diff options
Diffstat (limited to 'Documentation/driver-api/gpio')
| -rw-r--r-- | Documentation/driver-api/gpio/bt8xxgpio.rst | 62 | ||||
| -rw-r--r-- | Documentation/driver-api/gpio/index.rst | 1 |
2 files changed, 63 insertions, 0 deletions
diff --git a/Documentation/driver-api/gpio/bt8xxgpio.rst b/Documentation/driver-api/gpio/bt8xxgpio.rst new file mode 100644 index 000000000000..d7e75f1234e7 --- /dev/null +++ b/Documentation/driver-api/gpio/bt8xxgpio.rst @@ -0,0 +1,62 @@ +=================================================================== +A driver for a selfmade cheap BT8xx based PCI GPIO-card (bt8xxgpio) +=================================================================== + +For advanced documentation, see https://bues.ch/cms/unmaintained/btgpio.html + +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 + diff --git a/Documentation/driver-api/gpio/index.rst b/Documentation/driver-api/gpio/index.rst index c5b8467f9104..5b61032aa4ea 100644 --- a/Documentation/driver-api/gpio/index.rst +++ b/Documentation/driver-api/gpio/index.rst @@ -13,6 +13,7 @@ Contents: board drivers-on-gpio legacy + bt8xxgpio Core ==== |