firmware: arm_scmi: Add debugfs ABI documentation for raw mode

Add description of the debugfs SCMI raw mode ABI.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20230118121426.492864-14-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/Documentation/ABI/testing/debugfs-scmi-raw b/Documentation/ABI/testing/debugfs-scmi-raw
new file mode 100644 (file)
index 0000000..45817d4
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-scmi-raw
@@ -0,0 +1,66 @@
+What:          /sys/kernel/debug/scmi/<n>/raw/message
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   SCMI Raw synchronous message injection/snooping facility; write
+               a complete SCMI synchronous command message (header included)
+               in little-endian binary format to have it sent to the configured
+               backend SCMI server for instance <n>.
+               Any subsequently received response can be read from this same
+               entry if it arrived within the configured timeout.
+               Each write to the entry causes one command request to be built
+               and sent while the replies are read back one message at time
+               (receiving an EOF at each message boundary).
+Users:         Debugging, any userspace test suite
+
+What:          /sys/kernel/debug/scmi/<n>/raw/message_async
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   SCMI Raw asynchronous message injection/snooping facility; write
+               a complete SCMI asynchronous command message (header included)
+               in little-endian binary format to have it sent to the configured
+               backend SCMI server for instance <n>.
+               Any subsequently received response can be read from this same
+               entry if it arrived within the configured timeout.
+               Any additional delayed response received afterwards can be read
+               from this same entry too if it arrived within the configured
+               timeout.
+               Each write to the entry causes one command request to be built
+               and sent while the replies are read back one message at time
+               (receiving an EOF at each message boundary).
+Users:         Debugging, any userspace test suite
+
+What:          /sys/kernel/debug/scmi/<n>/raw/errors
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   SCMI Raw message errors facility; any kind of timed-out or
+               generally unexpectedly received SCMI message, for instance <n>,
+               can be read from this entry.
+               Each read gives back one message at time (receiving an EOF at
+               each message boundary).
+Users:         Debugging, any userspace test suite
+
+What:          /sys/kernel/debug/scmi/<n>/raw/notification
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   SCMI Raw notification snooping facility; any notification
+               emitted by the backend SCMI server, for instance <n>, can be
+               read from this entry.
+               Each read gives back one message at time (receiving an EOF at
+               each message boundary).
+Users:         Debugging, any userspace test suite
+
+What:          /sys/kernel/debug/scmi/<n>/raw/reset
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   SCMI Raw stack reset facility; writing a value to this entry
+               causes the internal queues of any kind of received message,
+               still pending to be read out for instance <n>, to be immediately
+               flushed.
+               Can be used to reset and clean the SCMI Raw stack between to
+               different test-run.
+Users:         Debugging, any userspace test suite