On Mon, Oct 3, 2011 at 1:40 PM, Mark Brown <broo...@opensource.wolfsonmicro.com> wrote: > So, I made two suggestions above and it sounds like you want the second > one but you've only responded to the first one without commenting on the > second. My second suggestion was that if the block is sufficiently > isoltated from the core we should be able instantiate it from the device > tree without requiring explicit code in the core driver.
Sorry, hadn't quite grasped what you meant there. I understand now. It is an interesting idea but leaves me with some questions/problems: The GPIO controller needs to find its register space by looking at the PCI device (the ISA bridge). So probing it independently could maybe be viewed by some as a hierarchy violation as it would have to then hunt around for its PCI dev. According to Grant's hard rule, the parent device needs to be the thing that passes the of_node to the child. So we would still need a driver for the parent ISA bridge instantiating the child GPIO controller. Wouldn't that bring us straight back to the same problem (that the "core" needs code to instantiate the child)? Also, not an argument against the direction, but an outstanding problem that would need to be resolved: the x86 device tree implementation doesn't seem to follow Grant's design for how things should work (or maybe I misunderstood something), so work would be needed there first. See the unfinished discussion at http://lists.ozlabs.org/pipermail/devicetree-discuss/2011-July/006853.html Thanks, Daniel _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss