On Thu, 2 Sep 2021 23:51:01 +0200 Miquel Raynal <miquel.raynal@xxxxxxxxxxx> 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@xxxxxxxxxxx> You addressed my comment on v1 in that thread so I'm fine with this. 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>; > + };
