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Message-ID: <20250905135547.934729-9-antonio.borneo@foss.st.com>
Date: Fri, 5 Sep 2025 15:55:46 +0200
From: Antonio Borneo <antonio.borneo@...s.st.com>
To: Linus Walleij <linus.walleij@...aro.org>, Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>,
Maxime Coquelin <mcoquelin.stm32@...il.com>,
Alexandre Torgue
<alexandre.torgue@...s.st.com>,
Bartosz Golaszewski <brgl@...ev.pl>, <linux-gpio@...r.kernel.org>,
<devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-stm32@...md-mailman.stormreply.com>,
<linux-arm-kernel@...ts.infradead.org>
CC: Antonio Borneo <antonio.borneo@...s.st.com>,
Christophe Roullier
<christophe.roullier@...s.st.com>,
Fabien Dessenne
<fabien.dessenne@...s.st.com>,
Valentin Caron <valentin.caron@...s.st.com>
Subject: [PATCH v2 8/9] dt-bindings: pinctrl: stm32: Support I/O synchronization parameters
Document the support of the I/O synchronization parameters:
- skew-delay;
- skew-delay-direction;
- st,io-sync.
Require 'skew-delay-direction' when 'skew-delay' is non zero.
Allow the new properties only with compatibles that support them.
Add an example that uses all the new properties.
Co-developed-by: Fabien Dessenne <fabien.dessenne@...s.st.com>
Signed-off-by: Fabien Dessenne <fabien.dessenne@...s.st.com>
Signed-off-by: Antonio Borneo <antonio.borneo@...s.st.com>
---
.../bindings/pinctrl/st,stm32-pinctrl.yaml | 92 +++++++++++++++++++
1 file changed, 92 insertions(+)
diff --git a/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml
index 961161c2ab62b..d20669fd5d9c9 100644
--- a/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml
@@ -225,12 +225,82 @@ patternProperties:
$ref: /schemas/types.yaml#/definitions/uint32
enum: [0, 1, 2, 3]
+ skew-delay:
+ description: |
+ IO synchronization delay applied to the input or output path
+ depending on 'skew-delay-direction' property
+ 0: No delay
+ 1: Delay 0.30 ns
+ 2: Delay 0.50 ns
+ 3: Delay 0.75 ns
+ 4: Delay 1.00 ns
+ 5: Delay 1.25 ns
+ 6: Delay 1.50 ns
+ 7: Delay 1.75 ns
+ 8: Delay 2.00 ns
+ 9: Delay 2.25 ns
+ 10: Delay 2.50 ns
+ 11: Delay 2.75 ns
+ 12: Delay 3.00 ns
+ 13: Delay 3.25 ns
+ minimum: 0
+ maximum: 13
+ default: 0
+
+ skew-delay-direction:
+ description: |
+ IO synchronization delay path location
+ 1: Delay on the output path
+ 2: Delay on the input path
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [1, 2]
+
+ st,io-sync:
+ description: |
+ IO synchronization through re-sampling or inversion
+ 0: data or clock GPIO pass-through
+ 1: clock GPIO inverted
+ 2: data GPIO re-sampled on clock rising edge
+ 3: data GPIO re-sampled on clock falling edge
+ 4: data GPIO re-sampled on both clock edges
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [0, 1, 2, 3, 4]
+ default: 0
+
required:
- pinmux
+ allOf:
+ - if:
+ not:
+ properties:
+ skew-delay:
+ const: 0
+ then:
+ required:
+ - skew-delay-direction
+
allOf:
- $ref: pinctrl.yaml#
+ - if:
+ not:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - st,stm32mp257-pinctrl
+ - st,stm32mp257-z-pinctrl
+ then:
+ patternProperties:
+ '-[0-9]*$':
+ patternProperties:
+ '^pins':
+ properties:
+ skew-delay: false
+ skew-delay-direction: false
+ st,io-sync: false
+
required:
- compatible
- '#address-cells'
@@ -311,4 +381,26 @@ examples:
pinctrl-names = "default";
};
+ - |
+ #include <dt-bindings/pinctrl/stm32-pinfunc.h>
+ //Example 4 skew-delay and st,io-sync
+ pinctrl: pinctrl@...40000 {
+ compatible = "st,stm32mp257-pinctrl";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0 0x44240000 0xa0400>;
+
+ eth3_rgmii_pins_a: eth3-rgmii-0 {
+ pins1 {
+ pinmux = <STM32_PINMUX('A', 6, AF14)>;
+ st,io-sync = <4>;
+ };
+ pins2 {
+ pinmux = <STM32_PINMUX('H', 2, AF14)>;
+ skew-delay = <2>;
+ skew-delay-direction = <1>;
+ };
+ };
+ };
+
...
--
2.34.1
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