1Device tree bindings for TI's ADS7843, ADS7845, ADS7846, ADS7873, TSC2046 2SPI driven touch screen controllers. 3 4The node for this driver must be a child node of a SPI controller, hence 5all mandatory properties described in 6 7 Documentation/devicetree/bindings/spi/spi-bus.txt 8 9must be specified. 10 11Additional required properties: 12 13 compatible Must be one of the following, depending on the 14 model: 15 "ti,tsc2046" 16 "ti,ads7843" 17 "ti,ads7845" 18 "ti,ads7846" 19 "ti,ads7873" 20 21 interrupt-parent 22 interrupts An interrupt node describing the IRQ line the chip's 23 !PENIRQ pin is connected to. 24 vcc-supply A regulator node for the supply voltage. 25 26 27Optional properties: 28 29 ti,vref-delay-usecs vref supply delay in usecs, 0 for 30 external vref (u16). 31 ti,vref-mv The VREF voltage, in millivolts (u16). 32 Set to 0 to use internal references 33 (ADS7846). 34 ti,keep-vref-on set to keep vref on for differential 35 measurements as well 36 ti,swap-xy swap x and y axis 37 ti,settle-delay-usec Settling time of the analog signals; 38 a function of Vcc and the capacitance 39 on the X/Y drivers. If set to non-zero, 40 two samples are taken with settle_delay 41 us apart, and the second one is used. 42 ~150 uSec with 0.01uF caps (u16). 43 ti,penirq-recheck-delay-usecs If set to non-zero, after samples are 44 taken this delay is applied and penirq 45 is rechecked, to help avoid false 46 events. This value is affected by the 47 material used to build the touch layer 48 (u16). 49 ti,x-plate-ohms Resistance of the X-plate, 50 in Ohms (u16). 51 ti,y-plate-ohms Resistance of the Y-plate, 52 in Ohms (u16). 53 ti,x-min Minimum value on the X axis (u16). 54 ti,y-min Minimum value on the Y axis (u16). 55 ti,x-max Maximum value on the X axis (u16). 56 ti,y-max Minimum value on the Y axis (u16). 57 ti,pressure-min Minimum reported pressure value 58 (threshold) - u16. 59 ti,pressure-max Maximum reported pressure value (u16). 60 ti,debounce-max Max number of additional readings per 61 sample (u16). 62 ti,debounce-tol Tolerance used for filtering (u16). 63 ti,debounce-rep Additional consecutive good readings 64 required after the first two (u16). 65 ti,pendown-gpio-debounce Platform specific debounce time for the 66 pendown-gpio (u32). 67 pendown-gpio GPIO handle describing the pin the !PENIRQ 68 line is connected to. 69 wakeup-source use any event on touchscreen as wakeup event. 70 (Legacy property support: "linux,wakeup") 71 72 73Example for a TSC2046 chip connected to an McSPI controller of an OMAP SoC:: 74 75 spi_controller { 76 tsc2046@0 { 77 reg = <0>; /* CS0 */ 78 compatible = "ti,tsc2046"; 79 interrupt-parent = <&gpio1>; 80 interrupts = <8 0>; /* BOOT6 / GPIO 8 */ 81 spi-max-frequency = <1000000>; 82 pendown-gpio = <&gpio1 8 0>; 83 vcc-supply = <®_vcc3>; 84 85 ti,x-min = /bits/ 16 <0>; 86 ti,x-max = /bits/ 16 <8000>; 87 ti,y-min = /bits/ 16 <0>; 88 ti,y-max = /bits/ 16 <4800>; 89 ti,x-plate-ohms = /bits/ 16 <40>; 90 ti,pressure-max = /bits/ 16 <255>; 91 92 wakeup-source; 93 }; 94 }; 95