Re: [PATCH v8 4/9] mfd: Add binding document for NVIDIA Tegra XUSB

Lee Jones
2015-05-14T07:30:02Z

On Wed, 13 May 2015, Andrew Bresticker wrote:

> On Wed, May 13, 2015 at 9:50 AM, Lee Jones <lee.jones@linaro.org> wrote:
> > On Wed, 13 May 2015, Andrew Bresticker wrote:
> >
> >> Lee,
> >>
> >> On Wed, May 13, 2015 at 7:39 AM, Lee Jones <lee.jones@linaro.org> 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@chromium.org>
> >> >> Cc: Rob Herring <robh+dt@kernel.org>
> >> >> Cc: Pawel Moll <pawel.moll@arm.com>
> >> >> Cc: Mark Rutland <mark.rutland@arm.com>
> >> >> Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
> >> >> Cc: Kumar Gala <galak@codeaurora.org>
> >> >> Cc: Samuel Ortiz <sameo@linux.intel.com>
> >> >> Cc: Lee Jones <lee.jones@linaro.org>
> >> >> ---
> >> >> 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]>;
> >> > };
> >>
> >> Then what will set up the shared regmap? The point of using an MFD
> >> here was to share a register set with both the mailbox and xHCI
> >> drivers and avoid having to map the same register set twice in two
> >> separate drivers.
> >
> > Can you share the mapping please?
>
> What do you mean? That's what the MFD is doing now by setting up an
> MMIO regmap to be shared between the two devices.

I mean, can you share the documentation with me. :)

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
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