Hi Rob, On Fri, Oct 27, 2017 at 5:29 AM, Rob Herring <robh@xxxxxxxxxx> wrote: > On Mon, Oct 23, 2017 at 11:57:18PM +0200, Martin Blumenstingl wrote: >> This extends the existing example from the USB xHCI binding >> documentation so it includes the roothub and an actual device. >> The goal of this is to show that the roothub is specified alongside the >> actual devices on the USB bus (which is important because a device on >> the USB bus - for example a hub - might need it's own phys / phy-names >> properties. modelling the roothub as separate device and not nesting the >> other devices on the bus below the roothub allows us to keep the >> properties, for example the PHYs, separated). >> >> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> >> --- >> Documentation/devicetree/bindings/usb/usb-xhci.txt | 23 ++++++++++++++++++++++ >> 1 file changed, 23 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt >> index 5b49ba9f2f9a..20e5ce2b016a 100644 >> --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt >> +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt >> @@ -42,4 +42,27 @@ Example: >> compatible = "generic-xhci"; >> reg = <0xf0931000 0x8c8>; >> interrupts = <0x0 0x4e 0x0>; >> + >> + #address-cells = <1>; >> + #size-cells = <0>; >> + >> + /* see usb-roothub.txt */ >> + roothub@0 { >> + compatible = "usb1d6b,3", "usb1d6b,2"; >> + #address-cells = <1>; >> + #size-cells = <0>; >> + reg = <0>; >> + >> + port@1 { >> + reg = <1>; >> + phys = <&usb2_phy1>, <&usb3_phy1>; >> + phy-names = "usb2-phy", "usb3-phy"; >> + }; >> + }; >> + >> + /* see usb-device.txt */ >> + hub: genesys@1 { > > What do the 0 and 1 addresses correspond to? 0 is the address of the root-hub, 1 is the first device on the root-hub based on my previous dt-binding patch Arnd assumed that the devices would be moved in the hierarchy: [0] however, my understanding is that (at least for now) the root-hub node (identified by reg = <0>) is used to describe only the root-hub (which allows initializing the PHYs), not the devices that are connected to it here's an example from my Khadas VIM (which matches the example from my patch, except: a) it has a different USB hub connected at port 1 b) it has two ports on the root-hub) this is a stripped and commented version of "cat /sys/kernel/debug/usb/devices" T: Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=5000 MxCh= 0 D: Ver= 3.00 Cls=09(hub ) Sub=00 Prot=03 MxPS= 9 #Cfgs= 1 P: Vendor=1d6b ProdID=0003 Rev= 3.14 -> (USB3 root-hub from a dwc3 controller) in the device-tree example this belongs to &usb/roothub@0 T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh= 2 D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=01 MxPS=64 #Cfgs= 1 P: Vendor=1d6b ProdID=0002 Rev= 3.14 -> (USB2 root-hub from a dwc3 controller) in the device-tree example this also belongs to &usb/roothub@0 T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=480 MxCh= 4 D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=01 MxPS=64 #Cfgs= 1 P: Vendor=1a40 ProdID=0801 Rev= 1.00 -> (USB2 hub soldered to the board, connected to root-hub port 1) in the device-tree example this belongs to &usb/genesys@1 T: Bus=01 Lev=02 Prnt=02 Port=02 Cnt=01 Dev#= 3 Spd=480 MxCh= 0 D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=090c ProdID=1000 Rev= 7.22 -> USB thumb drive connected to the USB hub, not listed in the device-tree example but it would be listed below &usb/genesys@1 >> + compatible = "usb5e3,608"; >> + reg = <1>; >> + }; >> }; >> -- >> 2.14.2 >> Martin [0] http://lists.infradead.org/pipermail/linux-amlogic/2017-October/005091.html -- 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