On Mon, Oct 24, 2011 at 09:48:19AM +0200, Linus Walleij wrote: > On Mon, Oct 24, 2011 at 9:36 AM, Grant Likely <grant.lik...@secretlab.ca> > wrote: > > On Mon, Oct 24, 2011 at 09:26:38AM +0200, Linus Walleij wrote: > (...) > >> I was more thinking along the lines of one device per GPIO controller, > >> then you ioctl() to ask /dev/gpio0 how many pins it has or so. > > > > And there is also the question of whether it is even a good idea to > > export pinctrl manipulation to userspace. > > The application I've seen is in automatic control. > > I think people do things like connect they GPIO pins to electrical > relays, plus on top of that they use all the stuff in drivers/staging/iio. > > All that from userspace. Controlling entire factories and industrial > robots, weapon systems too, I'm afraid. > > The control of these dangerous things runs on a realtime-patched > kernel, in a single userspace app with a few threads and they have > done some realtime-tetris scheduling the beast more or less > manually with SCHED_FIFO. Basically that app is all that runs on > the board, and its threads take precedence over everything else > on the system. > > That is the typical beast that is poking around on the GPIO sysfs > interfaces...
... which maybe should be encouraged to use some form of uio driver. :-) g. _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
