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/adi,ad7879.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: Analog Devices AD7879(-1)/AD7889(-1) touchscreen interface (SPI/I2C)
8
9 maintainers:
10 - Frank Li <Frank.Li@nxp.com>
11
12 properties:
13 compatible:
14 description: |
15 for SPI slave, use "adi,ad7879"
16 for I2C slave, use "adi,ad7879-1"
17 enum:
18 - adi,ad7879
19 - adi,ad7879-1
20
21 reg:
22 maxItems: 1
23
24 interrupts:
25 maxItems: 1
26
27 touchscreen-max-pressure:
28 $ref: /schemas/types.yaml#/definitions/uint32
29 description: maximum reported pressure
30
31 adi,resistance-plate-x:
32 $ref: /schemas/types.yaml#/definitions/uint32
33 description: total resistance of X-plate (for pressure calculation)
34
35 touchscreen-swapped-x-y:
36 $ref: /schemas/types.yaml#/definitions/flag
37 description: X and Y axis are swapped (boolean)
38
39 adi,first-conversion-delay:
40 $ref: /schemas/types.yaml#/definitions/uint8
41 default: 0
42 minimum: 0
43 maximum: 15
44 description: |
45 0-12: In 128us steps (starting with 128us)
46 13 : 2.560ms
47 14 : 3.584ms
48 15 : 4.096ms
49 This property has to be a '/bits/ 8' value
50
51 adi,acquisition-time:
52 $ref: /schemas/types.yaml#/definitions/uint8
53 default: 0
54 enum: [0, 1, 2, 3]
55 description: |
56 0: 2us
57 1: 4us
58 2: 8us
59 3: 16us
60 This property has to be a '/bits/ 8' value
61
62 adi,median-filter-size:
63 $ref: /schemas/types.yaml#/definitions/uint8
64 default: 0
65 enum: [0, 1, 2, 3]
66 description: |
67 0: disabled
68 1: 4 measurements
69 2: 8 measurements
70 3: 16 measurements
71 This property has to be a '/bits/ 8' value
72
73 adi,averaging:
74 $ref: /schemas/types.yaml#/definitions/uint8
75 default: 0
76 enum: [0, 1, 2, 3]
77 description: |
78 0: 2 middle values (1 if median disabled)
79 1: 4 middle values
80 2: 8 middle values
81 3: 16 values
82 This property has to be a '/bits/ 8' value
83
84 adi,conversion-interval:
85 $ref: /schemas/types.yaml#/definitions/uint8
86 default: 0
87 description: |
88 0 : convert one time only
89 1-255: 515us + val * 35us (up to 9.440ms)
90 This property has to be a '/bits/ 8' value
91
92 gpio-controller: true
93
94 "#gpio-cells":
95 const: 1
96
97 required:
98 - compatible
99 - reg
100
101 allOf:
102 - $ref: /schemas/spi/spi-peripheral-props.yaml
103
104 unevaluatedProperties: false
105
106 examples:
107 - |
108 #include <dt-bindings/interrupt-controller/irq.h>
109 i2c {
110 #address-cells = <1>;
111 #size-cells = <0>;
112
113 touchscreen0@2c {
114 compatible = "adi,ad7879-1";
115 reg = <0x2c>;
116 interrupt-parent = <&gpio1>;
117 interrupts = <13 IRQ_TYPE_EDGE_FALLING>;
118 touchscreen-max-pressure = <4096>;
119 adi,resistance-plate-x = <120>;
120 adi,first-conversion-delay = /bits/ 8 <3>;
121 adi,acquisition-time = /bits/ 8 <1>;
122 adi,median-filter-size = /bits/ 8 <2>;
123 adi,averaging = /bits/ 8 <1>;
124 adi,conversion-interval = /bits/ 8 <255>;
125 };
126 };
127
128 - |
129 #include <dt-bindings/interrupt-controller/irq.h>
130 spi {
131 #address-cells = <1>;
132 #size-cells = <0>;
133
134 touchscreen1@1 {
135 compatible = "adi,ad7879";
136 reg = <1>;
137 spi-max-frequency = <5000000>;
138 gpio-controller;
139 #gpio-cells = <1>;
140 interrupt-parent = <&gpio1>;
141 interrupts = <13 IRQ_TYPE_EDGE_FALLING>;
142 touchscreen-max-pressure = <4096>;
143 adi,resistance-plate-x = <120>;
144 adi,first-conversion-delay = /bits/ 8 <3>;
145 adi,acquisition-time = /bits/ 8 <1>;
146 adi,median-filter-size = /bits/ 8 <2>;
147 adi,averaging = /bits/ 8 <1>;
148 adi,conversion-interval = /bits/ 8 <255>;
149 };
150 };
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