Re: [PARPORT] ppdev and EPP mode

From: Tim Waugh (
Date: Mon Apr 10 2000 - 05:05:35 EDT

  • Next message: Tim Waugh: "Re: [PARPORT] more on the simple driver"

    On Sun, 9 Apr 2000, Vince Weaver wrote:

    > I was trying to do this using the ppdev driver, thinking it would best
    > to do this simple communication in user-space. I was having great
    > trouble trying to get this to work, only to dig into the ppdev.c code
    > to find it with comments saying "this hasn't been tested yet", and it
    > seemingly is doing it in software instead of hardware!

    That's right. I haven't back-ported the hardware support to 2.2.x.

    > I then looked at kernel 2.3.99-pre3 thinking it might have more mature
    > support, and it looks like all references to EPP have been stripped
    > out of ppdev...

    But the interface is still the same. Set the mode to IEEE1284_MODE_EPP
    and use read/write. To follow the code, start from pp_write in ppdev.c,
    then follow it to parport_write in ieee1284.c, which then calls access
    functions that are implemented in the port drivers (look in parport_pc.c
    for example).

    > so the question is, can EPP be done with ppdev?

    Yes, and it's even been tested a little bit in 2.3.x.


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