From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH] ARM: tegra: add "nor-jedec" flash compatible binding Date: Fri, 08 May 2015 14:01:40 -0600 Message-ID: <554D1624.5030608@wwwdotorg.org> References: <1431066098-19821-1-git-send-email-zajec5@gmail.com> <554CDD8C.7050000@wwwdotorg.org> <20150508184317.GZ32500@ld-irv-0074> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20150508184317.GZ32500@ld-irv-0074> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Brian Norris Cc: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= , linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Alexandre Courbot , Thierry Reding , linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ezequiel Garcia , Marek Vasut , linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 05/08/2015 12:43 PM, Brian Norris wrote: > On Fri, May 08, 2015 at 10:00:12AM -0600, Stephen Warren wrote: >> On 05/08/2015 12:21 AM, Rafa=C5=82 Mi=C5=82ecki wrote: >>> Starting with commits >>> 8ff16cf ("Documentation: devicetree: m25p80: add "nor-jedec" bindin= g") >>> 1103b85 ("mtd: m25p80: bind to "nor-jedec" ID, for auto-detection") >>> we have "nor-jedec" binding indicating support for JEDEC identifica= tion. >> >> The documentation looks quite incomplete. "nor-jedec" sounds like >> it's intended to be something generic. As such, it should be >> documented in e.g. >> Documentation/devicetree/bindings/mtd/nor-jedec.txt, not buried in >> one particular flash device's binding. If it's not intended to be >> generic, why isn't the existing "winbond,w25q32dw" enough? > > It is generic, though there are plenty of additional manufacturer/dev= ice > pairs that could go on top of it. m25p80 was (one of?) the first > supported, so the naming has been based on legacy, and we're in the > process of unwinding a bit of that. If it helps, we could move the do= c > to .../mtd/spi-nor,nor-jedec.txt or something like that. Yes, moving the documentation to a generic location would be appropriat= e=20 in my opinion. >> Equally, "nor-jedec" doesn't sound like the right name. It doesn't >> differentiate between SPI and parallel NOR flash, which presumably >> need different compatible values, since the programming model is >> quite different, and the compatible value is supposed to >> define/imply the SW-visible programming model. > > It's definitely for SPI only. There was much discussion about this a > few months back. Somewhere along the way, it was mentioned that the > context (SPI slave is a child of SPI master) would make this clear. I= 'm > still not sure why we didn't end up with something more descriptive, > though, like "spi-nor,nor-jedec". > > I'm open to change, as this binding is new in 4.1-rc1. I don't believe compatible values should be interpreted according to=20 context; compatible value matching isn't implemented that way AFAIK, an= d=20 I'm not aware of any precedent for it to work that way. Did the discussion involve the core DT maintainers? If so, whatever the= y=20 decided can stick. Otherwise, the discussion should be rubn by them.