projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| b122bcd9 LJ |
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 | For more information about the expected DT format [See: ../opp/opp.txt]. | |
| 10 | ||
| 11 | Frequency Scaling only | |
| 12 | ---------------------- | |
| 13 | ||
| 14 | No vendor specific driver required for this. | |
| 15 | ||
| 16 | Located in CPU's node: | |
| 17 | ||
| 18 | - operating-points : [See: ../power/opp.txt] | |
| 19 | ||
| 20 | Example [safe] | |
| 21 | -------------- | |
| 22 | ||
| 23 | cpus { | |
| 24 | cpu@0 { | |
| 25 | /* kHz uV */ | |
| 26 | operating-points = <1500000 0 | |
| 27 | 1200000 0 | |
| 28 | 800000 0 | |
| 29 | 500000 0>; | |
| 30 | }; | |
| 31 | }; | |
| 32 | ||
| 33 | Dynamic Voltage and Frequency Scaling (DVFS) | |
| 34 | -------------------------------------------- | |
| 35 | ||
| 36 | This requires the ST CPUFreq driver to supply 'process' and 'version' info. | |
| 37 | ||
| 38 | Located in CPU's node: | |
| 39 | ||
| 40 | - operating-points-v2 : [See ../power/opp.txt] | |
| 41 | ||
| 42 | Example [unsafe] | |
| 43 | ---------------- | |
| 44 | ||
| 45 | cpus { | |
| 46 | cpu@0 { | |
| 47 | operating-points-v2 = <&cpu0_opp_table>; | |
| 48 | }; | |
| 49 | }; | |
| 50 | ||
| 51 | cpu0_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 | }; |