[PARPORT] Re: ECPSW mode error?

From: Tim Waugh (twaugh@redhat.com)
Date: Wed Apr 26 2000 - 06:43:15 EDT

  • Next message: zhu qun ying: "[PARPORT] Re: ECPSW mode error?"

    On Wed, Apr 26, 2000 at 04:40:11PM +0800, qyzhu@krdl.org.sg wrote:

    > So my question will be is my understanding of frob_control()
    > correct? From what I read from the code, it seems what ever in the
    > mask gets set to high, and what ever in the value (within the mask)
    > gets low.

    I think you misunderstand the purpose of frob_control. You tell it
    which lines you are interested in changing (the mask) and you tell it
    what those lines should do (the value).

    So, bits not specified in the mask are unchanged, whereas bits
    specified in the mask take on the corresponding bits in 'value'.

    frob_control (port, INIT, 0) means set INIT to 0
    frob_control (port, INIT, INIT) means set INIT to 1
    frob_control (port, A | B, A) means set A to 1 and B to 0.

    > I think the software ECP mod need a careful review of all the
    > control signals. I have the standard on hand so I will do the work
    > if my doubt is cleared first.

    Yes, please review it.


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