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Nuvoton NAU8824 audio codec
This device supports I2C only.
Required properties:
- compatible : Must be "nuvoton,nau8824"
- reg : the I2C address of the device. This is either 0x1a (CSB=0) or 0x1b (CSB=1).
Optional properties:
- nuvoton,jkdet-polarity: JKDET pin polarity. 0 - active high, 1 - active low.
- nuvoton,vref-impedance: VREF Impedance selection
0 - Open
1 - 25 kOhm
2 - 125 kOhm
3 - 2.5 kOhm
- nuvoton,micbias-voltage: Micbias voltage level.
0 - VDDA
1 - VDDA
2 - VDDA * 1.1
3 - VDDA * 1.2
4 - VDDA * 1.3
5 - VDDA * 1.4
6 - VDDA * 1.53
7 - VDDA * 1.53
- nuvoton,sar-threshold-num: Number of buttons supported
- nuvoton,sar-threshold: Impedance threshold for each button. Array that contains up to 8 buttons configuration. SAR value is calculated as
SAR = 255 * MICBIAS / SAR_VOLTAGE * R / (2000 + R)
where MICBIAS is configured by 'nuvoton,micbias-voltage', SAR_VOLTAGE is configured by 'nuvoton,sar-voltage', R - button impedance.
Refer datasheet section 10.2 for more information about threshold calculation.
- nuvoton,sar-hysteresis: Button impedance measurement hysteresis.
- nuvoton,sar-voltage: Reference voltage for button impedance measurement.
0 - VDDA
1 - VDDA
2 - VDDA * 1.1
3 - VDDA * 1.2
4 - VDDA * 1.3
5 - VDDA * 1.4
6 - VDDA * 1.53
7 - VDDA * 1.53
- nuvoton,sar-compare-time: SAR compare time
0 - 500 ns
1 - 1 us
2 - 2 us
3 - 4 us
- nuvoton,sar-sampling-time: SAR sampling time
0 - 2 us
1 - 4 us
2 - 8 us
3 - 16 us
- nuvoton,short-key-debounce: Button short key press debounce time.
0 - 30 ms
1 - 50 ms
2 - 100 ms
- nuvoton,jack-eject-debounce: Jack ejection debounce time.
0 - 0 ms
1 - 1 ms
2 - 10 ms
Example:
headset: nau8824@1a {
compatible = "nuvoton,nau8824";
reg = <0x1a>;
interrupt-parent = <&gpio>;
interrupts = <TEGRA_GPIO(E, 6) IRQ_TYPE_LEVEL_LOW>;
nuvoton,vref-impedance = <2>;
nuvoton,micbias-voltage = <6>;
// Setup 4 buttons impedance according to Android specification
nuvoton,sar-threshold-num = <4>;
nuvoton,sar-threshold = <0xc 0x1e 0x38 0x60>;
nuvoton,sar-hysteresis = <0>;
nuvoton,sar-voltage = <6>;
nuvoton,sar-compare-time = <1>;
nuvoton,sar-sampling-time = <1>;
nuvoton,short-key-debounce = <0>;
nuvoton,jack-eject-debounce = <1>;
};
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