Re: [PATCH] powerpc/fsl: add device tree binding for QE firmware

[Grant Likely <grant.likely@secretlab.ca>]

On Tue, Mar 23, 2010 at 3:42 PM, Timur Tabi <timur@freescale.com> wrote:
> Define a binding for embedding a QE firmware blob into the device tree.  Also
> define a new property for the QE node that links to a firmware node.
>
> Signed-off-by: Timur Tabi <timur@freescale.com>
> ---
>  .../powerpc/dts-bindings/fsl/cpm_qe/qe.txt         |   50 ++++++++++++++++++++
>  1 files changed, 50 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt
> index 6e37be1..d9d6431 100644
> --- a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt
> +++ b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt
> @@ -20,6 +20,14 @@ Required properties:
>  - fsl,qe-num-riscs: define how many RISC engines the QE has.
>  - fsl,qe-num-snums: define how many serial number(SNUM) the QE can use for the
>   threads.
> +- fsl,firmware-phandle:
> +    Usage: required
> +    Value type: <phandle>
> +    Definition: Points to a firmware node (see "QE Firmware Node" below)
> +        that contains the firmware that should be uploaded for this QE.
> +        The compatible property for the firmware node should say,
> +        "fsl,qe-firmware".
> +

Why the phandle redirection?  Why not just put the firmware blob into
a property in the QE node, or as a subnode?

g.

>
>  Recommended properties
>  - brg-frequency : the internal clock source frequency for baud-rate
> @@ -59,3 +67,45 @@ Example:
>                reg = <0 c000>;
>        };
>      };
> +
> +* QE Firmware Node
> +
> +This node defines a firmware binary that is embedded in the device tree, for
> +the purpose of passing the firmware from bootloader to the kernel, or from
> +the hypervisor to the guest.
> +
> +The firmware node itself contains the firmware binary contents, a compatible
> +property, and any firmware-specific properties.  The node itself can be located
> +anywhere, but should probably be placed at the top level.  The QE node
> +that needs the firmware should define a property that links to the firmware
> +node's phandle.
> +
> +This node is typically not defined in the DTS.  Instead, the boot loader
> +normally creates the node from scratch, using a firmware binary that is already
> +located in non-volatile storage or transferred from a tftp server.
> +
> +Required properties:
> +  - compatible
> +      Usage: required
> +      Value type: <string>
> +      Definition: A standard property.  Specify a string that indicates what
> +          kind of firmware it is.  For QE, this should be "fsl,qe-firmware".
> +
> +   - fsl,firmware
> +      Usage: required
> +      Value type: <prop-encoded-array>, encoded as an array of bytes
> +      Definition: A standard property.  This property contains the firmware
> +          binary "blob".
> +
> +Example:
> +       qe@e0080000 {
> +               compatible = "fsl,qe";
> +               fsl,firmware-phandle = <&qe_firmware>;
> +               ...
> +       }
> +
> +       qe_firmware:qe-firmware {
> +               compatible = "fsl,qe-firmware";
> +               fsl,firmware = <0x70 0xcd 0x00 0x00 0x01 0x46 0x45 0x63 ...>
> +       }
> +
> --
> 1.6.5
>
> _______________________________________________
> devicetree-discuss mailing list
> devicetree-discuss@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/devicetree-discuss
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.