device/xhci: Add xHCI utility to enumerate capabilities

This will allow enumerating an xHCI controller to allow dynamically
generating the ACPI device nodes.

BUG=b:154756391
TEST=Boot trembyle and see capabilities printed on console
xHCI Supported Protocol:
  Major: 0x2, Minor: 0x0, Protocol: 'USB '
  Port Offset: 1, Port Count: 2
xHCI Supported Protocol:
  Major: 0x3, Minor: 0x10, Protocol: 'USB '
  Port Offset: 3, Port Count: 1

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: I3065c3fffad01b5378a55cfe904f971079b13d0f
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41899
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/src/include/device/xhci.h b/src/include/device/xhci.h
new file mode 100644
index 0000000000..25f950be2e
--- /dev/null
+++ b/src/include/device/xhci.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __DEVICE_XHCI_H__
+#define __DEVICE_XHCI_H__
+
+#include <stdint.h>
+#include <device/device.h>
+#include <commonlib/bsd/cb_err.h>
+
+#define XHCI_HCCPARAMS1_XECP 0x12
+
+#define XHCI_ECP_CAP_ID_LEGACY 1
+#define XHCI_ECP_CAP_ID_SUPP 2
+
+struct xhci_supported_protocol {
+	union {
+		uint32_t reg0;
+		struct {
+			uint32_t cap_id : 8;
+			uint32_t next_ptr : 8;
+			uint32_t minor_rev : 8;
+			uint32_t major_rev : 8;
+		};
+	};
+	union {
+		uint32_t reg1;
+		char name[4];
+	};
+	union {
+		uint32_t reg2;
+		struct {
+			uint32_t port_offset : 8;
+			uint32_t port_count : 8;
+			uint32_t reserved : 12;
+			uint32_t protocol_speed_id_count : 4;
+		};
+	};
+};
+
+struct xhci_ext_cap {
+	uint32_t cap_id;
+	/* cap_id is used to select the correct struct in the union. */
+	union {
+		struct xhci_supported_protocol supported_protocol;
+	};
+};
+
+/**
+ * Iterates over the xHCI Extended Capabilities List.
+ */
+enum cb_err xhci_for_each_ext_cap(const struct device *device, void *context,
+				  void (*callback)(void *context,
+						   const struct xhci_ext_cap *cap));
+
+void xhci_print_supported_protocol(const struct xhci_supported_protocol *supported_protocol);
+
+#endif /* __DEVICE_XHCI_H__ */