Re: [PATCH v2 1/2] gpio: Add driver for Zynq GPIO controller

From: Baruch Siach
Date: Fri Jul 11 2014 - 02:28:23 EST


Hi Linus,

On Tue, Jul 08, 2014 at 11:27:57AM +0200, Linus Walleij wrote:
> On Mon, Jul 7, 2014 at 5:23 PM, Baruch Siach <baruch@xxxxxxxxxx> wrote:
> > On Mon, Jul 07, 2014 at 04:51:56PM +0200, Linus Walleij wrote:
>
> >> This needs someone to step in and provide a replacement, my preferred
> >> mechanism would be a /dev/gpiochip0/... hierarchy using char devices.
> >
> > I really like the ability to control GPIOs from shell, both interactively and
> > scripted. I find it useful for quick hardware level debugging,
>
> I would be happy to carry it in the unstable-ABI debugfs for sure.
> It's the supported ABI that bothers me.
>
> > and for boot
> > time scripting (mainly in initramfs).
>
> What is the usecase here?

During boot I need to know, for example, when an FPGA is ready to be
programmed, and when said FPGA has finished its initialization. I also read
the sate of on-board DIP switches to determine the desired boot method. I find
the current sysfs interface quite convenient for these and similar tasks.

baruch

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