nau8825: Add driver for I2C codec

The Nuvoton NAU8825 audio codec is an I2C device that has a number of
tunable parameters that can be provided to the kernel device driver for
basic configuration and optimal operation.

The configuration options are exposed to devicetree as registers and then
presented as Device Properties via ACPI to the operation system.

This sample configuration in devicetree:

device pci 19.2 on
  chip drivers/i2c/nau8825
    register "irq" = "IRQ_LEVEL_LOW(GPP_F10_IRQ)"
    register "jkdet_enable" = "1"
    register "sar_threshold_num" = "2"
    register "sar_threshold[0]" = "0x0c"
    register "sar_threshold[1]" = "0x1c"
    device i2c 1a on end
  end
end

Will generate the following code in the SSDT, trimmed for this commit
message as there are more properties that can be configured:

Scope (\_SB.PCI0.I2C4)
{
  Name (_HID, "10508825")
  Name (_UID, Zero)
  Name (_DDN, "Nuvoton NAU8825 Codec")
  Method (_STA) { Return (0xF) }
  Name (_CRS, ResourceTemplate () {
    I2cSerialBus (0x1A, ControllerInitiated, 0x61A80, AddressingMode7Bit,
                  "\_SB.PCI0.I2C4", 0, ResourceConsumer)
    Interrupt (ResourceConsumer, Level, ActiveLow) { 0x3A }
  })
  Name (_DSD, Package () {
    ToUUID ("daffd814-6eba-4d8c-8a91-bc9bff4aa301"),
    Package () {
      Package () { "nuvoton,jkdet-enable", 1 },
      Package () { "nuvoton,sar-threshold-num", 2 },
      Package () { "nuvoton,sar-threshold", Package () { 0x0c, 0x1c } }
    }
  })
}

Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Change-Id: I480d72daf5ac3dded9b1cbb5fbc737b9dfde3834
Reviewed-on: https://review.coreboot.org/15015
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/drivers/i2c/nau8825/Makefile.inc b/src/drivers/i2c/nau8825/Makefile.inc
new file mode 100644
index 0000000000..6f32643439
--- /dev/null
+++ b/src/drivers/i2c/nau8825/Makefile.inc
@@ -0,0 +1 @@
+ramstage-$(CONFIG_DRIVERS_I2C_NAU8825) += nau8825.c