From: Xiubo Li <Li.Xiubo@freescale.com>
To: <broonie@kernel.org>, <mark.rutland@arm.com>
CC: <robh+dt@kernel.org>, <pawel.moll@arm.com>,
        <ijc+devicetree@hellion.org.uk>, <galak@codeaurora.org>,
        <gregkh@linuxfoundation.org>, <linux-kernel@vger.kernel.org>,
        <devicetree@vger.kernel.org>, Xiubo Li <Li.Xiubo@freescale.com>
Subject: [PATCHv5 2/2] dt/bindings: Add the DT binding documentation for endianness
Date: Tue, 15 Jul 2014 12:18:24 +0800
Message-ID: <1405397904-31202-3-git-send-email-Li.Xiubo@freescale.com>
In-Reply-To: <1405397904-31202-1-git-send-email-Li.Xiubo@freescale.com>
References: <1405397904-31202-1-git-send-email-Li.Xiubo@freescale.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org

Device-Tree binding for device endianness
Index     Device     Endianness properties
---------------------------------------------------
1         BE         'big-endian'
2         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.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
---
 .../devicetree/bindings/regmap/regmap.txt          | 48 ++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regmap/regmap.txt

diff --git a/Documentation/devicetree/bindings/regmap/regmap.txt b/Documentation/devicetree/bindings/regmap/regmap.txt
new file mode 100644
index 0000000..cc5f7f8
--- /dev/null
+++ b/Documentation/devicetree/bindings/regmap/regmap.txt
@@ -0,0 +1,48 @@
+Device-Tree binding for device endianness
+
+The endianness mode of CPU & Device scenarios:
+Index    CPU       Device     Endianness properties
+------------------------------------------------------------
+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{,-*}: these are boolean properties, if absent
+  meaning that the CPU and the Device are in the same endianness mode.
+
+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{,-*};
+};
-- 
1.8.5

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