Patch merged into coreboot/master: generic: Add a Maxim 98357A codec driver

the following patch was just integrated into master:
commit 7db15094c259f9417d16cbba102cea100eb2bcf8
Author: Duncan Laurie 
Date:   Wed May 11 11:27:47 2016 -0700

generic: Add a Maxim 98357A codec driver

The Maxim Integrated 98357A codec is an I2S slave device that has no
    control channel for configuration and instead provides a GPIO that is
    used for channel selection and power down.  This means it does not fit
    into a bus hierarchy easily and is instead represented as a generic
    device and found with a static bus scan using the devicetree.

This driver provides configuration options for passing the "sdmode" GPIO
    descriptor as well as a second option for "sdmode delay" which can
    configure the timing of the sdmode toggling in relation to the I2S
    channel output.

In addition an GPIO can be provided to indicate to the driver whether
    this device is present or not.  This can be used for board designs that
    may have different codec possibilities that are selected by HW strap.

Sample usage for this device driver:

device pci 1f.3 on
      chip drivers/generic/max98357a
        register "sdmode_gpio" = "ACPI_GPIO_OUTPUT(GPP_C6)"
        register "sdmode_delay" = "100"
        device generic 0 on end
      end
    end

Will result in the following code in the SSDT:

Scope (_SB.PCI0.HDAS) {
      Device (MAXM) {
        Name (_HID, "MX98357A")
        Name (_UID, Zero)
        Name (_DDN, "Maxim Integrated 98357A Amplifier")
        Method (_STA) { Return (0xF) }
        Name (_CRS, ResourceTemplate () {
          GpioIo (Exclusive, PullDefault, 0, 0, IoRestrictionOutputOnly,
                  "\_SB.PCI0.GPIO", 0, ResourceConsumer)
        })
        Name (_DSD, Package () {
          ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
          Package () {
            Package () { "maxim,sdmode-gpio", _SB.PCI0.HDAS.MAXM, 0, 0, 0 }
            Package () { "maxim,sdmode-delay", 100 }
            Package () { "sdmode-delay", 100 }
          }
        })
      }
    }

Change-Id: Ia0bafe49bea9bbe4a3cc0f9f9cdb6f6390da57b5
    Signed-off-by: Duncan Laurie 
    Reviewed-on: https://review.coreboot.org/15017
    Tested-by: build bot (Jenkins)
    Reviewed-by: Aaron Durbin

See https://review.coreboot.org/15017 for details.

-gerrit