Messages in this thread | | | From | David Brownell <> | Subject | Re: [PATCH 2/4] powerpc/qe: new call to revert a gpio to a dedicated function | Date | Wed, 24 Sep 2008 11:54:59 -0700 |
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On Wednesday 24 September 2008, Anton Vorontsov wrote: > > what do you mean by dedicated function.. be a bit clearer in the commit > > log. > > This term is from the QE spec, I didn't invent anything. ;-) > > "Each pin in the I/O ports can be configured as a general-purpose > I/O signal or as a dedicated peripheral interface signal. ...many > dedicated peripheral functions are multiplexed onto the ports."
Which, to me, highlights the point I've made previously: the right abstraction for you to work with is "pin", not GPIO.
You need to switch a QE "pin" from one of its roles to the other.
Evil things, like oopsing, will happen if you try to use this call on a GPIO that's not backed by a QE pin.
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