On Fri, 30 Nov 2012 17:49:48 -0700, Jason Gunthorpe <jguntho...@obsidianresearch.com> wrote: > On Fri, Nov 30, 2012 at 09:48:05AM +0000, Grant Likely wrote: > > > > If you attempt to stick a 'reg' in a block nested below a > > > 'device_type="pci"' the kernel throws lots of error messsages and > > > generates bad address mappings. > > > > Have you added the appropriate #address-cells and #size-cells to the pci > > device node to go back to a non-pci addressing mode? > > assigned-addresses > > Switching away from the 5 dword address format is not ideal > because then there is no way to specify the resource region (prefetch, > io, mmio) and mmio would have to be assumed.
You don't need to switch away from using 5 cells if that works best for you, but I'd be surprised if it was the ideal representation. I would expect you to use a representation that makes sense for the internal bus architecture of the device. If if exactly matches the PCI address, then go ahead with 5 cells, but if it is one or more 32bit busses, then use 1 or 2 for #address-cells and 1 for #size-cells. > > > only makes sense in the pci-device node itself. reg should work for all > > nodes below that, and if it doesn't then it is a bug that we need to > > fix. > > Okay.. but how should the DTS be constructed? > pcie_bus { // The PCI-E bus device_type = "pci"; ranges = <5dw ranges>; #address-cells = <3>; #size-cells = <2>; soc_bridge { // The PCI-E device device_type = "pci"; // These are important to set up the address format in the child // nodes #address-cells = <3>; #size-cells = <2>; // Translation from PCI bus space to local bus space. ranges = <5dw ranges>; soc_device { // Internal device reg = <5dw regs> }; }; }; > > This is what I have now, the soc_bridge PCI-E device is DTS modeled as > a PCI bridge - it has a ranges with its memory location, and the > children nodes are relative to those ranges. This would not be typical > for a non-bridge PCI-E device. Now, if the children of soc_bridge really are PCI devices (and not just plain-vanilla memory mapped IP cores like I assume above), then they shouldn't be registered in the kernel as platform_devices at all. In that case register them as PCI devices and the existing PCI infrastructure should do the naming correctly. > The reason for the 'assigned-address' requirement with the current > kernel code is the device_type=pci on soc_bridge. This makes > of_match_bus(parent) for soc_device return the PCI structure, which > has '.addresses = "assigned-addresses",' If the soc_devices are getting triggered on that and they shouldn't be, then we need a mechanism in the soc_bridge node to kick out of that behavoir for its children. g. _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss