[PATCH 2/2] arm64: dts: qcom: talos: Add EL2 overlay

[Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>]

All the existing variants Talos boards are using Gunyah hypervisor
which means that, so far, Linux-based OS could only boot in EL1 on
those devices.  However, it is possible for us to boot Linux at EL2
on these devices [1].

When running under Gunyah, the remote processor firmware IOMMU streams
are controlled by Gunyah. However, without Gunyah, the IOMMU is managed
by the consumer of this DeviceTree. Therefore, describe the firmware
streams for each remote processor.

Add a EL2-specific DT overlay and apply it to Talos IOT variant
devices to create -el2.dtb for each of them alongside "normal" dtb.

[1]
https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi

Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
---
This patch has dependency on https://lore.kernel.org/lkml/20260121-qcs615-spin-2-v7-0-52419b263e92@oss.qualcomm.com/#t
which adds gpu_zap_shader.


 arch/arm64/boot/dts/qcom/Makefile       |  4 ++++
 arch/arm64/boot/dts/qcom/talos-el2.dtso | 28 +++++++++++++++++++++++++
 2 files changed, 32 insertions(+)
 create mode 100644 arch/arm64/boot/dts/qcom/talos-el2.dtso

diff --git a/arch/arm64/boot/dts/qcom/Makefile b/arch/arm64/boot/dts/qcom/Makefile
index cbf7d89e432c..48ecbea17a4e 100644
--- a/arch/arm64/boot/dts/qcom/Makefile
+++ b/arch/arm64/boot/dts/qcom/Makefile
@@ -141,6 +141,10 @@ dtb-$(CONFIG_ARCH_QCOM)	+= qcm6490-shift-otter.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= qcs404-evb-1000.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= qcs404-evb-4000.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= qcs615-ride.dtb
+
+qcs615-ride-el2-dtbs := qcs615-ride.dtb talos-el2.dtbo
+
+dtb-$(CONFIG_ARCH_QCOM)	+= qcs615-ride-el2.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= qcs6490-radxa-dragon-q6a.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= qcs6490-rb3gen2.dtb
 
diff --git a/arch/arm64/boot/dts/qcom/talos-el2.dtso b/arch/arm64/boot/dts/qcom/talos-el2.dtso
new file mode 100644
index 000000000000..03ca04c44976
--- /dev/null
+++ b/arch/arm64/boot/dts/qcom/talos-el2.dtso
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+/*
+ * Talos specific modifications required to boot in EL2.
+ */
+
+/dts-v1/;
+/plugin/;
+
+/* We can't and don't need to use zap shader in EL2 as linux can zap the gpu on it's own. */
+&gpu_zap_shader {
+	status = "disabled";
+};
+
+&remoteproc_adsp {
+	iommus = <&apps_smmu 0x1720 0x0>;
+};
+
+&remoteproc_cdsp {
+	iommus = <&apps_smmu 0x1080 0x0>;
+};
+
+&venus {
+	status = "disabled";
+};
-- 
2.50.1