On Tue, Aug 07, 2007 at 01:28:06PM +1000, David Gibson wrote:
> It would be possible, I guess, to define a 'swizzled-ranges' property
> or something which allows child devices to be embedded in the parent's
> address range in a not-direct way. However, the swizzling on the
> flash bank is really a property of the flash bank, not of the parent
> bus - requiring it to be encoded in the parent is pretty yucky -
> especially if the flash bank is just part of a larger chunk of bus
> address space, defined by a single large ranges entry in the parent.
It's more a property of the connection between the bus and the flash
chips, and that connection could be described as its own "bus" node,
something like:
localbus {
#address-cells = <1>;
#size-cells = <1>;
ranges;
[EMAIL PROTECTED] {
reg = <ff000000 800000>;
...
};
[EMAIL PROTECTED] {
#address-cells = <1>;
#size-cells = <1>;
compatible = "with-enough-lsd";
swizzle-bytes = <4>;
swizzle-ranges = <0 ff800000 00800000 2 3 0 1>;
[EMAIL PROTECTED] {
compatible = "cfi-flash";
reg = <0 800000>;
bank-width = <4>;
device-width = <2>;
};
};
};
Similar intermediary buses could be used for flashes with indirect
access (SPI and such).
-Scott
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