[PATCH 1/2][v5] dt-bindings: mtd-physmap: Add endianness supports
From: Boris Brezillon <hidden>
Date: 2018-03-01 17:12:48
Also in:
linux-devicetree
On Wed, 28 Feb 2018 13:03:34 +0530 Prabhakar Kushwaha [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Connection between flash and controller is not necessary to be always of same type. It may varies from platform to platform. Adding endianness (optional) property to provide connection type information. Signed-off-by: Prabhakar Kushwaha <redacted> Reviewed-by: Rob Herring <robh@kernel.org> --- Changes for v2: updated subject Changes for v3: fixed typo for "big-endian" Changes for v4: Moved binding definition in mtd-physmap.txt as discussed at https://patchwork.ozlabs.org/patch/842543/ Changes for v5: Sending as it is Documentation/devicetree/bindings/mtd/mtd-physmap.txt | 5 +++++ 1 file changed, 5 insertions(+)diff --git a/Documentation/devicetree/bindings/mtd/mtd-physmap.txt b/Documentation/devicetree/bindings/mtd/mtd-physmap.txt index 4a0a48bf4ecb..961a8eed9d0d 100644 --- a/Documentation/devicetree/bindings/mtd/mtd-physmap.txt +++ b/Documentation/devicetree/bindings/mtd/mtd-physmap.txt@@ -41,6 +41,11 @@ additional (optional) property is defined: - erase-size : The chip's physical erase block size in bytes. + The device tree may optionally contain endianness property. + little-endian or big-endian : It represents connection between controller and + flash.
Hm, I'm not even sure it has to do with the HW connection of the data lines (D0:X), probably more something related to how the flash was programmed (some people program the flash using a dedicated programmer before soldering it on the board) and the current platform endianness (which for some platforms, can be changed with a Kconfig option).
If this property is absent, flash is considered + to be host-endian.
The second sentence is no longer valid. Now, if the property is missing the behavior is platform/configuration dependent, not necessarily host-endian.
+ The device tree may optionally contain sub-nodes describing partitions of the address space. See partition.txt for more detail.
-- Boris Brezillon, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com