1Binding for ST's CPUFreq driver 2=============================== 3 4ST's CPUFreq driver attempts to read 'process' and 'version' attributes 5from the SoC, then supplies the OPP framework with 'prop' and 'supported 6hardware' information respectively. The framework is then able to read 7the DT and operate in the usual way. 8 9For more information about the expected DT format [See: ../opp/opp.txt]. 10 11Frequency Scaling only 12---------------------- 13 14No vendor specific driver required for this. 15 16Located in CPU's node: 17 18- operating-points : [See: ../power/opp.txt] 19 20Example [safe] 21-------------- 22 23cpus { 24 cpu@0 { 25 /* kHz uV */ 26 operating-points = <1500000 0 27 1200000 0 28 800000 0 29 500000 0>; 30 }; 31}; 32 33Dynamic Voltage and Frequency Scaling (DVFS) 34-------------------------------------------- 35 36This requires the ST CPUFreq driver to supply 'process' and 'version' info. 37 38Located in CPU's node: 39 40- operating-points-v2 : [See ../power/opp.txt] 41 42Example [unsafe] 43---------------- 44 45cpus { 46 cpu@0 { 47 operating-points-v2 = <&cpu0_opp_table>; 48 }; 49}; 50 51cpu0_opp_table: opp_table { 52 compatible = "operating-points-v2"; 53 54 /* ############################################################### */ 55 /* # WARNING: Do not attempt to copy/replicate these nodes, # */ 56 /* # they are only to be supplied by the bootloader !!! # */ 57 /* ############################################################### */ 58 opp0 { 59 /* Major Minor Substrate */ 60 /* 2 all all */ 61 opp-supported-hw = <0x00000004 0xffffffff 0xffffffff>; 62 opp-hz = /bits/ 64 <1500000000>; 63 clock-latency-ns = <10000000>; 64 65 opp-microvolt-pcode0 = <1200000>; 66 opp-microvolt-pcode1 = <1200000>; 67 opp-microvolt-pcode2 = <1200000>; 68 opp-microvolt-pcode3 = <1200000>; 69 opp-microvolt-pcode4 = <1170000>; 70 opp-microvolt-pcode5 = <1140000>; 71 opp-microvolt-pcode6 = <1100000>; 72 opp-microvolt-pcode7 = <1070000>; 73 }; 74 75 opp1 { 76 /* Major Minor Substrate */ 77 /* all all all */ 78 opp-supported-hw = <0xffffffff 0xffffffff 0xffffffff>; 79 opp-hz = /bits/ 64 <1200000000>; 80 clock-latency-ns = <10000000>; 81 82 opp-microvolt-pcode0 = <1110000>; 83 opp-microvolt-pcode1 = <1150000>; 84 opp-microvolt-pcode2 = <1100000>; 85 opp-microvolt-pcode3 = <1080000>; 86 opp-microvolt-pcode4 = <1040000>; 87 opp-microvolt-pcode5 = <1020000>; 88 opp-microvolt-pcode6 = <980000>; 89 opp-microvolt-pcode7 = <930000>; 90 }; 91}; 92