mei: add ABI documentation for fw_status exported through sysfs

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-mei b/Documentation/ABI/testing/sysfs-class-mei
index 0ec8b8178c41..80d9888a8ece 100644
--- a/Documentation/ABI/testing/sysfs-class-mei
+++ b/Documentation/ABI/testing/sysfs-class-mei
@@ -14,3 +14,18 @@ Description:
                 The /sys/class/mei/meiN directory is created for
                 each probed mei device
 
+What:           /sys/class/mei/meiN/fw_status
+Date:           Nov 2014
+KernelVersion:  3.19
+Contact:        Tomas Winkler <tomas.winkler@intel.com>
+Description:    Display fw status registers content
+
+                The ME FW writes its status information into fw status
+                registers for BIOS and OS to monitor fw health.
+
+                The register contains running state, power management
+                state, error codes, and others. The way the registers
+                are decoded depends on PCH or SoC generation.
+                Also number of registers varies between 1 and 6
+                depending on generation.
+