On Sat, Feb 07, 2015 at 06:18:23AM +0800, Mark Brown wrote:
> On Thu, Feb 05, 2015 at 12:53:39PM -0800, Kenneth Westfield wrote:
>
> > +- qcom,system-clock-shift : Add this bool property if the default
> > + frequency of the system clock needs to
> > + be reduced.
> > +- qcom,system-clock-shift-compare : A numerical value used to right-shift
> > + the default system clock frequency for
> > + comparison with the target bit clock
> > + frequency.
> > +- qcom,system-clock-shift-amount : A numerical value used to right-shift
> > + the default system clock frequency.
> > +- qcom,alternate-sysclk : Add this bool property if the default
> > + frequency of the system clock cannot
> > + divide down to the target bit clock
> > + frequency.
> > +- qcom,alternate-sysclk-bitwidth : A numerical value representing the
> > + sample bitwidth which requires use of
> > + the alternate system clock frequency.
> > +- qcom,alternate-sysclk-frequency : A numerical value representing the new
> > + system clock frequency to use.
>
> None of these seem like they are appropriate for device tree properties,
> they appear to be choosing a specific clocking configuration which is
> something that would normally be done as part of the system integration
> in the machine driver rather than in the DAI driver. This binding won't
> work in cases where the clocks are being changed at runtime and would
> limit systems where that becomes possible in future.
So I add a machine driver that selects the clocking freq in hw_params
and calls set_sysclk in the DAIs.
The DT node for the machine driver would look something like:
default_system_clock_frequency = < xxxxxx >;
alternate_system_clock_frequency = < xxxxxx >;
cpu_dai = < &cpu >;
codec_dai = < &codec >;
pinctrl... ?
Does this sound ok? Also, would it make sense to move the pinctrl back
to the machine driver?
--
Kenneth Westfield
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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