From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kumar Gala Subject: Re: [PATCHv3 resend 1/2] dt/bindings: Add the DT binding documentation for endianness Date: Thu, 1 May 2014 11:00:14 -0700 Message-ID: References: <1398847921-9322-1-git-send-email-Li.Xiubo@freescale.com> <1398847921-9322-2-git-send-email-Li.Xiubo@freescale.com> Mime-Version: 1.0 (Mac OS X Mail 7.2 \(1874\)) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <1398847921-9322-2-git-send-email-Li.Xiubo@freescale.com> Sender: linux-doc-owner@vger.kernel.org To: Xiubo Li Cc: mark.rutland@arm.com, broonie@kernel.org, robh+dt@kernel.org, pawel.moll@arm.com, ijc+devicetree@hellion.org.uk, rob@landley.net, richardcochran@gmail.com, gregkh@linuxfoundation.org, mpa@pengutronix.de, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org On Apr 30, 2014, at 1:52 AM, Xiubo Li wrote: > Signed-off-by: Xiubo Li > --- > .../devicetree/bindings/endianness/endianness.txt | 47 ++++++++++++++++++++++ > 1 file changed, 47 insertions(+) > create mode 100644 Documentation/devicetree/bindings/endianness/endianness.txt > > diff --git a/Documentation/devicetree/bindings/endianness/endianness.txt b/Documentation/devicetree/bindings/endianness/endianness.txt > new file mode 100644 > index 0000000..49458a1 > --- /dev/null > +++ b/Documentation/devicetree/bindings/endianness/endianness.txt > @@ -0,0 +1,47 @@ > +Device-Tree binding for device endianness > + > +The endianness mode of CPU & Device scenarios: > +Index CPU Device Endianess flag for DT bool property > +------------------------------------------------------------ > +1 LE LE - > +2 LE BE 'big-endian{,-*}' > +3 BE BE - > +4 BE LE 'little-endian{,-*}' > + > +For one device driver, which will run in different scenarios above > +on different SoCs using the devicetree, we need one way to simplify > +this. > + > +Required properties: > +- {big,little}-endian{,-*}: this is one boolean property. > + what is the {,-*} all about? > +Examples: > +Scenario 1 : CPU in LE mode & device in LE mode. > +dev: dev@40031000 { > + compatible = "name"; > + reg = <0x40031000 0x1000>; > + ... > +}; > + > +Scenario 2 : CPU in LE mode & device in BE mode. > +dev: dev@40031000 { > + compatible = "name"; > + reg = <0x40031000 0x1000>; > + ... > + big-endian{,-*}; > +}; > + > +Scenario 3 : CPU in BE mode & device in BE mode. > +dev: dev@40031000 { > + compatible = "name"; > + reg = <0x40031000 0x1000>; > + ... > +}; > + > +Scenario 4 : CPU in BE mode & device in LE mode. > +dev: dev@40031000 { > + compatible = "name"; > + reg = <0x40031000 0x1000>; > + ... > + little-endian{,-*}; > +}; > -- > 1.8.4 > -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation