i2c: mv64xxx: Document the newly introduced Armada XP A0 compatible

gclement · Jason Cooper · commit f8b94beb7e6a · 2014-01-14T02:09:17.000Z
The first variants of Armada XP SoCs (A0 stepping) have issues related to the i2c controller which prevent to use the offload mechanism and lead to a kernel hang during boot. The commit introduces a new the compatible string marvell,mv78230-a0-i2c for the i2c controller. Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Acked-by: Arnd Bergmann <arnd@arndb.de> cc: devicetree@vger.kernel.org Cc: stable@vger.kernel.org # v3.12+: af8d1c6: ARM: mvebu: Add support to get the ID and the revision of a SoC Cc: stable@vger.kernel.org # v3.12+: 85e618a: ARM: mvebu: Add quirk for i2c for the OpenBlocks AX3-4 board Cc: stable@vger.kernel.org # v3.12+: 6cf70ae: i2c: mv64xxx: Fix bus hang on A0 version of the Armada XP SoCs Cc: stable@vger.kernel.org # v3.12+ Fixes: 930ab3d (i2c: mv64xxx: Add I2C Transaction Generator support) Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
@@ -5,7 +5,11 @@ Required properties :
 
  - reg             : Offset and length of the register set for the device
  - compatible      : Should be "marvell,mv64xxx-i2c" or "allwinner,sun4i-i2c"
-                     or "marvell,mv78230-i2c"
+                     or "marvell,mv78230-i2c" or "marvell,mv78230-a0-i2c"
+                     Note: Only use "marvell,mv78230-a0-i2c" for a very rare,
+                     initial version of the SoC which had broken offload
+                     support.  Linux auto-detects this and sets it
+                     appropriately.
  - interrupts      : The interrupt number
 
 Optional properties :
