[U-Boot] [PATCH 2/2] pdm360ng: add EDID property to FDT display node

[Detlev Zundel <dzu@denx.de>]

Hi Anatolij,

> Hello Wolfgang,
>
> On Mon, 16 Aug 2010 16:02:14 +0200
> Wolfgang Denk <wd@denx.de> wrote:
> ...
>> I have one (probably stupid) question:
>> 
>> > +static unsigned char edid_buf[128] = {
>> > +	0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00,
>> > +	0x42, 0xC9, 0x34, 0x12, 0x01, 0x00, 0x00, 0x00,
>> > +	0x0A, 0x0C, 0x01, 0x03, 0x80, 0x98, 0x5B, 0x78,
>> > +	0xCA, 0x7E, 0x50, 0xA0, 0x58, 0x4E, 0x96, 0x25,
>> > +	0x1E, 0x50, 0x54, 0x00, 0x00, 0x00, 0x01, 0x01,
>> > +	0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
>> > +	0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x80, 0x0C,
>> > +	0x20, 0x00, 0x31, 0xE0, 0x2D, 0x10, 0x2A, 0x80,
>> > +	0x12, 0x08, 0x30, 0xE4, 0x10, 0x00, 0x00, 0x18,
>> > +	0x00, 0x00, 0x00, 0xFD, 0x00, 0x38, 0x3C, 0x1F,
>> > +	0x3C, 0x04, 0x0A, 0x20, 0x20, 0x20, 0x20, 0x20,
>> > +	0x20, 0x20, 0x00, 0x00, 0x00, 0xFF, 0x00, 0x50,
>> > +	0x4D, 0x30, 0x37, 0x30, 0x57, 0x4C, 0x33, 0x0A,
>> > +	0x0A, 0x0A, 0x0A, 0x0A, 0x00, 0x00, 0x00, 0xFF,
>> > +	0x00, 0x41, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
>> > +	0x30, 0x30, 0x30, 0x30, 0x30, 0x31, 0x00, 0xD4,
>> > +};
>> 
>> Is there a way to make these magic numbers readbale for a mere human?
>
> The numbers encode some strings (manufacturer, date,
> display name, etc.) and display parameter numbers.
> I already thought about the way how to easily generate the
> structure. Using some macros doesn't make sense, I think.
> Better would be to describe the display in a file and
> write a tool that generates the edid data structure from
> this description.

I don't believe that currently we have a need for such a tool.  When we
can document "verbally" how to generate the data and if it is used often
enough, then maybe someone comes up with a cleverer solution.

>> How do you generate these?
>
> I generated the block using Phoenix EDID Designer 1.3
> (a tool for Windows). This creates a text file like:
>
> EDID BYTES:
> 0x   00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
>     ------------------------------------------------
> 00 | 00 FF FF FF FF FF FF 00 42 C9 34 12 01 00 00 00
> 10 | 0A 0C 01 03 80 98 5B 78 CA 7E 50 A0 58 4E 96 25
> 20 | 1E 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01
> 30 | 01 01 01 01 01 01 80 0C 20 40 31 E0 26 10 18 80
> 40 | 36 00 30 E4 10 00 00 18 00 00 00 FD 00 38 3C 1F
> 50 | 3C 04 0A 20 20 20 20 20 20 20 00 00 00 FF 00 50
> 60 | 4D 30 37 30 57 4C 33 0A 0A 0A 0A 0A 00 00 00 FF
> 70 | 00 41 30 30 30 30 30 30 30 30 30 30 30 31 00 91
>
> Then I manualy converted the needed bytes to a char array.

Then put this text as a "how-to comment" next to the data.  This _is_
valuable informatino which we do not want to loose.  Rather then putting
it in a commit message, this will keep the comment intact once people
begin copying the construct around.

Cheers
  Detlev

-- 
... what [Microsoft] Exchange provides is *like* email, but it is *not* email.
Once you start trying to use it for real email, you find it's broken by design
in a large number of ways.  It makes no  sense for [a company] to require that
you use Exchange for Internet email, because that's not what Exchange does.
                      -- David Woodhouse <1281348164.12908.47.camel@localhost>
--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de