diff options
| author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-06-27 20:39:22 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-07-15 16:03:02 +0200 |
| commit | baa293e9544bea71361950d071579f0e4d5713ed (patch) | |
| tree | 29e0400c806016783a3fd7a380be40a201956653 /Documentation/driver-api/bt8xxgpio.rst | |
| parent | docs: admin-guide: add a series of orphaned documents (diff) | |
| download | linux-baa293e9544bea71361950d071579f0e4d5713ed.tar.xz linux-baa293e9544bea71361950d071579f0e4d5713ed.zip | |
docs: driver-api: add a series of orphaned documents
There are lots of documents under Documentation/*.txt and a few other
orphan documents elsehwere that belong to the driver-API book.
Move them to their right place.
Reviewed-by: Cornelia Huck <cohuck@redhat.com> # vfio-related parts
Acked-by: Logan Gunthorpe <logang@deltatee.com> # switchtec
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'Documentation/driver-api/bt8xxgpio.rst')
| -rw-r--r-- | Documentation/driver-api/bt8xxgpio.rst | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/Documentation/driver-api/bt8xxgpio.rst b/Documentation/driver-api/bt8xxgpio.rst new file mode 100644 index 000000000000..a845feb074de --- /dev/null +++ b/Documentation/driver-api/bt8xxgpio.rst @@ -0,0 +1,62 @@ +=================================================================== +A driver for a selfmade cheap BT8xx based PCI GPIO-card (bt8xxgpio) +=================================================================== + +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 + |