soc/amd/cezanne,common: expose eMMC device in ACPI when enabled

When the eMMC MMIO device is enabled in the devicetree, it needs to be
exposed in ACPI in order for the OS driver to be able to attach to it.
The Cezanne eMMC controller isn't used in google/guybrush, so this the
code path where the eMMC MMIO device is enabled in the devicetree can't
be easily tested.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I69ff79b2d1c6a08cf333a2bb3996931962c2c102
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77989
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>

src/soc/amd/cezanne/acpi/mmio.asl

@@ -58,6 +58,42 @@ Device (GPIO)
 	}
 }
 
+Device (MMC0)
+{
+	Name (_HID, "AMDI0040")
+	Name (_UID, 0x0)
+	Method (_CRS, 0) {
+		Local0 = ResourceTemplate() {
+			Interrupt (
+				ResourceConsumer,
+				Level,
+				ActiveLow,
+				Exclusive, , , IRQR)
+			{ 0 }
+			Memory32Fixed (ReadWrite, APU_EMMC_BASE, 0x1000)
+		}
+		CreateDWordField (Local0, IRQR._INT, IRQN)
+		If (PICM) {
+			IRQN = IMMC
+		} Else {
+			IRQN = PMMC
+		}
+		If (IRQN == 0x1f) {
+			Return (ResourceTemplate(){
+				Memory32Fixed (ReadWrite, APU_EMMC_BASE, 0x1000)
+			})
+		} Else {
+			Return (Local0)
+		}
+	}
+
+	Name (STAT, 0x0)
+	Method (_STA, 0x0, NotSerialized)
+	{
+		Return (STAT)
+	}
+}
+
 Device (FUR0)
 {
 	Name (_HID, "AMDI0020")

src/soc/amd/common/block/emmc/emmc.c

@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
+#include <acpi/acpigen.h>
 #include <amdblocks/aoac.h>
 #include <device/device.h>
 #include <soc/aoac_defs.h>
@@ -15,9 +16,23 @@ static void emmc_enable(struct device *dev)
 		power_off_aoac_device(FCH_AOAC_DEV_EMMC);
 }
 
+static const char *emmc_acpi_name(const struct device *dev)
+{
+	return "MMC0";
+}
+
+static void emmc_acpi_fill_ssdt(const struct device *dev)
+{
+	acpigen_write_scope(acpi_device_path(dev));
+	acpigen_write_store_int_to_namestr(acpi_device_status(dev), "STAT");
+	acpigen_pop_len(); /* Scope */
+}
+
 struct device_operations amd_emmc_mmio_ops = {
 	.read_resources = emmc_read_resources,
 	.set_resources = noop_set_resources,
 	.scan_bus = scan_static_bus,
 	.enable = emmc_enable,
+	.acpi_name = emmc_acpi_name,
+	.acpi_fill_ssdt = emmc_acpi_fill_ssdt,
 };