msm: clock-8x60: Allow hand-offs of already-running RCG clocks at boot

Inherit the rate of running rate-settable clocks at boot if the
same rate is supported by the Linux kernel.  These clocks will
still be disabled by the auto-off code in late-init if no driver
explicitly enables them before that.

This feature allows Linux drivers to keep a clock enabled all the
way through boot.  For glitch-free clocks, drivers can set the
rate of the clock to any supported value at boot and enable it
with no interruption of the clock signal.  Non-glitch-free clocks
will still experience some interruption, but this can be avoided
by calling clk_set_rate() with the same rate that was set by the
bootloader (which can be returned by calling clk_get_rate()).

Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
5 files changed