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 interrupts An interrupt node describing the IRQ line the chip's 22 !PENIRQ pin is connected to. 23 vcc-supply A regulator node for the supply voltage. 24 25 26Optional properties: 27 28 ti,vref-delay-usecs vref supply delay in usecs, 0 for 29 external vref (u16). 30 ti,vref-mv The VREF voltage, in millivolts (u16). 31 Set to 0 to use internal references 32 (ADS7846). 33 ti,keep-vref-on set to keep vref on for differential 34 measurements as well 35 ti,settle-delay-usec Settling time of the analog signals; 36 a function of Vcc and the capacitance 37 on the X/Y drivers. If set to non-zero, 38 two samples are taken with settle_delay 39 us apart, and the second one is used. 40 ~150 uSec with 0.01uF caps (u16). 41 ti,penirq-recheck-delay-usecs If set to non-zero, after samples are 42 taken this delay is applied and penirq 43 is rechecked, to help avoid false 44 events. This value is affected by the 45 material used to build the touch layer 46 (u16). 47 ti,x-plate-ohms Resistance of the X-plate, 48 in Ohms (u16). 49 ti,y-plate-ohms Resistance of the Y-plate, 50 in Ohms (u16). 51 ti,x-min Minimum value on the X axis (u16). 52 ti,y-min Minimum value on the Y axis (u16). 53 ti,debounce-tol Tolerance used for filtering (u16). 54 ti,debounce-rep Additional consecutive good readings 55 required after the first two (u16). 56 ti,pendown-gpio-debounce Platform specific debounce time for the 57 pendown-gpio (u32). 58 pendown-gpio GPIO handle describing the pin the !PENIRQ 59 line is connected to. 60 ti,hsync-gpios GPIO line to poll for hsync 61 wakeup-source use any event on touchscreen as wakeup event. 62 (Legacy property support: "linux,wakeup") 63 touchscreen-size-x General touchscreen binding, see [1]. 64 touchscreen-size-y General touchscreen binding, see [1]. 65 touchscreen-max-pressure General touchscreen binding, see [1]. 66 touchscreen-min-pressure General touchscreen binding, see [1]. 67 touchscreen-average-samples General touchscreen binding, see [1]. 68 touchscreen-inverted-x General touchscreen binding, see [1]. 69 touchscreen-inverted-y General touchscreen binding, see [1]. 70 touchscreen-swapped-x-y General touchscreen binding, see [1]. 71 72[1] All general touchscreen properties are described in 73 Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt. 74 75Deprecated properties: 76 77 ti,swap-xy swap x and y axis 78 ti,x-max Maximum value on the X axis (u16). 79 ti,y-max Maximum value on the Y axis (u16). 80 ti,pressure-min Minimum reported pressure value 81 (threshold) - u16. 82 ti,pressure-max Maximum reported pressure value (u16). 83 ti,debounce-max Max number of additional readings per 84 sample (u16). 85 86Example for a TSC2046 chip connected to an McSPI controller of an OMAP SoC:: 87 88 spi_controller { 89 tsc2046@0 { 90 reg = <0>; /* CS0 */ 91 compatible = "ti,tsc2046"; 92 interrupt-parent = <&gpio1>; 93 interrupts = <8 0>; /* BOOT6 / GPIO 8 */ 94 spi-max-frequency = <1000000>; 95 pendown-gpio = <&gpio1 8 0>; 96 vcc-supply = <®_vcc3>; 97 98 ti,x-min = /bits/ 16 <0>; 99 ti,x-max = /bits/ 16 <8000>; 100 ti,y-min = /bits/ 16 <0>; 101 ti,y-max = /bits/ 16 <4800>; 102 ti,x-plate-ohms = /bits/ 16 <40>; 103 ti,pressure-max = /bits/ 16 <255>; 104 105 wakeup-source; 106 }; 107 }; 108