Hi,
On Fri, Nov 12, 2021 at 04:32:48PM -0600, Rob Herring wrote:
> On Fri, Nov 12, 2021 at 4:23 PM Rafał Miłecki <zajec5@xxxxxxxxx> wrote:
> >
> > On 12.11.2021 23:18, Rob Herring wrote:
> > > On Tue, Nov 2, 2021 at 10:22 AM Rafał Miłecki <zajec5@xxxxxxxxx> wrote:
> > >>
> > >> From: Rafał Miłecki <rafal@xxxxxxxxxx>
> > >>
> > >> During my work on MFD binding for Broadcom's TWD block I received
> > >> comment from Rob saying that "syscon-reboot" should use "reg" property.
> > >> I'm not sure if my understanding & implementation are correct so I'm
> > >> sending this RFC.
> > >>
> > >> What bothers me is non-standard "reg" property usage. Treating it as a
> > >> simple (unsigned) integer number means different logic when it comes to
> > >> ranges.
> > >
> > > It shouldn't be. The idea is that 'reg' works like normal. See below.
> > >
> > >> Consider this example:
> > >>
> > >> timer@400 {
> > >> compatible = "simple-mfd", "syscon";
> > >> reg = <0x400 0x3c>;
> > >> ranges;
> > >
> > > ranges = <0 0x400 0x100>; // Just guessing for size
> > >
> > >>
> > >> #address-cells = <1>;
> > >> #size-cells = <1>;
> > >>
> > >> reboot@434 {
> > >
> > > reboot@34
> > >
> > > Just reading 'reg' is fine, but really, Linux should be either getting
> > > the translated address or have a function to get the offset from the
> > > parent base. IOW, it should also work if you just changed 'reg' to
> > > '<0x434 0x4>'.
> >
> > Are you aware of anyone working on support for getting translated
> > address? Do you recall any efforts on implementing such a helper?
>
> All the DT address functions give you translated addresses. It's the
> latter that doesn't exist that I'm aware of offhand. It's just
> of_address_to_resource() on the child and parent nodes and then
> calculate the offset.
Has a new version beent sent with this change, that I missed?
-- Sebastian
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