soc/amd/picasso: Add driver for handling PCIE GPP bridges

This change adds a driver pcie_gpp.c which provides device_operations
for external and internal PCIe GPP bridges. These device operations
include standard PCI bridge operations as well as operations for
generating ACPI node for the device and returning appropriate ACPI
name for it.

Signed-off-by: Furquan Shaikh <furquan@google.com>
Change-Id: I9f8809c2735bdc09435deda91a570c89e71e8062
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43312
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

3 files changed, 61 insertions, 36 deletions

diff --git a/src/soc/amd/picasso/Makefile.inc b/src/soc/amd/picasso/Makefile.inc
index 593d17b82d..b6c0ddb915 100644
--- a/src/soc/amd/picasso/Makefile.inc
+++ b/src/soc/amd/picasso/Makefile.inc
@@ -78,6 +78,7 @@ ramstage-y += fsp_params.c
 ramstage-y += config.c
 ramstage-y += update_microcode.c
 ramstage-y += graphics.c
+ramstage-y += pcie_gpp.c
 
 smm-y += smihandler.c
 smm-y += smi_util.c
diff --git a/src/soc/amd/picasso/chip.c b/src/soc/amd/picasso/chip.c
index 2e5fae58e5..7d56323d96 100644
--- a/src/soc/amd/picasso/chip.c
+++ b/src/soc/amd/picasso/chip.c
@@ -56,24 +56,6 @@ const char *soc_acpi_name(const struct device *dev)
 			return "GNB";
 		case IOMMU_DEVFN:
 			return "IOMM";
-		case PCIE_GPP_0_DEVFN:
-			return "PBR0";
-		case PCIE_GPP_1_DEVFN:
-			return "PBR1";
-		case PCIE_GPP_2_DEVFN:
-			return "PBR2";
-		case PCIE_GPP_3_DEVFN:
-			return "PBR3";
-		case PCIE_GPP_4_DEVFN:
-			return "PBR4";
-		case PCIE_GPP_5_DEVFN:
-			return "PBR5";
-		case PCIE_GPP_6_DEVFN:
-			return "PBR6";
-		case PCIE_GPP_A_DEVFN:
-			return "PBRA";
-		case PCIE_GPP_B_DEVFN:
-			return "PBRB";
 		case LPC_DEVFN:
 			return "LPCB";
 		case SMBUS_DEVFN:
@@ -111,15 +93,6 @@ struct device_operations pci_domain_ops = {
 	.acpi_name	  = soc_acpi_name,
 };
 
-static struct device_operations pci_ops_ops_bus_ab = {
-	.read_resources		= pci_bus_read_resources,
-	.set_resources		= pci_dev_set_resources,
-	.enable_resources	= pci_bus_enable_resources,
-	.scan_bus		= pci_scan_bridge,
-	.reset_bus		= pci_bus_reset,
-	.acpi_fill_ssdt		= acpi_device_write_pci_dev,
-};
-
 static void set_mmio_dev_ops(struct device *dev)
 {
 	switch (dev->path.mmio.addr) {
@@ -144,15 +117,6 @@ static void enable_dev(struct device *dev)
 		dev->ops = &pci_domain_ops;
 	} else if (dev->path.type == DEVICE_PATH_CPU_CLUSTER) {
 		dev->ops = &cpu_bus_ops;
-	} else if (dev->path.type == DEVICE_PATH_PCI) {
-		if (dev->bus->dev->path.type == DEVICE_PATH_DOMAIN) {
-			switch (dev->path.pci.devfn) {
-			case PCIE_GPP_A_DEVFN:
-			case PCIE_GPP_B_DEVFN:
-				dev->ops = &pci_ops_ops_bus_ab;
-			}
-		}
-		sb_enable(dev);
 	} else if (dev->path.type == DEVICE_PATH_MMIO) {
 		set_mmio_dev_ops(dev);
 	}
diff --git a/src/soc/amd/picasso/pcie_gpp.c b/src/soc/amd/picasso/pcie_gpp.c
new file mode 100644
index 0000000000..73de80365d
--- /dev/null
+++ b/src/soc/amd/picasso/pcie_gpp.c
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <acpi/acpigen.h>
+#include <device/device.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+#include <soc/pci_devs.h>
+#include <stdio.h>
+
+static const char *pcie_gpp_acpi_name(const struct device *dev)
+{
+	if (dev->path.type != DEVICE_PATH_PCI)
+		return NULL;
+
+	switch (dev->path.pci.devfn) {
+	case PCIE_GPP_0_DEVFN:
+		return "PBR0";
+	case PCIE_GPP_1_DEVFN:
+		return "PBR1";
+	case PCIE_GPP_2_DEVFN:
+		return "PBR2";
+	case PCIE_GPP_3_DEVFN:
+		return "PBR3";
+	case PCIE_GPP_4_DEVFN:
+		return "PBR4";
+	case PCIE_GPP_5_DEVFN:
+		return "PBR5";
+	case PCIE_GPP_6_DEVFN:
+		return "PBR6";
+	case PCIE_GPP_A_DEVFN:
+		return "PBRA";
+	case PCIE_GPP_B_DEVFN:
+		return "PBRB";
+	}
+
+	return NULL;
+}
+
+static struct device_operations pcie_gpp_ops = {
+	.read_resources		= pci_bus_read_resources,
+	.set_resources		= pci_dev_set_resources,
+	.enable_resources	= pci_bus_enable_resources,
+	.scan_bus		= pci_scan_bridge,
+	.reset_bus		= pci_bus_reset,
+	.acpi_name		= pcie_gpp_acpi_name,
+	.acpi_fill_ssdt		= acpi_device_write_pci_dev,
+};
+
+static const unsigned short pci_device_ids[] = {
+	PCI_DEVICE_ID_AMD_FAM17H_PCIE_GPP,
+	PCI_DEVICE_ID_AMD_FAM17H_PCIE_GPP_BUSA,
+	PCI_DEVICE_ID_AMD_FAM17H_PCIE_GPP_BUSB,
+	0
+};
+
+static const struct pci_driver pcie_gpp_driver __pci_driver = {
+	.ops			= &pcie_gpp_ops,
+	.vendor			= PCI_VENDOR_ID_AMD,
+	.devices		= pci_device_ids,
+};