Documentation: add sysfs entries for mtd docg3 chips

Add documentation for MSystems disk-on-chip docg3 chips
sysfs entries, which enable and disable protection areas,
giving or disabling access to the chip's memory.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-devices-platform-docg3 b/Documentation/ABI/testing/sysfs-devices-platform-docg3
new file mode 100644
index 000000000000..8aa36716882f
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-platform-docg3
@@ -0,0 +1,34 @@
+What:           /sys/devices/platform/docg3/f[0-3]_dps[01]_is_keylocked
+Date:           November 2011
+KernelVersion:  3.3
+Contact:        Robert Jarzmik <robert.jarzmik@free.fr>
+Description:
+                Show whether the floor (0 to 4), protection area (0 or 1) is
+                keylocked. Each docg3 chip (or floor) has 2 protection areas,
+                which can cover any part of it, block aligned, called DPS.
+                The protection has information embedded whether it blocks reads,
+                writes or both.
+                The result is:
+                0 -> the DPS is not keylocked
+                1 -> the DPS is keylocked
+Users:          None identified so far.
+
+What:           /sys/devices/platform/docg3/f[0-3]_dps[01]_protection_key
+Date:           November 2011
+KernelVersion:  3.3
+Contact:        Robert Jarzmik <robert.jarzmik@free.fr>
+Description:
+                Enter the protection key for the floor (0 to 4), protection area
+                (0 or 1). Each docg3 chip (or floor) has 2 protection areas,
+                which can cover any part of it, block aligned, called DPS.
+                The protection has information embedded whether it blocks reads,
+                writes or both.
+                The protection key is a string of 8 bytes (value 0-255).
+                Entering the correct value toggle the lock, and can be observed
+                through f[0-3]_dps[01]_is_keylocked.
+                Possible values are:
+                        - 8 bytes
+                Typical values are:
+                        - "00000000"
+                        - "12345678"
+Users:          None identified so far.