[RFC/NOT FOR MERGING 2/3] serial: omap: remove hwmod dependency

Tony Lindgren tony at atomide.com
Fri Feb 15 11:30:32 EST 2013


* Santosh Shilimkar <santosh.shilimkar at ti.com> [130215 05:34]:
> On Friday 15 February 2013 06:57 PM, Russell King - ARM Linux wrote:
> >On Fri, Feb 15, 2013 at 06:56:47PM +0530, Santosh Shilimkar wrote:
> >>Whats your view on use of arch_ioremap_caller() hook ? This can allow
> >>us to avoid the dual ioremap() issue discussed here if the hook
> >>maintains the list of mapped ios.
> >>
> >>I was even thinking of having such intelligence within the core
> >>ioremap code but thought that might be too invasive.
> >
> >Why do you even need it?  There's no problem with ioremapping the same
> >space multiple times (you end up with multiple mappings but that
> >shouldn't be a problem, except for the additional space used.)
> >
> It just waste of iospace and Tony insisted to have just single ioremap()
> hence all this discussion

The main goal is to avoid duplicating data both in hwmod and DT.
That's pretty much solved as we can have the driver probe populate
the common data for hwmod from DT as Santosh has already demonstrated.

Then we also want the driver specific idle and reset code to be done
in the drivers rather than in hwmod and glue it together with hwmod
using runtime PM. The biggest issue there is how do we reset and idle
some piece of hardware for PM purposes when there's no driver loaded.

For the duplicate ioremapping, I don't think there's any need to
do it if we get things right.

Regards,

Tony



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