[U-Boot] [PATCH 2/4] efikamx: remove drive strength hack from early_init_f and move it to the DCD

[Matt Sealey]

On Sat, Aug 18, 2012 at 5:56 PM, stefano babic <sbabic at denx.de> wrote:
> Am 19/08/2012 00:29, schrieb Marek Vasut:
>> Dear Matt Sealey,
>>
>>> On Sat, Aug 18, 2012 at 10:34 AM, Stefano Babic <sbabic at denx.de> wrote:
>>>> On 17/08/2012 20:19, Matt Sealey wrote:
>>>>> The i.MX Boot ROM lets us set up certain registers before U-Boot even
>>>>> gets executed. Rather than setting up DDR, putting U-Boot in place, and
>>>>> getting into pre-relocation init to set up DDR again, just do it once
>>>>> in the correct place. This also solves an issue where the Smarttop DDR
>>>>> pad settings were being applied on Smartbook.
>>>>>
>>>>> While we're at it, configure PCBID0,1,2 and the LED GPIO since we've
>>>>> still got room in the DCD to do so.
>>>>>
>>>>> Signed-off-by: Matt Sealey <matt at genesi-usa.com>
>>>>> ---
>>>>
>>>> Hi Matt,
>>>>
>>>>> diff --git a/board/genesi/mx51_efikamx/imximage_mx.cfg
>>>>> b/board/genesi/mx51_efikamx/imximage_mx.cfg index 6fe0ff9..ac9aa9a
>>>>> 100644
>>>>> --- a/board/genesi/mx51_efikamx/imximage_mx.cfg
>>>>> +++ b/board/genesi/mx51_efikamx/imximage_mx.cfg
>>>>> @@ -1,7 +1,7 @@
>>>>>
>>>>>  #
>>>>>
>>>>> +# Copyright (C) 2009 Pegatron Corporation
>>>>>
>>>>                     ^---
>>>>
>>>> Was this added for mistake ? I think you should add only yours.
>>>
>>> The drive strength settings came from Pegatron a long, long time ago
>>> (2009 :) and our old config and the function is copyrighted to them.
>>> Just because Marek took them out and recopyrighted the file I derived
>>> them from in this case doesn't mean they lost their copyright..
>>
>> This file was taken from mx51evk. It's written there. Please stop this nonsense,
>> it's troubling me.
>
> Then Pegatron has nothing to do with it. The original comes from
> Freescale, and the copyright was set.

Here is the pedigree of the code from initial table to current
implementation, as it stands;

* 2009, Pegatron wrote their U-Boot port for the board
* 2009, Pegatron gave us these drive strength settings based on some
very expensive and laborious testing and calibration of the DDR
implementation on the board. They did not update the settings in the
DCD table, they just implemented this function which persisted in
Marek's port to mainline
* 2010, Marek took the mx51evk example and added the OLD DCD table to
imximage.cfg and left the Pegatron drive strength code in there. Marek
removed the Pegatron copyright, and Genesi's copyright, and
Freescale's copyright but left the original code copyright he took
from U-Boot. You cannot just remove the copyright pedigree from the
chain just because you decided the "source" of the code was one guy
when you copy paste it from some other place
* 2012, we put the Pegatron copyrights back in, removed the drive
strength function from the board file, re-integrated it into the
imximage.cfg layout, and added our copyrights since we did the
expensive and laborious testing of the values and cross-referencing of
the manual.

The copyrights on every Efika MX file, since they were ALL ported from
the original Pegatron reference code should be;

Copyright (C) 2009 Freescale Semiconductor
Copyright (C) 2009 Pegatron Corporation
Copyright (C) 2009-2012 Genesi USA, Inc.
<name of the guy who you copied the mx51evk board file or imximage.cfg from>
<your name here>

And that's that. We are looking to go about restoring the pedigree, that's all.

If this was a $5000 dog, you would be concerned if you found out
someone had accidentally removed some history where it's grandmother
bred with a mongrel and invalidated it's pure-bred status. I can
assure you the money spent on coding this original code was more than
the cost of a dog and the copyright chain should persist whether you
think you "wrote" the code yourself or "copied" it from elsewhere in
U-Boot.

The MX51EVK board files may have been where whoever originally
committed them sourced it from, but this is not the true source of the
code contained in the drive strength function we removed, the data
contained in it, or the PCB ID table that's listed in the comments.
The MX51EVK DDR settings in imximage.cfg are not the same as the ones
in the old Efika MX file, so these have been ported from Pegatron's
old DCD data. The new drive strength settings are sourced from the
function and moved back into the DCD. All I did was verify they worked
and we were not redundantly setting up the same register twice or
pushing defaults information via the DCD to registers (since we only
have 60 entries, doing every DDR pad control plus the required PCB ID
setup overflows the maximum).

-- 
Matt Sealey <matt at genesi-usa.com>
Product Development Analyst, Genesi USA, Inc.