diff mbox series

[v4,4/6] dt-bindings: display: stm32-ltdc: add optional st,fb-bpp property

Message ID 20230619165525.1035243-5-dario.binacchi@amarulasolutions.com
State New
Headers
Series Add display support on the stm32f746-disco board |

Commit Message

Dario Binacchi June 19, 2023, 4:55 p.m. UTC 
  Boards that use the STM32F{4,7} series have limited amounts of RAM. The
added property allows to size, within certain limits, the memory footprint
required by the framebuffer.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

(no changes since v1)

 .../devicetree/bindings/display/st,stm32-ltdc.yaml          | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Rob Herring June 19, 2023, 5:17 p.m. UTC | #1 
On Mon, 19 Jun 2023 18:55:23 +0200, Dario Binacchi wrote:
> Boards that use the STM32F{4,7} series have limited amounts of RAM. The
> added property allows to size, within certain limits, the memory footprint
> required by the framebuffer.
> 
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> ---
> 
> (no changes since v1)
> 
>  .../devicetree/bindings/display/st,stm32-ltdc.yaml          | 6 ++++++
>  1 file changed, 6 insertions(+)
> 

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/display/st,stm32-ltdc.yaml: properties:st,fb-bpp:maxItems: False schema does not allow 1
	from schema $id: http://devicetree.org/meta-schemas/core.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20230619165525.1035243-5-dario.binacchi@amarulasolutions.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.
Conor Dooley June 19, 2023, 8:18 p.m. UTC | #2 
Hey,

On Mon, Jun 19, 2023 at 06:55:23PM +0200, Dario Binacchi wrote:
> Boards that use the STM32F{4,7} series have limited amounts of RAM. The
> added property allows to size, within certain limits, the memory footprint
> required by the framebuffer.

Hmm, this sounds quite a lot like "software policy", since the actual
display doesn't have these limitations. Rob, Krzysztof?

> 
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> ---
> 
> (no changes since v1)

Really?
https://lore.kernel.org/all/?q=dfn:st,stm32-ltdc.yaml%20

You sure this shouldn't be "new in v4"?

>  .../devicetree/bindings/display/st,stm32-ltdc.yaml          | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/st,stm32-ltdc.yaml b/Documentation/devicetree/bindings/display/st,stm32-ltdc.yaml
> index d6ea4d62a2cf..1c3a3653579f 100644
> --- a/Documentation/devicetree/bindings/display/st,stm32-ltdc.yaml
> +++ b/Documentation/devicetree/bindings/display/st,stm32-ltdc.yaml
> @@ -42,6 +42,12 @@ properties:
>        - for internal dpi input of the MIPI DSI host controller.
>        Note: These 2 endpoints cannot be activated simultaneously.
>  
> +  st,fb-bpp:

Is there not a more understandable property name than this?
Maybe I just had to think about it because fbdev stuff aint something
I've worked with...

> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: |
> +      bit depth of framebuffer (8, 16 or 32)
> +    maxItems: 1

Why not make it an enum, since there are only 4 values?

Cheers,
Conor.

> +
>  required:
>    - compatible
>    - reg
> -- 
> 2.32.0
>
Rob Herring June 19, 2023, 10:11 p.m. UTC | #3 
On Mon, Jun 19, 2023 at 09:18:25PM +0100, Conor Dooley wrote:
> Hey,
> 
> On Mon, Jun 19, 2023 at 06:55:23PM +0200, Dario Binacchi wrote:
> > Boards that use the STM32F{4,7} series have limited amounts of RAM. The
> > added property allows to size, within certain limits, the memory footprint
> > required by the framebuffer.
> 
> Hmm, this sounds quite a lot like "software policy", since the actual
> display doesn't have these limitations. Rob, Krzysztof?

Indeed. This doesn't belong in DT.

Rob
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/display/st,stm32-ltdc.yaml b/Documentation/devicetree/bindings/display/st,stm32-ltdc.yaml
index d6ea4d62a2cf..1c3a3653579f 100644
--- a/Documentation/devicetree/bindings/display/st,stm32-ltdc.yaml
+++ b/Documentation/devicetree/bindings/display/st,stm32-ltdc.yaml
@@ -42,6 +42,12 @@  properties:
       - for internal dpi input of the MIPI DSI host controller.
       Note: These 2 endpoints cannot be activated simultaneously.
 
+  st,fb-bpp:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      bit depth of framebuffer (8, 16 or 32)
+    maxItems: 1
+
 required:
   - compatible
   - reg