[efi] Expose unused USB devices via EFI_USB_IO_PROTOCOL

Allow the UEFI platform firmware to provide drivers for unrecognised
devices, by exposing our own implementation of EFI_USB_IO_PROTOCOL.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/efi/efi_usb.h

@@ -0,0 +1,80 @@
+#ifndef _IPXE_EFI_USB_H
+#define _IPXE_EFI_USB_H
+
+/** @file
+ *
+ * USB I/O protocol
+ *
+ */
+
+#include <ipxe/list.h>
+#include <ipxe/efi/efi.h>
+#include <ipxe/efi/efi_driver.h>
+#include <ipxe/efi/Protocol/UsbIo.h>
+#include <ipxe/usb.h>
+
+/** An EFI USB device */
+struct efi_usb_device {
+	/** Name */
+	const char *name;
+	/** The underlying USB device */
+	struct usb_device *usb;
+	/** The underlying EFI device */
+	struct efi_device *efidev;
+	/** Configuration descriptor */
+	struct usb_configuration_descriptor *config;
+	/** Supported languages */
+	struct usb_descriptor_header *languages;
+	/** List of interfaces */
+	struct list_head interfaces;
+};
+
+/** An EFI USB device interface */
+struct efi_usb_interface {
+	/** Name */
+	char name[32];
+	/** Containing USB device */
+	struct efi_usb_device *usbdev;
+	/** List of interfaces */
+	struct list_head list;
+
+	/** Interface number */
+	unsigned int interface;
+	/** Alternate setting */
+	unsigned int alternate;
+	/** EFI handle */
+	EFI_HANDLE handle;
+	/** USB I/O protocol */
+	EFI_USB_IO_PROTOCOL usbio;
+	/** Device path */
+	EFI_DEVICE_PATH_PROTOCOL *path;
+
+	/** Opened endpoints */
+	struct efi_usb_endpoint *endpoint[32];
+};
+
+/** An EFI USB device endpoint */
+struct efi_usb_endpoint {
+	/** EFI USB device interface */
+	struct efi_usb_interface *usbintf;
+	/** USB endpoint */
+	struct usb_endpoint ep;
+
+	/** Most recent synchronous completion status */
+	int rc;
+
+	/** Asynchronous timer event */
+	EFI_EVENT event;
+	/** Asynchronous callback handler */
+	EFI_ASYNC_USB_TRANSFER_CALLBACK callback;
+	/** Asynchronous callback context */
+	void *context;
+};
+
+/** Asynchronous transfer fill level
+ *
+ * This is a policy decision.
+ */
+#define EFI_USB_ASYNC_FILL 2
+
+#endif /* _IPXE_EFI_USB_H */

src/include/ipxe/errfile.h

@@ -341,6 +341,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #define ERRFILE_efi_time	      ( ERRFILE_OTHER | 0x00480000 )
 #define ERRFILE_efi_watchdog	      ( ERRFILE_OTHER | 0x00490000 )
 #define ERRFILE_efi_pxe		      ( ERRFILE_OTHER | 0x004a0000 )
+#define ERRFILE_efi_usb		      ( ERRFILE_OTHER | 0x004b0000 )
 
 /** @} */