Change in coreboot[master]: drivers/amd/i2s_machine_dev: Populate _WOV ACPI method

[Karthik Ramasubramanian (Code Review)]

Karthik Ramasubramanian has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/55029 )

Change subject: drivers/amd/i2s_machine_dev: Populate _WOV ACPI method
......................................................................

drivers/amd/i2s_machine_dev: Populate _WOV ACPI method

In order to support Audio Co-processor (ACP) DMIC hardware runtime
detection on the platform, ACPI _WOV method is populated on the
concerned ACP device. This method returns the ACPI Integer value as 1
if ACP DMIC exists on the platform or else it will return zero. Since
DMIC select GPIO is optional, add a flag to indicate the presence of
DMIC.

BUG=b:182960979
TEST=Build and boot to OS in guybrush. Ensure that the _WOV ACPI method
is populated under the scope of ACP device.
    Scope (_SB.PCI0.GP41.ACPD)
    {
        Device (I2S0)
        {
            Name (_HID, "AMDI5682")  // _HID: Hardware ID
            Name (_UID, Zero)  // _UID: Unique ID
            Name (_DDN, "I2S machine driver")  // _DDN: DOS Device Name
            Method (_STA, 0, NotSerialized)  // _STA: Status
            {
                Return (0x0F)
            }

Method (_WOV, 0, NotSerialized)
            {
                Return (One)
            }
        }
    }

Change-Id: Ide84f45f5ea2ae42d5efe71ac6d1595886157045
Signed-off-by: Karthikeyan Ramasubramanian 
---
M src/drivers/amd/i2s_machine_dev/chip.h
M src/drivers/amd/i2s_machine_dev/i2s_machine_dev.c
2 files changed, 14 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/29/55029/1

diff --git a/src/drivers/amd/i2s_machine_dev/chip.h b/src/drivers/amd/i2s_machine_dev/chip.h
index 0ca00a8..a8e94ca 100644
--- a/src/drivers/amd/i2s_machine_dev/chip.h
+++ b/src/drivers/amd/i2s_machine_dev/chip.h
@@ -17,6 +17,12 @@
     * all the mics and select the right channel based on the use-case.
     */
    struct acpi_gpio dmic_select_gpio;
+
+	/*
+	 * DMIC present (optional) to support ACP DMIC hardware runtime detection on the
+	 * platform.
+	 */
+	bool dmic_present;
 };

#endif /* ___DRIVERS_AMD_I2S_MACHINE_DEV_H__ */
diff --git a/src/drivers/amd/i2s_machine_dev/i2s_machine_dev.c b/src/drivers/amd/i2s_machine_dev/i2s_machine_dev.c
index 7bd256d..06b8c00 100644
--- a/src/drivers/amd/i2s_machine_dev/i2s_machine_dev.c
+++ b/src/drivers/amd/i2s_machine_dev/i2s_machine_dev.c
@@ -69,6 +69,14 @@
    if (dmic_select_gpio->pin_count)
    	i2s_machine_dev_fill_crs_dsd(path, dmic_select_gpio);

+	/* For ACP DMIC hardware runtime detection on the platform, _WOV method is populated. */
+	acpigen_write_method("_WOV", 0);
+	if (dmic_select_gpio->pin_count || cfg->dmic_present)
+		acpigen_write_return_integer(1);
+	else
+		acpigen_write_return_integer(0);
+	acpigen_pop_len(); /* Method */
+
    acpigen_pop_len(); /* Device */
    acpigen_pop_len(); /* Scope */