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Re: RFC: gpio attachment for ppbus

On Tue, 29 Apr 2008, Hans Rosenfeld wrote:

On Tue, Apr 29, 2008 at 11:47:08AM +0200, Quentin Garnier wrote:
For some future extension of the gpio driver, I thought about adding an
ioctl() to specify a sequence of operations to perform, complete with
timing information. The actual operations would still be carried out
sequentially by the gpio driver, but you wouldn't need an ioctl() for
every read or write of a pin. But this still needs some more thought.

I think that belongs to a userspace lib, anyway.

That would miss the point of reducing the number of syscalls needed to
perform a large number of gpio operations. But maybe this issue is not
important enough to justify such a huge extension.

        Putting the interface in a library does not preclude adding
        a syscall or ioctl at a later point to improve performance,
        without needing to change the userland API. Hmm... plists...

                David/absolute       -- No hype required --

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