Re: [PATCH] dt-bindings: pinctrl: Convert stm32 pinctrl bindings to jason-schema

[Rob Herring]

What's jason-schema? ;)

On Fri, May 3, 2019 at 4:47 AM Alexandre Torgue <alexandre.torgue@xxxxxx> wrote:
>
> Convert the STM32 pinctrl binding to DT schema format using json-schema.
>
> Signed-off-by: Alexandre Torgue <alexandre.torgue@xxxxxx>
> ---
>
> Hi,
>
> First pacth to convert DT bindings file (here pinctrl STM32) to jsaon-schema
> in order to take advantage of devicetree validation tool for STM32.

> diff --git a/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml
> new file mode 100644
> index 0000000..fcceca0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml
> @@ -0,0 +1,271 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright (C) STMicroelectronics 2019.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pinctrl/st,stm32-pinctrl.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: STM32 GPIO and Pin Mux/Config controller
> +
> +maintainers:
> +  - Alexandre TORGUE <alexandre.torgue@xxxxxx>

nit: add a blank line

> +description: |
> +  STMicroelectronics's STM32 MCUs intregrate a GPIO and Pin mux/config hardware
> +  controller. It controls the input/output settings on the available pins and
> +  also provides ability to multiplex and configure the output of various
> +  on-chip controllers onto these pads.
> +
> +properties:
> +  compatible:
> +      items:

You can drop items since there is only 1.

> +        - enum:
> +          - st,stm32f429-pinctrl
> +          - st,stm32f469-pinctrl
> +          - st,stm32f746-pinctrl
> +          - st,stm32f769-pinctrl
> +          - st,stm32h743-pinctrl
> +          - st,stm32mp157-pinctrl
> +          - st,stm32mp157-z-pinctrl
> +
> +  '#address-cells':
> +    const: 1
> +  '#size-cells':
> +    const: 1
> +    description:
> +      Defines mapping between pin controller node (parent) to
> +      gpio-bank node (children).

Don't need description for common properties unless there's really
something binding specific to add. Same is true on a bunch of other
description entries.

> +
> +  ranges:
> +    description:
> +      Defines mapping between pin controller node (parent) to
> +      gpio-bank node (children).
> +  pins-are-numbered:
> +    description:
> +      Specify the subnodes are using numbered pinmux to
> +      specify pins.
> +  st,syscfg:

Needs to define the type (phandle-array).

> +    description: |
> +      Should be phandle/offset/mask:
> +        - The phandle to the syscon node which includes IRQ mux selection register.
> +        - The offset of the IRQ mux selection register
> +        - The field mask of IRQ mux, needed if different of 0xf.

This can be expressed as a constraint:

items:
  - items:
    - description: The phandle to the syscon node which includes IRQ
mux selection register.
    - description: The offset of the IRQ mux selection register
    - description: The field mask of IRQ mux, needed if different of 0xf.

Perhaps there are some constraints on the values of the cells.

> +
> +  hwlocks:
> +    description: Reference to a phandle of a hardware spinlock provider node.

No need for a description.

> +  st,package:
> +    description:
> +     Indicates the SOC package used.
> +     More details in include/dt-bindings/pinctrl/stm32-pinfunc.h
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +      - enum: [1, 2, 4, 8]
> +
> +patternProperties:
> +  '^gpio@[0-9a-z]*$':

Hex only: a-f

> +    properties:
> +      gpio-controller:
> +        description:
> +          Indicates this device is a GPIO controller.

No need to describe standard properties.

> +      '#gpio-cells':
> +        const: 2
> +        description: |
> +          The first cell is the pin number.
> +          The second one is the polarity
> +          * 0 for active high.
> +          * 1 for active low.

As long as this is the standard cell definition, no need to describe.

> +
> +      reg:
> +        description:
> +          The gpio address range, relative to the pinctrl range.

Need to say how many entries (maxItems), not what reg is.

> +      clocks:
> +        description:
> +          Clock that drives this bank.

ditto.

> +      st,bank-name:

type?

possible values or regex match?

> +        description:
> +          Should be a name string for this bank as specified in the datasheet.
> +      reset:

resets

How many items?

> +        description:
> +          Reference to the reset controller.
> +      gpio-ranges:
> +        description: |
> +          Define a dedicated mapping between a pin-controller and
> +          a gpio controller. Format is <&phandle a b c> with:
> +          -(phandle): phandle of pin-controller.
> +          -(a): gpio base offset in range.
> +          -(b): pin base offset in range.
> +          -(c): gpio count in range.

All common, so not needed here.

> +          This entry has to be used either if there are holes inside a bank:
> +          GPIOB0/B1/B2/B14/B15 (see example 2) or if banks are not contiguous:
> +          GPIOA/B/C/E...
> +          NOTE: If "gpio-ranges" is used for a gpio controller, all gpio-controller
> +          have to use a "gpio-ranges" entry.
> +          More details in Documentation/devicetree/bindings/gpio/gpio.txt.
> +
> +      ngpios:
> +        description:
> +          Number of available gpios in a bank.
> +        minimum: 1
> +        maximum: 16
> +
> +      st,bank-ioport:

type?

> +        description:
> +          Should correspond to the EXTI IOport selection (EXTI line used
> +          to select GPIOs as interrupts).
> +
> +    required:
> +      - gpio-controller
> +      - '#gpio-cells'
> +      - reg
> +      - clocks
> +      - st,bank-name
> +
> +  '-[0-9]*$':
> +    patternProperties:
> +      '^pins':
> +        description: |
> +          A pinctrl node should contain at least one subnode representing the
> +          pinctrl group available on the machine. Each subnode will list the
> +          pins it needs, and how they should be configured, with regard to muxer
> +          configuration, pullups, drive, output high/low and output speed.
> +        properties:
> +          pinmux:
> +            allOf:
> +              - $ref: "/schemas/types.yaml#/definitions/uint32-array"
> +            description: |
> +              Integer array, represents gpio pin number and mux setting.
> +              Supported pin number and mux varies for different SoCs, and are
> +              defined in dt-bindings/pinctrl/<soc>-pinfunc.h directly.
> +              These defines are calculated as: ((port * 16 + line) << 8) | function
> +              With:
> +              - port: The gpio port index (PA = 0, PB = 1, ..., PK = 11)
> +              - line: The line offset within the port (PA0 = 0, PA1 = 1, ..., PA15 = 15)
> +              - function: The function number, can be:
> +              * 0 : GPIO
> +              * 1 : Alternate Function 0
> +              * 2 : Alternate Function 1
> +              * 3 : Alternate Function 2
> +              * ...
> +              * 16 : Alternate Function 15
> +              * 17 : Analog
> +              To simplify the usage, macro is available to generate "pinmux" field.
> +              This macro is available here:
> +                - include/dt-bindings/pinctrl/stm32-pinfunc.h
> +              Some examples of using macro:
> +               /* GPIO A9 set as alernate function 2 */
> +               ... {
> +                          pinmux = <STM32_PINMUX('A', 9, AF2)>;
> +               };
> +               /* GPIO A9 set as GPIO  */
> +               ... {
> +                          pinmux = <STM32_PINMUX('A', 9, GPIO)>;
> +               };
> +               /* GPIO A9 set as analog */
> +               ... {
> +                          pinmux = <STM32_PINMUX('A', 9, ANALOG)>;
> +               };
> +
> +          bias-disable:
> +            type: boolean
> +          bias-pull-down:
> +            type: boolean
> +          bias-pull-up:
> +            type: boolean
> +          drive-push-pull:
> +            type: boolean
> +          drive-open-drain:
> +            type: boolean
> +          output-low:
> +            type: boolean
> +          output-high:
> +            type: boolean
> +          slew-rate:
> +            description: |
> +              0: Low speed
> +              1: Medium speed
> +              2: Fast speed
> +              3: High speed
> +            allOf:
> +              - $ref: /schemas/types.yaml#/definitions/uint32
> +              - enum: [0, 1, 2, 3]
> +
> +        required:
> +          - pinmux
> +
> +required:
> +  - compatible
> +  - '#address-cells'
> +  - '#size-cells'
> +  - ranges
> +  - pins-are-numbered
> +
> +examples:
> +  - |
> +    #include <dt-bindings/pinctrl/stm32-pinfunc.h>
> +    //Example 1
> +      pin-controller@40020000 {

Because we're horribly inconsistent, 'pinctrl' is the standard node name.

> +              #address-cells = <1>;
> +              #size-cells = <1>;
> +              compatible = "st,stm32f429-pinctrl";
> +              ranges = <0 0x40020000 0x3000>;
> +              pins-are-numbered;
> +
> +              gpioa: gpio@0 {
> +                      gpio-controller;
> +                      #gpio-cells = <2>;
> +                      reg = <0x0 0x400>;
> +                      resets = <&reset_ahb1 0>;
> +                      st,bank-name = "GPIOA";
> +              };
> +       };
> +
> +    //Example 2 (using gpio-ranges)
> +      pin-controller@50020000 {
> +              #address-cells = <1>;
> +              #size-cells = <1>;
> +              compatible = "st,stm32f429-pinctrl";
> +              ranges = <0 0x50020000 0x3000>;
> +              pins-are-numbered;
> +
> +              gpiob: gpio@1000 {
> +                      gpio-controller;
> +                      #gpio-cells = <2>;
> +                      reg = <0x1000 0x400>;
> +                      resets = <&reset_ahb1 0>;
> +                      st,bank-name = "GPIOB";
> +                      gpio-ranges = <&pinctrl 0 0 16>;
> +              };
> +
> +              gpioc: gpio@2000 {
> +                      gpio-controller;
> +                      #gpio-cells = <2>;
> +                      reg = <0x2000 0x400>;
> +                      resets = <&reset_ahb1 0>;
> +                      st,bank-name = "GPIOC";
> +                      ngpios = <5>;
> +                      gpio-ranges = <&pinctrl 0 16 3>,
> +                                    <&pinctrl 14 30 2>;
> +              };
> +      };
> +
> +    //Example 3 pin groups
> +      pin-controller@60020000 {
> +        usart1_pins_a: usart1-0 {
> +                pins1 {
> +                        pinmux = <STM32_PINMUX('A', 9, AF7)>;
> +                        bias-disable;
> +                        drive-push-pull;
> +                        slew-rate = <0>;
> +                };
> +                pins2 {
> +                        pinmux = <STM32_PINMUX('A', 10, AF7)>;
> +                        bias-disable;
> +                };
> +        };
> +    };
> +
> +    usart1 {
> +                pinctrl-0 = <&usart1_pins_a>;
> +                pinctrl-names = "default";
> +    };
> +
> +...
> --
> 2.7.4
>