Messages in this thread | | | Date | Fri, 7 Jun 2013 15:34:50 +0200 | From | Christian Ruppert <> | Subject | Re: [PATCH 1/2] pinmux: Add TB10x pinmux driver |
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On Fri, Jun 07, 2013 at 01:36:16PM +0200, Linus Walleij wrote: > On Mon, Jun 3, 2013 at 11:42 AM, Christian Ruppert > <christian.ruppert@abilis.com> wrote: > > > Ease of use is also the reason why I added the gpio-base property to the > > original driver: Finding out the global GPIO number to use in > > /sys/class/gpio for a given GPIO of a given bank seems to be a recurring > > headache for our customers and the definition of the bank's base number > > in the device tree is an attempt to improve this situation. > > What you need to do in that case is to find a way to name the pins > in sysfs (creating symbolic links with the GPIO pin name) so they > can use these names in sysfs instead. > > There is no ambition from my side to try to correlate the > GPIO sysfs interface and device trees. This is because the GPIO > sysfs is not universally liked. And when you say you want to make the > sysfs ABI easy to use that lights a big red light on my panel. I will > explain why. > > What is very important is that your customers understand that > the GPIO sysfs shall not be used for things like: > > - LEDs > - Switches > - Regulators > - Camera muxes > - etc > > From the kernel community we have tried (or atleast I have tried) > that this kind of hardware shall be handled by the apropriate linux > subsystems, and not by obscure userspace code.
I totally agree with that and we already declare the LEDs etc. on our PCBs in the device trees. However, we have at least one customer who has a user space driver for some peripheral on i2c which needs to be reset through GPIO. I'm not sure which framework to use for this sort of applications.
Greetings, Christian
-- Christian Ruppert , <christian.ruppert@abilis.com> /| Tel: +41/(0)22 816 19-42 //| 3, Chemin du Pré-Fleuri _// | bilis Systems CH-1228 Plan-les-Ouates -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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