On 16/06/16 14:50, Rob Rice wrote:

On Tue, Jun 14, 2016 at 10:42 AM, Sudeep Holla <sudeep.holla@arm.com
<mailto:sudeep.holla@arm.com>> wrote:



    On 14/06/16 15:02, Rob Rice wrote:

        From: Rob Rice <rrice@broadcom.com <mailto:rrice@broadcom.com>>

        Add the device tree binding documentation for the PDC hardware
        in Broadcom iProc SoCs.

        Signed-off-by: Rob Rice <rob.rice@broadcom.com
        <mailto:rob.rice@broadcom.com>>
        Acked-by: Rob Herring <robh@kernel.org <mailto:robh@kernel.org>>
        Reviewed-by: Ray Jui <ray.jui@broadcom.com
        <mailto:ray.jui@broadcom.com>>
        Reviewed-by: Anup Patel <anup.patel@broadcom.com
        <mailto:anup.patel@broadcom.com>>
        Reviewed-by: Scott Branden <scott.branden@broadcom.com
        <mailto:scott.branden@broadcom.com>>
        ---
           .../bindings/mailbox/brcm,iproc-pdc-mbox.txt       | 23
        ++++++++++++++++++++++
           1 file changed, 23 insertions(+)
           create mode 100644
        Documentation/devicetree/bindings/mailbox/brcm,iproc-pdc-mbox.txt

        diff --git
        a/Documentation/devicetree/bindings/mailbox/brcm,iproc-pdc-mbox.txt
        b/Documentation/devicetree/bindings/mailbox/brcm,iproc-pdc-mbox.txt
        new file mode 100644
        index 0000000..411ccf4
        --- /dev/null
        +++
        b/Documentation/devicetree/bindings/mailbox/brcm,iproc-pdc-mbox.txt
        @@ -0,0 +1,23 @@
        +The PDC driver manages data transfer to and from various
        offload engines
        +on some Broadcom SoCs. An SoC may have multiple PDC hardware
        blocks. There is
        +one device tree entry per block.
        +
        +Required properties:
        +- compatible : Should be "brcm,iproc-pdc-mbox".
        +- reg: Should contain PDC registers location and length.
        +- interrupts: Should contain the IRQ line for the PDC.
        +- #mbox-cells: 1
        +- brcm,rx-status-len: Length of metadata preceding received
        frames, in bytes.
        +


    Ideally the metadata is more associated with the software protocol built
    on top of the mailbox controller.

    Is this metadata added by the hardware ?

    Otherwise it's better to make it part of the protocol rather than the
    associating with the controller.


Yes, in fact this metadata is added by the PDC hardware itself. So it
seems correct for the DT property to be on the controller.

In that case, it's fine.

-- 
Regards,
Sudeep