| Message ID | 1522176722-12691-2-git-send-email-rishabhb@codeaurora.org (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
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.
On Tue, Mar 27, 2018 at 1:52 PM, Rishabh Bhatnagar <rishabhb@codeaurora.org> 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 ++++++++++++++++++++++ Bindings need to go to DT list for review. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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. + +== llcc device == + +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 { + compatible = "qcom,sdm845-llcc"; + reg = <0x01100000 0x250000>; + #cache-cells = <1>; + max-slices = <32>; + }; + +== Client == + +Required properties: +- cache-slice-names: + 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>; + };