92 lines
2.4 KiB
Plaintext
92 lines
2.4 KiB
Plaintext
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Binding for ST's CPUFreq driver
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===============================
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ST's CPUFreq driver attempts to read 'process' and 'version' attributes
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from the SoC, then supplies the OPP framework with 'prop' and 'supported
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hardware' information respectively. The framework is then able to read
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the DT and operate in the usual way.
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For more information about the expected DT format [See: ../opp/opp.txt].
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Frequency Scaling only
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----------------------
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No vendor specific driver required for this.
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Located in CPU's node:
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- operating-points : [See: ../power/opp.txt]
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Example [safe]
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--------------
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cpus {
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cpu@0 {
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/* kHz uV */
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operating-points = <1500000 0
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1200000 0
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800000 0
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500000 0>;
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};
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};
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Dynamic Voltage and Frequency Scaling (DVFS)
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--------------------------------------------
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This requires the ST CPUFreq driver to supply 'process' and 'version' info.
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Located in CPU's node:
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- operating-points-v2 : [See ../power/opp.txt]
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Example [unsafe]
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----------------
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cpus {
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cpu@0 {
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operating-points-v2 = <&cpu0_opp_table>;
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};
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};
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cpu0_opp_table: opp_table {
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compatible = "operating-points-v2";
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/* ############################################################### */
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/* # WARNING: Do not attempt to copy/replicate these nodes, # */
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/* # they are only to be supplied by the bootloader !!! # */
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/* ############################################################### */
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opp0 {
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/* Major Minor Substrate */
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/* 2 all all */
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opp-supported-hw = <0x00000004 0xffffffff 0xffffffff>;
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opp-hz = /bits/ 64 <1500000000>;
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clock-latency-ns = <10000000>;
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opp-microvolt-pcode0 = <1200000>;
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opp-microvolt-pcode1 = <1200000>;
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opp-microvolt-pcode2 = <1200000>;
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opp-microvolt-pcode3 = <1200000>;
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opp-microvolt-pcode4 = <1170000>;
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opp-microvolt-pcode5 = <1140000>;
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opp-microvolt-pcode6 = <1100000>;
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opp-microvolt-pcode7 = <1070000>;
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};
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opp1 {
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/* Major Minor Substrate */
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/* all all all */
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opp-supported-hw = <0xffffffff 0xffffffff 0xffffffff>;
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opp-hz = /bits/ 64 <1200000000>;
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clock-latency-ns = <10000000>;
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opp-microvolt-pcode0 = <1110000>;
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opp-microvolt-pcode1 = <1150000>;
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opp-microvolt-pcode2 = <1100000>;
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opp-microvolt-pcode3 = <1080000>;
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opp-microvolt-pcode4 = <1040000>;
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opp-microvolt-pcode5 = <1020000>;
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opp-microvolt-pcode6 = <980000>;
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opp-microvolt-pcode7 = <930000>;
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};
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};
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