On Thu, 14 May 2015, Jon Hunter wrote: > Hi Lee, > > On 13/05/15 15:39, Lee Jones wrote: > > On Mon, 04 May 2015, Andrew Bresticker wrote: > > > >> Add a binding document for the XUSB host complex on NVIDIA Tegra124 > >> and later SoCs. The XUSB host complex includes a mailbox for > >> communication with the XUSB micro-controller and an xHCI host-controller. > >> > >> Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx> > >> Cc: Rob Herring <robh+dt@xxxxxxxxxx> > >> Cc: Pawel Moll <pawel.moll@xxxxxxx> > >> Cc: Mark Rutland <mark.rutland@xxxxxxx> > >> Cc: Ian Campbell <ijc+devicetree@xxxxxxxxxxxxxx> > >> Cc: Kumar Gala <galak@xxxxxxxxxxxxxx> > >> Cc: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx> > >> Cc: Lee Jones <lee.jones@xxxxxxxxxx> > >> --- > >> Changes from v7: > >> - Move non-shared resources into child nodes. > >> New for v7. > >> --- > >> .../bindings/mfd/nvidia,tegra124-xusb.txt | 37 ++++++++++++++++++++++ > >> 1 file changed, 37 insertions(+) > >> create mode 100644 Documentation/devicetree/bindings/mfd/nvidia,tegra124-xusb.txt > >> > >> diff --git a/Documentation/devicetree/bindings/mfd/nvidia,tegra124-xusb.txt b/Documentation/devicetree/bindings/mfd/nvidia,tegra124-xusb.txt > >> new file mode 100644 > >> index 0000000..bc50110 > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/mfd/nvidia,tegra124-xusb.txt > >> @@ -0,0 +1,37 @@ > >> +NVIDIA Tegra XUSB host copmlex > >> +============================== > >> + > >> +The XUSB host complex on Tegra124 and later SoCs contains an xHCI host > >> +controller and a mailbox for communication with the XUSB micro-controller. > >> + > >> +Required properties: > >> +-------------------- > >> + - compatible: For Tegra124, must contain "nvidia,tegra124-xusb". > >> + Otherwise, must contain '"nvidia,<chip>-xusb", "nvidia,tegra124-xusb"' > >> + where <chip> is tegra132. > >> + - reg: Must contain the base and length of the XUSB FPCI registers. > >> + - ranges: Bus address mapping for the XUSB block. Can be empty since the > >> + mapping is 1:1. > >> + - #address-cells: Must be 2. > >> + - #size-cells: Must be 2. > >> + > >> +Example: > >> +-------- > >> + usb@0,70098000 { > >> + compatible = "nvidia,tegra124-xusb"; > >> + reg = <0x0 0x70098000 0x0 0x1000>; > >> + ranges; > >> + > >> + #address-cells = <2>; > >> + #size-cells = <2>; > >> + > >> + usb-host@0,70090000 { > >> + compatible = "nvidia,tegra124-xhci"; > >> + ... > >> + }; > >> + > >> + mailbox { > >> + compatible = "nvidia,tegra124-xusb-mbox"; > >> + ... > >> + }; > > > > This doesn't appear to be a proper MFD. I would have the USB and > > Mailbox devices probe seperately and use a phandle to point the USB > > device to its Mailbox. > > > > usb@xyz { > > mboxes = <&xusb-mailbox, [chan]>; > > }; > > > > I am assuming that Andrew had laid it out like this to reflect the hw > structure. The mailbox and xhci controller are part of the xusb > sub-system and hence appear as child nodes. My understanding is that for > device-tree we want the device-tree structure to reflect the actual hw. > Is this not the case? Yes, the DT files should reflect h/w. I have requested to see what the memory map looks like, so I might provide a more appropriate solution to accepting a pretty pointless MFD. Two solutions spring to mind. You can either call of_platform_populate() from the USB driver, as some already do: drivers/usb/dwc3/dwc3-exynos.c: ret = of_platform_populate(node, NULL, NULL, dev); drivers/usb/dwc3/dwc3-keystone.c: error = of_platform_populate(node, NULL, NULL, dev); drivers/usb/dwc3/dwc3-omap.c: ret = of_platform_populate(node, NULL, NULL, dev); drivers/usb/dwc3/dwc3-qcom.c: ret = of_platform_populate(node, NULL, NULL, qdwc->dev); drivers/usb/dwc3/dwc3-st.c: ret = of_platform_populate(node, NULL, NULL, dev); drivers/usb/musb/musb_am335x.c: ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev); Or use the "simple-mfd", which is currently in -next: git show next/master:Documentation/devicetree/bindings/mfd/mfd.txt -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html