Re: [PATCH 03/40] dt-bindings: touchscreen: ti,am3359-tsc: New yaml description

Rob Herring
2021-08-31T19:37:23Z

On Wed, Aug 25, 2021 at 05:24:41PM +0200, Miquel Raynal wrote:
> This touchscreen controller is already described in a text file:
> Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
>
> After introducing a proper description of the MFD, this is the second
> step. The file cannot be removed yet as it also contains an ADC
> description.
>
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
> .../input/touchscreen/ti,am3359-tsc.yaml | 89 +++++++++++++++++++
> 1 file changed, 89 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/input/touchscreen/ti,am3359-tsc.yaml
>
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/ti,am3359-tsc.yaml b/Documentation/devicetree/bindings/input/touchscreen/ti,am3359-tsc.yaml
> new file mode 100644
> index 000000000000..2d4ce6d04f53
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/ti,am3359-tsc.yaml
> @@ -0,0 +1,89 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/input/touchscreen/ti,am3359-tsc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: TI AM3359 Touchscreen controller
> +
> +maintainers:
> + - Miquel Raynal <miquel.raynal@bootlin.com>
> +
> +properties:
> + compatible:
> + const: ti,am3359-tsc
> +
> + ti,wires:
> + description: Wires refer to application modes i.e. 4/5/8 wire touchscreen
> + support on the platform.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [4, 5, 8]
> +
> + ti,x-plate-resistance:
> + description: X plate resistance
> + $ref: /schemas/types.yaml#/definitions/uint32
> +
> + ti,coordinate-readouts:
> + description: The sequencer supports a total of 16 programmable steps. Each
> + step is used to read a single coordinate. A single readout is enough but
> + multiple reads can increase the quality. A value of 5 means, 5 reads for
> + X, 5 for Y and 2 for Z (always). This utilises 12 of the 16 software steps
> + available. The remaining 4 can be used by the ADC.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 1
> + maximum: 6
> +
> + ti,wire-config:
> + description: Different boards could have a different order for connecting
> + wires on touchscreen. We need to provide an 8-bit number where the
> + first four bits represent the analog lines and the next 4 bits represent
> + positive/negative terminal on that input line. Notations to represent the
> + input lines and terminals respectively are as follows, AIN0 = 0, AIN1 = 1
> + and so on untill AIN7 = 7. XP = 0, XN = 1, YP = 2, YN = 3.
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + minItems: 4
> + maxItems: 8
> +
> + ti,charge-delay:
> + description: Length of touch screen charge delay step in terms of ADC clock
> + cycles. Charge delay value should be large in order to avoid false pen-up
> + events. This value effects the overall sampling speed, hence need to be
> + kept as low as possible, while avoiding false pen-up event. Start from a
> + lower value, say 0x400, and increase value until false pen-up events are
> + avoided. The pen-up detection happens immediately after the charge step,
> + so this does in fact function as a hardware knob for adjusting the amount
> + of "settling time".
> + $ref: /schemas/types.yaml#/definitions/uint32
> +
> +required:
> + - compatible
> + - ti,wires
> + - ti,x-plate-resistance
> + - ti,coordinate-readouts
> + - ti,wire-config
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/arm-gic.h>

I prefer that MFDs have just 1 complete example in the MFD schema.

> +
> + tscadc: tscadc@0 {

Drop unused labels.

> + compatible = "ti,am3359-tscadc";
> + reg = <0x0 0x1000>;
> + interrupts = <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>;
> + clocks = <&adc_tsc_fck>;
> + clock-names = "fck";
> + status = "disabled";

status, again.

> + dmas = <&edma 53 0>, <&edma 57 0>;
> + dma-names = "fifo0", "fifo1";
> +
> + tsc {
> + compatible = "ti,am3359-tsc";
> + ti,wires = <4>;
> + ti,x-plate-resistance = <200>;
> + ti,coordinate-readouts = <5>;
> + ti,wire-config = <0x00 0x11 0x22 0x33>;
> + ti,charge-delay = <0x400>;
> + };
> + };
> --
> 2.27.0
>
>