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- interrupts : touch controller interrupt 9- touchscreen-max-pressure : maximum reported pressure 10- adi,resistance-plate-x : total resistance of X-plate (for pressure 11 calculation) 12Optional properties: 13- touchscreen-swapped-x-y : X and Y axis are swapped (boolean) 14- adi,first-conversion-delay : 0-12: In 128us steps (starting with 128us) 15 13 : 2.560ms 16 14 : 3.584ms 17 15 : 4.096ms 18 This property has to be a '/bits/ 8' value 19- adi,acquisition-time : 0: 2us 20 1: 4us 21 2: 8us 22 3: 16us 23 This property has to be a '/bits/ 8' value 24- adi,median-filter-size : 0: disabled 25 1: 4 measurements 26 2: 8 measurements 27 3: 16 measurements 28 This property has to be a '/bits/ 8' value 29- adi,averaging : 0: 2 middle values (1 if median disabled) 30 1: 4 middle values 31 2: 8 middle values 32 3: 16 values 33 This property has to be a '/bits/ 8' value 34- adi,conversion-interval: : 0 : convert one time only 35 1-255: 515us + val * 35us (up to 9.440ms) 36 This property has to be a '/bits/ 8' value 37- gpio-controller : Switch AUX/VBAT/GPIO pin to GPIO mode 38 39Example: 40 41 touchscreen0@2c { 42 compatible = "adi,ad7879-1"; 43 reg = <0x2c>; 44 interrupt-parent = <&gpio1>; 45 interrupts = <13 IRQ_TYPE_EDGE_FALLING>; 46 touchscreen-max-pressure = <4096>; 47 adi,resistance-plate-x = <120>; 48 adi,first-conversion-delay = /bits/ 8 <3>; 49 adi,acquisition-time = /bits/ 8 <1>; 50 adi,median-filter-size = /bits/ 8 <2>; 51 adi,averaging = /bits/ 8 <1>; 52 adi,conversion-interval = /bits/ 8 <255>; 53 }; 54 55 touchscreen1@1 { 56 compatible = "adi,ad7879"; 57 spi-max-frequency = <5000000>; 58 reg = <1>; 59 spi-cpol; 60 spi-cpha; 61 gpio-controller; 62 interrupt-parent = <&gpio1>; 63 interrupts = <13 IRQ_TYPE_EDGE_FALLING>; 64 touchscreen-max-pressure = <4096>; 65 adi,resistance-plate-x = <120>; 66 adi,first-conversion-delay = /bits/ 8 <3>; 67 adi,acquisition-time = /bits/ 8 <1>; 68 adi,median-filter-size = /bits/ 8 <2>; 69 adi,averaging = /bits/ 8 <1>; 70 adi,conversion-interval = /bits/ 8 <255>; 71 }; 72