diff options
Diffstat (limited to 'Documentation/arm/sunxi')
| -rw-r--r-- | Documentation/arm/sunxi/clocks.rst | 57 |
1 files changed, 0 insertions, 57 deletions
diff --git a/Documentation/arm/sunxi/clocks.rst b/Documentation/arm/sunxi/clocks.rst deleted file mode 100644 index 23bd03f3e21f..000000000000 --- a/Documentation/arm/sunxi/clocks.rst +++ /dev/null @@ -1,57 +0,0 @@ -======================================================= -Frequently asked questions about the sunxi clock system -======================================================= - -This document contains useful bits of information that people tend to ask -about the sunxi clock system, as well as accompanying ASCII art when adequate. - -Q: Why is the main 24MHz oscillator gatable? Wouldn't that break the - system? - -A: The 24MHz oscillator allows gating to save power. Indeed, if gated - carelessly the system would stop functioning, but with the right - steps, one can gate it and keep the system running. Consider this - simplified suspend example: - - While the system is operational, you would see something like:: - - 24MHz 32kHz - | - PLL1 - \ - \_ CPU Mux - | - [CPU] - - When you are about to suspend, you switch the CPU Mux to the 32kHz - oscillator:: - - 24Mhz 32kHz - | | - PLL1 | - / - CPU Mux _/ - | - [CPU] - - Finally you can gate the main oscillator:: - - 32kHz - | - | - / - CPU Mux _/ - | - [CPU] - -Q: Were can I learn more about the sunxi clocks? - -A: The linux-sunxi wiki contains a page documenting the clock registers, - you can find it at - - http://linux-sunxi.org/A10/CCM - - The authoritative source for information at this time is the ccmu driver - released by Allwinner, you can find it at - - https://github.com/linux-sunxi/linux-sunxi/tree/sunxi-3.0/arch/arm/mach-sun4i/clock/ccmu |