Re: [PATCH v12 08/11] media: staging: dt-bindings: add Rockchip ISP1 yaml bindings

[Ezequiel Garcia <ezequiel@collabora.com>]

On Tue, 2020-01-07 at 01:59 +0200, Laurent Pinchart wrote:
> Hi Helen,
> 
> Thank you for the patch.
> 
> On Fri, Dec 27, 2019 at 05:01:13PM -0300, Helen Koike wrote:
> > Add yaml DT bindings for Rockchip ISP1.
> > 
> > This was tested and verified with:
> > mv drivers/staging/media/rkisp1/Documentation/devicetree/bindings/media/rockchip-isp1.yaml Documentation/devicetree/bindings/media/
> > make dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/media/rockchip-isp1.yaml
> > make dtbs_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/media/rockchip-isp1.yaml
> > 
> > Signed-off-by: Helen Koike <helen.koike@collabora.com>
> > 
> > ---
> > 
> > Changes in v12:
> > - The commit replaces the following commit in previous series named
> > media: staging: dt-bindings: Document the Rockchip ISP1 bindings
> > This new patch adds yaml binding and was verified with
> > make dtbs_check and make dt_binding_check
> > 
> > Changes in v11:
> > - add clock-names values
> > 
> > Changes in v10:
> > - unsquash
> > 
> > Changes in v9:
> > - squash
> > - move to staging
> > 
> > Changes in v8:
> > - fix title division style
> > 
> > Changes in v7:
> > - update document with new design and tested example
> > 
> >  .../bindings/media/rockchip-isp1.yaml         | 193 ++++++++++++++++++
> >  1 file changed, 193 insertions(+)
> >  create mode 100644 drivers/staging/media/rkisp1/Documentation/devicetree/bindings/media/rockchip-isp1.yaml
> > 
> > diff --git a/drivers/staging/media/rkisp1/Documentation/devicetree/bindings/media/rockchip-isp1.yaml
> > b/drivers/staging/media/rkisp1/Documentation/devicetree/bindings/media/rockchip-isp1.yaml
> > new file mode 100644
> > index 000000000000..4d1b2c67a4cd
> > --- /dev/null
> > +++ b/drivers/staging/media/rkisp1/Documentation/devicetree/bindings/media/rockchip-isp1.yaml
> > @@ -0,0 +1,193 @@
> > +# SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/media/rockchip-isp1.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Rockchip SoC Image Signal Processing unit v1
> > +
> > +maintainers:
> > +  - Helen Koike <helen.koike@collabora.com>
> > +
> > +description: |
> > +  Rockchip ISP1 is the Camera interface for the Rockchip series of SoCs
> > +  which contains image processing, scaling, and compression funcitons.
> > +
> > +properties:
> > +  compatible:
> > +    const: rockchip,rk3399-cif-isp
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  iommus:
> > +    maxItems: 1
> > +
> > +  power-domains:
> > +    maxItems: 1
> > +
> > +  phys:
> > +    maxItems: 1
> > +    description: phandle for the PHY port
> 
> According to http://opensource.rock-chips.com/wiki_Camera_driver, RK3388
> can route either of DPHY RX0 or DPHY RX1 to the single ISP instance,
> while RK3399 has one PHY per ISP instance, with DPHY RX1 being shared
> with the display. Have you given any thought on how we will support this
> in a backward-compatible way in the DT bindings ?
> 

As discussed on IRC, we could have multiple PHYs specifiers
in the phy property. The ISP would have multiple ports,
with one PHY per port.

> > +
> > +  phy-names:
> > +    const: dphy
> > +
> > +  clocks:
> > +    items:
> > +      - description: ISP clock
> > +      - description: ISP aclk clock
> > +      - description: ISP aclk wrapper clock
> > +      - description: ISP hclk clock
> > +      - description: ISP hclk wrapper clock
> 
> I wonder what aclk and hclk stand far. In any case those names match the
> CRU documentation, so that seems fine.
> 

IIRC, traditionally, Rockchip calls aclk to the AXI clock,
and hclk to the AHB. We'll improve this description.

> > +
> > +  clock-names:
> > +    items:
> > +      - const: clk_isp
> > +      - const: aclk_isp
> > +      - const: aclk_isp_wrap
> > +      - const: hclk_isp
> > +      - const: hclk_isp_wrap
> > +

I wonder if we should better amend the names as well.

> > +  # See ./video-interfaces.txt for details
> > +  ports:
> > +    type: object
> > +    additionalProperties: false
> > +
> > +    properties:
> > +      "#address-cells":
> > +        const: 1
> > +
> > +      "#size-cells":
> > +        const: 0
> > +
> > +      port@0:
> > +        type: object
> > +        additionalProperties: false
> 
> I think this should have a description to tell what this port
> corresponds to.
> 

OK.

> > +
> > +        properties:
> > +          "#address-cells":
> > +            const: 1
> > +
> > +          "#size-cells":
> > +            const: 0
> > +
> > +          reg:
> > +            const: 0
> > +            description: port identifier.
> 
> Here and for the endpoint below the description is probably not needed.
> 

OK.

> > +
> > +        patternProperties:
> > +          endpoint:
> > +            type: object
> > +            additionalProperties: false
> > +
> > +            properties:
> > +              reg:
> > +                maxItems: 1
> > +                description: endpoint identifier.
> > +
> > +              data-lanes:
> > +                minItems: 1
> > +                maxItems: 4
> > +
> > +              remote-endpoint: true
> > +
> > +    required:
> > +      - port@0
> > +
> > +required:
> > +  - compatible
> > +  - interrupts
> > +  - clocks
> > +  - clock-names
> > +  - power-domains
> > +  - iommus
> > +  - phys
> > +  - phy-names
> > +  - ports
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +
> > +    #include <dt-bindings/clock/rk3399-cru.h>
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +    #include <dt-bindings/power/rk3399-power.h>
> > +
> > +    parent0: parent@0 {
> > +        #address-cells = <2>;
> > +        #size-cells = <2>;
> > +
> > +        isp0: isp0@ff910000 {
> > +            compatible = "rockchip,rk3399-cif-isp";
> > +            reg = <0x0 0xff910000 0x0 0x4000>;
> > +            interrupts = <GIC_SPI 43 IRQ_TYPE_LEVEL_HIGH 0>;
> > +            clocks = <&cru SCLK_ISP0>,
> > +                     <&cru ACLK_ISP0>, <&cru ACLK_ISP0_WRAPPER>,
> > +                     <&cru HCLK_ISP0>, <&cru HCLK_ISP0_WRAPPER>;
> > +            clock-names = "clk_isp",
> > +                          "aclk_isp", "aclk_isp_wrap",
> > +                          "hclk_isp", "hclk_isp_wrap";
> > +            power-domains = <&power RK3399_PD_ISP0>;
> > +            iommus = <&isp0_mmu>;
> > +            phys = <&dphy>;
> > +            phy-names = "dphy";
> > +
> > +            ports {
> > +                #address-cells = <1>;
> > +                #size-cells = <0>;
> > +
> > +                port@0 {
> > +                    #address-cells = <1>;
> > +                    #size-cells = <0>;
> > +                    reg = <0>;
> > +
> > +                    mipi_in_wcam: endpoint@0 {
> > +                        reg = <0>;
> > +                        remote-endpoint = <&wcam_out>;
> > +                        data-lanes = <1 2>;
> > +                    };
> > +
> > +                    mipi_in_ucam: endpoint@1 {
> > +                        reg = <1>;
> > +                        remote-endpoint = <&ucam_out>;
> > +                        data-lanes = <1>;
> > +                    };
> 
> Are those two cameras connected to the same CSI-2 lines with at most one
> sensor out of reset ?
> 

Indeed, these are two cameras connected to the same DPHY,
and only one can work at a time.

> With the above small issues addressed,
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 

Thanks for the review!
Ezequiel