1* Analog Devices AD7879(-1)/AD7889(-1) touchscreen interface (SPI/I2C)
2
3Required properties:
4- compatible			: for SPI slave, use "adi,ad7879"
5				  for I2C slave, use "adi,ad7879-1"
6- reg				: SPI chipselect/I2C slave address
7				  See spi-bus.txt for more SPI slave properties
8- interrupt-parent		: the phandle for the interrupt controller
9- interrupts			: touch controller interrupt
10- touchscreen-max-pressure	: maximum reported pressure
11- adi,resistance-plate-x	: total resistance of X-plate (for pressure
12				  calculation)
13Optional properties:
14- touchscreen-swapped-x-y	: X and Y axis are swapped (boolean)
15- adi,first-conversion-delay	: 0-12: In 128us steps (starting with 128us)
16				  13  : 2.560ms
17				  14  : 3.584ms
18				  15  : 4.096ms
19				  This property has to be a '/bits/ 8' value
20- adi,acquisition-time		: 0: 2us
21				  1: 4us
22				  2: 8us
23				  3: 16us
24				  This property has to be a '/bits/ 8' value
25- adi,median-filter-size	: 0: disabled
26				  1: 4 measurements
27				  2: 8 measurements
28				  3: 16 measurements
29				  This property has to be a '/bits/ 8' value
30- adi,averaging			: 0: 2 middle values (1 if median disabled)
31				  1: 4 middle values
32				  2: 8 middle values
33				  3: 16 values
34				  This property has to be a '/bits/ 8' value
35- adi,conversion-interval:	: 0    : convert one time only
36				  1-255: 515us + val * 35us (up to 9.440ms)
37				  This property has to be a '/bits/ 8' value
38- gpio-controller		: Switch AUX/VBAT/GPIO pin to GPIO mode
39
40Example:
41
42	ad7879@2c {
43		compatible = "adi,ad7879-1";
44		reg = <0x2c>;
45		interrupt-parent = <&gpio1>;
46		interrupts = <13 IRQ_TYPE_EDGE_FALLING>;
47		touchscreen-max-pressure = <4096>;
48		adi,resistance-plate-x = <120>;
49		adi,first-conversion-delay = /bits/ 8 <3>;
50		adi,acquisition-time = /bits/ 8 <1>;
51		adi,median-filter-size = /bits/ 8 <2>;
52		adi,averaging = /bits/ 8 <1>;
53		adi,conversion-interval = /bits/ 8 <255>;
54	};
55
56	ad7879@1 {
57		compatible = "adi,ad7879";
58		spi-max-frequency = <5000000>;
59		reg = <1>;
60		spi-cpol;
61		spi-cpha;
62		gpio-controller;
63		interrupt-parent = <&gpio1>;
64		interrupts = <13 IRQ_TYPE_EDGE_FALLING>;
65		touchscreen-max-pressure = <4096>;
66		adi,resistance-plate-x = <120>;
67		adi,first-conversion-delay = /bits/ 8 <3>;
68		adi,acquisition-time = /bits/ 8 <1>;
69		adi,median-filter-size = /bits/ 8 <2>;
70		adi,averaging = /bits/ 8 <1>;
71		adi,conversion-interval = /bits/ 8 <255>;
72	};
73