mctp i3c: MCTP I3C driver

Provides MCTP network transport over an I3C bus, as specified in
DMTF DSP0233.

Each I3C bus (with "mctp-controller" devicetree property) gets an
"mctpi3cX" net device created. I3C devices are reachable as remote
endpoints through that net device. Link layer addressing uses the
I3C PID as a fixed hardware address for neighbour table entries.

The driver matches I3C devices that have the MIPI assigned DCR 0xCC for
MCTP.
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/mctp/Kconfig

@@ -33,6 +33,15 @@ config MCTP_TRANSPORT_I2C
 	  from DMTF specification DSP0237. A MCTP protocol network device is
 	  created for each I2C bus that has been assigned a mctp-i2c device.
 
+config MCTP_TRANSPORT_I3C
+	tristate "MCTP I3C transport"
+	depends on I3C
+	help
+	  Provides a driver to access MCTP devices over I3C transport,
+	  from DMTF specification DSP0233.
+	  A MCTP protocol network device is created for each I3C bus
+	  having a "mctp-controller" devicetree property.
+
 endmenu
 
 endif

drivers/net/mctp/Makefile

 obj-$(CONFIG_MCTP_SERIAL) += mctp-serial.o
 obj-$(CONFIG_MCTP_TRANSPORT_I2C) += mctp-i2c.o
+obj-$(CONFIG_MCTP_TRANSPORT_I3C) += mctp-i3c.o