From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lukas Wunner Subject: Re: [PATCH 3/4] dt-bindings: gpio: max3191x: Document new driver Date: Wed, 23 Aug 2017 11:44:38 +0200 Message-ID: <20170823094438.GA12416@wunner.de> References: <7fe7636eecba238d57ab6178cfa3f6b7deca98f1.1503319573.git.lukas@wunner.de> <20170823004847.jmkb53xtdmmn6vtf@rob-hp-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170823004847.jmkb53xtdmmn6vtf@rob-hp-laptop> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rob Herring Cc: Linus Walleij , Mathias Duckeck , Phil Elwell , linux-gpio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mark Rutland List-Id: devicetree@vger.kernel.org Thanks Rob for the helpful review! On Tue, Aug 22, 2017 at 07:48:47PM -0500, Rob Herring wrote: > On Mon, Aug 21, 2017 at 03:12:00PM +0200, Lukas Wunner wrote: > > + - modesel-gpios: GPIO pins to configure modesel of each chip. > > + The number of GPIOs must be equal to "maxim,nchips". > > + - fault-gpios: GPIO pins to read undervoltage fault of each chip. > > + - db0-gpios: GPIO pins to configure debounce of each chip. > > + - db1-gpios: GPIO pins to configure debounce of each chip. > > Perhaps an array db-gpios with 2 entries. Each of the db0-gpios and db1-gpios is already an array with one pin for each chip in the daisy-chain. So it would have to be a two-dimensional array, which AFAICS is not supported by the devicetree spec, or is it? However I realize that for clarity I should amend fault-gpios, db0-gpios and db1-gpios with the same text as modesel-gpios: The number of GPIOs must be equal to "maxim,nchips". > > + - maxim,no-vcc24v:Boolean, whether the chips are powered through > > + 5VOUT instead of VCC24V. > > Use the regulator binding here? I'd have to look at the regulator's current voltage to determine through which pin the chips in the daisy-chain are powered (5VOUT or VCC24V). But if the regulator is generating 5V I couldn't discern if it's a faulting 24V supply or a non-faulting 5V supply. So a boolean does seem necessary, however I realize now that "no-vcc24v" is misleading, I've changed it to "maxim,ignore-undervoltage" for clarity: - maxim,ignore-undervoltage: Boolean, whether to ignore undervoltage alarms signaled by the "maxim,fault-gpios" and by the status byte (in 16-bit mode). Use this if the chips are powered through 5VOUT instead of VCC24V, in which case they will constantly signal undervoltage. Thanks, Lukas -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html