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: Tue, 5 Sep 2017 10:16:24 +0200 Message-ID: <20170905081624.GA15374@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: Received: from mailout3.hostsharing.net ([176.9.242.54]:40105 "EHLO mailout3.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750989AbdIEIQR (ORCPT ); Tue, 5 Sep 2017 04:16:17 -0400 Content-Disposition: inline In-Reply-To: <20170823004847.jmkb53xtdmmn6vtf@rob-hp-laptop> Sender: linux-gpio-owner@vger.kernel.org List-Id: linux-gpio@vger.kernel.org To: Rob Herring Cc: Linus Walleij , Mathias Duckeck , Phil Elwell , linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, Mark Rutland Hi Rob, sorry to bother you again, one more question popped up regarding the MAX3191x DT bindings: 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: > > Add device tree bindings for Maxim MAX3191x industrial serializer. [snip] > > +Optional properties: > > + - maxim,nchips: Number of chips in the daisy-chain (default is 1). Many I/O chips are daisy-chainable, so I've been wondering if a common property should be introduced? The existing gpio-74x164.c uses "registers-number" to convey the number of chips in the daisy chain. (Sans vendor prefix, multiple vendors sell compatible versions of this chip.) gpio-pisosr.c takes a different approach and calculates the number of chips in the daisy-chain by taking the common "ngpios" property (Documentation/devicetree/bindings/gpio/gpio.txt) and dividing it by 8 (which assumes that each chip has 8 inputs). Thanks, Lukas