Re: [PATCH v5 1/4] dt-bindings: mailbox: Document Hi6220 mailbox driver

From: Rob Herring
Date: Mon Feb 01 2016 - 09:08:38 EST


On Mon, Feb 01, 2016 at 09:34:44PM +0800, Leo Yan wrote:
> Document DT binding for Hisilicon Hi6220 mailbox driver.
>
> Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
> ---
> .../bindings/mailbox/hisilicon,hi6220-mailbox.txt | 90 ++++++++++++++++++++++
> 1 file changed, 90 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
>
> diff --git a/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt b/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
> new file mode 100644
> index 0000000..96e6acc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt
> @@ -0,0 +1,90 @@
> +Hisilicon Hi6220 Mailbox Driver
> +===============================
> +
> +Hisilicon Hi6220 mailbox supports up to 32 channels. Each channel
> +is unidirectional with a maximum message size of 8 words. I/O is
> +performed using register access (there is no DMA) and the cell
> +raises an interrupt when messages are received.
> +
> +Mailbox Device Node:
> +====================
> +
> +Required properties:
> +--------------------
> +- compatible: Shall be "hisilicon,hi6220-mbox"
> +- reg: Contains the mailbox register address range (base
> + address and length); the first item is for IPC
> + registers, the second item is shared buffer for
> + slots.
> +- #mbox-cells Common mailbox binding property to identify the number
> + of cells required for the mailbox specifier. Should be 1.
> +- interrupts: Contains the interrupt information for the mailbox
> + device. The format is dependent on which interrupt
> + controller the SoCs use.
> +
> +Optional Properties:
> +--------------------
> +- hi6220,mbox-tx-noirq: Flag to allow the client user of this mailbox driver
> + to send messages without triggering a TX completion
> + interrupt.

I don't think this belongs in DT. This should be a flag the client
driver sets when it sends messages.

> +
> +Child Nodes:
> +============
> +A child node is used for representing the actual sub-mailbox device that is
> +used for the communication between the host processor and a remote processor.
> +Each child node should have a unique node name across all the different
> +mailbox device nodes.
> +
> +Required properties:
> +--------------------
> +- hi6220,mbox-tx: sub-mailbox descriptor property defining Tx channel
> +- hi6220,mbox-rx: sub-mailbox descriptor property defining Rx channel
> +
> +Sub-mailbox Descriptor Data
> +---------------------------
> +Each of the above hi6220,mbox-tx and hi6220,mbox-rx properties should have 3
> +cells of data that represent the following:
> + Cell #1 (slot_id) - mailbox slot id used either for transmitting
> + (hi6220,mbox-tx) or for receiving (hi6220,mbox-rx)
> + Cell #2 (dst_irq) - irq identifier index number which used by MCU.
> + Cell #3 (ack_irq) - irq identifier index number with generating a tx/rx
> + interrupt to application processor, mailbox driver
> + used this id to acknowledge interrupt.
> +
> +Example:
> +--------
> +
> + mailbox: mailbox@F7510000 {
> + #mbox-cells = <1>;
> + compatible = "hisilicon,hi6220-mbox";
> + reg = <0x0 0xF7510000 0x0 0x1000>, /* IPC_S */
> + <0x0 0x06DFF800 0x0 0x0800>; /* Mailbox */
> + interrupt-parent = <&gic>;
> + interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_HIGH>;
> + mbox_stub_clock: mbox_stub_clock {
> + hi6220,mbox-rx = <0 1 10>;
> + hi6220,mbox-tx = <1 0 11>;
> + };
> + };
> +
> +
> +Mailbox client
> +===============
> +
> +"mboxes" and the optional "mbox-names" (please see
> +Documentation/devicetree/bindings/mailbox/mailbox.txt for details). Each value
> +of the mboxes property should contain a phandle to the mailbox controller
> +device node and second argument is the channel index. It must be 0 (hardware

0? But the example has 1.

> +support only one channel). The equivalent "mbox-names" property value can be
> +used to give a name to the communication channel to be used by the client user.
> +
> +Example:
> +--------
> +
> + stub_clock: stub_clock {
> + compatible = "hisilicon,hi6220-stub-clk";
> + hisilicon,hi6220-clk-sram = <&sram>;
> + #clock-cells = <1>;
> + mbox-names = "mbox-tx";
> + mboxes = <&mailbox 1>;
> + };
> --
> 1.9.1
>