[PATCH] powerpc/fsl: add device tree binding for QE firmware
Timur Tabi
timur at freescale.com
Sat Mar 27 02:17:37 EST 2010
Grant Likely wrote:
> +- fsl,firmware:
> + Usage: Optional.
> + Value type: <prop-encoded-array>, encoded array of bytes
> + Definition: Contains the QUICC engine firmware blob.
> [plus any other properties needed for firmware metadata]
This would place the firmware metadata properties inside the QE node itself, which would break the QE binding.
> +Example:
> + qe1: qe at e0080000 {
> + compatible = "fsl,qe";
> + fsl,firmware = /bininc/("firmware-blob.bin"); /* Or
> squirted in by firmware */
> + ...
> + }
> +
> + qe at e0090000 {
> + compatible = "fsl,qe";
> + fsl,firmware-phandle = <&qe1>;
> + ...
> + }
>
> Putting the blob into just one of the qe nodes keeps everything nicely
> contained with the device it actually applies to. No debates about
> the best place to put device firmware blobs or new compatible values,
> and it is applicable to any device where firmware needs to be passed
> via the tree.
Except when you actually need to add metadata properties:
qe1: qe at e0080000 {
compatible = "fsl,qe";
fsl,firmware = /bininc/("firmware-blob.bin");
fsl,qe-firmware-eccr = <0x00000000 0x00001230>;
...
}
(The ECCR is stored in the QE firmware blob, but let's pretend it isn't and I need to specify it)
Here, the fsl,qe-firmware-eccr property is associated with the QE itself. This is why I want a compatible property for the firmware node, no matter where it is. Then you can do this:
qe1: qe at e0080000 {
compatible = "fsl,qe";
fsl,qe_firmware {
compatible="fsl,qe-firmware";
fsl,firmware = /bininc/("firmware-blob.bin");
fsl,qe-firmware-eccr = <0x00000000 0x00001230>;
}
...
}
Without the compatible property, the only way I'd know that the child node contains a firmware is to look at the actual name of the child node, which (as Scott and I believe) is not better than a compatible property.
--
Timur Tabi
Linux kernel developer at Freescale
More information about the Linuxppc-dev
mailing list