ASoC: cs43130: Add devicetree bindings for CS43130

CS43130 DAC

Required properties:

  - compatible : "cirrus,cs43130", "cirrus,cs4399", "cirrus,cs43131",

                 "cirrus,cs43198"

  - reg : the I2C address of the device for I2C

  - VA-supply, VP-supply, VL-supply, VCP-supply, VD-supply:

	power supplies for the device, as covered in

	Documentation/devicetree/bindings/regulator/regulator.txt.

Optional properties:

  - reset-gpios : Active low GPIO used to reset the device

  - cirrus,xtal-ibias:

   When external MCLK is generated by external crystal

   oscillator, CS43130 can be used to provide bias current

   for external crystal.  Amount of bias current sent is

   set as:

   1 = 7.5uA

   2 = 12.5uA

   3 = 15uA

  - cirrus,dc-measure:

   Boolean, define to enable headphone DC impedance measurement.

  - cirrus,ac-measure:

   Boolean, define to enable headphone AC impedance measurement.

   DC impedance must also be enabled for AC impedance measurement.

  - cirrus,dc-threshold:

   Define 2 DC impedance thresholds in ohms for HP output control.

   Default values are 50 and 120 Ohms.

  - cirrus,ac-freq:

   Define the frequencies at which to measure HP AC impedance.

   Only used if "cirrus,dc-measure" is defined.

   Exactly 10 frequencies must be defined.

   If this properties is undefined, by default,

   following frequencies are used:

   <24 43 93 200 431 928 2000 4309 9283 20000>

   The above frequencies are logarithmically equally spaced.

   Log base is 10.

Example:

cs43130: audio-codec@30 {

   compatible = "cirrus,cs43130";

   reg = <0x30>;

   reset-gpios = <&axi_gpio 54 0>;

   VA-supply = <&dummy_vreg>;

   VP-supply = <&dummy_vreg>;

   VL-supply = <&dummy_vreg>;

   VCP-supply = <&dummy_vreg>;

   VD-supply = <&dummy_vreg>;

   cirrus,xtal-ibias = <2>;

   interrupt-parent = <&gpio0>;

   interrupts = <55 8>;

   cirrus,dc-measure;

   cirrus,ac-measure;

   cirrus,dc-threshold = /bits/ 16 <20 100>;

   cirrus,ac-freq = /bits/ 16 <24 43 93 200 431 928 2000 4309 9283 20000>;

};