2018-04-04 15:04 GMT+09:00 Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>: > > Hi, > > Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> writes: >> 2018-04-04 14:36 GMT+09:00 Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>: >>> >>> Hi, >>> >>> Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> writes: >>>> Currently, DWC3 core IP (drivers/usb/dwc3/core.c) >>>> can take only one PHY phandle for each of SS, HS. >>>> (phy-names DT property is "usb2-phy" and "usb3-phy" for each) >>> >>> We never had any other requirements :-) >>> >>>> The DWC3 core IP is provided by Synopsys, >>>> but some SoC-dependent parts (a.k.a glue-layer) >>>> are implemented by SoC venders. >>>> >>>> The number of connected PHY instances are SoC-dependent. >>>> >>>> If you look at generic drivers such as >>>> drivers/usb/host/ehci-platform.c >>>> the driver can handle arbitrary number of PHY instances. >>>> >>>> However, as mentioned above, DWC3 core allows only one PHY phandle >>>> for each SS/HS. >>>> This can result in a strange DT structure. >>>> >>>> For example, Socionext PXs3 SoC is integrated with 2 instances of DWC3. >>>> >>>> The instance 0 of DWC3 is connected with 2 super-speed PHYs. >>> >>> why 2 super-speed phys? Is this a two-port host-only implementation? >> >> >> Socionext SoCs only support the host-mode. >> >> >> The instance 0 has 2 ports. >> In our integration, 1 SS PHY is needed for each port. >> That's why it needs 2 SS PHYs. >> >> Each DWC3 instance is connected with >> multiple HS PHYs and multiple SS PHYs, >> depending on the number of ports. > > in that case, you shouldn't need dwc3 at all. A Host-only dwc3 is xHCI > compliant. If you really don't have the gadget block, there's no need > for you to use dwc3. Just use xhci-plat directly. Sorry, I was misunderstanding. Some of our SoCs support gadget, so we need to use the dwc3 driver. >>>> Is this OK? >>> >>> I don't know, I need a bit more details about your integration :-) >> >> >> I can send a patch. >> >> My concern is the following commit. >> I do not know which parts are using this lookups. > > Samsung SoCs, probably ;-) > > Anyway, if your IP really is host-only, then you don't need dwc3 for > anything. Just go for xHCI directly. If xHCI needs to be extended when > it comes to PHY, then you can discuss with Mathias Nyman :-) > > -- > balbi -- Best Regards Masahiro Yamada -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
