Re: [PATCH 12/16] dt-bindings: media: Add DT bindings for TI CSI2RX driver

Laurent Pinchart
2021-04-02T10:02:15Z

On Thu, Apr 01, 2021 at 10:52:01AM -0500, Rob Herring wrote:
> On Tue, Mar 30, 2021 at 11:03:44PM +0530, Pratyush Yadav wrote:
> > TI's J721E uses the Cadence CSI2RX and DPHY peripherals to facilitate
> > capture over a CSI-2 bus. The TI CSI2RX platform driver glues all the
> > parts together.
> >
> > Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> > ---
> > .../devicetree/bindings/media/ti,csi2rx.yaml | 70 +++++++++++++++++++
> > 1 file changed, 70 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/media/ti,csi2rx.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/media/ti,csi2rx.yaml b/Documentation/devicetree/bindings/media/ti,csi2rx.yaml
> > new file mode 100644
> > index 000000000000..ebd894364391
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/ti,csi2rx.yaml
> > @@ -0,0 +1,70 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/media/ti,csi2rx.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: TI CSI2RX Wrapper Device Tree Bindings
> > +

A description would be useful, especially given that the TRM doesn't
mention "CSI2RX".

> > +maintainers:
> > + - Pratyush Yadav <p.yadav@ti.com>
> > +
> > +properties:
> > + compatible:
> > + items:
> > + - const: ti,csi2rx
> > +
> > + dmas:
> > + description: RX DMA Channel 0
>
> items:
> - description: RX DMA Channel 0
>
> Or just 'maxItems: 1'
>
> > +
> > + dma-names:
> > + items:
> > + - const: rx0
> > +
> > + reg:
> > + maxItems: 1
> > + description: Base address and size of the TI wrapper registers.
>
> That's all 'reg' properties, drop 'description'.

According to SPRUIL1B, there are four register banks for the CSI_RX_IF,
and two register banks for the DPHY_RX. What's your plan to support
these ? Not everything need to be implemented at once, but backward
compatibility need to be taken into account in the design.

> > +
> > + power-domains:
> > + maxItems: 1
> > + description:
> > + PM domain provider node and an args specifier containing
> > + the device id value.
>
> Drop.
>
> > +
> > + ranges: true
> > +
> > + "#address-cells":
> > + const: 2
> > +
> > + "#size-cells":
> > + const: 2
> > +
> > +patternProperties:
> > + "csi-bridge@":
>
> "^csi-bridge@"
>
> > + type: object
> > + description: CSI2 bridge node.
>
> Just an empty node?

Even if the node is optional, it would be useful to include it in the
example below, to show how it's supposed to be used.

> > +
> > +required:
> > + - compatible
> > + - reg
> > + - dmas
> > + - dma-names
> > + - power-domains
> > + - "#address-cells"
> > + - "#size-cells"
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > + - |
> > + #include <dt-bindings/soc/ti,sci_pm_domain.h>
> > +
> > + ti_csi2rx0: ticsi2rx {
> > + compatible = "ti,csi2rx";
> > + dmas = <&main_udmap 0x4940>;
> > + dma-names = "rx0";
> > + reg = <0x0 0x4500000 0x0 0x1000>;
> > + power-domains = <&k3_pds 26 TI_SCI_PD_EXCLUSIVE>;
> > + #address-cells = <2>;
> > + #size-cells = <2>;
> > + };

--
Regards,

Laurent Pinchart