[PATCH v5 2/3] dt-bindings: iommu: add DART iommu bindings

From: Sven Peter
Date: Tue Aug 03 2021 - 08:17:23 EST


DART (Device Address Resolution Table) is the iommu found on Apple
ARM SoCs such as the M1.

Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@xxxxxxxxxxxxx>
Signed-off-by: Sven Peter <sven@xxxxxxxxxxxxx>
---
.../devicetree/bindings/iommu/apple,dart.yaml | 81 +++++++++++++++++++
MAINTAINERS | 6 ++
2 files changed, 87 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iommu/apple,dart.yaml

diff --git a/Documentation/devicetree/bindings/iommu/apple,dart.yaml b/Documentation/devicetree/bindings/iommu/apple,dart.yaml
new file mode 100644
index 000000000000..94aa9e9afa59
--- /dev/null
+++ b/Documentation/devicetree/bindings/iommu/apple,dart.yaml
@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iommu/apple,dart.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple DART IOMMU
+
+maintainers:
+ - Sven Peter <sven@xxxxxxxxxxxxx>
+
+description: |+
+ Apple SoCs may contain an implementation of their Device Address
+ Resolution Table which provides a mandatory layer of address
+ translations for various masters.
+
+ Each DART instance is capable of handling up to 16 different streams
+ with individual pagetables and page-level read/write protection flags.
+
+ This DART IOMMU also raises interrupts in response to various
+ fault conditions.
+
+properties:
+ compatible:
+ const: apple,t8103-dart
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ clocks:
+ description:
+ Reference to the gate clock phandle if required for this IOMMU.
+ Optional since not all IOMMUs are attached to a clock gate.
+
+ '#iommu-cells':
+ const: 1
+ description:
+ Has to be one. The single cell describes the stream id emitted by
+ a master to the IOMMU.
+
+required:
+ - compatible
+ - reg
+ - '#iommu-cells'
+ - interrupts
+
+additionalProperties: false
+
+examples:
+ - |+
+ dart1: iommu@82f80000 {
+ compatible = "apple,t8103-dart";
+ reg = <0x82f80000 0x4000>;
+ interrupts = <1 781 4>;
+ #iommu-cells = <1>;
+ };
+
+ master1 {
+ iommus = <&dart1 0>;
+ };
+
+ - |+
+ dart2a: iommu@82f00000 {
+ compatible = "apple,t8103-dart";
+ reg = <0x82f00000 0x4000>;
+ interrupts = <1 781 4>;
+ #iommu-cells = <1>;
+ };
+ dart2b: iommu@82f80000 {
+ compatible = "apple,t8103-dart";
+ reg = <0x82f80000 0x4000>;
+ interrupts = <1 781 4>;
+ #iommu-cells = <1>;
+ };
+
+ master2 {
+ iommus = <&dart2a 0>, <&dart2b 1>;
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index c9467d2839f5..0f450f7d5336 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1262,6 +1262,12 @@ L: linux-input@xxxxxxxxxxxxxxx
S: Odd fixes
F: drivers/input/mouse/bcm5974.c

+APPLE DART IOMMU DRIVER
+M: Sven Peter <sven@xxxxxxxxxxxxx>
+L: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
+S: Maintained
+F: Documentation/devicetree/bindings/iommu/apple,dart.yaml
+
APPLE SMC DRIVER
M: Henrik Rydberg <rydberg@xxxxxxxxxxx>
L: linux-hwmon@xxxxxxxxxxxxxxx
--
2.25.1