Date: Sat, 26 Mar 2011 02:40:10 +0000
From: Jamie Iles <jamie@jamieiles.com>
To: Mike Frysinger <vapier@gentoo.org>
Cc: Jamie Iles <jamie@jamieiles.com>, Arnd Bergmann <arnd@arndb.de>,
        linux-kernel@vger.kernel.org, gregkh@suse.de
Subject: Re: [RFC PATCHv2 1/4] drivers/otp: add initial support for OTP memory
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On Fri, Mar 25, 2011 at 10:16:48PM -0400, Mike Frysinger wrote:
> On Fri, Mar 25, 2011 at 20:21, Jamie Iles wrote:
> > For the actual ioctl() we should assume byte addressing rather than
> > words though and do the conversion in the driver so we can cope with
> > devices that don't have 64-bit words and do the locking on a looping
> > word-by-word basis.
> >
> > ? ? ? ?struct otp_lock_req {
> > ? ? ? ? ? ? ? ?__u32 ? start_addr;
> > ? ? ? ? ? ? ? ?__u32 ? byte_count;
> > ? ? ? ?};
> 
> i would add an ABI field here too so if in the future we want to add
> stuff, we can do so without adding new ioctls.  like "u16 version; u16
> flags;".  then in the ioctl, if version isnt 0, we return ENOTSUP.  in
> the future, we can add flags or bump the version.

Sounds like a good idea.

> > Mike, would this be OK with you if we used a different ioctl() to the
> > one bfin-otp is using currently? ?I notice that it's using the OTPLOCK
> > ioctl() from MTD but I think it's using the argument in a different way.
> 
> i re-used OTPLOCK because it's exactly the name i wanted and it was
> easier than carving out my own namespace, but the args are different.
> i can see how people might find this undesirable.

OK, well seeing as we're making this generic we may as well reserve a 
range of ioctls.  I'll reserve a few of them and add OTP_LOCK_AREA for 
now.

Jamie
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