| Message ID | 1568123236-767-5-git-send-email-claudiu.beznea@microchip.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | add support for clocksource/clockevent DT selection | expand |
Hi, On 10/09/2019 15:47, Claudiu Beznea wrote: > From: Alexandre Belloni <alexandre.belloni@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. > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> > --- > Documentation/devicetree/bindings/chosen.txt | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt > index 45e79172a646..aad3034cdbdf 100644 > --- a/Documentation/devicetree/bindings/chosen.txt > +++ b/Documentation/devicetree/bindings/chosen.txt > @@ -135,3 +135,23 @@ e.g. > linux,initrd-end = <0x82800000>; > }; > }; > + > +linux,clocksource and linux,clockevent > +-------------------------------------- > + > +Those nodes have a timer property. This property is a phandle to the timer to be > +chosen as the clocksource or clockevent. This is only useful when the platform > +has multiple identical timers and it is not possible to let linux make the > +correct choice. > + > +/ { > + chosen { > + linux,clocksource { > + timer = <&timer0>; > + }; > + > + linux,clockevent { > + timer = <&timer1>; > + }; > + }; > +}; > Why not in aliases ? aliases { clocksource0 = &timer0; clockevent0 = &timer1; }; since we can have multiple of each, we should not limit ourselves to 1 clkevent and 1 clksource. In the aliases case, each driver would expose both capabilities, and the core would select what to enable. Neil
diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt index 45e79172a646..aad3034cdbdf 100644 --- a/Documentation/devicetree/bindings/chosen.txt +++ b/Documentation/devicetree/bindings/chosen.txt @@ -135,3 +135,23 @@ e.g. linux,initrd-end = <0x82800000>; }; }; + +linux,clocksource and linux,clockevent +-------------------------------------- + +Those nodes have a timer property. This property is a phandle to the timer to be +chosen as the clocksource or clockevent. This is only useful when the platform +has multiple identical timers and it is not possible to let linux make the +correct choice. + +/ { + chosen { + linux,clocksource { + timer = <&timer0>; + }; + + linux,clockevent { + timer = <&timer1>; + }; + }; +};