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Diffstat (limited to 'Documentation/frv/clock.txt')
| -rw-r--r-- | Documentation/frv/clock.txt | 65 |
1 files changed, 0 insertions, 65 deletions
diff --git a/Documentation/frv/clock.txt b/Documentation/frv/clock.txt deleted file mode 100644 index c72d350e177a..000000000000 --- a/Documentation/frv/clock.txt +++ /dev/null @@ -1,65 +0,0 @@ -Clock scaling -------------- - -The kernel supports scaling of CLCK.CMODE, CLCK.CM and CLKC.P0 clock -registers. If built with CONFIG_PM and CONFIG_SYSCTL options enabled, four -extra files will appear in the directory /proc/sys/pm/. Reading these files -will show: - - p0 -- current value of the P0 bit in CLKC register. - cm -- current value of the CM bits in CLKC register. - cmode -- current value of the CMODE bits in CLKC register. - -On all boards, the 'p0' file should also be writable, and either '1' or '0' -can be rewritten, to set or clear the CLKC_P0 bit respectively, hence -controlling whether the resource bus rate clock is halved. - -The 'cm' file should also be available on all boards. '0' can be written to it -to shift the board into High-Speed mode (normal), and '1' can be written to -shift the board into Medium-Speed mode. Selecting Low-Speed mode is not -supported by this interface, even though some CPUs do support it. - -On the boards with FR405 CPU (i.e. CB60 and CB70), the 'cmode' file is also -writable, allowing the CPU core speed (and other clock speeds) to be -controlled from userspace. - - -Determining current and possible settings ------------------------------------------ - -The current state and the available masks can be found in /proc/cpuinfo. For -example, on the CB70: - - # cat /proc/cpuinfo - CPU-Series: fr400 - CPU-Core: fr405, gr0-31, BE, CCCR - CPU: mb93405 - MMU: Prot - FP-Media: fr0-31, Media - System: mb93091-cb70, mb93090-mb00 - PM-Controls: cmode=0xd31f, cm=0x3, p0=0x3, suspend=0x9 - PM-Status: cmode=3, cm=0, p0=0 - Clock-In: 50.00 MHz - Clock-Core: 300.00 MHz - Clock-SDRAM: 100.00 MHz - Clock-CBus: 100.00 MHz - Clock-Res: 50.00 MHz - Clock-Ext: 50.00 MHz - Clock-DSU: 25.00 MHz - BogoMips: 300.00 - -And on the PDK, the PM lines look like the following: - - PM-Controls: cm=0x3, p0=0x3, suspend=0x9 - PM-Status: cmode=9, cm=0, p0=0 - -The PM-Controls line, if present, will indicate which /proc/sys/pm files can -be set to what values. The specification values are bitmasks; so, for example, -"suspend=0x9" indicates that 0 and 3 can be written validly to -/proc/sys/pm/suspend. - -The PM-Controls line will only be present if CONFIG_PM is configured to Y. - -The PM-Status line indicates which clock controls are set to which value. If -the file can be read, then the suspend value must be 0, and so that's not -included. |