[Patch] OE: add EDID parsing support for U-boot

[Petr Štetiar]

As discussed in previous thread[1], I'm sending the first patch and I've
better started the new thread for it.

Attached is patch for u-boot in OE which contains first attempt of EDID
parsing. I've made my u-boot edid branch available on github[2], you can find
there the bare parser[3] with EEPROM dumps for testing also. Example usage and
output of my 32" Samsung TV (I think, that we should hardcode the address of
EDID EEPROM, it's 50 always anyway):

OMAP3 beagleboard.org # i2c dev 2
Setting bus to 2

OMAP3 beagleboard.org # i2c edid 50
EDID version: 1.3
Product ID code: 03bc
Manufacturer: KJL
Serial number: 00000000
Manufactured in week: 47 year: 2007
Video input definition: analog signal
Monitor is RGB
Maximum visible display size: 16 cm x 9 cm
Power management features: no active off, no suspend, no standby
Estabilished timings:
640x480 75 Hz (VESA)
Standard timings:
1920x1080 67 Hz (detailed)
1280x720 71 Hz (detailed)
Monitor range limits, horizontal sync: 26-68 Hz, vertical refresh: 23-61 KHz
Monitor name: SAMSUNG
OMAP3 beagleboard.org #

Next step would be adding of board detection logic using EDID, but I'll better
wait for the comments first. Anyway, we need to define the content of the
vendor/product IDs to something similar we have for expansion board detection
already.

Questions, comments and patches are welcome. Thanks.

1. http://groups.google.com/group/beagleboard/browse_frm/thread/df33eee4618e06b4#
2. http://github.com/ynezz/u-boot-sakoman
3. http://github.com/ynezz/u-boot-edid

-- ynezz

[Maxim Podbereznyy]

"Maximum visible display size: 16 cm x 9 cm" and the TV is 32"? wierd :)

2010/9/19 Petr Štetiar <yn...@true.cz>

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[Petr Štetiar]

Maxim Podbereznyy <lisa...@gmail.com> [2010-09-19 21:13:04]:

> "Maximum visible display size: 16 cm x 9 cm" and the TV is 32"? wierd :)

Tell that Samsung, ok? :-)

-- ynezz

[Ricardo Salveti de Araujo]

Hey,

I also created an u-boot patch to try to probe the EDID and then set the proper
mode, but then decided to move to the kernel, as soon we'll have a similar
functionality for OMAP 4.

While hacking it for ubuntu's kernel (2.6.35) I created a first draft of the
EDID parser for OMAP 3, little bit similar to what we had in the past at this
list. You can find the patches at http://kernel.ubuntu.com/git?p=rsalveti/ubuntu-maverick.git;a=shortlog;h=refs/heads/omap3-edid-parsing.

Currently it's basically a draft because I first wanted to make sure it'd work
the way I needed, using current kernel API. There's still a lot of room for
improvements, like finding a proper place for the code (maybe at the display
driver?) and a proper way to identify the bus number (i2c bus 3 for Omap 3). I
also want it to probe the best resolution respecting the monitor aspect ratio,
to get a better looking image.

With this patch series I can get 1280x1024@56 as the highest resolution from my
monitor, so fell free to test and give me any feedback. Patches for improvements
are also welcome :-)

Cheers,
--
Ricardo Salveti de Araujo