This patch introduces support for I3C slave mode, which is referenced with a PCIe Endpoint system. It also establishes a configuration framework (configfs) for the I3C slave controller driver and the I3C slave function driver Typic usage as The user can configure the i3c-slave-tty device using configfs entry. In order to change the vendorid, the following commands can be used # echo 0x011b > functions/tty/func1/vendor_id # echo 0x1000 > functions/tty/func1/part_id # echo 0x6 > functions/tty/t/bcr Binding i3c-slave-tty Device to slave Controller ------------------------------------------------ In order for the slave function device to be useful, it has to be bound to a I3C slave controller driver. Use the configfs to bind the function device to one of the controller driver present in the system:: # ln -s functions/pci_epf_test/func1 controllers/44330000.i3c-slave/ Host side: cat /dev/ttyI3C0 Slave side: echo abc >/dev/ttyI3C0 Master side patch: https://lore.kernel.org/imx/20231018211111.3437929-1-Frank.Li@xxxxxxx/T/#u Frank Li (5): i3c: add slave mode support dt-bindings: i3c: svc: add compatible string i3c: silvaco,i3c-slave i3c: slave: add svc slave controller support i3c: slave: func: add tty driver Documentation: i3c: Add I3C slave mode controller and function .../bindings/i3c/silvaco,i3c-master.yaml | 8 +- Documentation/driver-api/i3c/index.rst | 1 + .../driver-api/i3c/slave/i3c-slave-cfs.rst | 109 +++ .../driver-api/i3c/slave/i3c-slave.rst | 189 +++++ .../driver-api/i3c/slave/i3c-tty-function.rst | 103 +++ .../driver-api/i3c/slave/i3c-tty-howto.rst | 109 +++ Documentation/driver-api/i3c/slave/index.rst | 13 + drivers/i3c/Kconfig | 30 + drivers/i3c/Makefile | 4 + drivers/i3c/func/Kconfig | 9 + drivers/i3c/func/Makefile | 3 + drivers/i3c/func/tty.c | 548 ++++++++++++ drivers/i3c/i3c-cfs.c | 389 +++++++++ drivers/i3c/slave.c | 453 ++++++++++ drivers/i3c/slave/Kconfig | 9 + drivers/i3c/slave/Makefile | 4 + drivers/i3c/slave/svc-i3c-slave.c | 795 ++++++++++++++++++ include/linux/i3c/slave.h | 503 +++++++++++ 18 files changed, 3276 insertions(+), 3 deletions(-) create mode 100644 Documentation/driver-api/i3c/slave/i3c-slave-cfs.rst create mode 100644 Documentation/driver-api/i3c/slave/i3c-slave.rst create mode 100644 Documentation/driver-api/i3c/slave/i3c-tty-function.rst create mode 100644 Documentation/driver-api/i3c/slave/i3c-tty-howto.rst create mode 100644 Documentation/driver-api/i3c/slave/index.rst create mode 100644 drivers/i3c/func/Kconfig create mode 100644 drivers/i3c/func/Makefile create mode 100644 drivers/i3c/func/tty.c create mode 100644 drivers/i3c/i3c-cfs.c create mode 100644 drivers/i3c/slave.c create mode 100644 drivers/i3c/slave/Kconfig create mode 100644 drivers/i3c/slave/Makefile create mode 100644 drivers/i3c/slave/svc-i3c-slave.c create mode 100644 include/linux/i3c/slave.h -- 2.34.1