diff mbox series

[6/8] dt-bindings: media: nxp,imx-mipi-csi2: Add fsl,num-channels property

Message ID 20250608235840.23871-7-laurent.pinchart@ideasonboard.com
State New
Headers show
Series media: imx-mipi-csis: Cleanups and debugging improvements | expand

Commit Message

Laurent Pinchart June 8, 2025, 11:58 p.m. UTC
The CSI-2 receiver can be instantiated with up to four output channels.
This is an integration-specific property, specify the number of
instantiated channels through a new fsl,num-channels property. The
property is optional, and defaults to 1 as only one channel is currently
supported by drivers.

The only known SoC to have more than one channel is the i.MX8MP. As the
binding examples do not cover that SoC, don't update them.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../devicetree/bindings/media/nxp,imx-mipi-csi2.yaml       | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Frank Li June 9, 2025, 5:58 p.m. UTC | #1
On Mon, Jun 09, 2025 at 12:53:48PM -0500, Adam Ford wrote:
> On Mon, Jun 9, 2025 at 10:32 AM Frank Li <Frank.li@nxp.com> wrote:
> >
> > On Mon, Jun 09, 2025 at 02:58:38AM +0300, Laurent Pinchart wrote:
> > > The CSI-2 receiver can be instantiated with up to four output channels.
> > > This is an integration-specific property, specify the number of
> > > instantiated channels through a new fsl,num-channels property. The
> > > property is optional, and defaults to 1 as only one channel is currently
> > > supported by drivers.
> > >
> > > The only known SoC to have more than one channel is the i.MX8MP. As the
> > > binding examples do not cover that SoC, don't update them.
> > >
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > ---
> > >  .../devicetree/bindings/media/nxp,imx-mipi-csi2.yaml       | 7 +++++++
> > >  1 file changed, 7 insertions(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml b/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml
> > > index db4889bf881e..41ad5b84eaeb 100644
> > > --- a/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml
> > > +++ b/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml
> > > @@ -68,6 +68,13 @@ properties:
> > >      default: 166000000
> > >      deprecated: true
> > >
> > > +  fsl,num-channels:
> > > +    $ref: /schemas/types.yaml#/definitions/uint32
> > > +    description: Number of output channels
> > > +    minimum: 1
> > > +    maximum: 4
> > > +    default: 1
> > > +
> >
> > Look like it is fixed value for each compabiable string, So it is not
> > suitable for adding new property. It should be in driver data of each
> > compatible strings.
> >
> > I met similar case before. DT team generally don't agree on add such
> > property, unless there are two instances in the same chip, which have
> > difference channel number.
>
> If the DT changes are rejected, can the number of channels be added to
> the data structure inside mipi_csis_of_match?  We have compatibles for
> 8mm and imx7.  If we add an imx8mp compatible we could add a reference
> to the number of channels.

Yes, that's prefer method.

Frank

>
> adam
> >
> > Frank
> >
> > >    ports:
> > >      $ref: /schemas/graph.yaml#/properties/ports
> > >
> > > --
> > > Regards,
> > >
> > > Laurent Pinchart
> > >
> >
Frank Li June 9, 2025, 7:08 p.m. UTC | #2
On Mon, Jun 09, 2025 at 09:20:33PM +0300, Laurent Pinchart wrote:
> On Mon, Jun 09, 2025 at 12:53:48PM -0500, Adam Ford wrote:
> > On Mon, Jun 9, 2025 at 10:32 AM Frank Li wrote:
> > > On Mon, Jun 09, 2025 at 02:58:38AM +0300, Laurent Pinchart wrote:
> > > > The CSI-2 receiver can be instantiated with up to four output channels.
> > > > This is an integration-specific property, specify the number of
> > > > instantiated channels through a new fsl,num-channels property. The
> > > > property is optional, and defaults to 1 as only one channel is currently
> > > > supported by drivers.
> > > >
> > > > The only known SoC to have more than one channel is the i.MX8MP. As the
> > > > binding examples do not cover that SoC, don't update them.
> > > >
> > > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > > ---
> > > >  .../devicetree/bindings/media/nxp,imx-mipi-csi2.yaml       | 7 +++++++
> > > >  1 file changed, 7 insertions(+)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml b/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml
> > > > index db4889bf881e..41ad5b84eaeb 100644
> > > > --- a/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml
> > > > +++ b/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml
> > > > @@ -68,6 +68,13 @@ properties:
> > > >      default: 166000000
> > > >      deprecated: true
> > > >
> > > > +  fsl,num-channels:
> > > > +    $ref: /schemas/types.yaml#/definitions/uint32
> > > > +    description: Number of output channels
> > > > +    minimum: 1
> > > > +    maximum: 4
> > > > +    default: 1
> > > > +
> > >
> > > Look like it is fixed value for each compabiable string, So it is not
> > > suitable for adding new property. It should be in driver data of each
> > > compatible strings.
> > >
> > > I met similar case before. DT team generally don't agree on add such
> > > property, unless there are two instances in the same chip, which have
> > > difference channel number.
> >
> > If the DT changes are rejected, can the number of channels be added to
> > the data structure inside mipi_csis_of_match?  We have compatibles for
> > 8mm and imx7.  If we add an imx8mp compatible we could add a reference
> > to the number of channels.
>
> I thought about it, and decided to add a new property because the number
> of channels is really a synthesis time configuration parameter, and
> could differ between different CSIS instances in the same SoC.

Need add such information at binding doc's commit message, ideally provide
an example for it.

Frank
>
> > > >    ports:
> > > >      $ref: /schemas/graph.yaml#/properties/ports
> > > >
>
> --
> Regards,
>
> Laurent Pinchart
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml b/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml
index db4889bf881e..41ad5b84eaeb 100644
--- a/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml
+++ b/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml
@@ -68,6 +68,13 @@  properties:
     default: 166000000
     deprecated: true
 
+  fsl,num-channels:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Number of output channels
+    minimum: 1
+    maximum: 4
+    default: 1
+
   ports:
     $ref: /schemas/graph.yaml#/properties/ports