[PATCH v4 4/8] dt-bindings: pinctrl: realtek: Improve 'realtek,duty-cycle' description
From: Yu-Chun Lin <eleanor.lin@realtek.com>
Date: 2026-03-17 11:57:00
Also in:
linux-devicetree, linux-gpio, lkml
Subsystem:
open firmware and flattened device tree bindings, pin control subsystem, the rest · Maintainers:
Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Walleij, Linus Torvalds
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 <conor.dooley@microchip.com> Reviewed-by: Linus Walleij <linusw@kernel.org> Signed-off-by: Yu-Chun Lin <eleanor.lin@realtek.com> --- Changes in v4: - Add Reviewed-by from Linus and Acked-by tag from Conor. .../bindings/pinctrl/realtek,rtd1315e-pinctrl.yaml | 7 +++++-- .../bindings/pinctrl/realtek,rtd1319d-pinctrl.yaml | 7 +++++-- .../bindings/pinctrl/realtek,rtd1619b-pinctrl.yaml | 7 +++++-- 3 files changed, 15 insertions(+), 6 deletions(-)
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
--
2.34.1