Re: [PATCH 46/58] clocksource/drivers: Add a new driver for the Atmel ARM TC blocks

From: Alexandre Belloni
Date: Wed Jun 07 2017 - 11:28:06 EST


On 07/06/2017 at 16:17:35 +0200, Daniel Lezcano wrote:
> > You mean you don't like how it is used? Or you don't think having the
> > timer full name is useful?
>
> The field is not needed, the only place where it is used is where we affect it.
>

It is used in tcb_clksrc_register:

tc.clksrc.name = tc.name;

> > The main reason is that RobH doesn't want to have the use (clocksource
> > or clockevent) of the timer in the DT so when probing a timer, I need to
> > know whether I already have a clocksource to decide when it is time to
> > register a clockevent.
>
> Yes, we had this discussion some weeks ago.
>
> This registered hack forces the DT to define first the clocksource, then the
> clockevent.
>
> So, I suggest you fold the timer definition into a single one like the other
> drivers.

I was going to agree but this is not flexible enough because the
quadrature decoder always uses the first two channels. So on some
products, we may have:
- TCB0:
o channels 0,1: qdec
o channel 2: clocksource

- TCB1:
o channels 0,1: qdec
o channel 2: clockevent

This avoids wasting TCB channels.

--
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com