On Thu, Nov 26, 2015 at 3:44 PM, Mason <slash.tmp@xxxxxxx> wrote:
> On 26/11/2015 14:59, Russell King - ARM Linux wrote:
>> On Thu, Nov 26, 2015 at 02:16:16PM +0100, Mason wrote:
>>> #define SCU_BASE 0x20000000
>>>
>>> scu: scu@XXX {
>>> compatible = "arm,cortex-a9-scu";
>>> reg = <SCU_BASE 0x100>;
>>>
>>> gic: interrupt-controller@XXX {
>>> compatible = "arm,cortex-a9-gic";
>>> reg = <SCU_BASE+0x1000 0x1000>, <SCU_BASE+0x100 0x0100>;
>>
>> You don't get preprocessor arithmetic here. What you get is this passed
>> to DTC:
>>
>> reg = <0x20000000+0x1000 0x1000>...
>>
>> The only time the preprocessor does arithmetic is when it needs to
>> evaluate an expression, eg, in an #if statement.
>
> Doh! Brain malfunction. No arithmetic indeed.
> Working with the preprocessor would have to involve token-pasting.
>
> #define SCU_BASE(OFFSET) 2000##OFFSET
> #define SCU_BASEX(OFFSET) 0x2000##OFFSET
>
> gic: interrupt-controller@SCU_BASE(1000) {
> reg = <SCU_BASEX(1000) 0x1000>, <SCU_BASEX(0100) 0x0100>;
> };
>
> My very own abomination!
Yeah! ;-)
I guess this would work, too?
scu_container@20000000 {
compatible = "simple-bus";
ranges = <0x0 0x20000000 0x10000>;
#address-cells = <1>;
#size-cells = <1>;
scu: scu@0 {
compatible = "arm,cortex-a9-scu";
reg = <0x0000 0x100>;
gic: interrupt-controller@1000 {
compatible = "arm,cortex-a9-gic";
reg = <0x1000 0x1000>, <0x0100 0x0100>;
twd-timer@0600 {
compatible = "arm,cortex-a9-twd-timer";
reg = <0x0600 0x10>;
};
No more explicit arithmetic needed, just substitue "20000000".
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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