[RFC,v3,2/3] dt-bindings: crypto: Add Inside Secure SafeXcel EIP-93 crypto engine

Add bindings for the Inside Secure SafeXcel EIP-93 crypto engine.

The IP is present on Airoha SoC and on various Mediatek devices and
other SoC under different names like mtk-eip93 or PKTE.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
Changes v3:
- Add SoC compatible with generic one
Changes v2:
- Change to better compatible
- Add description for EIP93 models

 .../crypto/inside-secure,safexcel-eip93.yaml  | 63 +++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/crypto/inside-secure,safexcel-eip93.yaml

On Mon, Oct 21, 2024 at 05:50:25PM +0100, Conor Dooley wrote:
> On Mon, Oct 21, 2024 at 04:56:38PM +0200, Christian Marangi wrote:
> > Add bindings for the Inside Secure SafeXcel EIP-93 crypto engine.
> > 
> > The IP is present on Airoha SoC and on various Mediatek devices and
> > other SoC under different names like mtk-eip93 or PKTE.
> > 
> > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> > ---
> > Changes v3:
> > - Add SoC compatible with generic one
> > Changes v2:
> > - Change to better compatible
> > - Add description for EIP93 models
> 
> RFC v3, but I don't see any comments explaining what you're seeking
> comments on.

I feel comments for the DT part are finished, if Rob is ok with the
following compatibles.

The RFC is more for the driver part and this is patch part of the series.

On Mon, Oct 21, 2024 at 06:58:35PM +0200, Christian Marangi wrote:
> On Mon, Oct 21, 2024 at 05:50:25PM +0100, Conor Dooley wrote:
> > On Mon, Oct 21, 2024 at 04:56:38PM +0200, Christian Marangi wrote:
> > > Add bindings for the Inside Secure SafeXcel EIP-93 crypto engine.
> > > 
> > > The IP is present on Airoha SoC and on various Mediatek devices and
> > > other SoC under different names like mtk-eip93 or PKTE.
> > > 
> > > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> > > ---
> > > Changes v3:
> > > - Add SoC compatible with generic one
> > > Changes v2:
> > > - Change to better compatible
> > > - Add description for EIP93 models
> > 
> > RFC v3, but I don't see any comments explaining what you're seeking
> > comments on.
> 
> I feel comments for the DT part are finished, if Rob is ok with the
> following compatibles.
> 
> The RFC is more for the driver part and this is patch part of the series.

I didn't see anything there either, that pointed out what made it an
RFC. Please be more explicit in the future - possibly in your cover
letter.

On Mon, Oct 21, 2024 at 04:56:38PM +0200, Christian Marangi wrote:
> Add bindings for the Inside Secure SafeXcel EIP-93 crypto engine.
> 
> The IP is present on Airoha SoC and on various Mediatek devices and
> other SoC under different names like mtk-eip93 or PKTE.
> 
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> ---
> Changes v3:
> - Add SoC compatible with generic one
> Changes v2:
> - Change to better compatible
> - Add description for EIP93 models
> 
>  .../crypto/inside-secure,safexcel-eip93.yaml  | 63 +++++++++++++++++++
>  1 file changed, 63 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/crypto/inside-secure,safexcel-eip93.yaml
> 
> diff --git a/Documentation/devicetree/bindings/crypto/inside-secure,safexcel-eip93.yaml b/Documentation/devicetree/bindings/crypto/inside-secure,safexcel-eip93.yaml
> new file mode 100644
> index 000000000000..13341710ee31
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/crypto/inside-secure,safexcel-eip93.yaml
> @@ -0,0 +1,63 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/crypto/inside-secure,safexcel-eip93.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Inside Secure SafeXcel EIP-93 cryptographic engine
> +
> +maintainers:
> +  - Christian Marangi <ansuelsmth@gmail.com>
> +
> +description: |
> +  The Inside Secure SafeXcel EIP-93 is a cryptographic engine IP block
> +  integrated in varios devices with very different and generic name from
> +  PKTE to simply vendor+EIP93. The real IP under the hood is actually
> +  developed by Inside Secure and given to license to vendors.
> +
> +  The IP block is sold with different model based on what feature are
> +  needed and are identified with the final letter. Each letter correspond
> +  to a specific set of feature and multiple letter reflect the sum of the
> +  feature set.
> +
> +  EIP-93 models:
> +    - EIP-93i: (basic) DES/Triple DES, AES, PRNG, IPsec ESP, SRTP, SHA1
> +    - EIP-93ie: i + SHA224/256, AES-192/256
> +    - EIP-93is: i + SSL/DTLS/DTLS, MD5, ARC4
> +    - EIP-93ies: i + e + s
> +    - EIP-93iw: i + AES-XCB-MAC, AES-CCM

This implies that you should have a non-trivial set of fallbacks, with
the "i" model as the base for that. eg:

"ie", "i"
"is", "i"
"iw", "i"
"ies", "ie, "is", "i" (I dunno which would be a better order here)

> +
> +properties:
> +  compatible:
> +    items:
> +      - const: airoha,crypto-eip93
> +      - enum:
> +          - inside-secure,safexcel-eip93i
> +          - inside-secure,safexcel-eip93ie
> +          - inside-secure,safexcel-eip93is
> +          - inside-secure,safexcel-eip93ies
> +          - inside-secure,safexcel-eip93iw

I don't really get what's going on here. Why is the first compatible the
generic one? That seems suspect to me, as I doubt the crypto block on a
particular SoC varies? I'd expect to see some soc-specific compatibles
with a fallback to the inside-secure IP version that it integrates.

Cheers,
Conor.

> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> +    crypto@1e004000 {
> +      compatible = "airoha,crypto-eip93", "inside-secure,safexcel-eip93ies";
> +      reg = <0x1fb70000 0x1000>;
> +
> +      interrupts = <GIC_SPI 44 IRQ_TYPE_LEVEL_HIGH>;
> +    };
> -- 
> 2.45.2
>