Cirrus Logic Madera class audio codecs multi-function device

These devices are audio SoCs with extensive digital capabilities and a range
of analogue I/O.

See also the child driver bindings in:
bindings/extcon/extcon-madera.txt
bindings/gpio/gpio-madera.txt
bindings/interrupt-controller/cirrus,madera.txt
bindings/regulator/madera-ldo1.txt
bindings/regulator/madera-micsupp.txt
bindings/sound/madera.txt
bindings/switch/madera.txt

Required properties:

  - compatible : One of the following chip-specific strings:
        "cirrus,cs47l35"
        "cirrus,cs47l85"
        "cirrus,cs47l90"
        "cirrus,cs47l91"
        "cirrus,wm1840"

  - reg : I2C slave address when connected using I2C, chip select number when
    using SPI.

  - DCVDD-supply : Power supply for the device as defined in
    bindings/regulator/regulator.txt
    Mandatory on CS47L35, CS47L90, CS47L91
    Optional on CS47L85, WM1840

  - AVDD-supply, DBVDD1-supply, DBVDD2-supply, CPVDD1-supply, CPVDD2-supply :
    Power supplies for the device

  - DBVDD3-supply, DBVDD4-supply : Power supplies for the device
    (CS47L85, CS47L90, CS47L91, WM1840)

  - SPKVDDL-supply, SPKVDDR-supply : Power supplies for the device
    (CS47L85, WM1840)

  - SPKVDD-supply : Power supplies for the device
    (CS47L35)

Optional properties:

  , MICVDD-supply : Power supply, only need to be specified if
    powered externally

  - cirrus,reset-gpios : One entry specifying the GPIO controlling /RESET.
    As defined in bindings/gpio.txt.

  - cirrus,clk32k-src : set input source for codec 32kHz clock.
      0 = default, 1 = MCLK1, 2 = MCLK2, 3 = None

  - cirrus,gpio-defaults : A list of values for the GPn_CONFIGx registers.
    There are two entries for each GPIO, corresponding to the GPn_CONFIG1 and
    GPn_CONFIG2 registers for that GPIO. Defines for the appropriate values can
    be found in <dt-bindings/mfd/madera.h>. If absent, no configuration of these
    registers is performed. If any entry has a value >0xFFFF the chip default
    will be used.

  - cirrus,micbias1 : Configuration for the micbias regulator, there are 8 cells
    <vout cap disA disB disC disD soft bypass>
    where
      vout is the output voltage in millivolts
      cap is non-zero value if an external capacitor is fitted
      disA,B,C,D non-zero if that output should be actively discharged
      soft non-zero to enable soft-start
      bypass non-zero to enable bypass
  - cirrus,micbias2 : See cirrus,micbias1
  - cirrus,micbias3 : See cirrus,micbias1
  - cirrus,micbias4 : See cirrus,micbias1

Example:

codec: cs47l85@0 {
	compatible = "cirrus,cs47l85";
	reg = <0>;

        cirrus,reset-gpios = <&gpio 0>;

	cirrus,gpio-defaults = <
		Madera_GP_FN_TXLRCLK
		Madera_GP_DEFAULT
		Madera_GP_DEFAULT
		Madera_GP_DEFAULT
		Madera_GP_DEFAULT
	>;

	cirrus,micbias2 = <2600 0 1 0 0 0 1 0>;
};