Re: Support ePAPR compliant phandle properties

[Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>]

On Wed, Nov 25, 2009 at 9:37 PM, David Gibson
<david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org> wrote:
> Currently, the Linux kernel, libfdt and dtc, when using flattened
> device trees encode a node's phandle into a property named
> "linux,phandle".  The ePAPR specification, however - aiming as it is
> to not be a Linux specific spec - requires that phandles be encoded in
> a property named simply "phandle".
>
> This patch adds support for this newer approach to dtc and libfdt.
> Specifically:
>
>        - fdt_get_phandle() will now return the correct phandle if it
>          is supplied in either of these properties
>
>        - fdt_node_offset_by_phandle() will correctly find a node with
>          the given phandle encoded in either property.
>
>        - By default, when auto-generating phandles, dtc will encode
>          it into both properties for maximum compatibility.  A new -H
>          option allows either only old-style or only new-style
>          properties to be generated.
>
>        - If phandle properties are explicitly supplied in the dts
>          file, dtc will not auto-generate ones in the alternate format.
>
>        - If both properties are supplied, dtc will check that they
>          have the same value.
>
>        - Some existing testcases are updated to use a mix of old and
>          new-style phandles, partially testing the changes.
>
>        - A new phandle_format test further tests the libfdt support,
>          and the -H option.

Haven't reviewed the code, but the approach seems sound.  FWIW, ACK.

g.