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From: Grant Likely <grant.likely@secretlab.ca>
Date: Thu, 28 May 2009 07:34:02 -0600
Message-ID: <fa686aa40905280634m153ff338j5791a22dba3ad790@mail.gmail.com>
Subject: Re: [RFC] [PATCH] Device Tree on ARM platform
To: Wolfram Sang <w.sang@pengutronix.de>
Cc: Robert Schwebel <r.schwebel@pengutronix.de>,
       Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>,
       devicetree-discuss <devicetree-discuss@ozlabs.org>,
       Russell King - ARM Linux <linux@arm.linux.org.uk>,
       linux-kernel@vger.kernel.org, linux-arm-kernel@lists.arm.linux.org.uk,
       Jon Smirl <jonsmirl@gmail.com>, Scott Wood <scottwood@freescale.com>,
       Janboe Ye <yuan-bo.ye@motorola.com>, Timur Tabi <timur@freescale.com>
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On Thu, May 28, 2009 at 12:34 AM, Wolfram Sang <w.sang@pengutronix.de> wrote:
>
>> It is inherent in the value "atmel,24c08".  Because the exact device
>> model is specified, the kernel can know what the page size and flags
>> are for that device.
>
> I am afraid this is not the case. I remember that we once had two revisions of
> the same eeprom, and the vendor decided to increase the page size without
> changing the naming of the eeprom. (Can't point to any documentation yet, would
> have to dig this up.) Those eeproms can be really weird.
>
> Also, there are _a lot_ of eeprom manufacturers out there, so the match table
> will be enormous....

... which is the whole point of "compatible".  Every possible variant
doesn't get listed in the device driver; device nodes in the tree
claim compatibility with older, already known parts.

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.