmade cheap BT8xx based PCI GPIO-card ==
|
||
|
|
== ==
|
||
|
|
== For advanced documentation, see ==
|
||
|
|
== http://www.bu3sch.de/btgpio.php ==
|
||
|
|
===============================================================
|
||
|
|
|
||
|
|
|
||
|
|
A generic digital 24-port PCI GPIO card can be built out of an ordinary
|
||
|
|
Brooktree bt848, bt849, bt878 or bt879 based analog TV tuner card. The
|
||
|
|
Brooktree chip is used in old analog Hauppauge WinTV PCI cards. You can easily
|
||
|
|
find them used for low prices on the net.
|
||
|
|
|
||
|
|
The bt8xx chip does have 24 digital GPIO ports.
|
||
|
|
These ports are accessible via 24 pins on the SMD chip package.
|
||
|
|
|
||
|
|
|
||
|
|
==============================================
|
||
|
|
== How to physically access the GPIO pins ==
|
||
|
|
==============================================
|
||
|
|
|
||
|
|
The are several ways to access these pins. One might unsolder the whole chip
|
||
|
|
and put it on a custom PCI board, or one might only unsolder each individual
|
||
|
|
GPIO pin and solder that to some tiny wire. As the chip package really is tiny
|
||
|
|
there are some advanced soldering skills needed in any case.
|
||
|
|
|
||
|
|
The physical pinouts are drawn in the following ASCII art.
|
||
|
|
The GPIO pins are marked with G00-G23
|
||
|
|
|
||
|
|
G G G G G G G G G G G G G G G G G G
|
||
|
|
0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
|
||
|
|
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7
|
||
|
|
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
|
||
|
|
---------------------------------------------------------------------------
|
||
|
|
--| ^ ^ |--
|
||
|
|
--| pin 86 pin 67 |--
|
||
|
|
--| |--
|
||
|
|
--| pin 61 > |-- G18
|
||
|
|
--| |-- G19
|
||
|
|
--| |-- G20
|
||
|
|
--| |-- G21
|
||
|
|
--| |-- G22
|
||
|
|
--| pin 56 > |-- G23
|
||
|
|
--| |--
|
||
|
|
--| Brooktree 878/879 |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| |--
|
||
|
|
--| O |--
|
||
|
|
--| |--
|
||
|
|
---------------------------------------------------------------------------
|
||
|
|
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
|
||
|
|
^
|
||
|
|
This is pin 1
|
||
|
|
|