From 6958024ad5cdd78deae4da47a8722b06317dff45 Mon Sep 17 00:00:00 2001
From: Aaron Sierra <asierra@xes-inc.com>
Date: Thu, 25 Sep 2014 12:20:24 -0500
Subject: mtd: map_rom: Support UBI on ROM
UBI needs to know the physical erase block size, even on read-only
devices, since it defines the on-device layout. Use a device-tree
provided value to support previously written UBI on read-only NOR.
UBI also needs a non-zero writebufsize, so we set it to one.
Note: This was implemented because hardware write-protected CFI
NOR cannot be probed for the physical erase block size.
Signed-off-by: Joe Schultz <jschultz@xes-inc.ccom>
Signed-off-by: Aaron Sierra <asierra@xes-inc.ccom>
[Brian: removed unneeded #ifdef, note 'optional' erase-size property]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
---
Documentation/devicetree/bindings/mtd/mtd-physmap.txt | 5 +++++
1 file changed, 5 insertions(+)
(limited to 'Documentation')
diff --git a/Documentation/devicetree/bindings/mtd/mtd-physmap.txt b/Documentation/devicetree/bindings/mtd/mtd-physmap.txt
index 6b9f680cb579..4a0a48bf4ecb 100644
--- a/Documentation/devicetree/bindings/mtd/mtd-physmap.txt
+++ b/Documentation/devicetree/bindings/mtd/mtd-physmap.txt
@@ -36,6 +36,11 @@ are defined:
- vendor-id : Contains the flash chip's vendor id (1 byte).
- device-id : Contains the flash chip's device id (1 byte).
+For ROM compatible devices (and ROM fallback from cfi-flash), the following
+additional (optional) property is defined:
+
+ - erase-size : The chip's physical erase block size in bytes.
+
The device tree may optionally contain sub-nodes describing partitions of the
address space. See partition.txt for more detail.
--
cgit