Re: [PATCH v2] dt-bindings: iio: adc: stm32-adc: convert bindings to json-schema

From: Rob Herring
Date: Tue Dec 17 2019 - 18:43:50 EST


On Fri, Dec 06, 2019 at 05:17:08PM +0100, Fabrice Gasnier wrote:
> Convert the STM32 ADC binding to DT schema format using json-schema
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
> ---
> Note: this applies on top of IIO tree currently (iio-for-5.5c).
>
> Changes in V2:
> - Take almost all of Rob suggestions (removed reg generic description,
> added minItems, maxItems, st,max-clk-rate-hz range, drop some pipes,
> simplify clock-names, remove unneeded allOfs)
> - For now, keep all in one file despite there are lots of if/thens in the
> bindings
> ---
> .../devicetree/bindings/iio/adc/st,stm32-adc.txt | 149 -------
> .../devicetree/bindings/iio/adc/st,stm32-adc.yaml | 454 +++++++++++++++++++++
> 2 files changed, 454 insertions(+), 149 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt
> create mode 100644 Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml


> diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml
> new file mode 100644
> index 00000000..60a0212
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml
> @@ -0,0 +1,454 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/bindings/iio/adc/st,stm32-adc.yaml#";
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#";
> +
> +title: STMicroelectronics STM32 ADC bindings
> +
> +description: |
> + STM32 ADC is a successive approximation analog-to-digital converter.
> + It has several multiplexed input channels. Conversions can be performed
> + in single, continuous, scan or discontinuous mode. Result of the ADC is
> + stored in a left-aligned or right-aligned 32-bit data register.
> + Conversions can be launched in software or using hardware triggers.
> +
> + The analog watchdog feature allows the application to detect if the input
> + voltage goes beyond the user-defined, higher or lower thresholds.
> +
> + Each STM32 ADC block can have up to 3 ADC instances.
> +
> +maintainers:
> + - Fabrice Gasnier <fabrice.gasnier@xxxxxx>
> +
> +properties:
> + compatible:
> + enum:
> + - st,stm32f4-adc-core
> + - st,stm32h7-adc-core
> + - st,stm32mp1-adc-core
> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + description: |
> + One or more interrupts for ADC block, depending on part used:
> + - stm32f4 and stm32h7 share a common ADC interrupt line.
> + - stm32mp1 has two separate interrupt lines, one for each ADC within
> + ADC block.
> + minItems: 1
> + maxItems: 2
> +
> + clocks:
> + description: |
> + Core can use up to two clocks, depending on part used:
> + - "adc" clock: for the analog circuitry, common to all ADCs.
> + It's required on stm32f4.
> + It's optional on stm32h7 and stm32mp1.
> + - "bus" clock: for registers access, common to all ADCs.
> + It's not present on stm32f4.
> + It's required on stm32h7 and stm32mp1.
> +
> + clock-names: true
> +
> + st,max-clk-rate-hz:
> + description:
> + Allow to specify desired max clock rate used by analog circuitry.
> +
> + vdda-supply:
> + description: Phandle to the vdda input analog voltage.
> +
> + vref-supply:
> + description: Phandle to the vref input analog reference voltage.
> +
> + booster-supply:
> + description:
> + Phandle to the embedded booster regulator that can be used to supply ADC
> + analog input switches on stm32h7 and stm32mp1.
> +
> + vdd-supply:
> + description:
> + Phandle to the vdd input voltage. It can be used to supply ADC analog
> + input switches on stm32mp1.
> +
> + st,syscfg:
> + description:
> + Phandle to system configuration controller. It can be used to control the
> + analog circuitry on stm32mp1.
> + allOf:
> + - $ref: "/schemas/types.yaml#/definitions/phandle-array"
> +
> + interrupt-controller: true
> +
> + '#interrupt-cells':
> + const: 1
> +
> + '#address-cells':
> + const: 1
> +
> + '#size-cells':
> + const: 0
> +
> +allOf:
> + - if:
> + properties:
> + compatible:
> + contains:
> + const: st,stm32f4-adc-core
> +
> + then:
> + properties:
> + clocks:
> + maxItems: 1
> +
> + clock-names:
> + const: adc
> +
> + interrupts:
> + items:
> + - description: interrupt line common for all ADCs
> +
> + st,max-clk-rate-hz:
> + minimum: 600000
> + maximum: 36000000
> + default: 36000000
> +
> + booster-supply: false
> +
> + vdd-supply: false
> +
> + st,syscfg: false
> +
> + - if:
> + properties:
> + compatible:
> + contains:
> + const: st,stm32h7-adc-core
> +
> + then:
> + properties:
> + clocks:
> + minItems: 1
> + maxItems: 2
> +
> + clock-names:
> + items:
> + - const: bus
> + - const: adc
> + minItems: 1
> + maxItems: 2
> +
> + interrupts:
> + items:
> + - description: interrupt line common for all ADCs
> +
> + st,max-clk-rate-hz:
> + minimum: 120000
> + maximum: 36000000
> + default: 36000000
> +
> + vdd-supply: false
> +
> + st,syscfg: false
> +
> + - if:
> + properties:
> + compatible:
> + contains:
> + const: st,stm32mp1-adc-core
> +
> + then:
> + properties:
> + clocks:
> + minItems: 1
> + maxItems: 2
> +
> + clock-names:
> + items:
> + - const: bus
> + - const: adc
> + minItems: 1
> + maxItems: 2
> +
> + interrupts:
> + items:
> + - description: interrupt line for ADC1
> + - description: interrupt line for ADC2
> +
> + st,max-clk-rate-hz:
> + minimum: 120000
> + maximum: 36000000
> + default: 36000000
> +
> +additionalProperties: false
> +
> +required:
> + - compatible
> + - reg
> + - interrupts
> + - clocks
> + - clock-names
> + - vdda-supply
> + - vref-supply
> + - interrupt-controller
> + - '#interrupt-cells'
> + - '#address-cells'
> + - '#size-cells'
> +
> +patternProperties:
> + "^adc@[0-9]+$":
> + type: object
> + description:
> + An ADC block node should contain at least one subnode, representing an
> + ADC instance available on the machine.
> +
> + properties:
> + compatible:
> + enum:
> + - st,stm32f4-adc
> + - st,stm32h7-adc
> + - st,stm32mp1-adc
> +
> + reg:
> + description: |
> + Offset of ADC instance in ADC block. Valid values are:
> + - 0x0: ADC1
> + - 0x100: ADC2
> + - 0x200: ADC3 (stm32f4 only)
> + maxItems: 1
> +
> + '#io-channel-cells':
> + const: 1
> +
> + interrupts:
> + description: |
> + IRQ Line for the ADC instance. Valid values are:
> + - 0 for adc@0
> + - 1 for adc@100
> + - 2 for adc@200 (stm32f4 only)
> + maxItems: 1
> +
> + clocks:
> + description:
> + Input clock private to this ADC instance. It's required only on
> + stm32f4, that has per instance clock input for registers access.
> + maxItems: 1
> +
> + dmas:
> + description: RX DMA Channel
> + maxItems: 1
> +
> + dma-names:
> + const: rx
> +
> + assigned-resolution-bits:
> + description: |
> + Resolution (bits) to use for conversions:
> + - can be 6, 8, 10 or 12 on stm32f4
> + - can be 8, 10, 12, 14 or 16 on stm32h7 and stm32mp1
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
> +
> + st,adc-channels:
> + description: |
> + List of single-ended channels muxed for this ADC. It can have up to:
> + - 16 channels, numbered from 0 to 15 (for in0..in15) on stm32f4
> + - 20 channels, numbered from 0 to 19 (for in0..in19) on stm32h7 and
> + stm32mp1.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32-array
> +
> + st,adc-diff-channels:
> + description: |
> + List of differential channels muxed for this ADC. Some channels can
> + be configured as differential instead of single-ended on stm32h7 and
> + on stm32mp1. Positive and negative inputs pairs are listed:
> + <vinp vinn>, <vinp vinn>,... vinp and vinn are numbered from 0 to 19.
> +
> + Note: At least one of "st,adc-channels" or "st,adc-diff-channels" is
> + required. Both properties can be used together. Some channels can be
> + used as single-ended and some other ones as differential (mixed). But
> + channels can't be configured both as single-ended and differential.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32-matrix
> + - items:
> + items:
> + - description: |
> + "vinp" indicates positive input number
> + minimum: 0
> + maximum: 19
> + - description: |
> + "vinn" indicates negative input number
> + minimum: 0
> + maximum: 19
> +
> + st,min-sample-time-nsecs:
> + description:
> + Minimum sampling time in nanoseconds. Depending on hardware (board)
> + e.g. high/low analog input source impedance, fine tune of ADC
> + sampling time may be recommended. This can be either one value or an
> + array that matches "st,adc-channels" and/or "st,adc-diff-channels"
> + list, to set sample time resp. for all channels, or independently for
> + each channel.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32-array
> +
> + allOf:
> + - if:
> + properties:
> + compatible:
> + contains:
> + const: st,stm32f4-adc
> +
> + then:
> + properties:
> + reg:
> + enum:
> + - 0x0
> + - 0x100
> + - 0x200
> +
> + interrupts:
> + minimum: 0
> + maximum: 2
> +
> + assigned-resolution-bits:
> + enum: [6, 8, 10, 12]
> + default: 12
> +
> + st,adc-channels:
> + minItems: 1
> + maxItems: 16
> + minimum: 0
> + maximum: 15

You are mixing array and scalar constraints here. You need:

minItems: 1
maxItems:16
items:
minimum: 0
maximum: 15

Update dtschema. It will now catch this. There's a few others too.


> +
> + st,adc-diff-channels: false
> +
> + st,min-sample-time-nsecs:
> + minItems: 1
> + maxItems: 16
> + minimum: 80
> +
> + required:
> + - clocks
> +
> + - if:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - st,stm32h7-adc
> + - st,stm32mp1-adc
> +
> + then:
> + properties:
> + reg:
> + enum:
> + - 0x0
> + - 0x100
> +
> + interrupts:
> + minimum: 0
> + maximum: 1
> +
> + assigned-resolution-bits:
> + enum: [8, 10, 12, 14, 16]
> + default: 16
> +
> + st,adc-channels:
> + minItems: 1
> + maxItems: 20
> + minimum: 0
> + maximum: 19
> +
> + st,min-sample-time-nsecs:
> + minItems: 1
> + maxItems: 20
> + minimum: 40
> +
> + additionalProperties: false
> +
> + anyOf:
> + - required:
> + - st,adc-channels
> + - required:
> + - st,adc-diff-channels
> +
> + required:
> + - compatible
> + - reg
> + - interrupts
> + - '#io-channel-cells'
> +
> +examples:
> + - |
> + // Example 1: with stm32f429
> + adc123: adc@40012000 {
> + compatible = "st,stm32f4-adc-core";
> + reg = <0x40012000 0x400>;
> + interrupts = <18>;
> + clocks = <&rcc 0 168>;
> + clock-names = "adc";
> + st,max-clk-rate-hz = <36000000>;
> + vdda-supply = <&vdda>;
> + vref-supply = <&vref>;
> + interrupt-controller;
> + #interrupt-cells = <1>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + adc@0 {
> + compatible = "st,stm32f4-adc";
> + #io-channel-cells = <1>;
> + reg = <0x0>;
> + clocks = <&rcc 0 168>;
> + interrupt-parent = <&adc123>;
> + interrupts = <0>;
> + st,adc-channels = <8>;
> + dmas = <&dma2 0 0 0x400 0x0>;
> + dma-names = "rx";
> + assigned-resolution-bits = <8>;
> + };
> + // ...
> + // other adc child nodes follow...
> + };
> +
> + - |
> + // Example 2: with stm32mp157c to setup ADC1 with:
> + // - channel 1 as single-ended
> + // - channels 2 & 3 as differential (with resp. 6 & 7 negative inputs)
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + #include <dt-bindings/clock/stm32mp1-clks.h>
> + adc12: adc@48003000 {
> + compatible = "st,stm32mp1-adc-core";
> + reg = <0x48003000 0x400>;
> + interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 90 IRQ_TYPE_LEVEL_HIGH>;
> + clocks = <&rcc ADC12>, <&rcc ADC12_K>;
> + clock-names = "bus", "adc";
> + booster-supply = <&booster>;
> + vdd-supply = <&vdd>;
> + vdda-supply = <&vdda>;
> + vref-supply = <&vref>;
> + st,syscfg = <&syscfg>;
> + interrupt-controller;
> + #interrupt-cells = <1>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + adc@0 {
> + compatible = "st,stm32mp1-adc";
> + #io-channel-cells = <1>;
> + reg = <0x0>;
> + interrupt-parent = <&adc12>;
> + interrupts = <0>;
> + st,adc-channels = <1>;
> + st,adc-diff-channels = <2 6>, <3 7>;
> + st,min-sample-time-nsecs = <5000>;
> + dmas = <&dmamux1 9 0x400 0x05>;
> + dma-names = "rx";
> + };
> + // ...
> + // other adc child node follow...
> + };
> +
> +...
> --
> 2.7.4
>