Re: [-mm patch 1/4] GPIO framework for AVR32

From: David Brownell
Date: Wed Nov 08 2006 - 17:12:50 EST


> The request/free calls aren't really arch-specific, are they?

Remember that where one platform may use numbers 32-159 for GPIOs, another
might use 0-71 ... GPIO numbering has an arch-specific core, but whether
a given board adds more GPIOs from an FPGA or other non-SOC chip is even
more variable than "arch-specific".


> I implement the actual allocation mechanism using atomic bitops.

That's a fair way to implement it, sure; but if you look at e.g. how
OMAP does it, the bitmap is inside a per-controller structure. When
one chip has two different _types_ of GPIO controller, and multiple
instances of one (plus restrictions applying to specific instances),
the notion of an arch-neutral implementation there seems unworkable.

- Dave

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