On Thu, Jan 8, 2015 at 8:12 AM, Nikhil Devshatwar <nikhil.nd@xxxxxx> wrote:
> Current device tree compiler allows to define multiple labels when defining
> the device node the first time. Typically device nodes are defined in
> DTSI files. Now these nodes can be overriden for updating some of the
> properties. Typically, device nodes are overridden in DTS files.
>
> When working with adapter boards, most of the time adapter board can fit to
> multiple base boards. But depending on which base board it is connected to,
> the devices on the adapter board would be children of different devices.
>
> e.g. On dra7-evm.dts, i2c2 is exported for expansion connector whereas
> on dra72-evm.dts, i2c5 is exported for expansion connector.
> This causes a problem when writing a generic device tree file for
> the adapter board. Because, you cannot know wheather all the devices on
s/wheather/whether/
> adpter board are present on i2c or i2c5.
s/adpter/adapter/
> The problem can be solved by adding a common label (e.g. i2cexp) in both
> of the DTS files when overriding the device nodes for i2c2 or i2c5.
> This way, generic adapter board file would override the i2cexp. And
> depending on which base board you use the adpter board, all the devices
s/adpter/adapter/
> are automatically added for correct device nodes.
>
> Change-Id: I3ad7247a79baed7268a91fc691360aece73d6d1b
Get rid of this Gerrit nonsense.
> Signed-off-by: Nikhil Devshatwar <nikhil.nd@xxxxxx>
> ---
> scripts/dtc/dtc-parser.y | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
You need to send this against upstream dtc, not the copy in the kernel.
Seems like a reasonable change, but I'm not too familar with dtc source.
> diff --git a/scripts/dtc/dtc-parser.y b/scripts/dtc/dtc-parser.y
> index f412460..d9ed3b7 100644
> --- a/scripts/dtc/dtc-parser.y
> +++ b/scripts/dtc/dtc-parser.y
> @@ -145,6 +145,18 @@ devicetree:
> {
> $$ = merge_nodes($1, $3);
> }
> +
> + | devicetree DT_LABEL DT_REF nodedef
> + {
> + struct node *target = get_node_by_ref($1, $3);
> +
> + add_label(&target->labels, $2);
> + if (target)
> + merge_nodes(target, $4);
> + else
> + print_error("label or path, '%s', not found", $2);
> + $$ = $1;
> + }
> | devicetree DT_REF nodedef
> {
> struct node *target = get_node_by_ref($1, $2);
> --
> 1.7.9.5
>
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