Convert the Freescale MXS Low-Resoulution ADC (LRADC) device tree
binding documentation to json-schema.
The clocks and #io-channel-cells properties have also been added; They
are present in the respective SoC DTSI files but were missing from the
old mxs-lradc.txt file.
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
---
Changes in v3:
- Add Reviewed-by tag of Conor Dooley
.../devicetree/bindings/mfd/mxs-lradc.txt | 45 --------
.../devicetree/bindings/mfd/mxs-lradc.yaml | 106 ++++++++++++++++++
2 files changed, 106 insertions(+), 45 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/mfd/mxs-lradc.txt
create mode 100644 Documentation/devicetree/bindings/mfd/mxs-lradc.yaml
diff --git a/Documentation/devicetree/bindings/mfd/mxs-lradc.txt b/Documentation/devicetree/bindings/mfd/mxs-lradc.txt
deleted file mode 100644
index 755cbef0647d..000000000000
--- a/Documentation/devicetree/bindings/mfd/mxs-lradc.txt
+++ /dev/null
@@ -1,45 +0,0 @@
-* Freescale MXS LRADC device driver
-
-Required properties:
-- compatible: Should be "fsl,imx23-lradc" for i.MX23 SoC and "fsl,imx28-lradc"
- for i.MX28 SoC
-- reg: Address and length of the register set for the device
-- interrupts: Should contain the LRADC interrupts
-
-Optional properties:
-- fsl,lradc-touchscreen-wires: Number of wires used to connect the touchscreen
- to LRADC. Valid value is either 4 or 5. If this
- property is not present, then the touchscreen is
- disabled. 5 wires is valid for i.MX28 SoC only.
-- fsl,ave-ctrl: number of samples per direction to calculate an average value.
- Allowed value is 1 ... 32, default is 4
-- fsl,ave-delay: delay between consecutive samples. Allowed value is
- 2 ... 2048. It is used if 'fsl,ave-ctrl' > 1, counts at
- 2 kHz and its default is 2 (= 1 ms)
-- fsl,settling: delay between plate switch to next sample. Allowed value is
- 1 ... 2047. It counts at 2 kHz and its default is
- 10 (= 5 ms)
-
-Example for i.MX23 SoC:
-
- lradc@80050000 {
- compatible = "fsl,imx23-lradc";
- reg = <0x80050000 0x2000>;
- interrupts = <36 37 38 39 40 41 42 43 44>;
- fsl,lradc-touchscreen-wires = <4>;
- fsl,ave-ctrl = <4>;
- fsl,ave-delay = <2>;
- fsl,settling = <10>;
- };
-
-Example for i.MX28 SoC:
-
- lradc@80050000 {
- compatible = "fsl,imx28-lradc";
- reg = <0x80050000 0x2000>;
- interrupts = <10 14 15 16 17 18 19 20 21 22 23 24 25>;
- fsl,lradc-touchscreen-wires = <5>;
- fsl,ave-ctrl = <4>;
- fsl,ave-delay = <2>;
- fsl,settling = <10>;
- };
diff --git a/Documentation/devicetree/bindings/mfd/mxs-lradc.yaml b/Documentation/devicetree/bindings/mfd/mxs-lradc.yaml
new file mode 100644
index 000000000000..90391b02c715
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/mxs-lradc.yaml
@@ -0,0 +1,106 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/mxs-lradc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale MXS Low-Resoulution ADC (LRADC)
+
+maintainers:
+ - Dario Binacchi <dario.binacchi@amarulasolutions.com>
+
+description: |
+ The LRADC provides 16 physical channels of 12-bit resolution
+ for analog-to-digital conversion and includes an integrated
+ 4-wire/5-wire touchscreen controller.
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - fsl,imx23-lradc
+ - fsl,imx28-lradc
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ minItems: 1
+
+ interrupts:
+ minItems: 9
+ maxItems: 13
+
+ fsl,lradc-touchscreen-wires:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Number of wires used to connect the touchscreen to LRADC.
+ If this property is not present, then the touchscreen is disabled.
+
+ fsl,ave-ctrl:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 1
+ maximum: 32
+ default: 4
+ description: |
+ Number of samples per direction to calculate an average value.
+
+ fsl,ave-delay:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 2
+ maximum: 2048
+ default: 2
+ description: |
+ Delay between consecutive samples.
+ It is used if 'fsl,ave-ctrl' > 1, counts at 2 kHz and its
+ default value (i. e. 2) is 1 ms.
+
+ fsl,settling:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 1
+ maximum: 2047
+ default: 10
+ description: |
+ Delay between plate switch to next sample.
+ It counts at 2 kHz and its default (i. e. 10) is 5 ms.
+
+ "#io-channel-cells":
+ const: 1
+
+required:
+ - compatible
+ - reg
+ - clocks
+ - interrupts
+
+if:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - fsl,imx23-lradc
+then:
+ properties:
+ fsl,lradc-touchscreen-wires:
+ const: 4
+else:
+ properties:
+ fsl,lradc-touchscreen-wires:
+ enum: [4, 5]
+
+additionalProperties: false
+
+examples:
+ - |
+ lradc@80050000 {
+ compatible = "fsl,imx23-lradc";
+ reg = <0x80050000 0x2000>;
+ interrupts = <36>, <37>, <38>, <39>, <40>,
+ <41>, <42>, <43>, <44>;
+ clocks = <&clks 26>;
+ #io-channel-cells = <1>;
+ fsl,lradc-touchscreen-wires = <4>;
+ fsl,ave-ctrl = <4>;
+ fsl,ave-delay = <2>;
+ fsl,settling = <10>;
+ };
--
2.43.0On Thu, May 29, 2025 at 10:31:04AM +0200, Dario Binacchi wrote:
> Convert the Freescale MXS Low-Resoulution ADC (LRADC) device tree
> binding documentation to json-schema.
>
> The clocks and #io-channel-cells properties have also been added; They
> are present in the respective SoC DTSI files but were missing from the
> old mxs-lradc.txt file.
>
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
>
> ---
>
> Changes in v3:
> - Add Reviewed-by tag of Conor Dooley
>
> .../devicetree/bindings/mfd/mxs-lradc.txt | 45 --------
> .../devicetree/bindings/mfd/mxs-lradc.yaml | 106 ++++++++++++++++++
> 2 files changed, 106 insertions(+), 45 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/mfd/mxs-lradc.txt
> create mode 100644 Documentation/devicetree/bindings/mfd/mxs-lradc.yaml
>
> diff --git a/Documentation/devicetree/bindings/mfd/mxs-lradc.txt b/Documentation/devicetree/bindings/mfd/mxs-lradc.txt
> deleted file mode 100644
> index 755cbef0647d..000000000000
> --- a/Documentation/devicetree/bindings/mfd/mxs-lradc.txt
> +++ /dev/null
> @@ -1,45 +0,0 @@
> -* Freescale MXS LRADC device driver
> -
> -Required properties:
> -- compatible: Should be "fsl,imx23-lradc" for i.MX23 SoC and "fsl,imx28-lradc"
> - for i.MX28 SoC
> -- reg: Address and length of the register set for the device
> -- interrupts: Should contain the LRADC interrupts
> -
> -Optional properties:
> -- fsl,lradc-touchscreen-wires: Number of wires used to connect the touchscreen
> - to LRADC. Valid value is either 4 or 5. If this
> - property is not present, then the touchscreen is
> - disabled. 5 wires is valid for i.MX28 SoC only.
> -- fsl,ave-ctrl: number of samples per direction to calculate an average value.
> - Allowed value is 1 ... 32, default is 4
> -- fsl,ave-delay: delay between consecutive samples. Allowed value is
> - 2 ... 2048. It is used if 'fsl,ave-ctrl' > 1, counts at
> - 2 kHz and its default is 2 (= 1 ms)
> -- fsl,settling: delay between plate switch to next sample. Allowed value is
> - 1 ... 2047. It counts at 2 kHz and its default is
> - 10 (= 5 ms)
> -
> -Example for i.MX23 SoC:
> -
> - lradc@80050000 {
> - compatible = "fsl,imx23-lradc";
> - reg = <0x80050000 0x2000>;
> - interrupts = <36 37 38 39 40 41 42 43 44>;
> - fsl,lradc-touchscreen-wires = <4>;
> - fsl,ave-ctrl = <4>;
> - fsl,ave-delay = <2>;
> - fsl,settling = <10>;
> - };
> -
> -Example for i.MX28 SoC:
> -
> - lradc@80050000 {
> - compatible = "fsl,imx28-lradc";
> - reg = <0x80050000 0x2000>;
> - interrupts = <10 14 15 16 17 18 19 20 21 22 23 24 25>;
> - fsl,lradc-touchscreen-wires = <5>;
> - fsl,ave-ctrl = <4>;
> - fsl,ave-delay = <2>;
> - fsl,settling = <10>;
> - };
> diff --git a/Documentation/devicetree/bindings/mfd/mxs-lradc.yaml b/Documentation/devicetree/bindings/mfd/mxs-lradc.yaml
> new file mode 100644
> index 000000000000..90391b02c715
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/mxs-lradc.yaml
> @@ -0,0 +1,106 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mfd/mxs-lradc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Freescale MXS Low-Resoulution ADC (LRADC)
> +
> +maintainers:
> + - Dario Binacchi <dario.binacchi@amarulasolutions.com>
> +
> +description: |
Don't need '|' unless there is formatting to preserve.
> + The LRADC provides 16 physical channels of 12-bit resolution
> + for analog-to-digital conversion and includes an integrated
> + 4-wire/5-wire touchscreen controller.
Wrap lines at 80 char.
> +
> +properties:
> + compatible:
> + items:
> + - enum:
> + - fsl,imx23-lradc
> + - fsl,imx28-lradc
> +
> + reg:
> + maxItems: 1
> +
> + clocks:
> + minItems: 1
> +
> + interrupts:
> + minItems: 9
> + maxItems: 13
Please describe what each interrupt is. Unless they are all the same
(e.g. 1 interrupt per ADC channel), you need to list them out.
> +
> + fsl,lradc-touchscreen-wires:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: |
> + Number of wires used to connect the touchscreen to LRADC.
> + If this property is not present, then the touchscreen is disabled.
Don't need '|'. Unless this is supposed to be 2 paragraphs. In that
case, add a blank line between paragraphs. Same comment on the rest.
> +
> + fsl,ave-ctrl:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 1
> + maximum: 32
> + default: 4
> + description: |
> + Number of samples per direction to calculate an average value.
> +
> + fsl,ave-delay:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 2
> + maximum: 2048
> + default: 2
> + description: |
> + Delay between consecutive samples.
> + It is used if 'fsl,ave-ctrl' > 1, counts at 2 kHz and its
> + default value (i. e. 2) is 1 ms.
> +
> + fsl,settling:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 1
> + maximum: 2047
> + default: 10
> + description: |
> + Delay between plate switch to next sample.
> + It counts at 2 kHz and its default (i. e. 10) is 5 ms.
> +
> + "#io-channel-cells":
> + const: 1
> +
> +required:
> + - compatible
> + - reg
> + - clocks
> + - interrupts
> +
> +if:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - fsl,imx23-lradc
> +then:
> + properties:
> + fsl,lradc-touchscreen-wires:
> + const: 4
> +else:
> + properties:
> + fsl,lradc-touchscreen-wires:
> + enum: [4, 5]
Move this constraint to the top level and drop the 'else'.
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + lradc@80050000 {
> + compatible = "fsl,imx23-lradc";
> + reg = <0x80050000 0x2000>;
> + interrupts = <36>, <37>, <38>, <39>, <40>,
> + <41>, <42>, <43>, <44>;
> + clocks = <&clks 26>;
> + #io-channel-cells = <1>;
> + fsl,lradc-touchscreen-wires = <4>;
> + fsl,ave-ctrl = <4>;
> + fsl,ave-delay = <2>;
> + fsl,settling = <10>;
> + };
> --
> 2.43.0
>
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