Messages in this thread | | | From | "Hawkins, Nick" <> | Subject | Re: [PATCH v4 3/5] ARM: dts: add GXP Support for fans and SPI | Date | Thu, 12 Jan 2023 19:58:23 +0000 |
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> If the two ranges are actually translated separately on the > bus, you could also decide to enumerate the translations with > a 64-bit local address and make the upper word an enumeration, > such as
> ranges = <0x1 0x0 0x80000000 0xf000000>, > <0x2 0x0 0xc0000000 0x30000000>;
I am not finding a good example on how this would affect the node addresses and reg properties. I believe I will stick with the current format if that is acceptable.
> Now it almost matches, except for the final byte, as the > range actually ends at 0xfffffffe not 0xffffffff if you make > the size one byte less than 1GB.
> Is there a special register in the last byte?
No there is not I will now have ranges as:
ranges = <0x0 0x80000000 0xf000000>, /* 0x80000000 - 0x8f000000 */ <0x40000000 0xc0000000 0x40000000>; /* 0xc0000000 - 0xffffffff */
> I suppose the physical address in the old mapping was actually > outside of the 0xc0000000-0xefffffff range, so it wasn't > even accessible. If the addresses are interpreted to wrap around > at the end of the mapping, that would have made the CPU visible > address 0xe0f00000 (0xc0000000 + (0x80f00000 % 0x30000000)). > If it just wrapped around as a 32-bit number, it would be > 0x40f00000 ((0xc0000000 + 0x80f00000)% 0x100000000), but I > don't see you you'd get to 80f00000.
It was not intended to wrap around; it was an error before and was not accessible.
The updated section of the device tree will be:
ahb@80000000 { compatible = "simple-bus"; #address-cells = <1>; #size-cells = <1>; ranges = <0x0 0x80000000 0xf000000>, /* 0x80000000 - 0x8f000000 */ <0x40000000 0xc0000000 0x40000000>; /* 0xc0000000 - 0xffffffff */ dma-ranges;
...
vic0: interrupt-controller@4eff0000 { /* 0xceff0000 */ compatible = "arm,pl192-vic"; reg = <0x4eff0000 0x1000>; interrupt-controller; #interrupt-cells = <1>; };
vic1: interrupt-controller@f00000 { /* 0x80f00000 */ compatible = "arm,pl192-vic"; reg = <0xf00000 0x1000>; interrupt-controller; #interrupt-cells = <1>; };
... };
Thanks,
-Nick Hawkins
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