PandaBoard audio routing requires 2 different DTB

[Fathi Boudra]

Forwarded from Péter Ujfalusi:

Currently we have one hwpack for PandaBoard4430 and PandaBoardES 4460
which means that when we install the hwpack on PandaBoardES the kernel
thinks it is running on PandaBoard 4430.
However there is a HW difference between the two boards:
Audio routing is different (for capture path).
Also the hdmi pin muxing need to be different (according to the DTS files).

I can see two ways of dealing with the different versions:

1. create separate hwpacks for the revisions where only the included
DTB file is different:
PandaBoard 4430: omap4-panda.dtb
PandaBoardES: omap4-panda-es.dtb

2. Or to have single hwpack for Panda:
With the included patch in u-boot
Include both omap4-panda.dtb and omap4-panda-es.dtb files to the boot partition.

Modify the boot.txt to load different dtb based on the board:
if is_pandaES; then
setenv bootcmd "fatload mmc 0:1 0x80200000 uImage; fatload mmc 0:1
0x81600000 uInitrd; fatload mmc 0:1 0x815f0000 omap4-panda-es.dtb;
bootm 0x80200000 0x81600000 0x815f0000";
else
setenv bootcmd "fatload mmc 0:1 0x80200000 uImage; fatload mmc 0:1
0x81600000 uInitrd; fatload mmc 0:1 0x815f0000 omap4-panda.dtb; bootm
0x80200000 0x81600000 0x815f0000";
fi;

For audio we need to tell the difference between the two revision and
this is done via different DTB blob.

[Fathi Boudra (fboudra)]

We've added --dtb-file option to linaro-media-create:
Select a DTB file from a hardware pack that contains more than one. If not specified, it will default to the first entry in 'dtb_files' list.