[POWERPC] Document the global utilities node define and example

[linux-2.6] / Documentation / powerpc / booting-without-of.txt

diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index d42d98107d494d906ded560a3e61bfad829e8911..06141cb200fa0734df549ebed4f6536aeba4409f 100644 (file)
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -51,6 +51,7 @@ Table of Contents
       h) Board Control and Status (BCSR)
       i) Freescale QUICC Engine module (QE)
       g) Flash chip nodes
+      k) Global Utilities Block
 
   VII - Specifying interrupt information for devices
     1) interrupts property
@@ -626,6 +627,14 @@ So the node content can be summarized as a start token, a full path,
 a list of properties, a list of child nodes, and an end token. Every
 child node is a full node structure itself as defined above.
 
+NOTE: The above definition requires that all property definitions for
+a particular node MUST precede any subnode definitions for that node.
+Although the structure would not be ambiguous if properties and
+subnodes were intermingled, the kernel parser requires that the
+properties come first (up until at least 2.6.22).  Any tools
+manipulating a flattened tree must take care to preserve this
+constraint.
+
 4) Device tree "strings" block
 
 In order to save space, property names, which are generally redundant,
@@ -1782,6 +1791,33 @@ platforms are moved over to use the flattened-device-tree model.
                partition-names = "fs\0firmware";
        };
 
+   k) Global Utilities Block
+
+   The global utilities block controls power management, I/O device
+   enabling, power-on-reset configuration monitoring, general-purpose
+   I/O signal configuration, alternate function selection for multiplexed
+   signals, and clock control.
+
+   Required properties:
+
+    - compatible : Should define the compatible device type for
+      global-utilities.
+    - reg : Offset and length of the register set for the device.
+
+  Recommended properties:
+
+    - fsl,has-rstcr : Indicates that the global utilities register set
+      contains a functioning "reset control register" (i.e. the board
+      is wired to reset upon setting the HRESET_REQ bit in this register).
+
+    Example:
+
+       global-utilities@e0000 {        /* global utilities block */
+               compatible = "fsl,mpc8548-guts";
+               reg = <e0000 1000>;
+               fsl,has-rstcr;
+       };
+
    More devices will be defined as this spec matures.
 
 VII - Specifying interrupt information for devices