From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-x243.google.com (mail-io0-x243.google.com [IPv6:2607:f8b0:4001:c06::243]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3wWpf95YrXzDqLf for ; Tue, 23 May 2017 05:30:25 +1000 (AEST) Received: by mail-io0-x243.google.com with SMTP id 12so14255550iol.1 for ; Mon, 22 May 2017 12:30:25 -0700 (PDT) MIME-Version: 1.0 Sender: geert.uytterhoeven@gmail.com In-Reply-To: References: <20170522140208.24652-1-javier@dowhile0.org> From: Geert Uytterhoeven Date: Mon, 22 May 2017 21:30:22 +0200 Message-ID: Subject: Re: [PATCH v4 00/20] eeprom: at24: Add OF device ID table To: Javier Martinez Canillas Cc: Rob Herring , "linux-kernel@vger.kernel.org" , Mark Rutland , Andrew Lunn , Wolfram Sang , Tony Lindgren , Catalin Marinas , Will Deacon , Russell King , Masahiro Yamada , Paul Mackerras , Linux I2C , Hongtao Jia , David Lechner , Herbert Xu , =?UTF-8?Q?Horia_Geant=C4=83?= , Michael Ellerman , Magnus Damm , Michal Simek , Andy Shevchenko , "linux-arm-kernel@lists.infradead.org" , Benjamin Herrenschmidt , Jason Cooper , Sebastian Hesselbarth , "devicetree@vger.kernel.org" , Mark Jackson , Sekhar Nori , Joachim Eastwood , Stuart Yoder , Scott Wood , Simon Horman , Santosh Shilimkar , Gregory Clement , "linux-omap@vger.kernel.org" , Sascha Hauer , =?UTF-8?Q?S=C3=B6ren_Brinkmann?= , Florian Larysch , "linuxppc-dev@lists.ozlabs.org" , Li Yang , Linux-Renesas , Dinh Nguyen , =?UTF-8?Q?Beno=C3=AEt_Cousson?= , Fabio Estevam , Shawn Guo Content-Type: text/plain; charset="UTF-8" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Javier, On Mon, May 22, 2017 at 7:15 PM, Javier Martinez Canillas wrote: >>> I also wonder why this is really needed if AFAIU "renesas,24c02" is >>> compatible with "atmel,24c02". IOW, the driver doesn't need to >>> differentiate between the two since the devices are the same and will >>> always match using "atmel,24c02". >> >> It is needed, so that when a difference is found, it can be handled >> without updating the DT. > > Yes, I understand this. What I tried to ask is if there could really > be a difference for the same chip type between different vendors, or > is just that people were using other manufacturers in the compatible > string as a consequence of the DT binding doc and the I2C core > ignoring the vendor prefix. The devices from different vendors are not the same. They contain FLASH ROM of a specific size, and glue logic to expose an i2c slave interface providing an AT24-compatible command set. They should behave similar within the limits of the AT24 "spec". But the actual implementation may be different. > I don't mind though, I will leave the manufacturers that are different > than the atmel variants in the mainline DTS as you and Geert asked. OK, thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds