From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lina Iyer Subject: Re: [PATCH v4 03/10] of/irq: document properties for wakeup interrupt parent Date: Thu, 4 Apr 2019 09:58:38 -0600 Message-ID: <20190404155838.GD10883@codeaurora.org> References: <20190313211844.29416-1-ilina@codeaurora.org> <20190313211844.29416-4-ilina@codeaurora.org> <20190318174236.072f0a95@why.wild-wind.fr.eu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Content-Disposition: inline In-Reply-To: <20190318174236.072f0a95@why.wild-wind.fr.eu.org> Sender: linux-kernel-owner@vger.kernel.org To: Marc Zyngier Cc: swboyd@chromium.org, evgreen@chromium.org, linux-kernel@vger.kernel.org, rplsssn@codeaurora.org, linux-arm-msm@vger.kernel.org, thierry.reding@gmail.com, bjorn.andersson@linaro.org, dianders@chromium.org, linus.walleij@linaro.org, Rob Herring List-Id: linux-arm-msm@vger.kernel.org On Mon, Mar 18 2019 at 11:54 -0600, Marc Zyngier wrote: >On Wed, 13 Mar 2019 15:18:37 -0600 >Lina Iyer wrote: > >Please do Cc Rob when posting DT related patches. > >> Some interrupt controllers in a SoC, are always powered on and have a >> select interrupts routed to them, so that they can wakeup the SoC from >> suspend. Add wakeup-parent DT property to refer to these interrupt >> controllers. >> >> If the interrupts routed to the wakeup parent are not sequential, than a >> map needs to exist to associate the same interrupt line on multiple >> interrupt controllers. Providing this map in every driver is cumbersome. >> Let's add this in the device tree and document the properties to map the >> interrupt specifiers >> >> Signed-off-by: Lina Iyer >> --- >> Changes in v4: >> - Added this documentation >> --- >> .../interrupt-controller/interrupts.txt | 39 +++++++++++++++++++ >> 1 file changed, 39 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt >> index 8a3c40829899..917b598317f5 100644 >> --- a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt >> +++ b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt >> @@ -108,3 +108,42 @@ commonly used: >> sensitivity = <7>; >> }; >> }; >> + >> +3) Interrupt wakeup parent >> +-------------------------- >> + >> +Some interrupt controllers in a SoC, are always powered on and have a select >> +interrupts routed to them, so that they can wakeup the SoC from suspend. These >> +interrupt controllers do not fall into the category of a parent interrupt >> +controller and can be specified by the "wakeup-parent" property and contain a >> +single phandle referring to the wakeup capable interrupt controller. >> + >> + Example: >> + wakeup-parent = <&pdc_intc>; >> + >> + >> +4) Interrupt mapping >> +-------------------- >> + >> +Sometimes interrupts may be detected by more than one interrupt controller >> +(depending on which controller is active). The interrupt controllers may not >> +be in hierarchy and therefore the interrupt controller driver is required to >> +establish the relationship between the same interrupt at different interrupt >> +controllers. If these interrupts are not sequential then a map needs to be >> +specified to help identify these interrupts. >> + >> +Mapping the interrupt specifiers in the device tree can be done using the >> +"irqdomain-map" property. The property contains interrupt specifier at the >> +current interrupt controller followed by the interrupt specifier at the mapped >> +interrupt controller. >> + >> + irqdomain-map = >> + >> +The optional properties "irqdomain-map-mask" and "irqdomain-map-pass-thru" may >> +be provided to help interpret the valid bits of the incoming and mapped >> +interrupt specifiers respectively. >> + >> + Example: >> + irqdomain-map = <22 0 &intc 36 0>, <24 0 &intc 37 0>; >> + irqdomain-map-mask = <0xff 0>; >> + irqdomain-map-pass-thru = <0 0xff>; > > >This doesn't quite explain how the mask and pass-thru properties are >used. I guess that the mask is used to define the 'useful bits' on the >incoming side, but pass-thru puzzles me. In your example, does it mean >that incoming lines map to outgoing interrupt <0 0>? > Sorry about the late reply. How about this to go with the rest of the documentation - In the above example, the input interrupt specifier map-mask <0xff 0> applied on the incoming interrupt specifier of the map <22 0>, <24 0>, returns the input interrupt 22, 24 etc. The second argument being irq type is immaterial from the map and is used from the incoming request instead. The pass-thru specifier parses the output interrupt specifier from the rest of the unparsed argments from the map <&intc 36 0>, <&intc 37 0> etc to return the output interrupt 36, 37 etc. --Lina