Messages in this thread | | | Subject | Re: [PATCH v3 2/4] gpiolib: Add ability to get GPIO pin direction | From | Peter Tyser <> | Date | Fri, 18 Feb 2011 14:27:23 -0600 |
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On Fri, 2011-02-18 at 19:49 +0100, Uwe Kleine-König wrote: > Hello Peter, > > On Fri, Feb 18, 2011 at 11:36:26AM -0600, Peter Tyser wrote: > > On Fri, 2011-02-18 at 09:57 +0100, Uwe Kleine-König wrote: > > > On Thu, Feb 17, 2011 at 05:03:17PM -0600, Peter Tyser wrote: > > > > Add a new get_direction() function to the gpio_chip structure. This is > > > > useful so that the direction of a pin can be determined when its > > > > initially exported. Previously, the direction defaulted to "unknown" > > > > regardless of the actual configuration of the GPIO pin. > > > > > > > > If a GPIO driver implements get_direction(), it is called in > > > > gpio_request() to set the initial direction of the pin accurately. > > > IMHO the commit log is conceptually wrong, because it talks about a > > > "pin". Better use gpio here. > > > > I don't follow. I used "pin" to make it clear that the get_direction() > > function operates on a pin-by-pin basis, and to help reduce any > > ambiguity about if a gpio chip or gpio pin is being referred to. Would > > you prefer that the "pin" references are clarified to be "GPIO pin"? > Maybe it's just that we use different terms. For me a "pin" is an > entry/exit point into/from a cpu or other chip. A gpio is (hmm, how > should I say) a concept how to drive a pin. A gpio might or might not > be "connected" to a pin at a given time.
Ahh, I see... The GPIO subsystem doesn't have the capability to multiplex a GPIO to different physical pins at the moment, so I always equate a GPIO with a specific pin, even if its not "connected" all the time. I'll remove the "pin" references when I resubmit if you think it is more accurate.
Peter
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