From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Brezillon Subject: Re: [PATCH v3 18/27] mtd: nand: omap2: Implement NAND ready using gpiolib Date: Tue, 27 Oct 2015 09:12:35 +0100 Message-ID: <20151027091235.03dba8c5@bbrezillon> References: <1442588029-13769-1-git-send-email-rogerq@ti.com> <1442588029-13769-19-git-send-email-rogerq@ti.com> <20151026204900.GI13239@google.com> <562F2FB6.7050806@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <562F2FB6.7050806@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Roger Quadros Cc: Brian Norris , tony@atomide.com, dwmw2@infradead.org, ezequiel@vanguardiasur.com.ar, javier@dowhile0.org, fcooper@ti.com, nsekhar@ti.com, linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Alex Smith , Harvey Hunt List-Id: linux-omap@vger.kernel.org Hi Roger, On Tue, 27 Oct 2015 10:03:02 +0200 Roger Quadros wrote: > On 26/10/15 22:49, Brian Norris wrote: > > > > Others have been looking at using GPIOs for the ready/busy pin too. At a > > minimum, we need an updated DT binding doc for this, since I see you're > > adding this via device tree in a later patch (I don't see any DT binding > > patch for this; but I could just be overlooking it). It'd also be great > > if this support was moved to nand_dt_init() so other platforms can > > benefit, but I won't require that. > > > > Also, previous [0] proposers had suggested 'rb-gpios', not 'ready-gpio' > > (the hardware docs typically call it 'rb' for ready/busy, FWIW). I don't > > really care, but the name should be going into a doc, so we can choose > > the same one everywhere. > > > > EDIT: looks like the discussion was partly here [1] and it seems we're > > landing on "rb-gpios" in the latest version [2]. Can we stick with that? > > Why should it be "rb-gpios" and not "rb-gpio"? > I don't think there are multiple gpios for r/b# function. Because it's supposed to be a generic binding, and some NAND chips embed several dies, thus exposing several CS and RB pins, hence the rb-gpios name. Also, as described here [1], the convention is to name your property -gpios even if you only need one gpio. Best Regards, Boris [1]http://lxr.free-electrons.com/source/Documentation/devicetree/bindings/gpio/gpio.txt#L16 -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com