Re: [PATCH v3 2/3] dt-bindings: rng: update bindings for MediaTek ARMv8 SoCs

From: Rob Herring
Date: Tue Jun 11 2019 - 18:58:31 EST


On Mon, Jun 10, 2019 at 06:36:23PM +0800, Neal Liu wrote:
> Document the binding used by the MediaTek ARMv8 SoCs random
> number generator with TrustZone enabled.
>
> Signed-off-by: Neal Liu <neal.liu@xxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/rng/mtk-rng.txt | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/rng/mtk-rng.txt b/Documentation/devicetree/bindings/rng/mtk-rng.txt
> index 2bc89f1..fb3dd59 100644
> --- a/Documentation/devicetree/bindings/rng/mtk-rng.txt
> +++ b/Documentation/devicetree/bindings/rng/mtk-rng.txt
> @@ -3,9 +3,13 @@ found in MediaTek SoC family
>
> Required properties:
> - compatible : Should be
> - "mediatek,mt7622-rng", "mediatek,mt7623-rng" : for MT7622
> - "mediatek,mt7629-rng", "mediatek,mt7623-rng" : for MT7629
> - "mediatek,mt7623-rng" : for MT7623
> + "mediatek,mt7622-rng", "mediatek,mt7623-rng" for MT7622
> + "mediatek,mt7629-rng", "mediatek,mt7623-rng" for MT7629
> + "mediatek,mt7623-rng" for MT7623
> + "mediatek,mtk-sec-rng" for MediaTek ARMv8 SoCs with
> + security RNG

Is there any commonality with the prior h/w? If not, make this a
separate binding doc.

> +
> +Optional properties:
> - clocks : list of clock specifiers, corresponding to
> entries in clock-names property;
> - clock-names : Should contain "rng" entries;
> @@ -19,3 +23,8 @@ rng: rng@1020f000 {
> clocks = <&infracfg CLK_INFRA_TRNG>;
> clock-names = "rng";
> };
> +
> +/* secure RNG */
> +hwrng: hwrng {
> + compatible = "mediatek,mtk-sec-rng";

How does one access this? Seems like this should be part of a node for
firmware? What about other functions?

> +};
> --
> 1.7.9.5
>