[2/2] dt-bindings: rng: Add MediaTek MT7981 TRNG

Commit Message

Daniel Golle Feb. 15, 2023, 1:27 p.m. UTC

Add documentation to describe the MediaTek true random number generator
which is provided by ARM TrustedFirmware-A of the MT7981.

Signed-off-by: Daniel Golle <[e-mail]>
---
 .../bindings/rng/mediatek,mt7981-rng.yaml     | 39 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 40 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml

Comments

Krzysztof Kozlowski Feb. 16, 2023, 9:14 a.m. UTC | #1

On 15/02/2023 14:27, Daniel Golle wrote:
> Add documentation to describe the MediaTek true random number generator
> which is provided by ARM TrustedFirmware-A of the MT7981.
> 
> Signed-off-by: Daniel Golle <[e-mail]>
> ---
>  .../bindings/rng/mediatek,mt7981-rng.yaml     | 39 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 40 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml
> 
> diff --git a/Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml b/Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml
> new file mode 100644
> index 000000000000..d577d60538d8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml
> @@ -0,0 +1,39 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/rng/mediatek,mt7981-rng.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MediaTek Random number generator (v2/SMC)
> +
> +maintainers:
> +  - Daniel Golle <[e-mail]>
> +
> +properties:
> +  $nodename:
> +    pattern: "^rng$"

1. We don't enforce it in device bindings, so drop it.
2. It's not even correct. You have reg.


> +
> +  compatible:
> +    enum:
> +      - mediatek,mt7981-rng
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  clock-names:
> +    items:
> +      - const: rng

Drop clock-names and rely on index.

> +
> +required:
> +  - compatible

and reg?

> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    rng {
> +      compatible = "mediatek,mt7981-rng";
> +    };

Best regards,
Krzysztof

Daniel Golle Feb. 16, 2023, 9:19 a.m. UTC | #2

On Thu, Feb 16, 2023 at 10:14:33AM +0100, Krzysztof Kozlowski wrote:
> On 15/02/2023 14:27, Daniel Golle wrote:
> > Add documentation to describe the MediaTek true random number generator
> > which is provided by ARM TrustedFirmware-A of the MT7981.
> > 
> > Signed-off-by: Daniel Golle <[e-mail]>
> > ---
> >  .../bindings/rng/mediatek,mt7981-rng.yaml     | 39 +++++++++++++++++++
> >  MAINTAINERS                                   |  1 +
> >  2 files changed, 40 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml b/Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml
> > new file mode 100644
> > index 000000000000..d577d60538d8
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml
> > @@ -0,0 +1,39 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/rng/mediatek,mt7981-rng.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: MediaTek Random number generator (v2/SMC)
> > +
> > +maintainers:
> > +  - Daniel Golle <[e-mail]>
> > +
> > +properties:
> > +  $nodename:
> > +    pattern: "^rng$"
> 
> 1. We don't enforce it in device bindings, so drop it.

Ack.

> 2. It's not even correct. You have reg.

No, there isn't any reg, as this driver does not access a MMIO mapped
resource but rather uses Secure Monitor Call interface to access the
TRNG via ARM TrustedFirmware-A.

> 
> 
> > +
> > +  compatible:
> > +    enum:
> > +      - mediatek,mt7981-rng
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    maxItems: 1
> > +
> > +  clock-names:
> > +    items:
> > +      - const: rng
> 
> Drop clock-names and rely on index.

Will drop, reg, clocks and clock-names, that slipped in from the
document I used as template for this one. The driver uses neither of
those.

> 
> > +
> > +required:
> > +  - compatible
> 
> and reg?
> 
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    rng {
> > +      compatible = "mediatek,mt7981-rng";
> > +    };
> 
> Best regards,
> Krzysztof
> 
>

Patch

diff --git a/Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml b/Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml
new file mode 100644
index 000000000000..d577d60538d8
--- /dev/null
+++ b/Documentation/devicetree/bindings/rng/mediatek,mt7981-rng.yaml
@@ -0,0 +1,39 @@ 
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rng/mediatek,mt7981-rng.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek Random number generator (v2/SMC)
+
+maintainers:
+  - Daniel Golle <[e-mail]>
+
+properties:
+  $nodename:
+    pattern: "^rng$"
+
+  compatible:
+    enum:
+      - mediatek,mt7981-rng
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: rng
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    rng {
+      compatible = "mediatek,mt7981-rng";
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index 90d82aba6d73..523f1abf00d5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13148,6 +13148,7 @@  F:	drivers/leds/leds-mt6323.c
 MEDIATEK RANDOM NUMBER GENERATOR SUPPORT
 M:	Sean Wang <[e-mail]>
 S:	Maintained
+F:	Documentation/devicetree/bindings/rng/mediatek,*
 F:	drivers/char/hw_random/mtk-rng-v2.c
 F:	drivers/char/hw_random/mtk-rng.c