Messages in this thread | | | Date | Wed, 14 Feb 2018 11:34:19 -0800 | From | Bjorn Andersson <> | Subject | Re: [PATCH v2 2/2] dt-bindings: introduce Command DB for QCOM SoCs |
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On Thu 08 Feb 11:51 PST 2018, Lina Iyer wrote:
> From: Mahesh Sivasubramanian <msivasub@codeaurora.org> > > Command DB provides information on shared resources like clocks, > regulators etc., probed at boot by the remote subsytem and made > available in shared memory. > > Cc: devicetree@vger.kernel.org > Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org> > Signed-off-by: Lina Iyer <ilina@codeaurora.org> > --- > .../devicetree/bindings/arm/msm/cmd-db.txt | 38 ++++++++++++++++++++++ > 1 file changed, 38 insertions(+) > create mode 100644 Documentation/devicetree/bindings/arm/msm/cmd-db.txt > > diff --git a/Documentation/devicetree/bindings/arm/msm/cmd-db.txt b/Documentation/devicetree/bindings/arm/msm/cmd-db.txt > new file mode 100644 > index 000000000000..e21666e40ebf > --- /dev/null > +++ b/Documentation/devicetree/bindings/arm/msm/cmd-db.txt > @@ -0,0 +1,38 @@ > +Command DB > +--------- > + > +Command DB is a database that provides a mapping between resource key and the > +resource address for a system resource managed by a remote processor. The data > +is stored in a shared memory region and is loaded by the remote processor. > + > +Some of the Qualcomm Technologies Inc SoC's have hardware accelerators for > +controlling shared resources. Depending on the board configuration the shared > +resource properties may change. These properties are dynamically probed by the > +remote processor and made available in the shared memory. > + > +The devicetree representation of the command DB driver should be: > + > +PROPERTIES: > +- compatible: > + Usage: required > + Value type: <string> > + Definition: Should be "qcom,cmd-db" > + > +- memory-region: > + Usage: required > + Value type: <phandle> > + Definition: The phandle to the reserved memory region. > + > +Example: > + > + reserved-memory { > + [...] > + cmd_db_mem: qcom,cmd-db@c3f000c { > + reg = <0x0 0xc3f000c 0x0 0x8>;
I was hoping that we can describe the actual memory here, as I got the impression that it will also be a chunk of memory carved out from System RAM.
If not it would seem unlikely that there's a 8 byte carveout in the middle of DDR, what else is here?
> + }; > + }; > + > + qcom,cmd-db@c3f000c { > + compatible = "qcom,cmd-db";
Add "qcom,cmd-db" to "reserved_mem_matches" in drivers/of/platform.c, use of_reserved_mem_lookup(pdev->dev.of_node) to get the reserved_mem and you can just put the compatible directly on the reserved-memory node.
That way you don't need this separate node that doesn't really represent anything.
> + memory-region = <&cmd_db_mem>; > + };
Regards, Bjorn
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