Re: [PATCH v2 6/7] Watchdog: introduce ARM SBSA watchdog driver

From: Guenter Roeck
Date: Thu May 21 2015 - 12:00:07 EST


On Thu, May 21, 2015 at 11:46:53PM +0800, Fu Wei wrote:
> Hi Guenter,
>
[ ... ]

> >> >> +
> >> >> + /*
> >> >> + * Try to determine the frequency from the arch_timer interface
> >> >> + */
> >> >> + clk = arch_timer_get_rate();
> >> >
> >> >
> >> > arch_timer_get_rate() does not seem to be exported. Did you try to build
> >> > the driver as module ?
> >>
> >> yes, I have built it as a ko module, that is why I made a patch to
> >> export this interface in the first patch of this patchset
> >>
> >> but I will confirm it again :-)
> >>
> > Guess I'll give it a try myself. I don't really understand how this
> > can work unless arch_timer_get_rate() is exported in your tree.
>
> yes, I have exported it , I think it make sense to export it.
> Because other driver maybe need to get system counter info
>
> Do you agree ? :-)
>
I don't think it is for me to agree or not. The arm maintainers
will need to be involved. You can not just export such a function
without maintainer Ack.

Having said that, my personal preference would be for the counter
and rate to be exported through the clock subsystem (ie with
clk_get_rate). But that would still not provide the current counter
value, so maybe that isn't even possible.

Thanks,
Guenter
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