On Friday 16 May 2014 14:30:56 Kishon Vijay Abraham I wrote: > On Wednesday 14 May 2014 06:15 PM, Arnd Bergmann wrote: > > On Wednesday 14 May 2014 11:14:45 Kishon Vijay Abraham I wrote: > > / { > > #address-cells = <1>; // or <2> if you support > 4GB address space > > #size-cells = <1>; > > > > soc { > > #address-cells <1>; > > #size-cells = <1>; > > ranges; > > dma-ranges; > > > > ... // all normal devices > > > > axi@20000000 { > > #size-cells = <1>; > > #address-cells = <1>; > > dma-ranges; // can access all 4GB outbound > > ranges = <0 0x20000000 0x10000000>; // 28-bit bus > > > > pci@0 { > > reg = <0x0 0x1000>, // internal regs > > <0x1000 0x2000>; // config space > > The internal reg address space starts at 0x51000000. By Using this <0 > 0x20000000 0x10000000>; as ranges, we are not able to get the memory resource > properly. Can we use multiple ranges? how do we specify which ranges the *reg* > property to use? Yes, multiple ranges will work fine. You can make up a representation yourself if you don't know what the hardware really does. Two possible ways of doing this would be a) /* two separate physical connections represented as one logical bus */ axi@20000000 { #address-cells = <2>; #size-cells = <1>; ranges = <0 0 0x20000000 0x10000000>, /* configurable registers */ <1 0 0x51000000 0x01000000>; /* PCI host registers */ pci@1.0 { reg = <1 0 0x01000000>, /* host registers */ <0 0x1000 0x2000>; /* config space */ } }; b) /* one physical bus, with some address munging */ axi@20000000 { #address-cells = <1>; #size-cells = <1>; ranges = <0 0x20000000 0x10000000>, /* configurable registers */ <0x51000000 0x51000000 0x01000000>; /* PCI host registers */ pci@1.0 { reg = <0x51000000 0x01000000>, /* host registers */ <0x1000 0x2000>; /* config space */ } }; > Btw I was using *simple-bus* as compatible to *axi*. Or should I create a new > *axi* driver to create the pcie memory resources myself? simple-bus is best here, since you don't have a complex bus that needs to be set up using register accesses or that generates interrupts. Arnd -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html