On Mon, Oct 26, 2020 at 01:16:51AM +0300, Dmitry Osipenko wrote: > External Memory Controller can gather various hardware statistics that > are intended to be used for debugging purposes and for dynamic frequency > scaling of memory bus. > > Document the new mfd-simple compatible and EMC statistics sub-device. It's simple-mfd. That should only be used if the child has no dependencies on the parent node (and driver). > The subdev contains EMC DFS OPP table and interconnect paths to be used > for dynamic scaling of system's memory bandwidth based on EMC utilization > statistics. > > Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx> > --- > .../memory-controllers/nvidia,tegra20-emc.txt | 43 +++++++++++++++++-- > 1 file changed, 40 insertions(+), 3 deletions(-) > > diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt > index 8d09b228ac42..382aabcd6952 100644 > --- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt > +++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt > @@ -4,7 +4,7 @@ Properties: > - name : Should be emc > - #address-cells : Should be 1 > - #size-cells : Should be 0 > -- compatible : Should contain "nvidia,tegra20-emc". > +- compatible : Should contain "nvidia,tegra20-emc" and "simple-mfd". > - reg : Offset and length of the register set for the device > - nvidia,use-ram-code : If present, the sub-nodes will be addressed > and chosen using the ramcode board selector. If omitted, only one > @@ -17,7 +17,8 @@ Properties: > - core-supply: Phandle of voltage regulator of the SoC "core" power domain. > - operating-points-v2: See ../bindings/opp/opp.txt for details. > > -Child device nodes describe the memory settings for different configurations and clock rates. > +Child device nodes describe the memory settings for different configurations and clock rates, > +as well as EMC activity statistics collection sub-device. > > Example: > > @@ -31,17 +32,34 @@ Example: > ... > }; > > + emc_bw_dfs_opp_table: emc_opp_table1 { > + compatible = "operating-points-v2"; > + > + opp@36000000 { > + opp-hz = /bits/ 64 <36000000>; > + opp-peak-kBps = <144000>; > + }; > + ... > + }; > + > memory-controller@7000f400 { > #address-cells = < 1 >; > #size-cells = < 0 >; > #interconnect-cells = < 0 >; > - compatible = "nvidia,tegra20-emc"; > + compatible = "nvidia,tegra20-emc", "simple-mfd"; > reg = <0x7000f400 0x400>; > interrupts = <0 78 0x04>; > clocks = <&tegra_car TEGRA20_CLK_EMC>; > nvidia,memory-controller = <&mc>; > core-supply = <&core_vdd_reg>; > operating-points-v2 = <&emc_icc_dvfs_opp_table>; > + > + emc-stats { > + compatible = "nvidia,tegra20-emc-statistics"; > + operating-points-v2 = <&emc_bw_dfs_opp_table>; > + interconnects = <&mc TEGRA20_MC_MPCORER &emc>; > + interconnect-names = "cpu"; > + }; > } > > > @@ -120,3 +138,22 @@ Properties: > 0 0 0 0 0 0 0 0 0 0 0 0 0 0 > 0 0 0 0 >; > }; > + > + > + > +Embedded Memory Controller statistics gathering sub-device > + > +EMC statistics subdev gathers information about hardware utilization > +which is intended to be used for debugging purposes and for dynamic > +frequency scaling based on the collected stats. > + > +Properties: > +- name : Should be emc-stats. > +- compatible : Should contain "nvidia,tegra20-emc-statistics". > +- operating-points-v2: See ../bindings/opp/opp.txt for details. > +- interconnects: Should contain entries for memory clients sitting on > + MC->EMC memory interconnect path. > +- interconnect-names: Should include name of the interconnect path for each > + interconnect entry. Consult TRM documentation for > + information about available memory clients, see MEMORY > + CONTROLLER section. > -- > 2.27.0 > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel