Re: [PATCH V8 7/7] dt-bindings: bridge: samsung-dsim: Make some flags optional

From: Conor Dooley
Date: Fri May 26 2023 - 14:19:19 EST


Adam, Neil,

I meant to get to this earlier today, but broken CI got in the way...

On Thu, May 25, 2023 at 10:05:59PM -0500, Adam Ford wrote:
> In the event a device is connected to the samsung-dsim
> controller that doesn't support the burst-clock, the
> driver is able to get the requested pixel clock from the
> attached device or bridge. In these instances, the
> samsung,burst-clock-frequency isn't needed, so remove
> it from the required list.
>
> The pll-clock frequency can be set by the device tree entry
> for samsung,pll-clock-frequency, but in some cases, the
> pll-clock may have the same clock rate as sclk_mipi clock.
> If they are equal, this flag is not needed since the driver
> will use the sclk_mipi rate as a fallback.
>
> Signed-off-by: Adam Ford <aford173@xxxxxxxxx>
> ---
> .../bindings/display/bridge/samsung,mipi-dsim.yaml | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/samsung,mipi-dsim.yaml b/Documentation/devicetree/bindings/display/bridge/samsung,mipi-dsim.yaml
> index 9f61ebdfefa8..360fea81f4b6 100644
> --- a/Documentation/devicetree/bindings/display/bridge/samsung,mipi-dsim.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/samsung,mipi-dsim.yaml
> @@ -70,7 +70,9 @@ properties:
> samsung,burst-clock-frequency:
> $ref: /schemas/types.yaml#/definitions/uint32
> description:
> - DSIM high speed burst mode frequency.
> + DSIM high speed burst mode frequency when connected to devices
> + that support burst mode. If absent, the driver will use the pixel
> + clock from the attached device or bridge.

I'd rather this description did not say anything about drivers.
How about:
If absent, the pixel clock from the attached device or bridge
will be used instead.
Or perhaps "must be used"? Ditto below.

Description aside, the removal seems to be backwards compatible - but
can every device that this binding supports work using an "attached
device or bridge", or are these properties going to be required for
certain compatibles?

Thanks,
Conor.

>
> samsung,esc-clock-frequency:
> $ref: /schemas/types.yaml#/definitions/uint32
> @@ -80,7 +82,8 @@ properties:
> samsung,pll-clock-frequency:
> $ref: /schemas/types.yaml#/definitions/uint32
> description:
> - DSIM oscillator clock frequency.
> + DSIM oscillator clock frequency. If absent, the driver will
> + use the clock frequency of sclk_mipi.
>
> phys:
> maxItems: 1
> @@ -134,9 +137,7 @@ required:
> - compatible
> - interrupts
> - reg
> - - samsung,burst-clock-frequency
> - samsung,esc-clock-frequency
> - - samsung,pll-clock-frequency
>
> allOf:
> - $ref: ../dsi-controller.yaml#
> --
> 2.39.2
>

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