diff mbox series

[v2,2/4] dt-bindings: media: Add bindings for raspberrypi,rp1-cfe

Message ID 20240620-rp1-cfe-v2-2-b8b48fdba3b3@ideasonboard.com (mailing list archive)
State New
Headers
Series media: raspberrypi: Support RPi5's CFE |

Commit Message

Tomi Valkeinen June 20, 2024, 11:07 a.m. UTC 
  Add DT bindings for raspberrypi,rp1-cfe.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 .../bindings/media/raspberrypi,rp1-cfe.yaml        | 98 ++++++++++++++++++++++
 1 file changed, 98 insertions(+)

Comments

Krzysztof Kozlowski June 20, 2024, 3:41 p.m. UTC | #1 
On 20/06/2024 13:07, Tomi Valkeinen wrote:
> Add DT bindings for raspberrypi,rp1-cfe.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>


Best regards,
Krzysztof
Sakari Ailus Aug. 28, 2024, 11:06 a.m. UTC | #2 
Moi,

Thanks for the set!

On Thu, Jun 20, 2024 at 02:07:51PM +0300, Tomi Valkeinen wrote:
> Add DT bindings for raspberrypi,rp1-cfe.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
>  .../bindings/media/raspberrypi,rp1-cfe.yaml        | 98 ++++++++++++++++++++++
>  1 file changed, 98 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
> new file mode 100644
> index 000000000000..851533de2305
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
> @@ -0,0 +1,98 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/raspberrypi,rp1-cfe.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Raspberry Pi PiSP Camera Front End
> +
> +maintainers:
> +  - Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> +  - Raspberry Pi Kernel Maintenance <kernel-list@raspberrypi.com>
> +
> +description: |
> +  The Raspberry Pi PiSP Camera Front End is a module in Raspberrypi 5's RP1 I/O
> +  controller, that contains:
> +  - MIPI D-PHY
> +  - MIPI CSI-2 receiver
> +  - Simple image processor (called PiSP Front End, or FE)
> +
> +  The FE documentation is available at:
> +  https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf
> +
> +  The PHY and CSI-2 receiver part have no public documentation.
> +
> +properties:
> +  compatible:
> +    items:
> +      - const: raspberrypi,rp1-cfe
> +
> +  reg:
> +    items:
> +      - description: CSI-2 registers
> +      - description: D-PHY registers
> +      - description: MIPI CFG (a simple top-level mux) registers
> +      - description: FE registers
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  port:
> +    $ref: /schemas/graph.yaml#/$defs/port-base
> +    additionalProperties: false
> +    description: CSI-2 RX Port
> +
> +    properties:
> +      endpoint:
> +        $ref: video-interfaces.yaml#
> +        unevaluatedProperties: false
> +
> +        properties:
> +          data-lanes:
> +            minItems: 1
> +            maxItems: 4
> +
> +          clock-lanes:
> +            maxItems: 1

minItems needs to be 1 as well.

Or... is this actually configurable in hardware?

> +
> +        required:
> +          - clock-lanes
> +          - data-lanes
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - clocks
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    rp1 {
> +      #address-cells = <2>;
> +      #size-cells = <2>;
> +
> +      csi@110000 {
> +        compatible = "raspberrypi,rp1-cfe";
> +        reg = <0xc0 0x40110000 0x0 0x100>,
> +              <0xc0 0x40114000 0x0 0x100>,
> +              <0xc0 0x40120000 0x0 0x100>,
> +              <0xc0 0x40124000 0x0 0x1000>;
> +
> +        interrupts = <42>;
> +
> +        clocks = <&rp1_clocks>;
> +
> +        port {
> +          csi_ep: endpoint {
> +            remote-endpoint = <&cam_endpoint>;
> +            clock-lanes = <0>;
> +            data-lanes = <1 2>;
> +          };
> +        };
> +      };
> +    };
>
Laurent Pinchart Aug. 28, 2024, 11:12 a.m. UTC | #3 
On Wed, Aug 28, 2024 at 11:06:23AM +0000, Sakari Ailus wrote:
> On Thu, Jun 20, 2024 at 02:07:51PM +0300, Tomi Valkeinen wrote:
> > Add DT bindings for raspberrypi,rp1-cfe.
> > 
> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> > ---
> >  .../bindings/media/raspberrypi,rp1-cfe.yaml        | 98 ++++++++++++++++++++++
> >  1 file changed, 98 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
> > new file mode 100644
> > index 000000000000..851533de2305
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
> > @@ -0,0 +1,98 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/media/raspberrypi,rp1-cfe.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Raspberry Pi PiSP Camera Front End
> > +
> > +maintainers:
> > +  - Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> > +  - Raspberry Pi Kernel Maintenance <kernel-list@raspberrypi.com>
> > +
> > +description: |
> > +  The Raspberry Pi PiSP Camera Front End is a module in Raspberrypi 5's RP1 I/O
> > +  controller, that contains:
> > +  - MIPI D-PHY
> > +  - MIPI CSI-2 receiver
> > +  - Simple image processor (called PiSP Front End, or FE)
> > +
> > +  The FE documentation is available at:
> > +  https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf
> > +
> > +  The PHY and CSI-2 receiver part have no public documentation.
> > +
> > +properties:
> > +  compatible:
> > +    items:
> > +      - const: raspberrypi,rp1-cfe
> > +
> > +  reg:
> > +    items:
> > +      - description: CSI-2 registers
> > +      - description: D-PHY registers
> > +      - description: MIPI CFG (a simple top-level mux) registers
> > +      - description: FE registers
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    maxItems: 1
> > +
> > +  port:
> > +    $ref: /schemas/graph.yaml#/$defs/port-base
> > +    additionalProperties: false
> > +    description: CSI-2 RX Port
> > +
> > +    properties:
> > +      endpoint:
> > +        $ref: video-interfaces.yaml#
> > +        unevaluatedProperties: false
> > +
> > +        properties:
> > +          data-lanes:
> > +            minItems: 1
> > +            maxItems: 4
> > +
> > +          clock-lanes:
> > +            maxItems: 1
> 
> minItems needs to be 1 as well.
> 
> Or... is this actually configurable in hardware?

Looking at the driver, lane reordering is not supported, so we could
drop this property. If the hardware is found to support it later, it can
easily be added back without any backward compatibility issue.

> > +
> > +        required:
> > +          - clock-lanes
> > +          - data-lanes
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +  - clocks
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    rp1 {
> > +      #address-cells = <2>;
> > +      #size-cells = <2>;
> > +
> > +      csi@110000 {
> > +        compatible = "raspberrypi,rp1-cfe";
> > +        reg = <0xc0 0x40110000 0x0 0x100>,
> > +              <0xc0 0x40114000 0x0 0x100>,
> > +              <0xc0 0x40120000 0x0 0x100>,
> > +              <0xc0 0x40124000 0x0 0x1000>;
> > +
> > +        interrupts = <42>;
> > +
> > +        clocks = <&rp1_clocks>;
> > +
> > +        port {
> > +          csi_ep: endpoint {
> > +            remote-endpoint = <&cam_endpoint>;
> > +            clock-lanes = <0>;
> > +            data-lanes = <1 2>;
> > +          };
> > +        };
> > +      };
> > +    };
Tomi Valkeinen Aug. 28, 2024, 12:14 p.m. UTC | #4 
Hi,

On 28/08/2024 14:12, Laurent Pinchart wrote:
> On Wed, Aug 28, 2024 at 11:06:23AM +0000, Sakari Ailus wrote:
>> On Thu, Jun 20, 2024 at 02:07:51PM +0300, Tomi Valkeinen wrote:
>>> Add DT bindings for raspberrypi,rp1-cfe.
>>>
>>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>>> ---
>>>   .../bindings/media/raspberrypi,rp1-cfe.yaml        | 98 ++++++++++++++++++++++
>>>   1 file changed, 98 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
>>> new file mode 100644
>>> index 000000000000..851533de2305
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
>>> @@ -0,0 +1,98 @@
>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>>> +%YAML 1.2
>>> +---
>>> +$id: http://devicetree.org/schemas/media/raspberrypi,rp1-cfe.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: Raspberry Pi PiSP Camera Front End
>>> +
>>> +maintainers:
>>> +  - Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>>> +  - Raspberry Pi Kernel Maintenance <kernel-list@raspberrypi.com>
>>> +
>>> +description: |
>>> +  The Raspberry Pi PiSP Camera Front End is a module in Raspberrypi 5's RP1 I/O
>>> +  controller, that contains:
>>> +  - MIPI D-PHY
>>> +  - MIPI CSI-2 receiver
>>> +  - Simple image processor (called PiSP Front End, or FE)
>>> +
>>> +  The FE documentation is available at:
>>> +  https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf
>>> +
>>> +  The PHY and CSI-2 receiver part have no public documentation.
>>> +
>>> +properties:
>>> +  compatible:
>>> +    items:
>>> +      - const: raspberrypi,rp1-cfe
>>> +
>>> +  reg:
>>> +    items:
>>> +      - description: CSI-2 registers
>>> +      - description: D-PHY registers
>>> +      - description: MIPI CFG (a simple top-level mux) registers
>>> +      - description: FE registers
>>> +
>>> +  interrupts:
>>> +    maxItems: 1
>>> +
>>> +  clocks:
>>> +    maxItems: 1
>>> +
>>> +  port:
>>> +    $ref: /schemas/graph.yaml#/$defs/port-base
>>> +    additionalProperties: false
>>> +    description: CSI-2 RX Port
>>> +
>>> +    properties:
>>> +      endpoint:
>>> +        $ref: video-interfaces.yaml#
>>> +        unevaluatedProperties: false
>>> +
>>> +        properties:
>>> +          data-lanes:
>>> +            minItems: 1
>>> +            maxItems: 4
>>> +
>>> +          clock-lanes:
>>> +            maxItems: 1
>>
>> minItems needs to be 1 as well.

Hmm, I see a lot of

clock-lanes:
   maxItems: 1

in the device tree bindings. And 
https://docs.kernel.org/devicetree/bindings/writing-schema.html says 
"Cases that have only a single entry just need to express that with 
maxItems".

>>
>> Or... is this actually configurable in hardware?
> 
> Looking at the driver, lane reordering is not supported, so we could
> drop this property. If the hardware is found to support it later, it can
> easily be added back without any backward compatibility issue.

Re-ordering is not supported. I guess clock-lanes can be dropped, 
although I feel that if we have the clock lane in the hardware, and the 
numbering of data-lanes must take that into account, then:

clock-lanes = <0>;
data-lanes = <1 2>;

looks better than:

data-lanes = <1 2>; /* and implicit clk lane 0 */

But I can't think of any practical benefit it brings...

  Tomi
Sakari Ailus Aug. 28, 2024, 12:30 p.m. UTC | #5 
Heippa,

On Wed, Aug 28, 2024 at 03:14:47PM +0300, Tomi Valkeinen wrote:
> Hi,
> 
> On 28/08/2024 14:12, Laurent Pinchart wrote:
> > On Wed, Aug 28, 2024 at 11:06:23AM +0000, Sakari Ailus wrote:
> > > On Thu, Jun 20, 2024 at 02:07:51PM +0300, Tomi Valkeinen wrote:
> > > > Add DT bindings for raspberrypi,rp1-cfe.
> > > > 
> > > > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> > > > ---
> > > >   .../bindings/media/raspberrypi,rp1-cfe.yaml        | 98 ++++++++++++++++++++++
> > > >   1 file changed, 98 insertions(+)
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
> > > > new file mode 100644
> > > > index 000000000000..851533de2305
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
> > > > @@ -0,0 +1,98 @@
> > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > +%YAML 1.2
> > > > +---
> > > > +$id: http://devicetree.org/schemas/media/raspberrypi,rp1-cfe.yaml#
> > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > +
> > > > +title: Raspberry Pi PiSP Camera Front End
> > > > +
> > > > +maintainers:
> > > > +  - Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> > > > +  - Raspberry Pi Kernel Maintenance <kernel-list@raspberrypi.com>
> > > > +
> > > > +description: |
> > > > +  The Raspberry Pi PiSP Camera Front End is a module in Raspberrypi 5's RP1 I/O
> > > > +  controller, that contains:
> > > > +  - MIPI D-PHY
> > > > +  - MIPI CSI-2 receiver
> > > > +  - Simple image processor (called PiSP Front End, or FE)
> > > > +
> > > > +  The FE documentation is available at:
> > > > +  https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf
> > > > +
> > > > +  The PHY and CSI-2 receiver part have no public documentation.
> > > > +
> > > > +properties:
> > > > +  compatible:
> > > > +    items:
> > > > +      - const: raspberrypi,rp1-cfe
> > > > +
> > > > +  reg:
> > > > +    items:
> > > > +      - description: CSI-2 registers
> > > > +      - description: D-PHY registers
> > > > +      - description: MIPI CFG (a simple top-level mux) registers
> > > > +      - description: FE registers
> > > > +
> > > > +  interrupts:
> > > > +    maxItems: 1
> > > > +
> > > > +  clocks:
> > > > +    maxItems: 1
> > > > +
> > > > +  port:
> > > > +    $ref: /schemas/graph.yaml#/$defs/port-base
> > > > +    additionalProperties: false
> > > > +    description: CSI-2 RX Port
> > > > +
> > > > +    properties:
> > > > +      endpoint:
> > > > +        $ref: video-interfaces.yaml#
> > > > +        unevaluatedProperties: false
> > > > +
> > > > +        properties:
> > > > +          data-lanes:
> > > > +            minItems: 1
> > > > +            maxItems: 4
> > > > +
> > > > +          clock-lanes:
> > > > +            maxItems: 1
> > > 
> > > minItems needs to be 1 as well.
> 
> Hmm, I see a lot of
> 
> clock-lanes:
>   maxItems: 1
> 
> in the device tree bindings. And
> https://docs.kernel.org/devicetree/bindings/writing-schema.html says "Cases
> that have only a single entry just need to express that with maxItems".

Fair enough.

> 
> > > 
> > > Or... is this actually configurable in hardware?
> > 
> > Looking at the driver, lane reordering is not supported, so we could
> > drop this property. If the hardware is found to support it later, it can
> > easily be added back without any backward compatibility issue.
> 
> Re-ordering is not supported. I guess clock-lanes can be dropped, although I
> feel that if we have the clock lane in the hardware, and the numbering of
> data-lanes must take that into account, then:
> 
> clock-lanes = <0>;
> data-lanes = <1 2>;
> 
> looks better than:
> 
> data-lanes = <1 2>; /* and implicit clk lane 0 */
> 
> But I can't think of any practical benefit it brings...

The clock-lanes property is optional, it only provides any information if
the clock lane is configurable. Please drop it.
Laurent Pinchart Aug. 28, 2024, 12:53 p.m. UTC | #6 
On Wed, Aug 28, 2024 at 03:14:47PM +0300, Tomi Valkeinen wrote:
> On 28/08/2024 14:12, Laurent Pinchart wrote:
> > On Wed, Aug 28, 2024 at 11:06:23AM +0000, Sakari Ailus wrote:
> >> On Thu, Jun 20, 2024 at 02:07:51PM +0300, Tomi Valkeinen wrote:
> >>> Add DT bindings for raspberrypi,rp1-cfe.
> >>>
> >>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> >>> ---
> >>>   .../bindings/media/raspberrypi,rp1-cfe.yaml        | 98 ++++++++++++++++++++++
> >>>   1 file changed, 98 insertions(+)
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
> >>> new file mode 100644
> >>> index 000000000000..851533de2305
> >>> --- /dev/null
> >>> +++ b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
> >>> @@ -0,0 +1,98 @@
> >>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> >>> +%YAML 1.2
> >>> +---
> >>> +$id: http://devicetree.org/schemas/media/raspberrypi,rp1-cfe.yaml#
> >>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> >>> +
> >>> +title: Raspberry Pi PiSP Camera Front End
> >>> +
> >>> +maintainers:
> >>> +  - Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> >>> +  - Raspberry Pi Kernel Maintenance <kernel-list@raspberrypi.com>
> >>> +
> >>> +description: |
> >>> +  The Raspberry Pi PiSP Camera Front End is a module in Raspberrypi 5's RP1 I/O
> >>> +  controller, that contains:
> >>> +  - MIPI D-PHY
> >>> +  - MIPI CSI-2 receiver
> >>> +  - Simple image processor (called PiSP Front End, or FE)
> >>> +
> >>> +  The FE documentation is available at:
> >>> +  https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf
> >>> +
> >>> +  The PHY and CSI-2 receiver part have no public documentation.
> >>> +
> >>> +properties:
> >>> +  compatible:
> >>> +    items:
> >>> +      - const: raspberrypi,rp1-cfe
> >>> +
> >>> +  reg:
> >>> +    items:
> >>> +      - description: CSI-2 registers
> >>> +      - description: D-PHY registers
> >>> +      - description: MIPI CFG (a simple top-level mux) registers
> >>> +      - description: FE registers
> >>> +
> >>> +  interrupts:
> >>> +    maxItems: 1
> >>> +
> >>> +  clocks:
> >>> +    maxItems: 1
> >>> +
> >>> +  port:
> >>> +    $ref: /schemas/graph.yaml#/$defs/port-base
> >>> +    additionalProperties: false
> >>> +    description: CSI-2 RX Port
> >>> +
> >>> +    properties:
> >>> +      endpoint:
> >>> +        $ref: video-interfaces.yaml#
> >>> +        unevaluatedProperties: false
> >>> +
> >>> +        properties:
> >>> +          data-lanes:
> >>> +            minItems: 1
> >>> +            maxItems: 4
> >>> +
> >>> +          clock-lanes:
> >>> +            maxItems: 1
> >>
> >> minItems needs to be 1 as well.
> 
> Hmm, I see a lot of
> 
> clock-lanes:
>    maxItems: 1
> 
> in the device tree bindings. And 
> https://docs.kernel.org/devicetree/bindings/writing-schema.html says 
> "Cases that have only a single entry just need to express that with 
> maxItems".

The rules may have changed recently, I'm not entirely sure. I've asked
in https://lore.kernel.org/dri-devel/20240818173003.122025-1-krzysztof.kozlowski@linaro.org/T/#m7669ca56543567e36733af745798713ae0293654

> >> Or... is this actually configurable in hardware?
> > 
> > Looking at the driver, lane reordering is not supported, so we could
> > drop this property. If the hardware is found to support it later, it can
> > easily be added back without any backward compatibility issue.
> 
> Re-ordering is not supported. I guess clock-lanes can be dropped, 
> although I feel that if we have the clock lane in the hardware, and the 
> numbering of data-lanes must take that into account, then:
> 
> clock-lanes = <0>;
> data-lanes = <1 2>;
> 
> looks better than:
> 
> data-lanes = <1 2>; /* and implicit clk lane 0 */
> 
> But I can't think of any practical benefit it brings...
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
new file mode 100644
index 000000000000..851533de2305
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/raspberrypi,rp1-cfe.yaml
@@ -0,0 +1,98 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/raspberrypi,rp1-cfe.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Raspberry Pi PiSP Camera Front End
+
+maintainers:
+  - Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
+  - Raspberry Pi Kernel Maintenance <kernel-list@raspberrypi.com>
+
+description: |
+  The Raspberry Pi PiSP Camera Front End is a module in Raspberrypi 5's RP1 I/O
+  controller, that contains:
+  - MIPI D-PHY
+  - MIPI CSI-2 receiver
+  - Simple image processor (called PiSP Front End, or FE)
+
+  The FE documentation is available at:
+  https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf
+
+  The PHY and CSI-2 receiver part have no public documentation.
+
+properties:
+  compatible:
+    items:
+      - const: raspberrypi,rp1-cfe
+
+  reg:
+    items:
+      - description: CSI-2 registers
+      - description: D-PHY registers
+      - description: MIPI CFG (a simple top-level mux) registers
+      - description: FE registers
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  port:
+    $ref: /schemas/graph.yaml#/$defs/port-base
+    additionalProperties: false
+    description: CSI-2 RX Port
+
+    properties:
+      endpoint:
+        $ref: video-interfaces.yaml#
+        unevaluatedProperties: false
+
+        properties:
+          data-lanes:
+            minItems: 1
+            maxItems: 4
+
+          clock-lanes:
+            maxItems: 1
+
+        required:
+          - clock-lanes
+          - data-lanes
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    rp1 {
+      #address-cells = <2>;
+      #size-cells = <2>;
+
+      csi@110000 {
+        compatible = "raspberrypi,rp1-cfe";
+        reg = <0xc0 0x40110000 0x0 0x100>,
+              <0xc0 0x40114000 0x0 0x100>,
+              <0xc0 0x40120000 0x0 0x100>,
+              <0xc0 0x40124000 0x0 0x1000>;
+
+        interrupts = <42>;
+
+        clocks = <&rp1_clocks>;
+
+        port {
+          csi_ep: endpoint {
+            remote-endpoint = <&cam_endpoint>;
+            clock-lanes = <0>;
+            data-lanes = <1 2>;
+          };
+        };
+      };
+    };