[Arm-netbook] motherboard negotiation

[Henrik Nordström]

fre 2012-01-13 klockan 19:48 +0000 skrev lkcl luke:

>  ok, so, strictly speaking, there would need to be devicetree
> fragments, including:
> 
>  * one for the LCD interface
>  * one for the USB bus
>  * one for the I2C bus

Yes.

>  * one for SATA (or is this generic enough to just have a bit "yes or
> no" hmm no it isn't, you could have an SATA bus IC splitting to 16
> devices)

SATA port multiplexers is in many ways similar to USB hubs.

Strictly speaking the splitting is done at the SATA level. For the
device tree it's sufficient to describe that there is an sata channel.
The topology on that channel is then discovered usign SATA.

But there may need to be information about the physical ports so
operating system can describe ports correctly to the user.

>  * another for Ethernet (or is this generic enough to have one bit
> "yes or no" i think it might be)
>  * 16 for each of the GPIO pins
> 
> i don't think it's worthwhile worrying about the expansion header.

Well, the device tree will be in EEPROM, which means it's easy to fix up
for those using the expansion header.

> you know... this sounds like the allwinner system would actually be
> more flexible.

more flexible than?

Regards
Henrik