[PATCH] dt-bindings: pinctrl: mediatek: mt6795: document the slew-rate property

[PATCH] dt-bindings: pinctrl: mediatek: mt6795: document the slew-rate property

[Luca Leonardo Scorcia]

The driver for MT6795 pinctrl already supports the slew-rate property.
Add its description to the documentation.

Signed-off-by: Luca Leonardo Scorcia <l.scorcia@gmail.com>
---
 .../bindings/pinctrl/mediatek,mt6795-pinctrl.yaml         | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/pinctrl/mediatek,mt6795-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/mediatek,mt6795-pinctrl.yaml
index 68e91c05f122..9a937f414cc9 100644
--- a/Documentation/devicetree/bindings/pinctrl/mediatek,mt6795-pinctrl.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/mediatek,mt6795-pinctrl.yaml
@@ -152,6 +152,14 @@ patternProperties:
             $ref: /schemas/types.yaml#/definitions/uint32
             enum: [0, 1, 2, 3]
 
+          slew-rate:
+            description: |
+              Set the slew rate. Valid arguments are described as below:
+              0: Normal slew rate
+              1: Slower slew
+            $ref: /schemas/types.yaml#/definitions/uint32
+            enum: [0, 1]
+
         required:
           - pinmux
 
-- 
2.43.0

Re: [PATCH] dt-bindings: pinctrl: mediatek: mt6795: document the slew-rate property

[Linus Walleij]

Hi Luca,

thanks for your patch!

On Mon, Jun 1, 2026 at 5:27 PM Luca Leonardo Scorcia
<l.scorcia@gmail.com> wrote:

> The driver for MT6795 pinctrl already supports the slew-rate property.
> Add its description to the documentation.
>
> Signed-off-by: Luca Leonardo Scorcia <l.scorcia@gmail.com>
(...)
> +          slew-rate:
> +            description: |
> +              Set the slew rate. Valid arguments are described as below:
> +              0: Normal slew rate
> +              1: Slower slew
> +            $ref: /schemas/types.yaml#/definitions/uint32
> +            enum: [0, 1]

Ideally slew-rate is V/s (or V/us, any suitable prefixes).

Of course that would vary for any capacitance on the output line,
so that value would be for an infinite impedance (open circuit).

Do you know that value for the SoC to you can express it like
this and translate it in the driver?

Maybe we should even invent something like
slew-rate-volt-per-microsecond = <...>; to push this into
SI units.

That said, there are many SoC:s doing what you're doing
above so it's no strict requirement.

Yours,
Linus Walleij

Re: [PATCH] dt-bindings: pinctrl: mediatek: mt6795: document the slew-rate property

[Luca Leonardo Scorcia]

Hi!

> Do you know that value for the SoC to you can express it like
> this and translate it in the driver?

Unfortunately the data sheet I have doesn't say anything more - just
"Normal slew" or "Slower slew", and I don't have a scope to measure
it. All I know is that it flips a single bit in a configuration
register.

I found this missing property while working on the Xiaomi Mi Smart
Clock x04g (mt8167). I ported the current pinctrl driver for
mt8516/mt8167 to the paris platform driver (adding support for slew
rate and r1r0 pullups in the process) but the stock device tree sets a
slower slew rate for the speaker amp. Without this patch it would
trigger a dts error.

Thanks!
-- 
Luca

Re: [PATCH] dt-bindings: pinctrl: mediatek: mt6795: document the slew-rate property

[Conor Dooley]

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Acked-by: Conor Dooley <conor.dooley@microchip.com>
pw-bot: not-applicable

[-- Attachment #2: signature.asc --]
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Re: [PATCH] dt-bindings: pinctrl: mediatek: mt6795: document the slew-rate property

[Linus Walleij]

On Mon, Jun 1, 2026 at 5:27 PM Luca Leonardo Scorcia
<l.scorcia@gmail.com> wrote:

> The driver for MT6795 pinctrl already supports the slew-rate property.
> Add its description to the documentation.
>
> Signed-off-by: Luca Leonardo Scorcia <l.scorcia@gmail.com>

Patch applied!

Yours,
Linus Walleij