Re: [PATCH v2 1/3] dt-bindings: add device tree binding for Arm CryptoCell trng engine

[Rob Herring]

On Sun, Feb 02, 2020 at 03:26:59PM +0200, Hadar Gat wrote:
> The Arm CryptoCell is a hardware security engine. This patch adds DT
> bindings for its TRNG (True Random Number Generator) engine.
> 
> Signed-off-by: Hadar Gat <hadar.gat@xxxxxxx>
> ---
>  .../devicetree/bindings/rng/arm-cctrng.yaml        | 51 ++++++++++++++++++++++
>  1 file changed, 51 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/rng/arm-cctrng.yaml
> 
> diff --git a/Documentation/devicetree/bindings/rng/arm-cctrng.yaml b/Documentation/devicetree/bindings/rng/arm-cctrng.yaml
> new file mode 100644
> index 0000000..fe9422e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rng/arm-cctrng.yaml
> @@ -0,0 +1,51 @@
> +# SPDX-License-Identifier: GPL-2.0

Dual license new bindings:

(GPL-2.0-only OR BSD-2-Clause)

> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/rng/arm-cctrng.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Arm ZrustZone CryptoCell TRNG engine
> +
> +maintainers:
> +  - Hadar Gat <hadar.gat@xxxxxxx>
> +
> +description: |+
> +  Arm ZrustZone CryptoCell TRNG (True Random Number Generator) engine.
> +
> +properties:
> +  compatible:
> +    description: Should be "arm,cryptocell-7x3-trng"

Drop. That's what the schema says.

> +    const: arm,cryptocell-7x3-trng

Is 'x' a wildcard? We don't do wildcards unless you have other ways to 
get the specific version.

> +
> +  interrupts:
> +    description: Interrupt number for the device.

Drop. That's all 'interrupts'.

> +    maxItems: 1
> +
> +  reg:
> +    description: Base physical address of the engine and length of memory
> +                 mapped region.

Drop.

> +    maxItems: 1
> +
> +  rosc-ratio:
> +    description: Sampling ratio values from calibration for 4 ring oscillators.
> +    maxItems: 1

Is this an array?

Needs a vendor prefix, a type ref and any constraints you can come up 
with.
 
> +
> +  clocks:
> +    description: Reference to the crypto engine clock.

How many clocks?

> +
> +required:
> +  - compatible
> +  - interrupts
> +  - reg
> +  - rosc-ratio
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    arm_cctrng: arm_cctrng@60000000 {

rng@...

> +        compatible = "arm,cryptocell-7x3-trng";
> +        interrupts = <0 29 4>;
> +        reg = <0x60000000 0x10000>;
> +        rosc-ratio = <5000 1000 500 0>;
> +    };
> -- 
> 2.7.4
>