Signed-off-by: Laurent Pinchart <[EMAIL PROTECTED]>
---
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:
+
+ [EMAIL PROTECTED] {
+ 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
Belgium
T +32 (2) 387 42 59
F +32 (2) 387 42 75
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