xref: /freebsd/sys/contrib/device-tree/Bindings/sound/nau8824.txt (revision 911f0260390e18cf85f3dbf2c719b593efdc1e3c) 
1Nuvoton NAU8824 audio codec
2
3This device supports I2C only.
4
5Required properties:
6  - compatible : Must be "nuvoton,nau8824"
7
8  - reg : the I2C address of the device. This is either 0x1a (CSB=0) or 0x1b (CSB=1).
9
10Optional properties:
11  - nuvoton,jkdet-polarity: JKDET pin polarity. 0 - active high, 1 - active low.
12
13  - nuvoton,vref-impedance: VREF Impedance selection
14      0 - Open
15      1 - 25 kOhm
16      2 - 125 kOhm
17      3 - 2.5 kOhm
18
19  - nuvoton,micbias-voltage: Micbias voltage level.
20      0 - VDDA
21      1 - VDDA
22      2 - VDDA * 1.1
23      3 - VDDA * 1.2
24      4 - VDDA * 1.3
25      5 - VDDA * 1.4
26      6 - VDDA * 1.53
27      7 - VDDA * 1.53
28
29  - nuvoton,sar-threshold-num: Number of buttons supported
30  - nuvoton,sar-threshold: Impedance threshold for each button. Array that contains up to 8 buttons configuration. SAR value is calculated as
31    SAR = 255 * MICBIAS / SAR_VOLTAGE * R / (2000 + R)
32    where MICBIAS is configured by 'nuvoton,micbias-voltage', SAR_VOLTAGE is configured by 'nuvoton,sar-voltage', R - button impedance.
33    Refer datasheet section 10.2 for more information about threshold calculation.
34
35  - nuvoton,sar-hysteresis: Button impedance measurement hysteresis.
36
37  - nuvoton,sar-voltage: Reference voltage for button impedance measurement.
38      0 - VDDA
39      1 - VDDA
40      2 - VDDA * 1.1
41      3 - VDDA * 1.2
42      4 - VDDA * 1.3
43      5 - VDDA * 1.4
44      6 - VDDA * 1.53
45      7 - VDDA * 1.53
46
47  - nuvoton,sar-compare-time: SAR compare time
48      0 - 500 ns
49      1 - 1 us
50      2 - 2 us
51      3 - 4 us
52
53  - nuvoton,sar-sampling-time: SAR sampling time
54      0 - 2 us
55      1 - 4 us
56      2 - 8 us
57      3 - 16 us
58
59  - nuvoton,short-key-debounce: Button short key press debounce time.
60      0 - 30 ms
61      1 - 50 ms
62      2 - 100 ms
63
64  - nuvoton,jack-eject-debounce: Jack ejection debounce time.
65      0 - 0 ms
66      1 - 1 ms
67      2 - 10 ms
68
69
70Example:
71
72  headset: nau8824@1a {
73      compatible = "nuvoton,nau8824";
74      reg = <0x1a>;
75      interrupt-parent = <&gpio>;
76      interrupts = <TEGRA_GPIO(E, 6) IRQ_TYPE_LEVEL_LOW>;
77      nuvoton,vref-impedance = <2>;
78      nuvoton,micbias-voltage = <6>;
79      // Setup 4 buttons impedance according to Android specification
80      nuvoton,sar-threshold-num = <4>;
81      nuvoton,sar-threshold = <0xc 0x1e 0x38 0x60>;
82      nuvoton,sar-hysteresis = <0>;
83      nuvoton,sar-voltage = <6>;
84      nuvoton,sar-compare-time = <1>;
85      nuvoton,sar-sampling-time = <1>;
86      nuvoton,short-key-debounce = <0>;
87      nuvoton,jack-eject-debounce = <1>;
88  };
89