Re: [RFC v2 2/3] power: power_supply: Add core support for supplied_nodes

[Stephen Warren <swarren@wwwdotorg.org>]

On 02/21/2013 04:11 PM, Rhyland Klein wrote:
> With the growing support for dt, it make sense to try to make use of
> dt features to make the general code cleaner. This patch is an
> attempt to commonize how chargers and their supplies are linked.
> 
> Following common dt convention, the "supplied-to" char** list is
> replaced with phandle lists defined in the supplies which contain
> phandles of their suppliers.
> 
> This has the effect however of introducing an inversion in the internal
> mechanics of how this information is stored. In the case of non-dt,
> the char** list of supplies is stored in the charger. In the dt case,
> a device_node * list is stored in the supplies of their chargers,
> however this seems to be the only way to support this.

When parsing the DT, you can convert from phandle (or struct device_node
*) to the name of the referenced supply by simple lookup. So, you could
store supply names rather than device_node *. Can't you then also fill
in the referenced supply's existing char** list of supplies?

Of course, making this interact-with/use -EPROBE_DEFERRED might be
challenging, since this would be operating in the inverse order to other
producer/consumer relationships, which might cause loops.