xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/iio/adc/envelope-detector.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunBindings for ADC envelope detector using a DAC and a comparator
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunThe DAC is used to find the peak level of an alternating voltage input
4*4882a593Smuzhiyunsignal by a binary search using the output of a comparator wired to
5*4882a593Smuzhiyunan interrupt pin. Like so:
6*4882a593Smuzhiyun                          _
7*4882a593Smuzhiyun                         | \
8*4882a593Smuzhiyun    input +------>-------|+ \
9*4882a593Smuzhiyun                         |   \
10*4882a593Smuzhiyun           .-------.     |    }---.
11*4882a593Smuzhiyun           |       |     |   /    |
12*4882a593Smuzhiyun           |    dac|-->--|- /     |
13*4882a593Smuzhiyun           |       |     |_/      |
14*4882a593Smuzhiyun           |       |              |
15*4882a593Smuzhiyun           |       |              |
16*4882a593Smuzhiyun           |    irq|------<-------'
17*4882a593Smuzhiyun           |       |
18*4882a593Smuzhiyun           '-------'
19*4882a593Smuzhiyun
20*4882a593SmuzhiyunRequired properties:
21*4882a593Smuzhiyun- compatible: Should be "axentia,tse850-envelope-detector"
22*4882a593Smuzhiyun- io-channels: Channel node of the dac to be used for comparator input.
23*4882a593Smuzhiyun- io-channel-names: Should be "dac".
24*4882a593Smuzhiyun- interrupt specification for one client interrupt,
25*4882a593Smuzhiyun  see ../../interrupt-controller/interrupts.txt for details.
26*4882a593Smuzhiyun- interrupt-names: Should be "comp".
27*4882a593Smuzhiyun
28*4882a593SmuzhiyunExample:
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun	&i2c {
31*4882a593Smuzhiyun		dpot: mcp4651-104@28 {
32*4882a593Smuzhiyun			compatible = "microchip,mcp4651-104";
33*4882a593Smuzhiyun			reg = <0x28>;
34*4882a593Smuzhiyun			#io-channel-cells = <1>;
35*4882a593Smuzhiyun		};
36*4882a593Smuzhiyun	};
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun	dac: dac {
39*4882a593Smuzhiyun		compatible = "dpot-dac";
40*4882a593Smuzhiyun		vref-supply = <&reg_3v3>;
41*4882a593Smuzhiyun		io-channels = <&dpot 0>;
42*4882a593Smuzhiyun		io-channel-names = "dpot";
43*4882a593Smuzhiyun		#io-channel-cells = <1>;
44*4882a593Smuzhiyun	};
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun	envelope-detector {
47*4882a593Smuzhiyun		compatible = "axentia,tse850-envelope-detector";
48*4882a593Smuzhiyun		io-channels = <&dac 0>;
49*4882a593Smuzhiyun		io-channel-names = "dac";
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun		interrupt-parent = <&gpio>;
52*4882a593Smuzhiyun		interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
53*4882a593Smuzhiyun		interrupt-names = "comp";
54*4882a593Smuzhiyun	};
55