From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Hunter Subject: Re: [PATCH v8 4/9] mfd: Add binding document for NVIDIA Tegra XUSB Date: Thu, 14 May 2015 08:20:37 +0100 Message-ID: <55544CC5.9050001@nvidia.com> References: <1430761002-9327-1-git-send-email-abrestic@chromium.org> <1430761002-9327-5-git-send-email-abrestic@chromium.org> <20150513143954.GA3394@x1> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150513143954.GA3394@x1> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Lee Jones , Andrew Bresticker Cc: Stephen Warren , Thierry Reding , Alexandre Courbot , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Samuel Ortiz List-Id: devicetree@vger.kernel.org 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 >> Cc: Rob Herring >> Cc: Pawel Moll >> Cc: Mark Rutland >> Cc: Ian Campbell >> Cc: Kumar Gala >> Cc: Samuel Ortiz >> Cc: Lee Jones >> --- >> 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,-xusb", "nvidia,tegra124-xusb"' >> + where 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? Cheers Jon