Re: [PATCH 2/5] dt-bindings: Amlogic: add the documentation for the SECBUS2 registers

From: Rob Herring
Date: Thu Dec 31 2020 - 13:17:24 EST


On Wed, Dec 30, 2020 at 02:27:21AM +0100, Martin Blumenstingl wrote:
> The Meson8/Meson8b/Meson8m2 SoCs have a register bank called SECBUS2 which
> contains registers for various IP blocks such as pin-controller bits for
> the BSD_EN and TEST_N GPIOs as well as some AO ARC core control bits.
> The registers can be accessed directly when not running in "secure mode".
> When "secure mode" is enabled then these registers have to be accessed
> through secure monitor calls.
>
> So far these SoCs are always known to boot in "non-secure mode".
> Add a binding documentation using syscon (as these registers are shared
> across different IPs) for the SECBUS2 registers.
>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> ---
> .../arm/amlogic/amlogic,meson-mx-secbus2.yaml | 53 +++++++++++++++++++
> 1 file changed, 53 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/arm/amlogic/amlogic,meson-mx-secbus2.yaml
>
> diff --git a/Documentation/devicetree/bindings/arm/amlogic/amlogic,meson-mx-secbus2.yaml b/Documentation/devicetree/bindings/arm/amlogic/amlogic,meson-mx-secbus2.yaml
> new file mode 100644
> index 000000000000..cfa8e9de6c28
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/amlogic/amlogic,meson-mx-secbus2.yaml
> @@ -0,0 +1,53 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/arm/amlogic/amlogic,meson-mx-secbus2.yaml#";
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#";
> +
> +title: Amlogic Meson8/Meson8b/Meson8m2 SECBUS2 register interface
> +
> +maintainers:
> + - Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> +
> +description: |
> + The Meson8/Meson8b/Meson8m2 SoCs have a register bank called SECBUS2 which
> + contains registers for various IP blocks such as pin-controller bits for
> + the BSD_EN and TEST_N GPIOs as well as some AO ARC core control bits.
> + The registers can be accessed directly when not running in "secure mode".
> + When "secure mode" is enabled then these registers have to be accessed
> + through secure monitor calls.
> +
> +# We need a select here so we don't match all nodes with 'syscon'

No, you don't. The default 'select' will ignore 'syscon' and
'simple-mfd'.

> +select:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - amlogic,meson8-secbus2
> + - amlogic,meson8b-secbus2
> + required:
> + - compatible
> +
> +properties:
> + compatible:
> + items:
> + - enum:
> + - amlogic,meson8-secbus2
> + - amlogic,meson8b-secbus2
> + - const: syscon
> +
> + reg:
> + maxItems: 1
> +
> +required:
> + - compatible
> + - reg
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + secbus2: system-controller@4000 {
> + compatible = "amlogic,meson8-secbus2", "syscon";
> + reg = <0x4000 0x2000>;
> + };
> --
> 2.30.0
>