[RFC PATCH v1 0/3] clk: implement remuxing during set_rate

From: James Hogan
Date: Fri Mar 22 2013 - 11:45:20 EST


This patchset adds support for automatic selection of the best parent
for a clock mux, i.e. the one which can provide the closest clock rate
to that requested. It can be controlled by a new CLK_SET_RATE_REMUX flag
so that it doesn't happen unless explicitly allowed.

This works by way of adding a parameter to the round_rate clock op which
allows the clock driver to optionally select a different parent index.
This is used in clk_calc_new_rates to decide whether to initiate a
set_parent operation. This would obviously require the argument to be
added to all users of round_rate, something this patchset doesn't do as
I'm not sure if it's really the preferred method (hence the RFC).

An alternative would be to add a new callback, but that would complicate
the code in clk.c somewhat. I suppose it would also be possible for the
round_rate callback to call a function to set a struct clk member to
mark that the parent should change (it's all within mutex protected
code after all). Comments anyone?

James Hogan (3):
clk: abstract parent cache
clk: add support for clock remuxing
clk: clk-mux: implement remuxing

drivers/clk/clk-mux.c | 47 ++++++++++++++++++
drivers/clk/clk.c | 115 ++++++++++++++++++++++++++++++-------------
include/linux/clk-provider.h | 7 ++-
3 files changed, 133 insertions(+), 36 deletions(-)

--
1.8.1.2


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