From mboxrd@z Thu Jan  1 00:00:00 1970
Return-path: <linux-media-owner@vger.kernel.org>
Received: from gofer.mess.org ([80.229.237.210]:46096 "EHLO gofer.mess.org"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751510AbaKIVfW (ORCPT <rfc822;linux-media@vger.kernel.org>);
	Sun, 9 Nov 2014 16:35:22 -0500
Date: Sun, 9 Nov 2014 21:35:17 +0000
From: Sean Young <sean@mess.org>
To: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Andy Walls <awalls.cx18@gmail.com>,
	Jarod Wilson <jwilson@redhat.com>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>,
	linux-media@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: staging: media: lirc: lirc_zilog.c: replace custom print macros
 with dev_* and pr_*
Message-ID: <20141109213517.GA1349@gofer.mess.org>
References: <20141031130600.GA16310@mwanda>
 <20141031142644.GA4166@localhost.localdomain>
 <20141031143541.GM6890@mwanda>
 <20141106124629.GA898@gofer.mess.org>
 <20141106110549.1812acc7@recife.lan>
 <20141106132113.GA1367@gofer.mess.org>
 <697D038C-4BD9-4113-8E7E-B89BACF09AC2@gmail.com>
 <6BB6C08A-32A2-4A37-B6F7-332556C9626E@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <6BB6C08A-32A2-4A37-B6F7-332556C9626E@gmail.com>
Sender: linux-media-owner@vger.kernel.org
List-ID: <linux-media.vger.kernel.org>

On Thu, Nov 06, 2014 at 08:56:47AM -0500, Andy Walls wrote:
> On November 6, 2014 8:54:28 AM EST, Andy Walls <awalls.cx18@gmail.com> wrote:
> >Sean,
> >
> >Ir-kbd-i2c was never intended for Tx.
> >
> >You can transmit *short* arbitrary pulse-space streams with the zilog
> >chip, by feeding it a parameter block that has the pulse timing
> >information and then subsequently has been obfuscated.  The firmware
> >file that LIRC uses in userspace is full of predefined versions of
> >these things for RC5 and NEC IIRC.  This LIRC firmware file also holds
> >the (de)obfuscation key.
> >
> >I've got a bunch of old notes on this stuff from essentially reverse
> >engineering the firmware in the Z8.  IANAL, but to me, its use in
> >developing in-kernel stuff could be dubious.
> >
> >Regards,
> >Andy

Very interesting.

I had considered reverse engineering the z8 firmware but I never found a
way to access it. I guess we have three options:

1. I could use Andy's notes to implement Tx. I have not seen the original
   firmware code so I'm not contaminated by reverse engineering it. IANAL 
   but I thought this is an acceptable way of writing a driver.

2. Hauppauge could prove us with documentation to write a driver with.

3. Leave it as-is, lirc_zilog will eventually be deleted from staging as it
   can't be ported to rc-core.


Sean