| * Analog Devices AD7879(-1)/AD7889(-1) touchscreen interface (SPI/I2C) | |
| Required properties: | |
| - compatible : for SPI slave, use "adi,ad7879" | |
| for I2C slave, use "adi,ad7879-1" | |
| - reg : SPI chipselect/I2C slave address | |
| See spi-bus.txt for more SPI slave properties | |
| - interrupt-parent : the phandle for the interrupt controller | |
| - interrupts : touch controller interrupt | |
| - touchscreen-max-pressure : maximum reported pressure | |
| - adi,resistance-plate-x : total resistance of X-plate (for pressure | |
| calculation) | |
| Optional properties: | |
| - touchscreen-swapped-x-y : X and Y axis are swapped (boolean) | |
| - adi,first-conversion-delay : 0-12: In 128us steps (starting with 128us) | |
| 13 : 2.560ms | |
| 14 : 3.584ms | |
| 15 : 4.096ms | |
| This property has to be a '/bits/ 8' value | |
| - adi,acquisition-time : 0: 2us | |
| 1: 4us | |
| 2: 8us | |
| 3: 16us | |
| This property has to be a '/bits/ 8' value | |
| - adi,median-filter-size : 0: disabled | |
| 1: 4 measurements | |
| 2: 8 measurements | |
| 3: 16 measurements | |
| This property has to be a '/bits/ 8' value | |
| - adi,averaging : 0: 2 middle values (1 if median disabled) | |
| 1: 4 middle values | |
| 2: 8 middle values | |
| 3: 16 values | |
| This property has to be a '/bits/ 8' value | |
| - adi,conversion-interval: : 0 : convert one time only | |
| 1-255: 515us + val * 35us (up to 9.440ms) | |
| This property has to be a '/bits/ 8' value | |
| - gpio-controller : Switch AUX/VBAT/GPIO pin to GPIO mode | |
| Example: | |
| ad7879@2c { | |
| compatible = "adi,ad7879-1"; | |
| reg = <0x2c>; | |
| interrupt-parent = <&gpio1>; | |
| interrupts = <13 IRQ_TYPE_EDGE_FALLING>; | |
| touchscreen-max-pressure = <4096>; | |
| adi,resistance-plate-x = <120>; | |
| adi,first-conversion-delay = /bits/ 8 <3>; | |
| adi,acquisition-time = /bits/ 8 <1>; | |
| adi,median-filter-size = /bits/ 8 <2>; | |
| adi,averaging = /bits/ 8 <1>; | |
| adi,conversion-interval = /bits/ 8 <255>; | |
| }; | |
| ad7879@1 { | |
| compatible = "adi,ad7879"; | |
| spi-max-frequency = <5000000>; | |
| reg = <1>; | |
| spi-cpol; | |
| spi-cpha; | |
| gpio-controller; | |
| interrupt-parent = <&gpio1>; | |
| interrupts = <13 IRQ_TYPE_EDGE_FALLING>; | |
| touchscreen-max-pressure = <4096>; | |
| adi,resistance-plate-x = <120>; | |
| adi,first-conversion-delay = /bits/ 8 <3>; | |
| adi,acquisition-time = /bits/ 8 <1>; | |
| adi,median-filter-size = /bits/ 8 <2>; | |
| adi,averaging = /bits/ 8 <1>; | |
| adi,conversion-interval = /bits/ 8 <255>; | |
| }; |