On Fri, Feb 19, 2021 at 09:05:32AM -0600, Rob Herring wrote: > On Wed, Feb 17, 2021 at 7:33 PM Matthias Kaehlcke <mka@xxxxxxxxxxxx> wrote: > > > > Hi Rob, > > > > thanks for your review! > > > > On Wed, Feb 17, 2021 at 03:04:41PM -0600, Rob Herring wrote: > > > On Wed, Feb 10, 2021 at 09:10:36AM -0800, Matthias Kaehlcke wrote: > > > > Discrete onboard USB hubs (an example for such a hub is the Realtek > > > > RTS5411) need to be powered and may require initialization of other > > > > resources (like GPIOs or clocks) to work properly. This adds a device > > > > tree binding for these hubs. > > > > > > > > Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> > > > > --- > > > > > > > > Changes in v5: > > > > - updated 'title' > > > > - only use standard USB compatible strings > > > > - deleted 'usb_hub' node > > > > - renamed 'usb_controller' node to 'usb-controller' > > > > - removed labels from USB nodes > > > > - added 'vdd-supply' to USB nodes > > > > > > > > Changes in v4: > > > > - none > > > > > > > > Changes in v3: > > > > - updated commit message > > > > - removed recursive reference to $self > > > > - adjusted 'compatible' definition to support multiple entries > > > > - changed USB controller phandle to be a node > > > > > > > > Changes in v2: > > > > - removed 'wakeup-source' and 'power-off-in-suspend' properties > > > > - consistently use spaces for indentation in example > > > > > > > > .../bindings/usb/onboard_usb_hub.yaml | 49 +++++++++++++++++++ > > > > 1 file changed, 49 insertions(+) > > > > create mode 100644 Documentation/devicetree/bindings/usb/onboard_usb_hub.yaml > > > > > > > > diff --git a/Documentation/devicetree/bindings/usb/onboard_usb_hub.yaml b/Documentation/devicetree/bindings/usb/onboard_usb_hub.yaml > > > > new file mode 100644 > > > > index 000000000000..bf4ec52e6c7b > > > > --- /dev/null > > > > +++ b/Documentation/devicetree/bindings/usb/onboard_usb_hub.yaml > > > > @@ -0,0 +1,49 @@ > > > > +# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause > > > > +%YAML 1.2 > > > > +--- > > > > +$id: http://devicetree.org/schemas/usb/onboard_usb_hub.yaml# > > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > > + > > > > +title: Binding for discrete onboard USB hubs > > > > > > This isn't really generic. Maybe there's a set of hubs with only a > > > single supply much like 'simple-panel', but I kind of doubt that here. > > > There aren't hundreds of hub chips like panels. Though, we should put > > > this into bindings/usb/hub/ so we start collecting hub bindings in one > > > place. > > > > Ok, I agree that the name of the binding is too generic, I anticipated that > > the power supply section would need to be extended to support other hub > > chips. > > > > > A generic driver doesn't have to have a generic binding. > > > > That's a good point, it seems to make sense to have separate bindings in > > this case. > > > > > You can have a specific device binding which is handled by a generic > > > driver. Or not. Who knows. Maybe a simple user like u-boot has a generic > > > driver while something more feature rich has a device specific binding. > > > > > > > + > > > > +maintainers: > > > > + - Matthias Kaehlcke <mka@xxxxxxxxxxxx> > > > > > > Now we have usb-device.yaml, you need: > > > > > > allOf: > > > - $ref: usb-device.yaml# > > > > ok > > > > So with your comments addressed it seems we have a binding that could be > > acceptable. I'll still hold back a bit to see if we can make progress with > > the discussion about using the 'graph' binding (https://lore.kernel.org/patchwork/patch/1379002/#1578294). > > The one thing I don't like about the current binding is that it wouldn't > > work out of the box with a hierarchy of hubs. To make that work on the > > driver side an additional property would be needed to indicate that two > > (or more) USB hub devices are related (i.e. are provided by the same > > chip). This is needed to be able to decide whether the hub should be > > powered down during system suspend. > > How about a 'hub-companion' property or similar? Yes, something like that is what I had in mind. Another inconvenient is that collaboration from the controller / generic hub driver is needed, however it seems at least Alan would be ok with that.
