firmware: arm_scmi: Add debugfs ABI documentation for common entries

Add description of the debugfs SCMI common 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/20230118121426.492864-12-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/Documentation/ABI/testing/debugfs-scmi b/Documentation/ABI/testing/debugfs-scmi
new file mode 100644 (file)
index 0000000..ee7179a
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-scmi
@@ -0,0 +1,70 @@
+What:          /sys/kernel/debug/scmi/<n>/instance_name
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   The name of the underlying SCMI instance <n> described by
+               all the debugfs accessors rooted at /sys/kernel/debug/scmi/<n>,
+               expressed as the full name of the top DT SCMI node under which
+               this SCMI instance is rooted.
+Users:         Debugging, any userspace test suite
+
+What:          /sys/kernel/debug/scmi/<n>/atomic_threshold_us
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   An optional time value, expressed in microseconds, representing,
+               on this SCMI instance <n>, the threshold above which any SCMI
+               command, advertised to have an higher-than-threshold execution
+               latency, should not be considered for atomic mode of operation,
+               even if requested.
+Users:         Debugging, any userspace test suite
+
+What:          /sys/kernel/debug/scmi/<n>/transport/type
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   A string representing the type of transport configured for this
+               SCMI instance <n>.
+Users:         Debugging, any userspace test suite
+
+What:          /sys/kernel/debug/scmi/<n>/transport/is_atomic
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   A boolean stating if the transport configured on the underlying
+               SCMI instance <n> is capable of atomic mode of operation.
+Users:         Debugging, any userspace test suite
+
+What:          /sys/kernel/debug/scmi/<n>/transport/max_rx_timeout_ms
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   Timeout in milliseconds allowed for SCMI synchronous replies
+               for the currently configured SCMI transport for instance <n>.
+Users:         Debugging, any userspace test suite
+
+What:          /sys/kernel/debug/scmi/<n>/transport/max_msg_size
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   Max message size of allowed SCMI messages for the currently
+               configured SCMI transport for instance <n>.
+Users:         Debugging, any userspace test suite
+
+What:          /sys/kernel/debug/scmi/<n>/transport/tx_max_msg
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   Max number of concurrently allowed in-flight SCMI messages for
+               the currently configured SCMI transport for instance <n> on the
+               TX channels.
+Users:         Debugging, any userspace test suite
+
+What:          /sys/kernel/debug/scmi/<n>/transport/rx_max_msg
+Date:          March 2023
+KernelVersion: 6.3
+Contact:       cristian.marussi@arm.com
+Description:   Max number of concurrently allowed in-flight SCMI messages for
+               the currently configured SCMI transport for instance <n> on the
+               RX channels.
+Users:         Debugging, any userspace test suite