diff options
Diffstat (limited to 'Documentation/devicetree/bindings/input/touchscreen/ads7846.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/input/touchscreen/ads7846.txt | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/input/touchscreen/ads7846.txt b/Documentation/devicetree/bindings/input/touchscreen/ads7846.txt new file mode 100644 index 000000000..81f6bda97 --- /dev/null +++ b/Documentation/devicetree/bindings/input/touchscreen/ads7846.txt @@ -0,0 +1,106 @@ +Device tree bindings for TI's ADS7843, ADS7845, ADS7846, ADS7873, TSC2046 +SPI driven touch screen controllers. + +The node for this driver must be a child node of a SPI controller, hence +all mandatory properties described in + + Documentation/devicetree/bindings/spi/spi-bus.txt + +must be specified. + +Additional required properties: + + compatible Must be one of the following, depending on the + model: + "ti,tsc2046" + "ti,ads7843" + "ti,ads7845" + "ti,ads7846" + "ti,ads7873" + + interrupts An interrupt node describing the IRQ line the chip's + !PENIRQ pin is connected to. + vcc-supply A regulator node for the supply voltage. + + +Optional properties: + + ti,vref-delay-usecs vref supply delay in usecs, 0 for + external vref (u16). + ti,vref-mv The VREF voltage, in millivolts (u16). + Set to 0 to use internal references + (ADS7846). + ti,keep-vref-on set to keep vref on for differential + measurements as well + ti,settle-delay-usec Settling time of the analog signals; + a function of Vcc and the capacitance + on the X/Y drivers. If set to non-zero, + two samples are taken with settle_delay + us apart, and the second one is used. + ~150 uSec with 0.01uF caps (u16). + ti,penirq-recheck-delay-usecs If set to non-zero, after samples are + taken this delay is applied and penirq + is rechecked, to help avoid false + events. This value is affected by the + material used to build the touch layer + (u16). + ti,x-plate-ohms Resistance of the X-plate, + in Ohms (u16). + ti,y-plate-ohms Resistance of the Y-plate, + in Ohms (u16). + ti,x-min Minimum value on the X axis (u16). + ti,y-min Minimum value on the Y axis (u16). + ti,debounce-tol Tolerance used for filtering (u16). + ti,debounce-rep Additional consecutive good readings + required after the first two (u16). + ti,pendown-gpio-debounce Platform specific debounce time for the + pendown-gpio (u32). + pendown-gpio GPIO handle describing the pin the !PENIRQ + line is connected to. + wakeup-source use any event on touchscreen as wakeup event. + (Legacy property support: "linux,wakeup") + touchscreen-size-x General touchscreen binding, see [1]. + touchscreen-size-y General touchscreen binding, see [1]. + touchscreen-max-pressure General touchscreen binding, see [1]. + touchscreen-min-pressure General touchscreen binding, see [1]. + touchscreen-average-samples General touchscreen binding, see [1]. + touchscreen-inverted-x General touchscreen binding, see [1]. + touchscreen-inverted-y General touchscreen binding, see [1]. + touchscreen-swapped-x-y General touchscreen binding, see [1]. + +[1] All general touchscreen properties are described in + Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt. + +Deprecated properties: + + ti,swap-xy swap x and y axis + ti,x-max Maximum value on the X axis (u16). + ti,y-max Maximum value on the Y axis (u16). + ti,pressure-min Minimum reported pressure value + (threshold) - u16. + ti,pressure-max Maximum reported pressure value (u16). + ti,debounce-max Max number of additional readings per + sample (u16). + +Example for a TSC2046 chip connected to an McSPI controller of an OMAP SoC:: + + spi_controller { + tsc2046@0 { + reg = <0>; /* CS0 */ + compatible = "ti,tsc2046"; + interrupt-parent = <&gpio1>; + interrupts = <8 0>; /* BOOT6 / GPIO 8 */ + spi-max-frequency = <1000000>; + pendown-gpio = <&gpio1 8 0>; + vcc-supply = <®_vcc3>; + + ti,x-min = /bits/ 16 <0>; + ti,x-max = /bits/ 16 <8000>; + ti,y-min = /bits/ 16 <0>; + ti,y-max = /bits/ 16 <4800>; + ti,x-plate-ohms = /bits/ 16 <40>; + ti,pressure-max = /bits/ 16 <255>; + + wakeup-source; + }; + }; |