From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@bootlin.com (Boris Brezillon) Date: Thu, 1 Mar 2018 18:12:48 +0100 Subject: [PATCH 1/2][v5] dt-bindings: mtd-physmap: Add endianness supports In-Reply-To: <20180228073335.1758-1-prabhakar.kushwaha@nxp.com> References: <20180228073335.1758-1-prabhakar.kushwaha@nxp.com> Message-ID: <20180301181248.7212a5c5@bbrezillon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 28 Feb 2018 13:03:34 +0530 Prabhakar Kushwaha wrote: > 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 > Reviewed-by: Rob Herring > --- > 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 The second sentence is no longer valid.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