On Mon, Jun 27, 2022 at 06:36:53PM +0530, Harsh Agarwal wrote: > > On 6/10/2022 10:52 PM, Rob Herring wrote: > > On Fri, Jun 10, 2022 at 05:25:25PM +0530, Harsh Agarwal wrote: > > > On 6/9/2022 9:08 PM, Rob Herring wrote: > > > > On Wed, Jun 08, 2022 at 11:06:25PM +0530, Harsh Agarwal wrote: > > > > > Added support for multiport, mport, num_usb2_phy and num_usb3_phy > > > > > properties. These properties are used to support devices having > > > > > a multiport controller. > > > > > > > > > > Signed-off-by: Harsh Agarwal <quic_harshq@xxxxxxxxxxx> > > > > > --- > > > > > .../devicetree/bindings/usb/snps,dwc3.yaml | 53 ++++++++++++++++++++++ > > > > > 1 file changed, 53 insertions(+) > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml > > > > > index d41265b..9332fa2 100644 > > > > > --- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml > > > > > +++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml > > > > > @@ -343,6 +343,32 @@ properties: > > > > > This port is used with the 'usb-role-switch' property to connect the > > > > > dwc3 to type C connector. > > > > > + multiport: > > > > Again, I don't think this is going to play well if you need to describe > > > > USB devices in your DT. For example, a USB hub with additional DT > > > > properties. > > > Thanks for the review Rob. > > > Can you please explain why would one want to describe a USB hub in device > > > tree ? > > Because someone soldered a hub on the board and then connected extra > > things like resets, GPIOs, supplies which are all outside of standard > > USB. It's quite common... > > > > There's some flavors of Beagle boards that have a USB ethernet on board. > > Guess what, they skipped out on a eeprom and so the device and a MAC > > address has to be described in DT (if you want a stable MAC addr). > > > > > IF USB hub is attached to a root port , it would be enumerated by the SW. I > > > am not clear how DT is coming > > > into picture. Even if there was a scenario to add DT properties for a hub, > > > then this multiport node would be like a nop > > > as it just helps us to get the PHY phandles in a proper way. > > It won't be enumerated by the SW if it has to be powered on first using > > non-standard resources. > > > > > Do you feel we still might have a problem with multiport node ? > > A board design could have a hub or device on any or all your ports. > > > > > > > + description: > > > > > + If a single USB controller supports multiple ports, then it's referred to as > > > > > + a multiport controller. Each port of the multiport controller can support > > > > > + either High Speed or Super Speed or both and have their own PHY phandles. Each > > > > > + port is represented by "mport" node and all the "mport" nodes are grouped > > > > > + together inside the "multiport" node where individual "mport" node defines the > > > > > + PHYs supported by that port. > > > > > + > > > > > + num_usb2_phy: > > > > > + description: Total number of HS-PHYs defined by the multiport controller. > > > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > > > > + > > > > > + num_usb3_phy: > > > > > + description: Total number of SS-PHYs defined by the multiport controller. > > > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > > > > + > > > > > + mport: > > > > > + description: Each mport node represents one port of the multiport controller. > > > > > + oneOf: > > > > > + - required: > > > > > + - usb-phy > > > > This is deprecated. Why are you adding it? > > > Do you mean "usb-phy" is deprecated ? > > It is replaced by 'phys'. Any new user should use 'phys'. > > > > > Internally we use usb-phy with our downstream GLUE driver > > Upstream does not care about that. > > > > > > > + - required: > > > > > + - phys > > > > > + - phy-names > > > > Other multi port USB hosts just have a list of phys. Why can't you just > > > > use phy-names to identify each phy: > > > > > > > > phy-names = "port0-hs", "port0-ss", "port1-hs", "port1-ss", "port2-hs", > > > > "port3-hs"; > > > With the above method we would have to do some kind of string parsing on the > > > phy-names to get the HS and SS PHYs as we need to cater to different > > > combinations of Ports ( some support HS+SS , other supports SS only). > > You are doing string parsing anyways to get the child nodes and > > properties. > > > > > So one challenge here is with the "usb-phy". There we directly define the > > > phy phandles and that might/might-not have proper sub-strings. eg > > > USB_QMP_PHY . So extracting PHYS could be tricky if the phy-handle does not > > > have proper substring like "SS" "HS" etc. > > The schema can and should enforce that you have the proper strings. > Hi Rob, > Apologies for replying late. > > I get your concern. Yes we can remove the "multiport" node and instead > define the > USB phy phandles all in one place. Still I would need to add support for > both generic-phy and > usb-phy framework as downstream many vendors are using "usb-phy" and it's > supported by ACK as well. Upstream is not concerned with downstream. The generic PHY has replaced usb-phy for many years now. Furthermore, if downstream was using documented bindings, then we wouldn't be having this conversation. > This would not regress anything with Generic PHY. > > @Greg can you please comment as ACK has support for usb-phy framework. > > Now coming to implementation, let's consider a 4 port USB multiport > controller having > 4 HS PHYs and 2 SS PHYs. We can have two approaches here > > #1 -> If we could mandate using "HS" or "SS" as substring in > phy-names or usb-phy, then we can calculate number of HS and SS phy and also > get > corresponding PHY nodes. Only concern here is that downstream vendors might > need > to change their existing usb-phy names and add proper substring if they are > not doing so ; > > phy = <&usb-hs-phy>,<&usb-ss-phy>, > <&usb-hs-phy1>, <&usb-ss-phy1>, > <&usb-hs-phy2>, <&usb-hs-phy3>; > > phy-names = "port0-hs", "port0-ss", "port1-hs", "port1-ss", "port2-hs", > "port3-hs"; > > > OR > > > #2-> We could mandate defining the USB phy in HS - SS pairs. > For ports that has only HS PHY, we would need to define usb_nop_phy in SS > place. > Then we can calculate the number of HS & SS phys and get corresponding > PHY nodes by using simple fact that HS phy would be defined at odd places & > SS phy defined at even. Here substrings are not mandated. > > phy = <&usb-hs-phy>,<&usb-qmp-phy>, > <&usb-hs-phy1>, <&usb-qmp-phy1>, > <&usb-hs-phy2>, <&usb_nop_phy> > <&usb-hs-phy3>, <&usb_nop_phy>; > > phy-names = "port0-hs", "port0-ss", > "port1-hs", "port1-ss", > "port2-hs", "usb-nop", > "port3-hs", "usb-nop"; The whole reason for -names is to avoid something like this with filler entries. So I prefer #1 as I suggested. Rob
