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From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Tue, 25 Apr 2017 09:15:44 +0200
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Subject: Re: [PATCH v2 2/4] gpio - Add EXAR XRA1403 SPI GPIO expander driver
To: zoobab@gmail.com
Cc: Linus Walleij <linus.walleij@linaro.org>,
        Nandor Han <nandor.han@ge.com>, Greg KH <gregkh@linuxfoundation.org>,
        "David S. Miller" <davem@davemloft.net>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Alexandre Courbot <gnurou@gmail.com>, Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        "linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Semi Malinen <semi.malinen@ge.com>
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Hi Benjamin,

On Tue, Apr 25, 2017 at 9:07 AM, Benjamin Henrion <zoobab@gmail.com> wrote:
> On Mon, Apr 24, 2017 at 3:47 PM, Linus Walleij <linus.walleij@linaro.org> wrote:
>> On Thu, Apr 13, 2017 at 12:27 PM, Nandor Han <nandor.han@ge.com> wrote:
>>
>>> This is a simple driver that provides a /sys/class/gpio
>>> interface for controlling and configuring the GPIO lines.
>>> It does not provide support for chip select or interrupts.
>>>
>>> Signed-off-by: Nandor Han <nandor.han@ge.com>
>>> Signed-off-by: Semi Malinen <semi.malinen@ge.com>
>>
>> I almost want to make the driver depend on !GPIO_SYSFS because
>> of this commit message.
>>
>> DO NOT USE OR ENCOURAGE THE USE OF THE GPIO SYSFS
>> INTERFACE.
>>
>> Use the character device.
>
> I doubt you will be able to convince the majority of people toggling
> GPIOs via a simple shell script to switch to write a complex C
> program. Not to mention cross compilation and the libraries
> dependencies here.
>
> Is there some good cli tools to access the new char device? If they
> are shipped with most distros, that would reduce the pain.

https://github.com/brgl/libgpiod

A bit early to expect it to be shipped with all distros, though.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds