Re: [PATCH 1/2] dt-bindings: mailbox: add STMicroelectronics STM32 IPCC binding

[Rob Herring]

On Wed, Feb 28, 2018 at 02:24:29PM +0100, Fabien Dessenne wrote:
> Add a binding for the STMicroelectronics STM32 IPCC block exposing a
> mailbox mechanism between two processors.
> 
> Signed-off-by: Fabien Dessenne <fabien.dessenne@xxxxxx>
> Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
> ---
>  .../devicetree/bindings/mailbox/stm32-ipcc.txt     | 48 ++++++++++++++++++++++
>  1 file changed, 48 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mailbox/stm32-ipcc.txt
> 
> diff --git a/Documentation/devicetree/bindings/mailbox/stm32-ipcc.txt b/Documentation/devicetree/bindings/mailbox/stm32-ipcc.txt
> new file mode 100644
> index 0000000..2321689
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/stm32-ipcc.txt
> @@ -0,0 +1,48 @@
> +* STMicroelectronics STM32 IPCC (Inter-Processor Communication Controller)
> +
> +The IPCC block provides a non blocking signaling mechanism to post and
> +retrieve messages in an atomic way between two processors.
> +It provides the signaling for N bidirectionnal channels. The number of channels
> +(N) can be read from a dedicated register.
> +
> +Required properties:
> +- compatible:   Must be "st,stm32-ipcc"

Kind of generic. There's only 1 version of h/w across all stm32 parts?

> +- reg:          Register address range (base address and length)
> +- st,proc_id:   Processor id using the mailbox (0 or 1)

s/_/-/


> +- clocks:       Input clock
> +- interrupt-names: List of names for the interrupts described by the interrupt
> +                   property. Must contain the following entries:
> +                   - "rx"
> +                   - "tx"
> +- interrupts:   Interrupt specifiers for "rx channel occupied" and "tx channel
> +                free"
> +- #mbox-cells:  Number of cells required for the mailbox specifier. Must be 1.
> +                The data contained in the mbox specifier of the "mboxes"
> +                property in the client node is the mailbox channel index.
> +
> +Optional properties:
> +- wakeup-source: Flag to indicate whether this device can wake up the system

> +- interrupts:    Wakeup interrupt used to wake up the system.
> +- interrupt-names: "wakeup" for the wakeup interrupt.

Make these required. "wakeup-source" alone determines if you use it.

> +
> +
> +
> +Example:
> +	ipcc: mailbox@4c001000 {
> +		compatible = "st,stm32-ipcc";
> +		#mbox-cells = <1>;
> +		reg = <0x4c001000 0x400>;
> +		st,proc_id = <0>;
> +		interrupts-extended = <&intc GIC_SPI 100 IRQ_TYPE_NONE>,
> +				      <&intc GIC_SPI 101 IRQ_TYPE_NONE>,
> +				      <&aiec 62 1>;
> +		interrupt-names = "rx", "tx", "wakeup";
> +		clocks = <&rcc_clk IPCC>;
> +		wakeup-source;
> +	}
> +
> +Client:
> +	mbox_test {
> +		...
> +		mboxes = <&ipcc 0>, <&ipcc 1>;
> +	};
> -- 
> 2.7.4
>