[PATCH 4/7] dt-bindings: chosen: Add clocksource and clockevent selection

Claudiu.Beznea at microchip.com Claudiu.Beznea at microchip.com
Tue Sep 10 07:51:50 PDT 2019

On 10.09.2019 17:32, Sudeep Holla wrote:
> External E-Mail
> On Tue, Sep 10, 2019 at 04:47:13PM +0300, Claudiu Beznea wrote:
>> From: Alexandre Belloni <alexandre.belloni at bootlin.com>
>> Some timer drivers may behave either as clocksource or clockevent
>> or both. Until now, in case of platforms with multiple hardware
>> resources of the same type, the drivers were chosing the first
>> registered hardware resource as clocksource/clockevent and the
>> next one as clockevent/clocksource. Other were using different
>> compatibles (one for each functionality, although its about the
>> same hardware). Add DT bindings to be able to choose the
>> functionality of a timer.
> Is the piece of hardware not capable of serving as both clocksource
> and clockevent or is it just the platform choice ?

In my case, the hardware is not capable of serving at the same time
a clocksource device and a clockevent device.

First, I published v1 for a hardware device having this behavior at
[1] requesting 1st probed hardware device to work as clocksource and
the 2nd one to work as clockevent. The discussion at [1] ended up with
the idea of having a mechanism to specify which hardware device behaves
as clocksource and which one behaves as clockevent.

Thank you,
Claudiu Beznea

[1] https://lore.kernel.org/lkml/1552580772-8499-1-git-send-email-claudiu.beznea@microchip.com/

> --
> Regards,
> Sudeep

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