Re: [PATCH v2 1/3] dt-bindings: media: ov772x: Document endpoint properties
From: Jacopo Mondi <jacopo@jmondi.org>
Date: 2020-08-06 16:55:51
Also in:
linux-media, linux-renesas-soc, lkml
Hi Prabhakar, On Mon, Aug 03, 2020 at 12:39:11PM +0100, Lad Prabhakar wrote:
quoted hunk ↗ jump to hunk
Document endpoint properties required for parallel interface Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> --- .../devicetree/bindings/media/i2c/ov772x.txt | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)diff --git a/Documentation/devicetree/bindings/media/i2c/ov772x.txt b/Documentation/devicetree/bindings/media/i2c/ov772x.txt index 0b3ede5b8e6a..1f4153484717 100644 --- a/Documentation/devicetree/bindings/media/i2c/ov772x.txt +++ b/Documentation/devicetree/bindings/media/i2c/ov772x.txt@@ -21,6 +21,22 @@ subnode for its digital output video port, in accordance with the video interface bindings defined in Documentation/devicetree/bindings/media/ video-interfaces.txt. +Endpoint node required properties for parallel connection are: +- remote-endpoint: a phandle to the bus receiver's endpoint node.
we allow endpoints without a remote end connected usually. They can be filled in later, in example, with an overlay.
+- bus-width: shall be set to <8> for 8 bits parallel bus + or <10> for 10 bits parallel bus +- data-shift: shall be set to <2> for 8 bits parallel bus + (lines 9:2 are used) or <0> for 10 bits parallel bus
defining what is required or optional might be hard. I don't see the driver enforcing their presence and I assume they have safe default. Maybe make them optional and specify what the defaul value is ?
+- hsync-active: active state of the HSYNC signal, 0/1 for LOW/HIGH respectively. + (Not required for bus-type equal 6) +- vsync-active: active state of the VSYNC signal, 0/1 for LOW/HIGH respectively. + (Not required for bus-type equal 6)
If they're not required, they're optional, aren't they ? :)
+- pclk-sample: sample data on rising (1) or falling (0) edge of the pixel clock + signal. (Not required for bus-type equal 6)
Why the pclk polarity is does not apply to BT.656 ?
+- bus-type: data bus type. Possible values are: + 5 - Parallel + 6 - Bt.656
Are we making this required, or do we expect this to be deduced depending on which other properties have been specified ? Sakari it seems you would like this to become a properties that has to be specified most of the times, right ? (I tend to agree with that FWIW), but does it impact retro-compatibility ?
+
Example:
&i2c0 {
--
2.17.1