From: Yu-Chun Lin Date: Tue, 17 Mar 2026 11:54:06 +0000 (+0800) Subject: dt-bindings: pinctrl: realtek: Improve 'realtek,duty-cycle' description X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=56624479a98fe56b6e8b257b016c0bfd49f1b1cf;p=thirdparty%2Flinux.git dt-bindings: pinctrl: realtek: Improve 'realtek,duty-cycle' description The previous description was misleading because this hardware block is not a PWM generator. It does not generate a signal with a specific frequency and duty ratio. Instead, it provides a fixed nanosecond-level adjustment to the rising/ falling edges of an existing signal. The property name is kept as 'realtek,duty-cycle' rather than being renamed to strictly preserve Device Tree ABI backward compatibility. Acked-by: Conor Dooley Reviewed-by: Linus Walleij Signed-off-by: Yu-Chun Lin Signed-off-by: Linus Walleij --- diff --git a/Documentation/devicetree/bindings/pinctrl/realtek,rtd1315e-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/realtek,rtd1315e-pinctrl.yaml index 90bd49d87d2e..2a640e495cc7 100644 --- a/Documentation/devicetree/bindings/pinctrl/realtek,rtd1315e-pinctrl.yaml +++ b/Documentation/devicetree/bindings/pinctrl/realtek,rtd1315e-pinctrl.yaml @@ -135,8 +135,11 @@ patternProperties: realtek,duty-cycle: description: | - An integer describing the level to adjust output duty cycle, controlling - the proportion of positive and negative waveforms in nanoseconds. + An integer describing the level to adjust the output pulse width, it + provides a fixed nanosecond-level adjustment to the rising/falling + edges of an existing signal. It is used for Signal Integrity tuning + (adding/subtracting delay to fine-tune the high/low duration), rather + than generating a specific PWM frequency. Valid arguments are described as below: 0: 0ns 2: + 0.25ns diff --git a/Documentation/devicetree/bindings/pinctrl/realtek,rtd1319d-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/realtek,rtd1319d-pinctrl.yaml index b6211c8544ca..2136546adec8 100644 --- a/Documentation/devicetree/bindings/pinctrl/realtek,rtd1319d-pinctrl.yaml +++ b/Documentation/devicetree/bindings/pinctrl/realtek,rtd1319d-pinctrl.yaml @@ -134,8 +134,11 @@ patternProperties: realtek,duty-cycle: description: | - An integer describing the level to adjust output duty cycle, controlling - the proportion of positive and negative waveforms in nanoseconds. + An integer describing the level to adjust the output pulse width, it + provides a fixed nanosecond-level adjustment to the rising/falling + edges of an existing signal. It is used for Signal Integrity tuning + (adding/subtracting delay to fine-tune the high/low duration), rather + than generating a specific PWM frequency. Valid arguments are described as below: 0: 0ns 2: + 0.25ns diff --git a/Documentation/devicetree/bindings/pinctrl/realtek,rtd1619b-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/realtek,rtd1619b-pinctrl.yaml index e88bc649cc73..e8ea1362b16d 100644 --- a/Documentation/devicetree/bindings/pinctrl/realtek,rtd1619b-pinctrl.yaml +++ b/Documentation/devicetree/bindings/pinctrl/realtek,rtd1619b-pinctrl.yaml @@ -133,8 +133,11 @@ patternProperties: realtek,duty-cycle: description: | - An integer describing the level to adjust output duty cycle, controlling - the proportion of positive and negative waveforms in nanoseconds. + An integer describing the level to adjust the output pulse width, it + provides a fixed nanosecond-level adjustment to the rising/falling + edges of an existing signal. It is used for Signal Integrity tuning + (adding/subtracting delay to fine-tune the high/low duration), rather + than generating a specific PWM frequency. Valid arguments are described as below: 0: 0ns 2: + 0.25ns