Commit dcc35baa authored by Jeremy Kerr's avatar Jeremy Kerr Committed by Jakub Kicinski
Browse files

usb: Add base USB MCTP definitions 

Upcoming changes will add a USB host (and later gadget) driver for the
MCTP-over-USB protocol. Add a header that provides common definitions
for protocol support: the packet header format and a few framing
definitions. Add a define for the MCTP class code, as per
https://usb.org/defined-class-codes

.

Signed-off-by: default avatarJeremy Kerr <jk@codeconstruct.com.au>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20250221-dev-mctp-usb-v3-1-3353030fe9cc@codeconstruct.com.au


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent e6a53218

MAINTAINERS

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@@ -13896,6 +13896,7 @@ L: netdev@vger.kernel.org 
S:	Maintained

F:	Documentation/networking/mctp.rst

F:	drivers/net/mctp/

F:	include/linux/usb/mctp-usb.h

F:	include/net/mctp.h

F:	include/net/mctpdevice.h

F:	include/net/netns/mctp.h

include/linux/usb/mctp-usb.h

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/* SPDX-License-Identifier: GPL-2.0 */

/*

 * mctp-usb.h - MCTP USB transport binding: common definitions,

 * based on DMTF0283 specification:

 * https://www.dmtf.org/sites/default/files/standards/documents/DSP0283_1.0.1.pdf

 *

 * These are protocol-level definitions, that may be shared between host

 * and gadget drivers.

 *

 * Copyright (C) 2024-2025 Code Construct Pty Ltd

 */



#ifndef __LINUX_USB_MCTP_USB_H

#define __LINUX_USB_MCTP_USB_H



#include <linux/types.h>



struct mctp_usb_hdr {

	__be16	id;

	u8	rsvd;

	u8	len;

} __packed;



#define MCTP_USB_XFER_SIZE	512

#define MCTP_USB_BTU		68

#define MCTP_USB_MTU_MIN	MCTP_USB_BTU

#define MCTP_USB_MTU_MAX	(U8_MAX - sizeof(struct mctp_usb_hdr))

#define MCTP_USB_DMTF_ID	0x1ab4



#endif /*  __LINUX_USB_MCTP_USB_H */

include/uapi/linux/usb/ch9.h

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@@ -330,6 +330,7 @@ struct usb_device_descriptor { 
#define USB_CLASS_AUDIO_VIDEO		0x10

#define USB_CLASS_BILLBOARD		0x11

#define USB_CLASS_USB_TYPE_C_BRIDGE	0x12

#define USB_CLASS_MCTP			0x14

#define USB_CLASS_MISC			0xef

#define USB_CLASS_APP_SPEC		0xfe

#define USB_SUBCLASS_DFU			0x01