Documentation/devicetree/bindings/input/touchscreen/ti,ads7843.yaml

   1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2 %YAML 1.2
   3 ---
   4 $id: http://devicetree.org/schemas/input/touchscreen/ti,ads7843.yaml#
   5 $schema: http://devicetree.org/meta-schemas/core.yaml#
   6
   7 title: TI's SPI driven touch screen controllers
   8
   9 maintainers:
  10   - Alexander Stein <alexander.stein@ew.tq-group.com>
  11   - Dmitry Torokhov <dmitry.torokhov@gmail.com>
  12   - Marek Vasut <marex@denx.de>
  13
  14 description:
  15   TI's ADS7843, ADS7845, ADS7846, ADS7873, TSC2046 SPI driven touch screen
  16   controllers.
  17
  18 properties:
  19   compatible:
  20     enum:
  21       - ti,ads7843
  22       - ti,ads7845
  23       - ti,ads7846
  24       - ti,ads7873
  25       - ti,tsc2046
  26
  27   interrupts:
  28     maxItems: 1
  29
  30   pendown-gpio:
  31     maxItems: 1
  32     description:
  33       GPIO handle describing the pin the !PENIRQ line is connected to.
  34
  35   vcc-supply:
  36     description:
  37       A regulator node for the supply voltage.
  38
  39   wakeup-source: true
  40
  41   ti,debounce-max:
  42     deprecated: true
  43     $ref: /schemas/types.yaml#/definitions/uint16
  44     description:
  45       Max number of additional readings per sample.
  46
  47   ti,debounce-rep:
  48     $ref: /schemas/types.yaml#/definitions/uint16
  49     description:
  50       Additional consecutive good readings required after the first two.
  51
  52   ti,debounce-tol:
  53     $ref: /schemas/types.yaml#/definitions/uint16
  54     description:
  55       Tolerance used for filtering.
  56
  57   ti,hsync-gpios:
  58     maxItems: 1
  59     description:
  60       GPIO line to poll for hsync.
  61
  62   ti,keep-vref-on:
  63     $ref: /schemas/types.yaml#/definitions/flag
  64     description:
  65       Set to keep Vref on for differential measurements as well.
  66
  67   ti,pendown-gpio-debounce:
  68     $ref: /schemas/types.yaml#/definitions/uint32
  69     description:
  70       Platform specific debounce time for the pendown-gpio.
  71
  72   ti,penirq-recheck-delay-usecs:
  73     $ref: /schemas/types.yaml#/definitions/uint16
  74     description:
  75       If set to non-zero, after samples are taken this delay is applied and
  76       penirq is rechecked, to help avoid false events.  This value is
  77       affected by the material used to build the touch layer.
  78
  79   ti,pressure-max:
  80     deprecated: true
  81     $ref: /schemas/types.yaml#/definitions/uint16
  82     description:
  83       Maximum reported pressure value.
  84
  85   ti,pressure-min:
  86     deprecated: true
  87     $ref: /schemas/types.yaml#/definitions/uint16
  88     description:
  89       Minimum reported pressure value (threshold).
  90
  91   ti,settle-delay-usec:
  92     $ref: /schemas/types.yaml#/definitions/uint16
  93     description:
  94       Settling time of the analog signals; a function of Vcc and the
  95       capacitance on the X/Y drivers.  If set to non-zero, two samples are
  96       taken with settle_delay us apart, and the second one is used. ~150
  97       uSec with 0.01uF caps.
  98
  99   ti,swap-xy:
 100     deprecated: true
 101     $ref: /schemas/types.yaml#/definitions/flag
 102     description:
 103       Swap x and y axis.
 104
 105   ti,vref-delay-usecs:
 106     $ref: /schemas/types.yaml#/definitions/uint16
 107     description:
 108       Vref supply delay in usecs, 0 for external Vref.
 109
 110   ti,vref-mv:
 111     $ref: /schemas/types.yaml#/definitions/uint16
 112     description:
 113       The VREF voltage, in millivolts.
 114       Set to 0 to use internal references (ADS7846).
 115
 116   ti,x-plate-ohms:
 117     $ref: /schemas/types.yaml#/definitions/uint16
 118     description:
 119       Resistance of the X-plate, in Ohms.
 120
 121   ti,x-max:
 122     deprecated: true
 123     $ref: /schemas/types.yaml#/definitions/uint16
 124     description:
 125       Maximum value on the X axis.
 126
 127   ti,x-min:
 128     deprecated: true
 129     $ref: /schemas/types.yaml#/definitions/uint16
 130     description:
 131       Minimum value on the X axis.
 132
 133   ti,y-plate-ohms:
 134     $ref: /schemas/types.yaml#/definitions/uint16
 135     description:
 136       Resistance of the Y-plate, in Ohms.
 137
 138   ti,y-max:
 139     deprecated: true
 140     $ref: /schemas/types.yaml#/definitions/uint16
 141     description:
 142       Maximum value on the Y axis.
 143
 144   ti,y-min:
 145     deprecated: true
 146     $ref: /schemas/types.yaml#/definitions/uint16
 147     description:
 148       Minimum value on the Y axis.
 149
 150 required:
 151   - compatible
 152   - reg
 153
 154 allOf:
 155   - $ref: touchscreen.yaml#
 156   - $ref: /schemas/spi/spi-peripheral-props.yaml#
 157
 158 unevaluatedProperties: false
 159
 160 examples:
 161   - |
 162     spi{
 163         #address-cells = <1>;
 164         #size-cells = <0>;
 165
 166         touchscreen@0 {
 167            compatible = "ti,tsc2046";
 168            reg = <0>;   /* CS0 */
 169            interrupt-parent = <&gpio1>;
 170            interrupts = <8 0>;  /* BOOT6 / GPIO 8 */
 171            pendown-gpio = <&gpio1 8 0>;
 172            spi-max-frequency = <1000000>;
 173            vcc-supply = <&reg_vcc3>;
 174            wakeup-source;
 175
 176            ti,pressure-max = /bits/ 16 <255>;
 177            ti,x-max = /bits/ 16 <8000>;
 178            ti,x-min = /bits/ 16 <0>;
 179            ti,x-plate-ohms = /bits/ 16 <40>;
 180            ti,y-max = /bits/ 16 <4800>;
 181            ti,y-min = /bits/ 16 <0>;
 182        };
 183     };