lkml.org 
[lkml]   [2011]   [Oct]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [PATCH 1/3] mfd: allow mfd_cell association with device tree node
    From
    On Mon, Oct 3, 2011 at 1:40 PM, Mark Brown
    <broonie@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
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2011-10-03 14:55    [W:0.021 / U:18.784 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site