Messages in this thread | | | Subject | Re: [PATCH v3 1/2] Documentation: Documentation for qcom, llcc | From | Stanimir Varbanov <> | Date | Thu, 29 Mar 2018 11:25:31 +0300 |
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Hi,
On 03/27/2018 09:52 PM, Rishabh Bhatnagar wrote: > Documentation for last level cache controller device tree bindings, > client bindings usage examples. > > Signed-off-by: Channagoud Kadabi <ckadabi@codeaurora.org> > Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org> > --- > .../devicetree/bindings/arm/msm/qcom,llcc.txt | 70 ++++++++++++++++++++++ > 1 file changed, 70 insertions(+) > create mode 100644 Documentation/devicetree/bindings/arm/msm/qcom,llcc.txt > > diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,llcc.txt b/Documentation/devicetree/bindings/arm/msm/qcom,llcc.txt > new file mode 100644 > index 0000000..ceb20a4 > --- /dev/null > +++ b/Documentation/devicetree/bindings/arm/msm/qcom,llcc.txt > @@ -0,0 +1,70 @@ > +== Introduction== > + > +LLCC (Last Level Cache Controller) driver is implemented as a platform device. > +The driver Programs the SCT (system configuration table). The SCT programming > +divides the system cache into slices. Each slice is assigned an ID A.K.A > +SCID(Sub-cache ID). > +HW modules that are designated to use the system cache are known as clients. > +Each client must also be represented as a node in the device tree just like > +any other hw module. > +One client can have multiple SCID's assigned meaning each client could get > +multiple slices in the cache. Client can use the slices for various pre-defined > +usecases. Each client defines a set of names for these usecases in its > +device tree binding. > +Client makes a request to LLCC device to get cache-slices properties for each > +of its usecase. Client gets the information like cache slice ID and size of the > +cache slice.
All this describes the driver, please just describe what is LLCC and for what it used for.
> + > +== llcc device ==
drop this.
> + > +Properties: > +- compatible: > + Usage: required > + Value type: <string> > + Definition: must be "qcom,sdm855-llcc" > + > +- reg: > + Usage: required > + Value Type: <prop-encoded-array> > + Definition: must be addresses and sizes of the LLCC registers > + > +- #cache-cells: > + Usage: required > + Value Type: <u32> > + Definition: Number of cache cells, must be 1 > + > +- max-slices: > + usage: required > + Value Type: <u32> > + Definition: Number of cache slices supported by hardware > + > +Example: > + > + llcc: qcom,sdm855-llcc@01100000 {
this should be qcom,llcc@1100000
> + compatible = "qcom,sdm845-llcc"; > + reg = <0x01100000 0x250000>; > + #cache-cells = <1>; > + max-slices = <32>; > + }; > + > +== Client == > + > +Required properties: > +- cache-slice-names:
in my opinion this shouldn't be required but optional.
> + Usage: required > + Value type: <stringlist> > + Definition: A set of names that identify the usecase names of a client that > + uses cache slice. These strings are used to look up the cache slice > + entries by name. > + > +- cache-slices: > + Usage: required > + Value type: <prop-encoded-array> > + Definition: The tuple has phandle to llcc device as the first argument and > + the second argument is the usecase id of the client. > +For Example: > + > + venus { > + cache-slice-names = "vidsc0", "vidsc1"; > + cache-slices = <&llcc 2>, <&llcc 3>;
please make 2,3 and so on #defines.
-- regards, Stan
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