[PATCH 2/2] [POWERPC] Describe memory-mapped RAM&ROM chips of bindings

[Laurent Pinchart]

Signed-off-by: Laurent Pinchart <laurentp at cse-semaphore.com>
---
 Documentation/powerpc/booting-without-of.txt |   31 +++++++++++++++++++++++++-
 1 files changed, 30 insertions(+), 1 deletions(-)

diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index 7b4e8a7..53d1cf8 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -57,7 +57,8 @@ Table of Contents
       n) 4xx/Axon EMAC ethernet nodes
       o) Xilinx IP cores
       p) Freescale Synchronous Serial Interface
-	  q) USB EHCI controllers
+      q) USB EHCI controllers
+      r) Memory-mapped RAM & ROM
 
   VII - Specifying interrupt information for devices
     1) interrupts property
@@ -2816,6 +2817,34 @@ platforms are moved over to use the flattened-device-tree model.
 		   big-endian;
 	   };
 
+   r) Memory-mapped RAM & ROM
+
+    Dedicated RAM and ROM chips are often used as storage for temporary or
+    permanent data in embedded devices. Possible usage include non-volatile
+    storage in battery-backed SRAM, semi-permanent storage in dedicated SRAM
+    to preserve data accross reboots and firmware storage in dedicated ROM.
+
+     - compatible : should contain the specific model of RAM/ROM chip(s)
+       used, if known, followed by either "physmap-ram" or "physmap-rom"
+     - reg : Address range of the RAM/ROM chip
+     - bank-width : Width (in bytes) of the RAM/ROM bank. Equal to the
+       device width times the number of interleaved chips.
+     - device-width : (optional) Width of a single RAM/ROM chip. If
+       omitted, assumed to be equal to 'bank-width'.
+
+    Similarly to memory-mapped NOR flash, memory-mapped RAM & ROM chips
+    can be partionned. See the "j) CFI and JEDEC memory-mapped NOR flash"
+    section for information about how to represent partitions in the
+    device tree.
+
+    Example:
+
+	mmram at f2000000 {
+		compatible = "renesas,m5m5w816", "physmap-ram";
+		reg = <f2000000 00100000>;
+		bank-width = <2>;
+	};
+
 
    More devices will be defined as this spec matures.
 
-- 
1.5.0


-- 
Laurent Pinchart
CSE Semaphore Belgium

Chaussée de Bruxelles, 732A
B-1410 Waterloo
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T +32 (2) 387 42 59
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