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: Jeremy Kerr <jk@xxxxxxxxxxxxxxxxxxxx> --- v2: - add reference & URL to DSP0283 - update copyright year --- MAINTAINERS | 1 + include/linux/usb/mctp-usb.h | 30 ++++++++++++++++++++++++++++++ include/uapi/linux/usb/ch9.h | 1 + 3 files changed, 32 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 67665d9dd536873e94afffc00393c2fe2e8c2797..e7b326dba9a9e6f50c3beeb172d93641841f6242 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -13903,6 +13903,7 @@ L: netdev@xxxxxxxxxxxxxxx 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 diff --git a/include/linux/usb/mctp-usb.h b/include/linux/usb/mctp-usb.h new file mode 100644 index 0000000000000000000000000000000000000000..b19392aa29310eda504f65bd098c849bd02dc0a1 --- /dev/null +++ b/include/linux/usb/mctp-usb.h @@ -0,0 +1,30 @@ +/* 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 */ diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h index 91f0f7e214a5a57c8bee3f44c4dbf7b175843d8c..052290652046591fba46f1f0cb5cf77fd965f555 100644 --- a/include/uapi/linux/usb/ch9.h +++ b/include/uapi/linux/usb/ch9.h @@ -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 -- 2.39.5
