On Mon, Mar 09, 2015 at 04:52:26PM +0100, Linus Walleij wrote: > On Wed, Mar 4, 2015 at 1:43 PM, Alexandre Courbot <gnu...@gmail.com> wrote: > > On Tue, Mar 3, 2015 at 7:31 PM, Linus Walleij <linus.wall...@linaro.org> > > wrote: > >> On Tue, Mar 3, 2015 at 9:27 AM, Alexandre Courbot <gnu...@gmail.com> wrote: > >> > >>> It really comes down to how user-space wants to access GPIOs. I > >>> suspect the majority of sysfs accesses is done by scripts and other > >>> simple programs. If we introduce a char device that takes requires > >>> ioctls, it is then customary to add a small user-space library to > >>> abstract that (for both convenience and safety - think libdrm). Do we > >>> want to maintain libgpio? > >> > >> Good point. > >> > >> We have no clue about how the majority out there use the GPIO > >> sysfs, but I have heard of mission-critical systems just hammering > >> GPIOs from userspace. > >> > >> Sadly many of these industrial users are "I just want it to work, now" > >> types and they don't step forward much on these mailing lists. > >> (Learned from private conversations...) > >> > >> Maybe if noone voice their opinion and offer to help with this, we can > >> assume they don't exist (well obviously a community does not exist) > >> and their specific needs be ignored until they put their money where > >> their mouth is. > > > > That's the only way we can handle the situation if people don't > > manifest their needs. But does this mean that you would agree with a > > cleaner, multi-GPIO friendly sysfs-based solution, or I am > > misunderstanding you? > > I guess I'm just a bit grumpy. > > Whoever comes up with a cleaner sysfs or a clean device interface > will win the argument and lock the path for the other approach. > It's like a forking path with no going back or something.
There is no need to fork and in fact it would probably be a bad idea. At EMAC we support both sysfs and character device simultaneously. Sysfs for the ease of use and ioctl for real time advantages. Not saying that it is a good reference but the two interfaces "could" co-exist. > > Yours, > Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
