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 = <&reg_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