Re: ECP port driver

[Robert Creager <robert@carolinecreager.com>]

Ok, a little more description.  I will provide a
script which will start/stop (insmod/rmmod) the
driver, along with some necessary housekeeping.  Some
of this housekeeping involves removing/creating /dev
nodes when the script is loaded, as I'm doing an auto
claim of major/minor device numbers, or using devfs,
depending on how the kernel is built.

The port can be read using the standard
open/read/close.  ioctl support will not be added,
unless someone presents me with a good case for using
it (it adds more complexity to the driver).  This
driver should play with a printer on a switch box
(when no pictures are being taken), as the port is
claimed during the open, and released during the
close, while never yielding it.

The act of reading the device will send the command
out of the port to the camera, which will start the
data some time later.  The data will then be
transfered into the user supplied buffer.

I just ran across a driver (which doesn't use
parport), which appears to be downloading interleaved
data from a camera, very similar to what were doing,
and it's using DMA.  I hope to be able to glean some
good info from it for use in ours.  Maybe even getting
the parport_ecp_read_block_pio routine working (from
the parport driver source).

Want more info?  Just ask...

Later,
Rob

PS.  Depending on your Linux knowledge, you may not of
understood one bit of what I said.  This shouldn't
matter much, as the make/install/setup/etc will be
fairly transparent.

---- Robert Creager <Robert@CarolineCreager.com>
wrote:
> 
> Chris and all,
> 
> Here's the code and makefile.  I'm running late, so
a full description 
> will follow in a couple of hours.  Suffice to say, a
/dev file will exists 
> at some point, created through a script, and
open/close/read will 
> work on that dev file.  I'm thinking of creating a
tassiv directory 
> under the /dev directoryen maybe we can through some
stamp 
> driver nodes in there (device drivers are fun!). 
insmod won't work 
> just yet, as the read function isn't defined in the
file.  I was just 
> working on that.
> 
> Later,
> Rob
>