Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Wed, 20 Feb 2019 22:50:00 +0100 | Subject | Re: [PATCH] platform: set of_node in platform_device_register_full() |
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On Wed, Feb 20, 2019 at 1:26 PM Måns Rullgård <mans@mansr.com> wrote: > > "Rafael J. Wysocki" <rafael@kernel.org> writes: > > > On Wed, Feb 20, 2019 at 1:12 PM Måns Rullgård <mans@mansr.com> wrote: > >> > >> Johan Hovold <johan@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?
That's what I meant. :-)
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