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Date: Tue, 06 Dec 2011 17:22:39 -0600
From: Rob Herring <robherring2@gmail.com>
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To: Wolfram Sang <w.sang@pengutronix.de>
CC: Wolfgang Denk <wd@denx.de>, devicetree-discuss@lists.ozlabs.org,
        Heiko Schocher <hs@denx.de>, linux-kernel@vger.kernel.org,
        Vitaly Bordug <vbordug@ru.mvista.com>, linux-watchdog@vger.kernel.org
Subject: Re: [PATCH] drivers, char: add U-Boot bootcount driver
References: <1322991921-21096-1-git-send-email-hs@denx.de> <20111204114741.GA5788@pengutronix.de> <4EDCD7B2.5030409@denx.de> <20111206215056.GD14154@pengutronix.de> <20111206215609.5D1FF1A32820@gemini.denx.de> <20111206220620.GF14154@pengutronix.de>
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On 12/06/2011 04:06 PM, Wolfram Sang wrote:
> 
>>> bootcount itself is not a device. It is a feature of certain devices. And that
>>> needs to be implemented; possibly generic enough that it can work for register
>>> based, i2c based, and so forth, accesses.
>>
>> If "boot counter" is not a good name for such a device, then what name
>> would you suggest?
> 
> None.
> 
>> Or do you think a counter (which can be implemented in a number of
>> different ways, depending on hardware specifics) is not a device?
> 
> Yes.
> 
>> What would be such a device, then?
> 
> "maxim,ds1338"
> 
> Please have a look at the devicetree.org-wiki-page I just mentioned:
> 
> http://devicetree.org/Device_Tree_Usage
> 

Perhaps fs/pstore would be a good choice for the user space interface
(defining a new file bootcount). This can support any arbitrary backing
device although pretty much only ACPI is implemented.

Rob