Re: [RFC PATCH 3/6] dt-bindings: crypto: Add bindings for ZynqMP SHA3 driver

[Rob Herring <robh@kernel.org>]

On Tue, Dec 7, 2021 at 10:17 PM Harsha Harsha <harshah@xilinx.com> wrote:
>
> Hi Rob,
>
> Thanks for your review.
>
>
> > -----Original Message-----
> > From: Rob Herring <robh@kernel.org>
> > Sent: Wednesday, December 8, 2021 3:00 AM
> > To: Harsha Harsha <harshah@xilinx.com>
> > Cc: herbert@gondor.apana.org.au; davem@davemloft.net; linux-crypto@vger.kernel.org; linux-kernel@vger.kernel.org; Michal
> > Simek <michals@xilinx.com>; linux-arm-kernel@lists.infradead.org; devicetree@vger.kernel.org; Sarat Chand Savitala
> > <saratcha@xilinx.com>; Harsh Jain <harshj@xilinx.com>
> > Subject: Re: [RFC PATCH 3/6] dt-bindings: crypto: Add bindings for ZynqMP SHA3 driver
> >
> > On Tue, Nov 30, 2021 at 02:24:22PM +0530, Harsha wrote:
> > > This patch adds documentation to describe Xilinx ZynqMP SHA3 driver
> > > bindings.
> > >
> > > Signed-off-by: Harsha <harsha.harsha@xilinx.com>
> > > ---
> > >  .../bindings/crypto/xlnx,zynqmp-sha3.yaml          | 30 ++++++++++++++++++++++
> > >  1 file changed, 30 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/crypto/xlnx,zynqmp-sha3.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/crypto/xlnx,zynqmp-sha3.yaml
> > b/Documentation/devicetree/bindings/crypto/xlnx,zynqmp-sha3.yaml
> > > new file mode 100644
> > > index 0000000..45a8022
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/crypto/xlnx,zynqmp-sha3.yaml
> > > @@ -0,0 +1,30 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/crypto/xlnx,zynqmp-sha3.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Xilinx ZynqMP SHA3 Hardware Accelerator Device Tree Bindings
> > > +
> > > +maintainers:
> > > +  - Harsha Harsha<harsha.harsha@xilinx.com>
> >
> > space               ^
>
> Accepted. Will remove space in next version of patch series.
>
> >
> > > +
> > > +description: |
> >
> > Don't need '|' if no formatting to preserve.
>
> Accepted. Will remove | in next version of patch series.
>
> >
> > > +  The ZynqMP SHA3 hardened cryptographic accelerator is used to
> > > +  calculate the SHA3 hash for the given user data.
> > > +
> > > +properties:
> > > +  compatible:
> > > +    const: xlnx,zynqmp-sha3-384
> > > +
> > > +required:
> > > +  - compatible
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    xlnx_sha3_384: sha3-384 {
> >
> > crypto {
> >
> > > +      compatible = "xlnx,zynqmp-sha3-384";
> >
> > You need some way to access this h/w.
>
> Accepted. Will add required details similar to https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git/tree/Documentation/devicetree/bindings/crypto/xlnx,zynqmp-aes.yaml

Why do you need a node for each crypto algorithm? Can't your firmware
tell you what algorithms it supports? Worst case, try each possible
one and see what fails or not. None of this needs to be in DT.

Rob