[PATCH 15/16] Add device tree for Ebony

Segher Boessenkool segher at kernel.crashing.org
Thu Feb 15 11:17:30 EST 2007


> The device type specifies the programming model of the node for OF, 
> that
> is the set of words the driver will provide to OF. So that's something
> we don't necessarily care much about for non-OF implementation but 
> still
> we should avoid going too far from that model either (after all,
> somebody can very well want to use a real OF on a board with a SoC).

Exactly.  The "separate device tree" imitates a real OF,
so you will lose much of its value if you start to deviate
from how real OF works.

> The device type is also used by the kernel in some areas. For example,
> the spec specifies that PCI host controllers and P2P bridges have a
> device-type of "pci" and the kernel relies heavily on that. Same for
> ISA. It thus makes sense to continue that practice with other bus 
> types.

Yep, for peripheral busses the kernel's needs are quite the
same as the firmware's needs so it makes sense that both use
device_type.


Segher




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