From 28f9ec349ae47c91768b7bc5607db4442c818e11 Mon Sep 17 00:00:00 2001 From: Vitaly Wool Date: Mon, 20 Nov 2006 16:32:39 +0300 Subject: [POWERPC] Add of_platform support for ROM devices This adds support for flash device descriptions to the OF device tree. It's inspired by and partially borrowed from Sergei's patch "[RFC] Adding MTD to device tree.patch". Signed-off-by: Vitaly Wool Signed-off-by: Sergei Shtylyov Signed-off-by: Paul Mackerras --- Documentation/powerpc/booting-without-of.txt | 39 ++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'Documentation') diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt index 4ac2d64..b3bd366 100644 --- a/Documentation/powerpc/booting-without-of.txt +++ b/Documentation/powerpc/booting-without-of.txt @@ -6,6 +6,8 @@ IBM Corp. (c) 2005 Becky Bruce , Freescale Semiconductor, FSL SOC and 32-bit additions +(c) 2006 MontaVista Software, Inc. + Flash chip node definition May 18, 2005: Rev 0.1 - Initial draft, no chapter III yet. @@ -1693,6 +1695,43 @@ platforms are moved over to use the flattened-device-tree model. }; }; + g) Flash chip nodes + + Flash chips (Memory Technology Devices) are often used for solid state + file systems on embedded devices. + + Required properties: + + - device_type : has to be "rom" + - compatible : Should specify what this ROM device is compatible with + (i.e. "onenand"). Currently, this is most likely to be "direct-mapped" + (which corresponds to the MTD physmap mapping driver). + - regs : Offset and length of the register set (or memory mapping) for + the device. + + Recommended properties : + + - bank-width : Width of the flash data bus in bytes. Required + for the NOR flashes (compatible == "direct-mapped" and others) ONLY. + - partitions : Several pairs of 32-bit values where the first value is + partition's offset from the start of the device and the second one is + partition size in bytes with LSB used to signify a read only + partititon (so, the parition size should always be an even number). + - partition-names : The list of concatenated zero terminated strings + representing the partition names. + + Example: + + flash@ff000000 { + device_type = "rom"; + compatible = "direct-mapped"; + regs = ; + bank-width = <4>; + partitions = <00000000 00f80000 + 00f80000 00080001>; + partition-names = "fs\0firmware"; + }; + More devices will be defined as this spec matures. -- cgit v1.1