On 2018-08-03 16:46, Stephen Boyd wrote:
Quoting Taniya Das (2018-07-24 03:42:49)
diff --git
a/Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-hw.txt
b/Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-hw.txt
new file mode 100644
index 0000000..22d4355
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-hw.txt
@@ -0,0 +1,172 @@
[...]
+
+ CPU7: cpu@700 {
+ device_type = "cpu";
+ compatible = "qcom,kryo385";
+ reg = <0x0 0x700>;
+ enable-method = "psci";
+ next-level-cache = <&L2_700>;
+ qcom,freq-domain = <&freq_domain_table1>;
+ L2_700: l2-cache {
+ compatible = "cache";
+ next-level-cache = <&L3_0>;
+ };
+ };
+ };
+
+ qcom,cpufreq-hw {
+ compatible = "qcom,cpufreq-hw";
+
+ clocks = <&rpmhcc RPMH_CXO_CLK>;
+ clock-names = "xo";
+
+ #address-cells = <2>;
+ #size-cells = <2>;
+ ranges;
+ freq_domain_table0: freq_table0 {
+ reg = <0 0x17d43000 0 0x1400>;
+ };
+
+ freq_domain_table1: freq_table1 {
+ reg = <0 0x17d45800 0 0x1400>;
+ };
Sorry, this is just not proper DT design. The whole node should have a
reg property, and it should contain two (or three if we're handling the
L3 clk domain?) different offsets for the different power clusters. The
problem seems to still be that we don't have a way to map the CPUs to
the clk domains they're in provided by this hardware block. Making
subnodes is not the solution.
The problem is mapping clock domains to logical CPUs that CPUfreq uses.
The physical CPU to logical CPU mapping can be changed by the kernel
(even through DT if I'm not mistaken). So we need to have a way to tell
in DT which physical CPUs are connected to which CPU freq clock domain.
As for subnodes or not, we don't have any strong opinion, but couple of
other points to consider. Two or more CPUfreq policies might have a
common frequency table (read from HW), but separate control of
frequency. So, you also need a way to group frequency table with CPU
freq policies. If you have a better design, we are open to that
suggestion.
Thanks,
Saravana
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