RT5663 audio CODEC

This device supports I2C only.

Required properties:

- compatible : "realtek,rt5663".

- reg : The I2C address of the device.

- interrupts : The CODEC's interrupt output.

Optional properties:

- "realtek,dc_offset_l_manual"
- "realtek,dc_offset_r_manual"
- "realtek,dc_offset_l_manual_mic"
- "realtek,dc_offset_r_manual_mic"
  Based on the different PCB layout, add the manual offset value to
  compensate the DC offset for each L and R channel, and they are different
  between headphone and headset.
- "realtek,impedance_sensing_num"
  The matrix row number of the impedance sensing table.
  If the value is 0, it means the impedance sensing is not supported.
- "realtek,impedance_sensing_table"
  The matrix rows of the impedance sensing table are consisted by impedance
  minimum, impedance maximun, volume, DC offset w/o and w/ mic of each L and
  R channel accordingly. Example is shown as following.
  <   0    300  7  0xffd160  0xffd1c0  0xff8a10  0xff8ab0
    301  65535  4  0xffe470  0xffe470  0xffb8e0  0xffb8e0>
  The first and second column are defined for the impedance range. If the
  detected impedance value is in the range, then the volume value of the
  third column will be set to codec. In our codec design, each volume value
  should compensate different DC offset to avoid the pop sound, and it is
  also different between headphone and headset. In the example, the
  "realtek,impedance_sensing_num" is 2. It means that there are 2 ranges of
  impedance in the impedance sensing function.

Pins on the device (for linking into audio routes) for RT5663:

  * IN1P
  * IN1N
  * IN2P
  * IN2N
  * HPOL
  * HPOR

Example:

rt5663: codec@12 {
	compatible = "realtek,rt5663";
	reg = <0x12>;
	interrupts = <7 IRQ_TYPE_EDGE_FALLING>;
};
