Re: [PATCH v6 08/15] dt-bindings: media: Add bindings for bcm2835-unicam

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi Laurent,

Thanks for the set.

On Fri, Mar 01, 2024 at 11:32:23PM +0200, Laurent Pinchart wrote:
> From: Dave Stevenson <dave.stevenson@raspberrypi.com>
> 
> Introduce the dt-bindings documentation for bcm2835 CCP2/CSI2 Unicam
> camera interface.
> 
> Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
> Co-developed-by: Naushir Patuck <naush@raspberrypi.com>
> Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
> Co-developed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
> Changes since v5:
> 
> - Squash MAINTAINERS changes in
> 
> Changes since v3:
> 
> - Make MAINTAINERS its own patch
> - Describe the reg and clocks correctly
> - Use a vendor entry for the number of data lanes
> ---
>  .../bindings/media/brcm,bcm2835-unicam.yaml   | 117 ++++++++++++++++++
>  MAINTAINERS                                   |   6 +
>  2 files changed, 123 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> 
> diff --git a/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> new file mode 100644
> index 000000000000..1938ace23b3d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> @@ -0,0 +1,117 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/brcm,bcm2835-unicam.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Broadcom BCM283x Camera Interface (Unicam)
> +
> +maintainers:
> +  - Raspberry Pi Kernel Maintenance <kernel-list@raspberrypi.com>
> +
> +description: |-
> +  The Unicam block on BCM283x SoCs is the receiver for either
> +  CSI-2 or CCP2 data from image sensors or similar devices.
> +
> +  The main platform using this SoC is the Raspberry Pi family of boards.  On
> +  the Pi the VideoCore firmware can also control this hardware block, and
> +  driving it from two different processors will cause issues.  To avoid this,
> +  the firmware checks the device tree configuration during boot. If it finds
> +  device tree nodes whose name starts with 'csi' then it will stop the firmware
> +  accessing the block, and it can then safely be used via the device tree
> +  binding.
> +
> +properties:
> +  compatible:
> +    const: brcm,bcm2835-unicam
> +
> +  reg:
> +    items:
> +      - description: Unicam block.
> +      - description: Clock Manager Image (CMI) block.
> +
> +  reg-names:
> +    items:
> +      - const: unicam
> +      - const: cmi
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    items:
> +      - description: Clock to drive the LP state machine of Unicam.
> +      - description: Clock for the VPU (core clock).
> +
> +  clock-names:
> +    items:
> +      - const: lp
> +      - const: vpu
> +
> +  power-domains:
> +    items:
> +      - description: Unicam power domain
> +
> +  brcm,num-data-lanes:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    enum: [ 2, 4 ]
> +    description: |
> +      Number of CSI-2 data lanes supported by this Unicam instance. The number
> +      of data lanes actively used is specified with the data-lanes endpoint
> +      property.
> +
> +  port:
> +    $ref: /schemas/graph.yaml#/$defs/port-base
> +    unevaluatedProperties: false
> +
> +    properties:
> +      endpoint:
> +        $ref: /schemas/media/video-interfaces.yaml#
> +        unevaluatedProperties: false
> +
> +        properties:
> +          data-lanes: true
> +
> +        required:
> +          - data-lanes

As the device supports multiple data interfaces (at least so it seems when
looking at the driver code), you need to list the bus-type property here,
too.

> +
> +    required:
> +      - endpoint
> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - interrupts
> +  - clocks
> +  - clock-names
> +  - power-domains
> +  - brcm,num-data-lanes
> +  - port
> +
> +additionalProperties: False
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/bcm2835.h>
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/power/raspberrypi-power.h>
> +    csi1: csi@7e801000 {
> +        compatible = "brcm,bcm2835-unicam";
> +        reg = <0x7e801000 0x800>,
> +              <0x7e802004 0x4>;
> +        reg-names = "unicam", "cmi";
> +        interrupts = <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
> +        clocks = <&clocks BCM2835_CLOCK_CAM1>,
> +                 <&firmware_clocks 4>;
> +        clock-names = "lp", "vpu";
> +        power-domains = <&power RPI_POWER_DOMAIN_UNICAM1>;
> +        brcm,num-data-lanes = <2>;
> +        port {
> +                csi1_ep: endpoint {
> +                        remote-endpoint = <&imx219_0>;
> +                        data-lanes = <1 2>;
> +                };
> +        };
> +    };
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index fada59148cb5..e50a59654e6e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3997,6 +3997,12 @@ N:	bcm113*
>  N:	bcm216*
>  N:	kona
>  
> +BROADCOM BCM2835 CAMERA DRIVERS
> +M:	Raspberry Pi Kernel Maintenance <kernel-list@raspberrypi.com>
> +L:	linux-media@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml
> +
>  BROADCOM BCM47XX MIPS ARCHITECTURE
>  M:	Hauke Mehrtens <hauke@hauke-m.de>
>  M:	Rafał Miłecki <zajec5@gmail.com>

-- 
Regards,

Sakari Ailus