Re: [PATCH v7 1/2] dt-bindings: cpufreq: Introduce QCOM CPUFREQ Firmware bindings
From: Sudeep Holla <hidden>
Date: 2018-08-07 11:12:50
Also in:
linux-pm, lkml
On Mon, Aug 06, 2018 at 01:54:24PM -0700, skannan@codeaurora.org wrote:
On 2018-08-03 16:46, Stephen Boyd wrote:quoted
Quoting Taniya Das (2018-07-24 03:42:49)quoted
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 @@[...]quoted
+ + 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.
How about passing CPU freq clock domain id as along with phandle in qcom,freq-domain ? -- Regards, Sudeep