Re: [PATCH 1/4] dt-bindings: gpio: Replace DW APB GPIO legacy bindings with YAML-based one

From: Rob Herring
Date: Thu Mar 12 2020 - 09:48:12 EST


On Fri, Mar 6, 2020 at 7:25 AM <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> wrote:
>

Subject is kind of long and wordy. Perhaps:

dt-bindings: gpio: Convert snps,dw-apb-gpio to DT schema

> From: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
>
> Modern device tree bindings are supposed to be created as YAML-files
> in accordance with dt-schema. This commit replaces Synopsys DW GPIO
> legacy bare text bindings with YAML file. As before the bindings file
> states that the corresponding dts node is supposed to be compatible
> with generic DW I2C controller indicated by the "snps,dw-apb-gpio"
> compatible string and provide a mandatory registers memory range.
> It may also have an optional clocks and resets phandle references.
>
> There must be specified at least one subnode with
> "snps,dw-apb-gpio-port" compatible string indicating the GPIO port,
> which would actually export the GPIO controller functionality. Such
> nodes should have traditional GPIO controller properties together
> with optional interrupt-controller attributes if the corresponding
> controller was synthesized to detected and report the input values
> change to the parental IRQ controller.
>
> Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Alexey Malahov <Alexey.Malahov@xxxxxxxxxxxxxxxxxxxx>
> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> Cc: Paul Burton <paulburton@xxxxxxxxxx>
> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
>
> ---
>
> Synopsis DesignWare APB SSI controller has a bindings property
> "snps,nr-gpios" of numeric type, which means the number of GPIO pins
> exported by the corresponding controller port. There is also a generic
> pattern-property "*-gpios", which corresponds to a GPIOs array. As you
> can see the GPIOs array property wildcard matches the vendor-specific
> property "snps,nr-gpios" property while having an incompatible type.
> Due to this the DW APB GPIO dts-nodes evaluation will report the
> following error:
>
> snps,nr-gpios:0:0: 8 is not valid under any of the given schemas (Possible causes of the failure):
> snps,nr-gpios:0:0: missing phandle tag in 8
>
> I didn't manage to fix the problem by redefining the property schema (this
> might be impossible anyway). In my opinion the best way to solve it would be
> to change the DW APB SSI Controller bindings so the driver would accept the
> standard "ngpios" property for the same purpose. But in this case we would have
> to alter all the dts files currently having the "snps,dw-apb-ssi" compatible
> nodes (it's a lot). I know the bindings modifications aren't that much welcome
> in the kernel community and there are good reasons why. So what do you think
> would be the better way to fix the problem with the property types collision?

Does this change (to dt-schema) work for you?

diff --git a/schemas/gpio/gpio.yaml b/schemas/gpio/gpio.yaml
index 1d9c109f9791..d1c08ccfdc1a 100644
--- a/schemas/gpio/gpio.yaml
+++ b/schemas/gpio/gpio.yaml
@@ -34,7 +34,7 @@ properties:
- $ref: "/schemas/types.yaml#/definitions/phandle-array"

patternProperties:
- ".*-gpios?$":
+ "(?<!,nr)-gpios?$":
$ref: "/schemas/types.yaml#/definitions/phandle-array"
"^gpios$":
$ref: "/schemas/types.yaml#/definitions/phandle-array"


> ---
> .../bindings/gpio/snps,dw-apb-gpio.yaml | 136 ++++++++++++++++++
> .../bindings/gpio/snps-dwapb-gpio.txt | 65 ---------
> 2 files changed, 136 insertions(+), 65 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/gpio/snps,dw-apb-gpio.yaml
> delete mode 100644 Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt
>
> diff --git a/Documentation/devicetree/bindings/gpio/snps,dw-apb-gpio.yaml b/Documentation/devicetree/bindings/gpio/snps,dw-apb-gpio.yaml
> new file mode 100644
> index 000000000000..d9bc12e9e515
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/snps,dw-apb-gpio.yaml
> @@ -0,0 +1,136 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)

Do you have rights to add BSD?

> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/gpio/snps,dw-apb-gpio.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Synopsys DesignWare APB GPIO controller
> +
> +description: |
> + Synopsys DesignWare GPIO controllers have a configurable number of ports,
> + each of which are intended to be represented as child nodes with the generic
> + GPIO-controller properties as desribed in this bindings file.
> +
> +maintainers:
> + - Hoan Tran <hoan@xxxxxxxxxxxxxxxxxxxxxx>
> +
> +properties:
> + $nodename:
> + pattern: "^gpio@[0-9a-fA-F]+$"

Lowercase hex for unit-addresses.

> +
> + compatible:
> + const: snps,dw-apb-gpio
> +
> + "#address-cells":
> + const: 1
> +
> + "#size-cells":
> + const: 0
> +
> + reg:
> + maxItems: 1
> +
> + clocks:
> + items:
> + - description: APB interface clock source
> +
> + clock-names:
> + items:
> + - const: bus
> +
> + resets:
> + maxItems: 1
> +
> +patternProperties:
> + "^.*@[0-9a-fA-F]+$":

Shouldn't it be "^gpio@..." And unit-addresses should be lowercase.

> + type: object
> + properties:
> + compatible:
> + const: snps,dw-apb-gpio-port
> +
> + reg:
> + maxItems: 1
> +
> + gpio-controller: true
> +
> + '#gpio-cells':
> + const: 2
> +
> + snps,nr-gpios:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: The number of GPIO pins exported by the port.
> + default: 32
> + minimum: 1
> + maximum: 32
> +
> + interrupts:
> + description: |
> + The interrupts to the parent controller raised when GPIOs generate
> + the interrupts. If the controller provides one combined interrupt
> + for all GPIOs, specify a single interrupt. If the controller provides
> + one interrupt for each GPIO, provide a list of interrupts that
> + correspond to each of the GPIO pins.
> + minItems: 1
> + maxItems: 32
> +
> + interrupts-extended:

Drop this. It gets added by the tools automatically.

> + description: |
> + When specifying multiple interrupts, if any are unconnected, use
> + this property to specify the interrupts and set the interrupt
> + controller handle for unused interrupts to 0.
> + minItems: 1
> + maxItems: 32
> +
> + interrupt-controller: true
> +
> + '#interrupt-cells':
> + const: 2
> +
> + required:
> + - compatible
> + - reg
> + - gpio-controller
> + - '#gpio-cells'
> +
> + dependencies:
> + interrupt-controller: [ interrupts ]
> +
> + additionalProperties: false
> +
> +additionalProperties: false
> +
> +required:
> + - compatible
> + - reg
> + - "#address-cells"
> + - "#size-cells"
> +
> +examples:
> + - |
> + gpio: gpio@20000 {
> + compatible = "snps,dw-apb-gpio";
> + reg = <0x20000 0x1000>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + porta: gpio@0 {
> + compatible = "snps,dw-apb-gpio-port";
> + reg = <0>;
> + gpio-controller;
> + #gpio-cells = <2>;
> + snps,nr-gpios = <8>;
> + interrupt-controller;
> + #interrupt-cells = <2>;
> + interrupt-parent = <&vic1>;
> + interrupts = <0>;
> + };
> +
> + portb: gpio@1 {
> + compatible = "snps,dw-apb-gpio-port";
> + reg = <1>;
> + gpio-controller;
> + #gpio-cells = <2>;
> + snps,nr-gpios = <8>;
> + };
> + };
> +...