Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-microblaze.git] / Documentation / devicetree / bindings / iio / dac / dpot-dac.txt
1 Bindings for DAC emulation using a digital potentiometer
2
3 It is assumed that the dpot is used as a voltage divider between the
4 current dpot wiper setting and the maximum resistance of the dpot. The
5 divided voltage is provided by a vref regulator.
6
7                   .------.
8    .-----------.  |      |
9    | vref      |--'    .---.
10    | regulator |--.    |   |
11    '-----------'  |    | d |
12                   |    | p |
13                   |    | o |  wiper
14                   |    | t |<---------+
15                   |    |   |
16                   |    '---'       dac output voltage
17                   |      |
18                   '------+------------+
19
20 Required properties:
21 - compatible: Should be "dpot-dac"
22 - vref-supply: The regulator supplying the voltage divider.
23 - io-channels: Channel node of the dpot to be used for the voltage division.
24 - io-channel-names: Should be "dpot".
25
26 Example:
27
28         &i2c {
29                 dpot: mcp4651-503@28 {
30                         compatible = "microchip,mcp4651-503";
31                         reg = <0x28>;
32                         #io-channel-cells = <1>;
33                 };
34         };
35
36         dac {
37                 compatible = "dpot-dac";
38                 vref-supply = <&reg_3v3>;
39                 io-channels = <&dpot 0>;
40                 io-channel-names = "dpot";
41         };