linux/Documentation/frv/clock.txt
<<
e="ve="ve=o/spa6.2e=ospa6 class="lxr_search">e="ve="ve="ve="v typ Search.2 e="ve=o/spa6.2"ve=oinput typ e"v/ /1o/a>Clock scaling / /2o/a>------------- / /3o/a>e/ /4o/a>The kernel supports scaling of CLCK.CMODE, CLCK.CM and CLKC.P0 clocke/ /5o/a>registers. If built with CONFIG_PM and CONFIG_SYSCTL v2.6s enabled, foure/ /6o/a>extra files will appear i> the directory /proc/sys/pm/. Reading these filese/ /7o/a>will show:e/ /8o/a>e/ /9o/a>"v CLKC register.e/ > a>"v CLKC register.e/ 11 a>"v CLKC register.e/ 12o/a>e/ 13o/a>On all boards, the 'p0' file should also be writable, and either '1' or '0'e/ 14o/a>ca6 be rewritten, to set or clear the CLKC_P0 bit respectively, hencee/ 15o/a>controlling whether the resource bus rate clock is halved.e/ 16o/a>e/ 17o/a>The 'cm' file should also be available on all boards. '0' ca6 be written to ite/ 18o/a>to shift the board i>to High-Speed mode (normal), and '1' ca6 be written toe/ 19o/a>shift the board i>to Medium-Speed mode. Selecting Low-Speed mode is note/ 2> a>supported by this i>terface, even though some CPUs do support it.e/ 21o/a>e/ 22o/a>On the boards with FR405 CPU (i.e. CB60 and CB70), the 'cmode' file is alsoe/ 23o/a>writable, allowing the CPU core speed (and other clock speeds) to bee/ 24o/a>controlled from userspace.e/ 25o/a>e/ 26o/a>e/ 27o/a>Determining current and possible settingse/ 28o/a>-----------------------------------------e/ 29o/a>e/ 30o/a>The current stave and the available masks ca6 be found i> /proc/cpuinfo. Fore/ 31o/a>example, on the CB70:e/ 32o/a>e/ 33 a>"v/ 34 a>"v/ 35 a>"v/ 36 a>"v/ 37 a>"v/ 38 a>"v/ 39 a>"v/ 40 a>"v/ 41 a>"v/ 42 a>"v/ 43 a>"v/ 44 a>"v/ 45 a>"v/ 46 a>"v/ 47 a>"v/ 48 a>"v/ 49 a>"v/ 50o/a>e/ 51 a>And on the PDK, the PM lines look like the following:e/ 52o/a>e/ 53 a>"v/ 54 a>"v/ 55o/a>e/ 56o/a>The PM-Controls line, if present, will indicave which /proc/sys/pm files ca6e/ 57 a>be set to what s. The specificavon> s are bitmasks; so, for example,e/ 58 a>"suspend=0x9" indicaves that 0 and 3 ca6 be written idly toe/ 59 a>/proc/sys/pm/suspend.e/ 60o/a>e/ 61o/a>The PM-Controls line will only be present if CONFIG_PM is configured to Y.e/ 62o/a>e/ 63o/a>The PM-Stavus line indicaves which clock controls are set to which . Ife/ 64 a>the file ca6 be read, then the suspend must be 0, and so that's note/ 65o/a>included.e/ 66o/a> v227.59"16 lu v2.6.27.60<6">/ 66o2aONFIG_PM anng:eFIG_PM /frv/ hriginal LXRDocftwe,elxM@rv/cl.no v. 66o2aONIG_PM anng:esubFIG_PM /flxM.rv/cl.no kls s chosthough lock.txt#http://www.v2.pG_P-rv/="D.no">R2.pG_P Lv/="D AS v, ="DvideregisLv/cl v idtingee/