soc/intel/common: Add SSDT generation for Intel USB4 PCIe ports

This driver will generate the ACPI _DSD for the USB4 PCIe root port
properties instead of using static ASL.

It assigns the USB4 port number and marks the port as external and
hotplug capable.

Change-Id: I7086b06346ce63fab6bef4077fb76ae1d30dc1eb
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44915
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/common/block/usb4/Kconfig

@@ -4,3 +4,10 @@ config SOC_INTEL_COMMON_BLOCK_USB4
 	help
 	  Minimal PCI Driver for enabling SSDT generation for the DMA component
 	  of Intel Thunderbolt/USB4 ports.
+
+config SOC_INTEL_COMMON_BLOCK_USB4_PCIE
+	bool
+	default n
+	help
+	  Chip driver for adding PCI ops and SSDT generation for common Intel
+	  USB4/Thunderbolt root ports.

src/soc/intel/common/block/usb4/Makefile.inc

@@ -1 +1,2 @@
 ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_USB4) += usb4.c
+ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_USB4_PCIE) += pcie.c

src/soc/intel/common/block/usb4/chip.h

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DRIVERS_INTEL_USB4_PCIE_H__
+#define __DRIVERS_INTEL_USB4_PCIE_H__
+
+struct soc_intel_common_block_usb4_config {
+	const char *desc;
+
+	/* Pointer to USB4 device that this PCIe root port is routed to. */
+	DEVTREE_CONST struct device *usb4_port;
+};
+
+#endif /* __DRIVERS_INTEL_USB4_PCIE_H__ */

src/soc/intel/common/block/usb4/pcie.c

@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <acpi/acpigen.h>
+#include <console/console.h>
+#include <device/device.h>
+#include <device/path.h>
+#include <device/pci.h>
+#include <device/pci_def.h>
+#include <device/pci_ids.h>
+#include <stdlib.h>
+#include <string.h>
+#include <types.h>
+#include "chip.h"
+
+#define PCI_HOTPLUG_IN_D3_UUID	"6211E2C0-58A3-4AF3-90E1-927A4E0C55A4"
+#define PCI_EXTERNAL_PORT_UUID	"EFCC06CC-73AC-4BC3-BFF0-76143807C389"
+
+#if CONFIG(HAVE_ACPI_TABLES)
+static void usb4_pcie_fill_ssdt(const struct device *dev)
+{
+	const struct soc_intel_common_block_usb4_config *config;
+	const struct device *parent;
+	struct acpi_dp *dsd, *pkg;
+	const char *usb4_path;
+	int port_id;
+
+	/* Get parent PCI device */
+	parent = dev->bus->dev;
+	if (!parent) {
+		printk(BIOS_ERR, "%s: Unable to find parent device\n", __func__);
+		return;
+	}
+
+	if (!dev->enabled || !parent->enabled)
+		return;
+
+	config = config_of(dev);
+	if (!config->usb4_port) {
+		printk(BIOS_ERR, "%s: Unable to find reference to usb4_port\n", __func__);
+		return;
+	}
+
+	/* Get ACPI path to USB4 device. */
+	usb4_path = acpi_device_path(config->usb4_port);
+	if (!usb4_path) {
+		printk(BIOS_ERR, "%s: Unable to find ACPI path for usb4_port\n", __func__);
+		return;
+	}
+
+	usb4_path = strdup(usb4_path);
+	port_id = dev->path.generic.id;
+
+	acpigen_write_scope(acpi_device_path(dev));
+
+	/* Add pointer to USB4 port controller. */
+	dsd = acpi_dp_new_table("_DSD");
+	acpi_dp_add_reference(dsd, "usb4-host-interface", usb4_path);
+	acpi_dp_add_integer(dsd, "usb4-port-number", port_id);
+
+	/* Indicate that device supports hotplug in D3. */
+	pkg = acpi_dp_new_table(PCI_HOTPLUG_IN_D3_UUID);
+	acpi_dp_add_integer(pkg, "HotPlugSupportInD3", 1);
+	acpi_dp_add_package(dsd, pkg);
+
+	/* Indicate that port is external. */
+	pkg = acpi_dp_new_table(PCI_EXTERNAL_PORT_UUID);
+	acpi_dp_add_integer(pkg, "ExternalFacingPort", 1);
+	acpi_dp_add_integer(pkg, "UID", port_id);
+
+	acpi_dp_add_package(dsd, pkg);
+	acpi_dp_write(dsd);
+
+	acpigen_pop_len(); /* Scope */
+
+	printk(BIOS_INFO, "%s: %s at %s\n", acpi_device_path(dev), config->desc, dev_path(dev));
+}
+#endif
+
+static struct device_operations usb4_dev_ops = {
+	.read_resources		= pci_dev_read_resources,
+	.set_resources		= pci_dev_set_resources,
+	.enable_resources	= pci_dev_enable_resources,
+	.scan_bus		= scan_static_bus,
+#if CONFIG(HAVE_ACPI_TABLES)
+	.acpi_fill_ssdt		= usb4_pcie_fill_ssdt,
+#endif
+};
+
+static void pcie_enable(struct device *dev)
+{
+	dev->ops = &usb4_dev_ops;
+}
+
+struct chip_operations soc_intel_common_block_usb4_ops = {
+	CHIP_NAME("Intel USB4 Root Port")
+	.enable_dev = pcie_enable
+};