| Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 1 | Binding for ST's CPUFreq driver |
| 2 | =============================== |
| 3 | |
| 4 | ST's CPUFreq driver attempts to read 'process' and 'version' attributes |
| 5 | from the SoC, then supplies the OPP framework with 'prop' and 'supported |
| 6 | hardware' information respectively. The framework is then able to read |
| 7 | the DT and operate in the usual way. |
| 8 | |
| 9 | Frequency Scaling only |
| 10 | ---------------------- |
| 11 | |
| 12 | No vendor specific driver required for this. |
| 13 | |
| 14 | Located in CPU's node: |
| 15 | |
| 16 | - operating-points : [See: ../power/opp-v1.yaml] |
| 17 | |
| 18 | Example [safe] |
| 19 | -------------- |
| 20 | |
| 21 | cpus { |
| 22 | cpu@0 { |
| 23 | /* kHz uV */ |
| 24 | operating-points = <1500000 0 |
| 25 | 1200000 0 |
| 26 | 800000 0 |
| 27 | 500000 0>; |
| 28 | }; |
| 29 | }; |
| 30 | |
| 31 | Dynamic Voltage and Frequency Scaling (DVFS) |
| 32 | -------------------------------------------- |
| 33 | |
| 34 | This requires the ST CPUFreq driver to supply 'process' and 'version' info. |
| 35 | |
| 36 | Located in CPU's node: |
| 37 | |
| 38 | - operating-points-v2 : [See ../power/opp-v2.yaml] |
| 39 | |
| 40 | Example [unsafe] |
| 41 | ---------------- |
| 42 | |
| 43 | cpus { |
| 44 | cpu@0 { |
| 45 | operating-points-v2 = <&cpu0_opp_table>; |
| 46 | }; |
| 47 | }; |
| 48 | |
| 49 | cpu0_opp_table: opp_table { |
| 50 | compatible = "operating-points-v2"; |
| 51 | |
| 52 | /* ############################################################### */ |
| 53 | /* # WARNING: Do not attempt to copy/replicate these nodes, # */ |
| 54 | /* # they are only to be supplied by the bootloader !!! # */ |
| 55 | /* ############################################################### */ |
| 56 | opp0 { |
| 57 | /* Major Minor Substrate */ |
| 58 | /* 2 all all */ |
| 59 | opp-supported-hw = <0x00000004 0xffffffff 0xffffffff>; |
| 60 | opp-hz = /bits/ 64 <1500000000>; |
| 61 | clock-latency-ns = <10000000>; |
| 62 | |
| 63 | opp-microvolt-pcode0 = <1200000>; |
| 64 | opp-microvolt-pcode1 = <1200000>; |
| 65 | opp-microvolt-pcode2 = <1200000>; |
| 66 | opp-microvolt-pcode3 = <1200000>; |
| 67 | opp-microvolt-pcode4 = <1170000>; |
| 68 | opp-microvolt-pcode5 = <1140000>; |
| 69 | opp-microvolt-pcode6 = <1100000>; |
| 70 | opp-microvolt-pcode7 = <1070000>; |
| 71 | }; |
| 72 | |
| 73 | opp1 { |
| 74 | /* Major Minor Substrate */ |
| 75 | /* all all all */ |
| 76 | opp-supported-hw = <0xffffffff 0xffffffff 0xffffffff>; |
| 77 | opp-hz = /bits/ 64 <1200000000>; |
| 78 | clock-latency-ns = <10000000>; |
| 79 | |
| 80 | opp-microvolt-pcode0 = <1110000>; |
| 81 | opp-microvolt-pcode1 = <1150000>; |
| 82 | opp-microvolt-pcode2 = <1100000>; |
| 83 | opp-microvolt-pcode3 = <1080000>; |
| 84 | opp-microvolt-pcode4 = <1040000>; |
| 85 | opp-microvolt-pcode5 = <1020000>; |
| 86 | opp-microvolt-pcode6 = <980000>; |
| 87 | opp-microvolt-pcode7 = <930000>; |
| 88 | }; |
| 89 | }; |