"Rafael J. Wysocki" <raf...@kernel.org> writes:
> On Wed, Feb 20, 2019 at 1:12 PM Måns Rullgård <m...@mansr.com> wrote:
>>
>> Johan Hovold <jo...@kernel.org> writes:
>>
>> > On Wed, Feb 20, 2019 at 11:35:06AM +0000, Mans Rullgard wrote:
>> >> If the provided fwnode is an OF node, set dev.of_node as well.
>> >>
>> >> Some drivers are just shims that create extra "glue" devices with the
>> >> DT device as parent and have the real driver bind to these. In these
>> >> cases, the glue device needs to get a reference to the original DT node
>> >> in order for the main driver to access properties and child nodes.
>> >>
>> >> For example, the sunxi-musb driver creates such a glue device using
>> >> platform_device_register_full(). Consequently, devices attached to
>> >> this USB interface don't get associated with DT nodes, if present,
>> >> the way they do with EHCI.
>> >>
>> >> This change will allow sunxi-musb and similar driver to easily
>> >> propagate the DT node to child devices as required.
>> >
>> > Just a drive-by comment, didn't look to closely at this patch, but this
>> > all sounds familiar.
>> >
>> > Note that if both platform devices are bound to drivers you may end up
>> > with some resources like pinctrl which are handled automatically by
>> > driver core at probe time to be requested twice (and failing the second
>> > time).
>> >
>> > Take a look at 4e75e1d7dac9 ("driver core: add helper to reuse a
>> > device-tree node"), which provides a means to avoid this, and
>> > 49484abd93ab ("USB: musb: dsps: propagate device-tree node").
>>
>> Thanks, and ugh. So we should be setting the of_node_reused flag when
>> this is the case. It's easy for the musb-dsps driver since it doesn't
>> use platform_device_register_full() and can do this before the
>> device_add() call. How can we convey that this flag needs to be set?
>
> Through pdevinfo I guess?
Not without adding another field to it. The most direct is of course to
simply add an of_node_reused flag there too and copy it over. Would
that be OK, or is there a better way?
--
Måns Rullgård
