Merge branch 'mctp-add-mctp-over-usb-hardware-transport-binding'

Jeremy Kerr says:

====================
mctp: Add MCTP-over-USB hardware transport binding

Add an implementation of the DMTF standard DSP0283, providing an MCTP
channel over high-speed USB.

This is a fairly trivial first implementation, in that we only submit
one tx and one rx URB at a time. We do accept multi-packet transfers,
but do not yet generate them on transmit.

Of course, questions and comments are most welcome, particularly on the
USB interfaces.

v2: https://lore.kernel.org/20250212-dev-mctp-usb-v2-0-76e67025d764@codeconstruct.com.au
v1: https://lore.kernel.org/20250206-dev-mctp-usb-v1-0-81453fe26a61@codeconstruct.com.au
====================

Link: https://patch.msgid.link/20250221-dev-mctp-usb-v3-0-3353030fe9cc@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

MAINTAINERS

@@ -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

drivers/net/mctp/Kconfig

@@ -47,6 +47,16 @@ config MCTP_TRANSPORT_I3C
 	  A MCTP protocol network device is created for each I3C bus
 	  having a "mctp-controller" devicetree property.
 
+config MCTP_TRANSPORT_USB
+	tristate "MCTP USB transport"
+	depends on USB
+	help
+	  Provides a driver to access MCTP devices over USB transport,
+	  defined by DMTF specification DSP0283.
+
+	  MCTP-over-USB interfaces are peer-to-peer, so each interface
+	  represents a physical connection to one remote MCTP endpoint.
+
 endmenu
 
 endif

drivers/net/mctp/Makefile

@@ -1,3 +1,4 @@
 obj-$(CONFIG_MCTP_SERIAL) += mctp-serial.o
 obj-$(CONFIG_MCTP_TRANSPORT_I2C) += mctp-i2c.o
 obj-$(CONFIG_MCTP_TRANSPORT_I3C) += mctp-i3c.o
+obj-$(CONFIG_MCTP_TRANSPORT_USB) += mctp-usb.o