[PATCH V2 3/4] dt-bindings: arm: fsl: add scu binding doc

[robh@kernel.org (Rob Herring)]

On Sun, Jun 17, 2018 at 08:49:48PM +0800, Dong Aisheng wrote:
> The System Controller Firmware (SCFW) is a low-level system function
> which runs on a dedicated Cortex-M core to provide power, clock, and
> resource management. It exists on some i.MX8 processors. e.g. i.MX8QM
> (QM, QP), and i.MX8QX (QXP, DX).
> 
> Cc: Shawn Guo <shawnguo@kernel.org>
> Cc: Sascha Hauer <kernel@pengutronix.de>
> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: devicetree at vger.kernel.org
> Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
> ---
> v1->v2:
>  * remove status
>  * changed to mu1
> ---
>  .../devicetree/bindings/arm/freescale/fsl,scu.txt  | 38 ++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
> 
> diff --git a/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt b/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
> new file mode 100644
> index 0000000..9b7c9fe
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
> @@ -0,0 +1,38 @@
> +NXP i.MX System Controller Firmware (SCFW)
> +--------------------------------------------------------------------
> +
> +The System Controller Firmware (SCFW) is a low-level system function
> +which runs on a dedicated Cortex-M core to provide power, clock, and
> +resource management. It exists on some i.MX8 processors. e.g. i.MX8QM
> +(QM, QP), and i.MX8QX (QXP, DX).
> +
> +The AP communicates with the SC using a multi-ported MU module found
> +in the LSIO subsystem. The current definition of this MU module provides
> +5 remote AP connections to the SC to support up to 5 execution environments
> +(TZ, HV, standard Linux, etc.). The SC side of this MU module interfaces
> +with the LSIO DSC IP bus. The SC firmware will communicate with this MU
> +using the MSI bus.
> +
> +System Controller Device Node:
> +=============================
> +
> +Required properties:
> +-------------------
> +- compatible: should be "fsl,imx8qxp-scu" or "fsl,imx8qm-scu"
> +- fsl,mu: a phandle to the Message Unit used by SCU. Should be
> +	  one of LSIO MU0~M4 for imx8qxp and imx8qm. Users need
> +	  to make sure not use the one which is conflict with
> +	  other execution environments. e.g. ATF.

Use the mailbox binding even if you don't use the mailbox subsystem.

> +
> +Examples:
> +--------
> +lsio_mu1: mu at 5d1c0000 {
> +	compatible = "fsl,imx8qxp-mu";
> +	reg = <0x0 0x5d1c0000 0x0 0x10000>;
> +	interrupts = <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH>;
> +};
> +
> +scu {
> +	compatible = "fsl,imx8qxp-scu";
> +	fsl,mu = <&lsio_mu1>;
> +};
> -- 
> 2.7.4
>