June 2017
Intermediate to advanced
478 pages
13h 14m
English
Content preview from Mastering Embedded Linux Programming - Second Edition
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Using CPUFreq
Looking at the BeagleBone Black, we find that the OPPs are coded in the device tree. Here is an extract from am33xx.dtsi:
cpu0_opp_table: opp-table { compatible = "operating-points-v2-ti-cpu"; syscon = <&scm_conf>; opp50@300000000 { opp-hz = /bits/ 64 <300000000>; opp-microvolt = <950000 931000 969000>; opp-supported-hw = <0x06 0x0010>; opp-suspend; }; opp100@600000000 { opp-hz = /bits/ 64 <600000000>; opp-microvolt = <1100000 1078000 1122000>; opp-supported-hw = <0x06 0x0040>; }; opp120@720000000 { opp-hz = /bits/ 64 <720000000>; opp-microvolt = <1200000 1176000 1224000>; opp-supported-hw = <0x06 0x0080>; }; oppturbo@800000000 { opp-hz = /bits/ 64 <800000000>; opp-microvolt = <1260000 1234800 1285200>; opp-supported-hw = <0x06 ...Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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