drivers/usb/pci_xhci: Add a driver to generate xHCI ACPI nodes

We can use xhci_for_each_ext_cap to inspect the xHC so we generate the
correct number of device nodes.

    Scope (\_SB.PCI0.PBRA)
    {
        Device (XHC1)
        {
            Name (_ADR, 0x0000000000000004)  // _ADR: Address
            Method (_STA, 0, NotSerialized)  // _STA: Status
            {
                Return (0x0F)
            }

            Name (_PRW, Package (0x02)  // _PRW: Power Resources for Wake
            {
                0x1F,
                0x03
            })
            Device (RHUB)
            {
                Name (_ADR, Zero)  // _ADR: Address
                Device (HS01)
                {
                    Name (_ADR, 0x01)  // _ADR: Address
                }

                Device (HS02)
                {
                    Name (_ADR, 0x02)  // _ADR: Address
                }

                Device (SS01)
                {
                    Name (_ADR, 0x03)  // _ADR: Address
                }
            }

            Name (_S0W, Zero)  // _S0W: S0 Device Wake State
            Name (_S3W, 0x04)  // _S3W: S3 Device Wake State
            Name (_S4W, 0x04)  // _S4W: S4 Device Wake State
        }
    }

BUG=b:154756391
TEST=Boot trembyle and look at ACPI table. See all xHCI nodes.

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: I44ebaef342e45923bc181ceebef882358d33f0d1
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41900
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/drivers/usb/pci_xhci/Kconfig b/src/drivers/usb/pci_xhci/Kconfig
new file mode 100644
index 0000000..715af5b
--- /dev/null
+++ b/src/drivers/usb/pci_xhci/Kconfig
@@ -0,0 +1,6 @@
+config DRIVERS_USB_PCI_XHCI
+	def_bool n
+	depends on HAVE_ACPI_TABLES
+	select XHCI_UTILS
+	help
+	  PCI driver that generates ACPI nodes for an xHCI compatible controller.
diff --git a/src/drivers/usb/pci_xhci/Makefile.inc b/src/drivers/usb/pci_xhci/Makefile.inc
new file mode 100644
index 0000000..73f6b06
--- /dev/null
+++ b/src/drivers/usb/pci_xhci/Makefile.inc
@@ -0,0 +1 @@
+ramstage-$(CONFIG_DRIVERS_USB_PCI_XHCI) += pci_xhci.c
diff --git a/src/drivers/usb/pci_xhci/pci_xhci.c b/src/drivers/usb/pci_xhci/pci_xhci.c
new file mode 100644
index 0000000..cbd3c34
--- /dev/null
+++ b/src/drivers/usb/pci_xhci/pci_xhci.c
@@ -0,0 +1,184 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include "pci_xhci.h"
+#include <acpi/acpigen.h>
+#include <console/console.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+#include <device/xhci.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define PCI_XHCI_CLASSCODE	0x0c0330 /* USB3.0 xHCI controller */
+
+static unsigned int controller_count;
+static const struct device_operations xhci_pci_ops;
+
+struct port_counts {
+	unsigned int high_speed;
+	unsigned int super_speed;
+};
+
+__weak enum cb_err pci_xhci_get_wake_gpe(const struct device *dev, int *gpe)
+{
+	*gpe = -1;
+	return CB_SUCCESS;
+}
+
+static const char *xhci_acpi_name(const struct device *dev)
+{
+	char *name;
+	unsigned int port_id;
+
+	if (dev->path.type == DEVICE_PATH_USB) {
+		/* Ports index start at 1 */
+		port_id = dev->path.usb.port_id + 1;
+
+		switch (dev->path.usb.port_type) {
+		case 0:
+			return "RHUB";
+		case 2:
+			name = malloc(ACPI_NAME_BUFFER_SIZE);
+			snprintf(name, ACPI_NAME_BUFFER_SIZE, "HS%02d", port_id);
+			name[4] = '\0';
+
+			return name;
+		case 3:
+			name = malloc(ACPI_NAME_BUFFER_SIZE);
+			snprintf(name, ACPI_NAME_BUFFER_SIZE, "SS%02d", port_id);
+			name[4] = '\0';
+			return name;
+		}
+	} else if (dev->ops == &xhci_pci_ops) {
+		return dev->name;
+	}
+
+	printk(BIOS_ERR, "%s: Unknown device %s\n", __func__, dev_path(dev));
+	return NULL;
+}
+
+static void handle_xhci_ext_cap(void *context, const struct xhci_ext_cap *cap)
+{
+	const struct xhci_supported_protocol *data;
+	const char *format;
+	char buf[16];
+	struct port_counts *counts = context;
+	unsigned int *dev_num;
+
+	if (cap->cap_id != XHCI_ECP_CAP_ID_SUPP)
+		return;
+
+	data = &cap->supported_protocol;
+
+	xhci_print_supported_protocol(data);
+
+	if (memcmp(data->name, "USB ", 4)) {
+		printk(BIOS_INFO, "%s: Unknown Protocol: %.*s\n", __func__,
+		       (int)sizeof(data->name), data->name);
+		return;
+	}
+
+	if (data->major_rev == 3) {
+		format = "SS%02d";
+		dev_num = &counts->super_speed;
+	} else if (data->major_rev == 2) {
+		format = "HS%02d";
+		dev_num = &counts->high_speed;
+	} else {
+		printk(BIOS_INFO, "%s: Unknown USB Version: %#x\n", __func__, data->major_rev);
+		return;
+	}
+
+	for (unsigned int i = 0; i < data->port_count; ++i) {
+		snprintf(buf, sizeof(buf), format, ++(*dev_num));
+		acpigen_write_device(buf);
+		acpigen_write_name_byte("_ADR", data->port_offset + i);
+		acpigen_pop_len();
+	}
+}
+
+static void xhci_add_devices(const struct device *dev)
+{
+	/* Used by the callback to track how many ports have been seen. */
+	struct port_counts counts = {0, 0};
+
+	acpigen_write_device("RHUB");
+	acpigen_write_name_integer("_ADR", 0x00000000);
+
+	xhci_for_each_ext_cap(dev, &counts, handle_xhci_ext_cap);
+
+	acpigen_pop_len();
+}
+
+static void xhci_fill_ssdt(const struct device *dev)
+{
+	int gpe;
+
+	printk(BIOS_DEBUG, "xHCI SSDT generation\n");
+
+	acpigen_write_scope(acpi_device_scope(dev));
+	acpigen_write_device(acpi_device_name(dev));
+
+	acpigen_write_ADR_pci_device(dev);
+	acpigen_write_name_string("_DDN", "xHC - Extensible Host Controller");
+	acpigen_write_STA(acpi_device_status(dev));
+
+	if (pci_xhci_get_wake_gpe(dev, &gpe) == CB_SUCCESS) {
+		printk(BIOS_DEBUG, "%s: Got GPE %d for %s\n", __func__, gpe, dev_path(dev));
+	} else {
+		printk(BIOS_ERR, "%s: Error getting GPE for : %s\n", __func__, dev_path(dev));
+		gpe = -1;
+	}
+
+	if (gpe > 0) {
+		acpigen_write_PRW(gpe, SLP_TYP_S3);
+		acpigen_write_name_integer("_S0W", ACPI_DEVICE_SLEEP_D0);
+		acpigen_write_name_integer("_S3W", ACPI_DEVICE_SLEEP_D3_COLD);
+		acpigen_write_name_integer("_S4W", ACPI_DEVICE_SLEEP_D3_COLD);
+	}
+
+	xhci_add_devices(dev);
+
+	acpigen_pop_len();
+	acpigen_pop_len();
+}
+
+static void xhci_enable(struct device *dev)
+{
+	char *name;
+	uint32_t class = pci_read_config32(dev, PCI_CLASS_REVISION);
+	/* Class code, the upper 3 bytes of PCI_CLASS_REVISION. */
+	class >>= 8;
+
+	if (class != PCI_XHCI_CLASSCODE) {
+		printk(BIOS_ERR, "Incorrect xHCI class code: %#x\n", class);
+		dev->enabled = 0;
+		return;
+	}
+
+	name = malloc(ACPI_NAME_BUFFER_SIZE);
+	snprintf(name, ACPI_NAME_BUFFER_SIZE, "XHC%d", controller_count++);
+	dev->name = name;
+}
+
+static const struct device_operations xhci_pci_ops = {
+	.read_resources		= pci_dev_read_resources,
+	.set_resources		= pci_dev_set_resources,
+	.enable_resources	= pci_dev_enable_resources,
+	.init			= pci_dev_init,
+	.scan_bus		= scan_static_bus,
+	.enable			= xhci_enable,
+	.ops_pci		= &pci_dev_ops_pci,
+	.acpi_fill_ssdt		= xhci_fill_ssdt,
+	.acpi_name		= xhci_acpi_name,
+};
+
+static const unsigned short amd_pci_device_ids[] = {
+	0
+};
+
+static const struct pci_driver xhci_pci_driver __pci_driver = {
+	.ops = &xhci_pci_ops,
+	.vendor = PCI_VENDOR_ID_AMD,
+	.devices = amd_pci_device_ids,
+};
diff --git a/src/drivers/usb/pci_xhci/pci_xhci.h b/src/drivers/usb/pci_xhci/pci_xhci.h
new file mode 100644
index 0000000..a923351
--- /dev/null
+++ b/src/drivers/usb/pci_xhci/pci_xhci.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __DRIVERS_USB_PCI_XHCI__
+#define __DRIVERS_USB_PCI_XHCI__
+
+#include <commonlib/bsd/cb_err.h>
+#include <device/device.h>
+
+/*
+ * Returns the wake GPE for the Extensible Host Controller.
+ * Set gpe to -1 if there is no GPE is available.
+ */
+enum cb_err pci_xhci_get_wake_gpe(const struct device *dev, int *gpe);
+
+#endif /* __DRIVERS_USB_PCI_XHCI__ */