docs: ABI: testing: Document the OCC hwmon FFDC binary interface
Add documentation for the new binary sysfs that will dump the SBEFIFO
FFDC.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20211019205307.36946-4-eajames@linux.ibm.com
Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/Documentation/ABI/testing/sysfs-bus-platform-devices-occ-hwmon b/Documentation/ABI/testing/sysfs-bus-platform-devices-occ-hwmon
new file mode 100644
index 0000000..b24d7ab
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-platform-devices-occ-hwmon
@@ -0,0 +1,13 @@
+What: /sys/bus/platform/devices/occ-hwmon.X/ffdc
+KernelVersion: 5.15
+Contact: eajames@linux.ibm.com
+Description:
+ Contains the First Failure Data Capture from the SBEFIFO
+ hardware, if there is any from a previous transfer. Otherwise,
+ the file is empty. The data is cleared when it's been
+ completely read by a user. As the name suggests, only the data
+ from the first error is saved, until it's cleared upon read. The OCC hwmon driver, running on
+ a Baseboard Management Controller (BMC), communicates with
+ POWER9 and up processors over the Self-Boot Engine (SBE) FIFO.
+ In many error conditions, the SBEFIFO will return error data
+ indicating the type of error and system state, etc.
