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>

diff --git a/Documentation/ABI/testing/sysfs-devices-platform-docg3 b/Documentation/ABI/testing/sysfs-devices-platform-docg3
new file mode 100644 (file)
index 0000000..8aa3671
--- /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.