Re: [PATCH 0/6] GPIO character device skeleton

From: Linus Walleij <linus.walleij@linaro.org>
To: Alexandre Courbot <gnurou@gmail.com>
Cc: Markus Pargmann <mpa@pengutronix.de>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
	Johan Hovold <johan@kernel.org>,
	Alexandre Courbot <acourbot@nvidia.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Michael Welling <mwelling@ieee.org>,
	Mark Brown <broonie@kernel.org>,
	Amit Kucheria <amit.kucheria@linaro.org>
Subject: Re: [PATCH 0/6] GPIO character device skeleton
Date: Fri, 30 Oct 2015 20:48:44 +0100	[thread overview]
Message-ID: <CACRpkdYqsGsYOALT3oQwc7fFho2gNe_=3qJ_cHcEO=YR4HAi8w@mail.gmail.com> (raw)
In-Reply-To: <CAAVeFuJ7nykUpJjotmXyB6ngb3g3KF5amfO73nSWQfKSLHfFnw@mail.gmail.com>

On Fri, Oct 30, 2015 at 2:55 AM, Alexandre Courbot <gnurou@gmail.com> wrote:
> On Sun, Oct 25, 2015 at 3:42 AM, Markus Pargmann <mpa@pengutronix.de> wrote:

>> What happens if we have two I2C gpio expanders with the same I2C
>> addresses connected to different I2C busses? If I see this correctly
>> they would both show up with the same name. Is there an easy and
>> race-free way to see which GPIO chip is connected to which I2C bus?
>
> I suppose the bus path could be part of the GPIO chip name to avoid
> this ambiguity, something like: 7000c000.i2c/0-001c.gpio

For DT that is the simple solution.

Right now it used gpiochip->label if that is set, else the name of
the gpiochip device like gpiochip0, gpiochip1 etc.

Yours,
Linus Walleij