Date: Wed, 15 Dec 2010 02:25:11 +0100
From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
To: Greg KH <gregkh@suse.de>
Cc: linux-kernel@vger.kernel.org, Nicolas Ferre <nicolas.ferre@atmel.com>,
        Patrice VILCHEZ <patrice.vilchez@atmel.com>
Subject: Re: [PATCH] base: add sysfs socs info
Message-ID: <20101215012511.GQ19897@game.jcrosoft.org>
References: <1292330417-13703-1-git-send-email-plagnioj@jcrosoft.com>
 <20101214161130.GB1857@suse.de>
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On 08:11 Tue 14 Dec     , Greg KH wrote:
> On Tue, Dec 14, 2010 at 01:40:17PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > this provide an easy way to register soc information
> > 
> > arch, family, model, id, revision
> > 
> > as this for at91sam9g20
> > 
> > $ cat /sys/devices/system/soc/soc0/arch
> > current
> > $ cat /sys/devices/system/soc/soc0/family
> > at91
> > $ cat /sys/devices/system/soc/soc0/id
> > at91sam9g20
> > $ cat /sys/devices/system/soc/soc0/model
> > 0x00000000019905a0
> > $ cat /sys/devices/system/soc/soc0/revision
> > 1.1
> 
> What is this for?  When you add sysfs files, you are required to add
> entries to the Documentation/ABI/ files as well, please always provide
> this so we are able to review the code easier.
I'll add a doc in Documentation/ABI
 
> > +struct soc {
> > +	u64 id;
> > +	char *arch;
> > +	char *family;
> > +	char *model;
> > +	char *revision;
> > +	struct sys_device sysdev;
> > +};
> 
> What is a "SOC"?  A "Small Ordinary Creature"?
:) Systen On Chip
> 
> And does every system have one of these?  Just one?  Not multiple?  We
> need a whole lot more information here as to why this code is needed,
> and who will be using it.
> 
> Also, isn't this information already in /proc/cpu/ today?
no all this information are not present in /proc/cpu and a cpu is not a soc

basicaly on a board you will have one soc but some boards have more as example
some ST boards you have two sh4 soc or on some amcc you have two powerpc soc

with these information you are allow to dynamise the userspace based on the
soc or the companion soc and also be able to display this information in a UI

Best Regards,
J.
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