blob: 05274e1b56d1521508139f1356fcef9232497526 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
|
* Analog Devices AD7879-1/AD7889-1 touchscreen interface (I2C)
Required properties:
- compatible: must be "adi,ad7879-1"
- reg: i2c slave address
- interrupt-parent: the phandle for the interrupt controller
- interrupts: touch controller interrupt
- resistance-plate-x : total resistance of X-plate (for pressure
calculation)
- touchscreen-min-pressure : pressure threshold value
- touchscreen-max-pressure : maximum reported pressure
- touchscreen-swapped-x-y : X and Y axis are swapped (boolean)
Swapping is done after inverting the axis
Optional properties:
- first-conversion-delay : 0-12 in 128us steps (starting with 128us)
13: 2.560ms
14: 3.584ms
15: 4.096ms
- acquisition-time : 0: 2us
1: 4us
2: 8us
3: 16us
- median-filter-size : 0: disabled
1: 4 measurements
2: 8 measurements
3: 16 measurements
- averaging : 0: 2 middle values (1 if median disabled)
1: 4 middle values
2: 8 middle values
3: 16 values
- conversion-interval: : 0: convert one time only
1-255: 515us + val * 35us (up to 9.440ms)
Example:
ad7879@2c {
compatible = "adi,ad7879-1";
reg = <0x2c>;
interrupt-parent = <&gpio1>;
interrupts = <13 IRQ_TYPE_EDGE_FALLING>;
resistance-plate-x = <120>;
touchscreen-min-pressure = <0>;
touchscreen-max-pressure = <4096>;
first-conversion-delay = /bits/ 8 <3>;
acquisition-time = /bits/ 8 <1>;
median-filter-size = /bits/ 8 <2>;
averaging = /bits/ 8 <1>;
conversion-interval = /bits/ 8 <255>;
};
|
