From: Arnd Bergmann <arnd@arndb.de>
To: linux-arm-kernel@lists.infradead.org
Cc: Ray Jui <rjui@broadcom.com>, Alexandre Courbot <gnurou@gmail.com>,
        Mark Rutland <mark.rutland@arm.com>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Russell King <linux@arm.linux.org.uk>,
        Scott Branden <sbranden@broadcom.com>, Pawel Moll <pawel.moll@arm.com>,
        Ian Campbell <ijc+devicetree@hellion.org.uk>,
        Linus Walleij <linus.walleij@linaro.org>,
        Christian Daudt <bcm@fixthebug.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Matt Porter <mporter@linaro.org>, Joe Perches <joe@perches.com>,
        Rob Herring <robh+dt@kernel.org>,
        bcm-kernel-feedback-list@broadcom.com,
        "linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
        Kumar Gala <galak@codeaurora.org>,
        Grant Likely <grant.likely@linaro.org>
Subject: Re: [PATCH v5 1/3] gpio: Cygnus: define Broadcom Cygnus GPIO binding
Date: Mon, 15 Dec 2014 22:57:36 +0100
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On Monday 15 December 2014 13:35:47 Ray Jui wrote:
> 
> Like I said previously, dynamic GPIO allocation works fine in the 
> kernel, as long as all of our GPIO clients in the kernel use gpiod based 
> API, which is what we will enforce going forward. The only problem is 
> with some of our customers who use GPIO through sysfs and expect fixed 
> global GPIO numbers. Thinking about this more, it's probably not that 
> difficult to add a script for those customers to convert/map the GPIO 
> numbers based on readings parsed from sysfs, so I guess that's fine.
> 

I think we discussed the user space interface a number of times
in the past, but I forgot the outcome. Either there is already
a way to name gpio lines uniquely in sysfs, or there should be
one.

Can you reach the gpio interfaces using /sys/devices/0001234.bus/1234566.gpiocontroller/...? 

	Arnd
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