Messages in this thread | | | Subject | Re: [PATCH] gpio: add support for ITE IT87xx Super I/O GPIO. | From | Guenter Roeck <> | Date | Mon, 19 Mar 2012 09:39:50 -0700 |
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On Mon, 2012-03-19 at 10:05 -0400, Linus Walleij wrote: > On Mon, Mar 19, 2012 at 2:56 PM, Guenter Roeck > <guenter.roeck@ericsson.com> wrote: > > On Mon, Mar 19, 2012 at 04:26:44AM -0400, Linus Walleij wrote: > > >> OK that is pinmuxing, if that is to be software-controlled the place to do > >> it is in drivers/pinctrl. (Documentation/pinctrl.txt gives the backrgound.) > (...) > >> > > Personally I would not dare touch those pins. If a pin is configured as UART pin > > (or whatever), it is quite unlikely that it is exposed as GPIO pin. Worst case, > > changing the configuration may result in broken hardware. Not sure what is supposed > > to be gained by enabling the user to do that. > > Define "user", pinctrl does not have userspace interfaces if that's > what you mean. > > If you mean "kernel programmer", these creatures seem to not respect what > they should and shouldn't poke at ;-) > > The usecase is typically if the hardware is used in two different systems > where the ROM/bootcode/etc does not set up muxing correctly, or are setup > in a sub-optimal way (e.g. working but consuming too much power) and the > kernel needs to get involved. Unless you have any scenario like that, no > need to worry about it. > Ok, guess that makes sense.
Thanks, Guenter
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