Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 7 Apr 2023 13:36:55 +0200
From:   Stephan Gerhold <stephan@gerhold.net>
To:     Konrad Dybcio <konrad.dybcio@linaro.org>
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Rob Herring <robh@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Andy Gross <agross@kernel.org>, linux-kernel@vger.kernel.org,
        Shawn Guo <shawn.guo@linaro.org>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Marc Zyngier <maz@kernel.org>, linux-arm-msm@vger.kernel.org,
        devicetree@vger.kernel.org
Subject: Re: [PATCH v2 1/2] dt-bindings: interrupt-controller: mpm: Pass MSG
 RAM slice through phandle
Message-ID: <ZDAAToSzNLVo6le8@gerhold.net>
References: <20230328-topic-msgram_mpm-v2-0-e24a48e57f0d@linaro.org>
 <20230328-topic-msgram_mpm-v2-1-e24a48e57f0d@linaro.org>
 <168069726278.2356075.14351594478003012447.robh@kernel.org>
 <20230405134727.GA2461305-robh@kernel.org>
 <1e6e2590-ac78-400b-35ce-321d5e52f385@linaro.org>
 <9df12111-ec84-c4f7-fbcb-bccaef91b048@linaro.org>
 <3ce9b5ec-8b02-537a-c663-c849e80cab66@linaro.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <3ce9b5ec-8b02-537a-c663-c849e80cab66@linaro.org>
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Thu, Apr 06, 2023 at 09:55:40PM +0200, Konrad Dybcio wrote:
> [...]
> I don't really know what kind.. I can add something like:
> 
> rpm {
> 	compatible = "qcom,rpm", "simple-mfd";
> 
> 	mpm: interrupt-controller {
> 	...
> };
> 

IMO we should indeed add something like this, because the current
representation of the RPM below the top level /smd node is misleading.
"SMD" is not a device, bus, component or anything like that. It is just
the communication protocol. There should not be a top-level DT node for
this.

Instead there should be a dedicated device tree node for the RPM like in
your example above, which will allow adding properties and subnodes to
it as needed.

For unrelated reasons I actually have some patches for this, that switch
the /smd top-level node to a "remoteproc-like" node dedicated to the
RPM, similar to how WCNSS/ADSP/Modem/etc are represented. I need this to
add additional (optional) properties like "resets" and "iommus" for the
RPM, but it would allow adding arbitrary subnodes as well:

https://github.com/msm8916-mainline/linux/commit/35231ac28703805daa8220f1233847c7df34589e

I could finish those up and post them if that would help...

Thanks,
Stephan

diff --git a/arch/arm64/boot/dts/qcom/msm8916.dtsi b/arch/arm64/boot/dts/qcom/msm8916.dtsi
index dcbc5972248b22..1c24b01bd268c8 100644
--- a/arch/arm64/boot/dts/qcom/msm8916.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8916.dtsi
@@ -310,10 +310,10 @@
 		};
 	};
 
-	smd {
-		compatible = "qcom,smd";
+	rpm: remoteproc-rpm {
+		compatible = "qcom,msm8916-rpm-proc", "qcom,rpm-proc";
 
-		rpm {
+		smd-edge {
 			interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
 			qcom,ipc = <&apcs 8 0>;
 			qcom,smd-edge = <15>;