Commit a730bf75 authored by Antonio Borneo's avatar Antonio Borneo Committed by Linus Walleij
Browse files

dt-bindings: pinctrl: stm32: Support I/O synchronization parameters 



Document the support of the I/O synchronization parameters:
- skew-delay-input-ps;
- skew-delay-output-ps;
- st,io-sync.

Forbid 'skew-delay-input-ps' and 'skew-delay-output-ps' to be both
present on the same pin.
Allow the new properties only with compatibles that support them.
Add an example that uses the new properties.

Co-developed-by: default avatarFabien Dessenne <fabien.dessenne@foss.st.com>
Signed-off-by: default avatarFabien Dessenne <fabien.dessenne@foss.st.com>
Signed-off-by: default avatarAntonio Borneo <antonio.borneo@foss.st.com>
Reviewed-by: default avatarConor Dooley <conor.dooley@microchip.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent cf7a3d4d

Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml

+74 −0
Original line number Diff line number Diff line
@@ -220,12 +220,65 @@ patternProperties: 
            minimum: 0

            maximum: 3



          skew-delay-input-ps:

            description: |

              IO synchronization skew rate applied to the input path

            enum: [0, 300, 500, 750, 1000, 1250, 1500, 1750, 2000, 2250, 2500, 2750, 3000, 3250]



          skew-delay-output-ps:

            description: |

              IO synchronization latch delay applied to the output path

            enum: [0, 300, 500, 750, 1000, 1250, 1500, 1750, 2000, 2250, 2500, 2750, 3000, 3250]



          st,io-sync:

            $ref: /schemas/types.yaml#/definitions/string

            enum:

              - pass-through

              - clock inverted

              - data on rising edge

              - data on falling edge

              - data on both edges

            description: |

              IO synchronization through re-sampling or inversion

              "pass-through"         - data or clock GPIO pass-through

              "clock inverted"       - clock GPIO inverted

              "data on rising edge"  - data GPIO re-sampled on clock rising edge

              "data on falling edge" - data GPIO re-sampled on clock falling edge

              "data on both edges"   - data GPIO re-sampled on both clock edges

            default: pass-through



        required:

          - pinmux



        # Not allowed both skew-delay-input-ps and skew-delay-output-ps

        if:

          required:

            - skew-delay-input-ps

        then:

          properties:

            skew-delay-output-ps: false



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-input-ps: false

                skew-delay-output-ps: false

                st,io-sync: false



required:

  - compatible

  - '#address-cells'
@@ -306,4 +359,25 @@ examples: 
                pinctrl-names = "default";

    };



  - |

    #include <dt-bindings/pinctrl/stm32-pinfunc.h>

    //Example 4 skew-delay and st,io-sync

      pinctrl: pinctrl@44240000 {

              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 = "data on both edges";

                      };

                      pins2 {

                              pinmux = <STM32_PINMUX('H', 2, AF14)>;

                              skew-delay-output-ps = <500>;

                      };

              };

      };



...