Quoting Shiraz Hashim (2012-11-06 22:36:10) > On Wed, Nov 7, 2012 at 11:42 AM, Shiraz Hashim > <[email protected]> wrote: > > Hi Mike, Rob, > > > > Devices in a SoC can have multiple possible clock sources which is > > perfectly captured through clk framework. > > > > But the device itself may not be aware of the complex hierarchy above it. > > In this case how do you suggest a board (through DT) should select its > > preference. > > > > Is there some work already going on in this direction ? > > Just to make it clear, I already have referred the clock DT bindings and > Shawn Guo patch on removing clk look up registration from kernel code. > > Here I am talking about possibility of selecting desired clock hierarchy > by the boards about which device nodes are not aware. >
One way to achieve this is to use clk_set_rate as a way to switch parents at run-time. The OMAP CCF code currently does this when relocking PLLs and makes use of __clk_reparent to update the clock framework's representation of the hierarchy dynamically. Maybe something like the following is helpful to you: http://git.linaro.org/gitweb?p=people/mturquette/linux.git;a=blob;f=arch/arm/mach-omap2/dpll3xxx.c;h=f72dedb4eee892ce4cd5bdf22cc8c22510f3d526;hb=clk-omap-3.8#l542 Regards, Mike > -- > regards > Shiraz Hashim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
