Re: [PATCH v5 1/8] clocksource: dmtimer: Remove all the exports

From: Ladislav Michl
Date: Tue Dec 12 2017 - 13:03:46 EST


On Tue, Dec 12, 2017 at 09:00:54AM -0800, Tony Lindgren wrote:
> Hmm what do you mean? We don't want to export tons of custom functions from
> the timers in and then be in trouble when at some point we have a Linux
> generic hw timer framework. We already had to deal with these custom
> exports earlier with conversion to multiarch and then again with
> device tree.
>
> For now, it's best to pass the timer information to the pwm driver in
> platform data. In the long run that will be much easier to deal with than
> fixing random drivers tinkering with the timer registers directly.

All that register access would happen only in drivers/clocksource/timer-dm.c?
So platform data will hold all function pointers needed for event capture
and the pwm driver will do only interface to pwm framework.

> Ideally the pwm driver would just do a request_irq from the dmtimer code
> where dmtimer code would implement an interrupt controller. That would
> be already most fo the Linux generic hardware timer framework right there :)

I do not follow. Each general-purpose timer module has its own interrupt line,
so claiming that irq directly using request_irq seems enough. Could you
explain interrupt controller idea a bit more?

Thank you,
ladis