Re: [PATCHv3 resend 1/2] dt/bindings: Add the DT binding documentation for endianness

[Kumar Gala]

On Apr 30, 2014, at 1:52 AM, Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx> wrote:

> Signed-off-by: Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx>
> ---
> .../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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/