xref: /linux/Documentation/devicetree/bindings/input/touchscreen/brcm,iproc-touchscreen.txt (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
1* Broadcom's IPROC Touchscreen Controller
2
3Required properties:
4- compatible: must be "brcm,iproc-touchscreen"
5- ts_syscon: handler of syscon node defining physical base
6  address of the controller and length of memory mapped region.
7  If this property is selected please make sure MFD_SYSCON config
8  is enabled in the defconfig file.
9- clocks:  The clock provided by the SOC to driver the tsc
10- clock-names:  name for the clock
11- interrupts: The touchscreen controller's interrupt
12- address-cells: Specify the number of u32 entries needed in child nodes.
13  Should set to 1.
14- size-cells: Specify number of u32 entries needed to specify child nodes size
15  in reg property. Should set to 1.
16
17Optional properties:
18- scanning_period: Time between scans. Each step is 1024 us.  Valid 1-256.
19- debounce_timeout: Each step is 512 us.  Valid 0-255
20- settling_timeout: The settling duration (in ms) is the amount of time
21                    the tsc waits to allow the voltage to settle after
22                    turning on the drivers in detection mode.
23                    Valid values: 0-11
24                    0 =  0.008 ms
25                    1 =  0.01 ms
26                    2 =  0.02 ms
27                    3 =  0.04 ms
28                    4 =  0.08 ms
29                    5 =  0.16 ms
30                    6 =  0.32 ms
31                    7 =  0.64 ms
32                    8 =  1.28 ms
33                    9 =  2.56 ms
34                   10 =  5.12 ms
35                   11 = 10.24 ms
36- touch_timeout: The continuous number of scan periods in which touch is
37                not detected before the controller returns to idle state.
38                Valid values 0-255.
39- average_data: Number of data samples which are averaged before a final
40                data point is placed into the FIFO
41                Valid values 0-7
42                0 =   1 sample
43                1 =   2 samples
44                2 =   4 samples
45                3 =   8 samples
46                4 =  16 samples
47                5 =  32 samples
48                6 =  64 samples
49                7 = 128 samples
50- fifo_threshold: Interrupt is generated whenever the number of fifo
51                entries exceeds this value
52                Valid values 0-31
53- touchscreen-size-x: horizontal resolution of touchscreen (in pixels)
54- touchscreen-size-y: vertical resolution of touchscreen (in pixels)
55- touchscreen-fuzz-x: horizontal noise value of the absolute input
56                      device (in pixels)
57- touchscreen-fuzz-y: vertical noise value of the absolute input
58                      device (in pixels)
59- touchscreen-inverted-x: X axis is inverted (boolean)
60- touchscreen-inverted-y: Y axis is inverted (boolean)
61
62Example: An example of touchscreen node
63
64	ts_adc_syscon: ts_adc_syscon@180a6000 {
65		compatible = "brcm,iproc-ts-adc-syscon","syscon";
66		reg = <0x180a6000 0xc30>;
67	};
68
69	touchscreen: touchscreen@180a6000 {
70		compatible = "brcm,iproc-touchscreen";
71		#address-cells = <1>;
72		#size-cells = <1>;
73		ts_syscon = <&ts_adc_syscon>;
74		clocks = <&adc_clk>;
75		clock-names = "tsc_clk";
76		interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;
77
78		scanning_period = <5>;
79		debounce_timeout = <40>;
80		settling_timeout = <7>;
81		touch_timeout = <10>;
82		average_data = <5>;
83		fifo_threshold = <1>;
84		/* Touchscreen is rotated 180 degrees. */
85		touchscreen-inverted-x;
86		touchscreen-inverted-y;
87	};
88