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From: Xiubo Li <Li.Xiubo@freescale.com>
To: mark.rutland@arm.com, broonie@kernel.org
Cc: gregkh@linuxfoundation.org, mpa@pengutronix.de,
	devicetree@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, Xiubo Li <Li.Xiubo@freescale.com>
Subject: [PATCHv3 1/2] dt/bindings: Add the DT binding documentation for endianness
Date: Wed, 30 Apr 2014 12:43:48 +0800	[thread overview]
Message-ID: <1398833029-29546-2-git-send-email-Li.Xiubo@freescale.com> (raw)
In-Reply-To: <1398833029-29546-1-git-send-email-Li.Xiubo@freescale.com>

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
---
 .../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.
+
+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


  reply	other threads:[~2014-04-30  4:43 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-30  4:43 [PATCHv3 0/2] add DT endianness binding support Xiubo Li
2014-04-30  4:43 ` Xiubo Li [this message]
2014-04-30  4:43 ` [PATCHv3 2/2] regmap: " Xiubo Li
2014-04-30  6:56   ` Markus Pargmann
2014-04-30  7:10     ` Li.Xiubo
2014-04-30  7:10 ` [PATCHv3 0/2] " Richard Cochran
2014-04-30  7:14   ` Li.Xiubo
2014-04-30  9:26     ` Richard Cochran
2014-04-30 13:46     ` Richard Cochran
2014-04-30 18:25   ` Mark Brown
2014-05-01  3:43     ` Richard Cochran

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