Re: [RESEND PATCH 01/10] dt-bindings: crypto: k3: Add sa2ul bindings documentation

[Keerthy]

On 22/07/19 11:59 PM, Rob Herring wrote:
> On Fri, Jun 28, 2019 at 09:57:36AM +0530, Keerthy wrote:
> > The series adds Crypto hardware accelerator support for SA2UL.
> > SA2UL stands for security accelerator ultra lite.
> >
> > The Security Accelerator (SA2_UL) subsystem provides hardware
> > cryptographic acceleration for the following use cases:
> > â Encryption and authentication for secure boot
> > â Encryption and authentication of content in applications
> >    requiring DRM (digital rights management) and
> >    content/asset protection
> > The device includes one instantiation of SA2_UL named SA2_UL0
> >
> > SA2UL needs on tx channel and a pair of rx dma channels.
> >
> > Signed-off-by: Keerthy <j-keerthy@xxxxxx>
> > ---
> >   .../devicetree/bindings/crypto/sa2ul.txt      | 47 +++++++++++++++++++
> >   1 file changed, 47 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/crypto/sa2ul.txt
> >
> > diff --git a/Documentation/devicetree/bindings/crypto/sa2ul.txt b/Documentation/devicetree/bindings/crypto/sa2ul.txt
> > new file mode 100644
> > index 000000000000..81cc039673b4
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/crypto/sa2ul.txt
> > @@ -0,0 +1,47 @@
> > +K3 SoC SA2UL crypto module
> > +
> > +Required properties:
> > +
> > +- compatible : Should be:
> > +  - "ti,sa2ul-crypto"
>
> Needs to be SoC specific.

okay

> > +- reg : Offset and length of the register set for the module
> > +
> > +- dmas: DMA specifiers for tx and rx dma. sa2ul needs one tx channel
> > +	and 2 rx channels. First rx channel for < 256 bytes and
> > +	the other one for >=256 bytes. See the DMA client binding,
> > +        Documentation/devicetree/bindings/dma/dma.txt
> > +- dma-names: DMA request names has to have one tx and 2 rx names
> > +	corresponding to dmas abive.
> > +- ti,psil-config* - UDMA PSIL native Peripheral using packet mode.
> > +	SA2UL must have EPIB(Extended protocal information block)
> > +	and PSDATA(protocol specific data) properties.
>
> If ti,needs-epib is required, then why do you need to specify it in DT?
> In any case, this all seems like channel config info that should be part
> of the #dma-cells.

ti,needs-epib is the udma client(Here sa2ul) conveying the udma layer.
Not every udma client needs epib.

Peter,

Any thoughts on the above?

- Keerthy

> Also, don't use vendor prefixes on node names.

Okay

> > +
> > +Example AM654 SA2UL:
> > +crypto: crypto@4E00000 {
> > +	compatible = "ti,sa2ul-crypto";
> > +	reg = <0x0 0x4E00000 0x0 0x1200>;
> > +	ti,psil-base = <0x4000>;
> > +
> > +	dmas = <&main_udmap &crypto 0 UDMA_DIR_TX>,
> > +		<&main_udmap &crypto 0 UDMA_DIR_RX>,
> > +		<&main_udmap &crypto 1 UDMA_DIR_RX>;
> > +	dma-names = "tx", "rx1", "rx2";
> > +
> > +	ti,psil-config0 {
> > +		linux,udma-mode = <UDMA_PKT_MODE>;
> > +		ti,needs-epib;
> > +		ti,psd-size = <64>;
> > +	};
> > +
> > +	ti,psil-config1 {
> > +		linux,udma-mode = <UDMA_PKT_MODE>;
> > +		ti,needs-epib;
> > +		ti,psd-size = <64>;
> > +	};
> > +
> > +	ti,psil-config2 {
> > +		linux,udma-mode = <UDMA_PKT_MODE>;
> > +		ti,needs-epib;
> > +		ti,psd-size = <64>;
> > +	};
> > +};
> > --
> > 2.17.1