1Nuvoton NAU8825 audio codec
2
3This device supports I2C only.
4
5Required properties:
6  - compatible : Must be "nuvoton,nau8825"
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-enable: Enable jack detection via JKDET pin.
12  - nuvoton,jkdet-pull-enable: Enable JKDET pin pull. If set - pin pull enabled,
13      otherwise pin in high impedance state.
14  - nuvoton,jkdet-pull-up: Pull-up JKDET pin. If set then JKDET pin is pull up, otherwise pull down.
15  - nuvoton,jkdet-polarity: JKDET pin polarity. 0 - active high, 1 - active low.
16
17  - nuvoton,vref-impedance: VREF Impedance selection
18      0 - Open
19      1 - 25 kOhm
20      2 - 125 kOhm
21      3 - 2.5 kOhm
22
23  - nuvoton,micbias-voltage: Micbias voltage level.
24      0 - VDDA
25      1 - VDDA
26      2 - VDDA * 1.1
27      3 - VDDA * 1.2
28      4 - VDDA * 1.3
29      5 - VDDA * 1.4
30      6 - VDDA * 1.53
31      7 - VDDA * 1.53
32
33  - nuvoton,sar-threshold-num: Number of buttons supported
34  - nuvoton,sar-threshold: Impedance threshold for each button. Array that contains up to 8 buttons configuration. SAR value is calculated as
35    SAR = 255 * MICBIAS / SAR_VOLTAGE * R / (2000 + R)
36    where MICBIAS is configured by 'nuvoton,micbias-voltage', SAR_VOLTAGE is configured by 'nuvoton,sar-voltage', R - button impedance.
37    Refer datasheet section 10.2 for more information about threshold calculation.
38
39  - nuvoton,sar-hysteresis: Button impedance measurement hysteresis.
40
41  - nuvoton,sar-voltage: Reference voltage for button impedance measurement.
42      0 - VDDA
43      1 - VDDA
44      2 - VDDA * 1.1
45      3 - VDDA * 1.2
46      4 - VDDA * 1.3
47      5 - VDDA * 1.4
48      6 - VDDA * 1.53
49      7 - VDDA * 1.53
50
51  - nuvoton,sar-compare-time: SAR compare time
52      0 - 500 ns
53      1 - 1 us
54      2 - 2 us
55      3 - 4 us
56
57  - nuvoton,sar-sampling-time: SAR sampling time
58      0 - 2 us
59      1 - 4 us
60      2 - 8 us
61      3 - 16 us
62
63  - nuvoton,short-key-debounce: Button short key press debounce time.
64      0 - 30 ms
65      1 - 50 ms
66      2 - 100 ms
67      3 - 30 ms
68
69  - nuvoton,jack-insert-debounce: number from 0 to 7 that sets debounce time to 2^(n+2) ms
70  - nuvoton,jack-eject-debounce: number from 0 to 7 that sets debounce time to 2^(n+2) ms
71
72  - nuvoton,crosstalk-enable: make crosstalk function enable if set.
73
74  - clocks: list of phandle and clock specifier pairs according to common clock bindings for the
75      clocks described in clock-names
76  - clock-names: should include "mclk" for the MCLK master clock
77
78Example:
79
80  headset: nau8825@1a {
81      compatible = "nuvoton,nau8825";
82      reg = <0x1a>;
83      interrupt-parent = <&gpio>;
84      interrupts = <TEGRA_GPIO(E, 6) IRQ_TYPE_LEVEL_LOW>;
85      nuvoton,jkdet-enable;
86      nuvoton,jkdet-pull-enable;
87      nuvoton,jkdet-pull-up;
88      nuvoton,jkdet-polarity = <GPIO_ACTIVE_LOW>;
89      nuvoton,vref-impedance = <2>;
90      nuvoton,micbias-voltage = <6>;
91      // Setup 4 buttons impedance according to Android specification
92      nuvoton,sar-threshold-num = <4>;
93      nuvoton,sar-threshold = <0xc 0x1e 0x38 0x60>;
94      nuvoton,sar-hysteresis = <1>;
95      nuvoton,sar-voltage = <0>;
96      nuvoton,sar-compare-time = <0>;
97      nuvoton,sar-sampling-time = <0>;
98      nuvoton,short-key-debounce = <2>;
99      nuvoton,jack-insert-debounce = <7>;
100      nuvoton,jack-eject-debounce = <7>;
101      nuvoton,crosstalk-enable;
102
103      clock-names = "mclk";
104      clocks = <&tegra_car TEGRA210_CLK_CLK_OUT_2>;
105  };
106