[RFC PATCH] clk: add extension API
Peter De Schrijver
pdeschrijver at nvidia.com
Thu May 31 05:05:18 EDT 2012
>
> What if a module needs two clocks and you drive the reset on both of the
> clocks ? What would happen ?
>
Only 'leave clocks' have this reset method and a module can only have 1 of
them.
> > but then we would have the keep a list of IDs (1 per module) which the drivers
> > can use to call some tegra reset function which would in the end use registers
> > in the same memory area to cause a reset. (the registers controlling
> > modulereset are interleaved with those controlling the enable/disable of the
> > main moduleclock and bitpositions are identical)
>
> Well, under a generic device-level API, you could just call an internal
> clk_reset() function because you know which clocks feed into which
> devices anyway. It could look something like:
>
> on Tegra:
>
> device_reset(dev)
> -> dev_pm_domain->reset()
> -> tegra_periph_reset()
>
These methods are also needed internally by the powergating code.
> on OMAP:
>
> device_reset(dev)
> -> dev_pm_domain->reset()
> -> omap_hwmod_reset()
>
>
> btw:
>
> tegra_periph_reset(....)
> {
> tegra_periph_reset_assert(...);
> udelay(2);
> tegra_periph_reset_deassert(...);
> }
which uses the clockframework currently.
Cheers,
Peter.
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