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@xxxxxxxxxxx> Reviewed-by: Rob Herring <robh@xxxxxxxxxx> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> --- .../input/touchscreen/ti,am3359-tsc.yaml | 76 +++++++++++++++++++ 1 file changed, 76 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..e44cc65abc8c --- /dev/null +++ b/Documentation/devicetree/bindings/input/touchscreen/ti,am3359-tsc.yaml @@ -0,0 +1,76 @@ +# 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@xxxxxxxxxxx> + +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 until 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: + - | + 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
