[PATCH 1/3] dt-bindings: Add document of Rockchip mailbox

[Jassi Brar]

On Mon, Sep 14, 2015 at 4:36 PM, Caesar Wang <wxt at rock-chips.com> wrote:
> This add the necessary binding documentation for mailbox
> found on RK3368 SoC.
>
> Signed-off-by: Caesar Wang <wxt at rock-chips.com>
> ---
>
>  .../bindings/mailbox/rockchip-mailbox.txt          | 33 ++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mailbox/rockchip-mailbox.txt
>
> diff --git a/Documentation/devicetree/bindings/mailbox/rockchip-mailbox.txt b/Documentation/devicetree/bindings/mailbox/rockchip-mailbox.txt
> new file mode 100644
> index 0000000..b9b4768
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/rockchip-mailbox.txt
> @@ -0,0 +1,33 @@
> +Rockchip mailbox
> +
> +The Rockchip mailbox is used by the Rockchip CPU cores to communicate
> +requests to MCU processor.
> +
> +Refer to ./mailbox.txt for generic information about mailbox device-tree
> +bindings.
> +
> +Required properties:
> +
> + - compatible: should be one of the following.
> +   - "rockchip,rk3368-mbox" for rk3368
> + - reg: physical base address of the controller and length of memory mapped
> +       region.
> +       physical base address of the share buffer and length of memory mapped
> +       region.
Please make shared-sram a property of user drivers.

Location and size of shared-memory is a platform property, mailbox
controller doesn't need sram to function.
  For example, protocol on some platform, with this controller, may be
trivial enough to not need a shared sram... say only 32-bits wide
requests and responses which can be passed via mailbox registers
directly.   mbox_client.tx_prepare() is where the user driver sets up
the shared-memory.