Re: [PATCH v6] dt-bindings: iommu: Convert msm,iommu-v0 to yaml
From: David Heidelberg
Date: Thu Dec 21 2023 - 17:19:14 EST
On 21/12/2023 14:41, Rob Herring wrote:
On Tue, Dec 19, 2023 at 09:28:27PM +0100, David Heidelberg wrote:
Convert Qualcomm IOMMU v0 implementation to yaml format.
iommus part being ommited for the other bindings, as mdp4 one.
Signed-off-by: David Heidelberg <david@xxxxxxx>
---
v6:
- clean iommu-cells description (thx @Robin)
v5:
- updated example (thx @Konrad)
- ordering of requirements + dropped > and | and reformatted (thx @Konrad)
v4:
- renamed to qcom,apq8064-iommu as Rob requested
- changed title to Qualcomm APQ8064 IOMMU
- dropped quotes around URLs
- dropped mdp node
- dropped unused mdp_port0 label
v3:
- I kept the name as -v0, since we have other binding -v1 and it look
good, I can change thou in v4 if requested.
- dropped non-existent smmu_clk part (and adjusted example, which was
using it)
- dropped iommu description
- moved iommu-cells description to the property #iommu-cells
v2:
- fix wrong path in binding $id
- comment qcom,mdp4 node example (we don't want to validate it yet)
Signed-off-by: David Heidelberg <david@xxxxxxx>
.../bindings/iommu/msm,iommu-v0.txt | 64 ----------------
.../bindings/iommu/qcom,apq8064-iommu.yaml | 76 +++++++++++++++++++
2 files changed, 76 insertions(+), 64 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/iommu/msm,iommu-v0.txt
create mode 100644 Documentation/devicetree/bindings/iommu/qcom,apq8064-iommu.yaml
diff --git a/Documentation/devicetree/bindings/iommu/msm,iommu-v0.txt b/Documentation/devicetree/bindings/iommu/msm,iommu-v0.txt
deleted file mode 100644
index 20236385f26e..000000000000
--- a/Documentation/devicetree/bindings/iommu/msm,iommu-v0.txt
+++ /dev/null
@@ -1,64 +0,0 @@
-* QCOM IOMMU
-
-The MSM IOMMU is an implementation compatible with the ARM VMSA short
-descriptor page tables. It provides address translation for bus masters outside
-of the CPU, each connected to the IOMMU through a port called micro-TLB.
-
-Required Properties:
-
- - compatible: Must contain "qcom,apq8064-iommu".
- - reg: Base address and size of the IOMMU registers.
- - interrupts: Specifiers for the MMU fault interrupts. For instances that
- support secure mode two interrupts must be specified, for non-secure and
- secure mode, in that order. For instances that don't support secure mode a
- single interrupt must be specified.
- - #iommu-cells: The number of cells needed to specify the stream id. This
- is always 1.
- - qcom,ncb: The total number of context banks in the IOMMU.
- - clocks : List of clocks to be used during SMMU register access. See
- Documentation/devicetree/bindings/clock/clock-bindings.txt
- for information about the format. For each clock specified
- here, there must be a corresponding entry in clock-names
- (see below).
-
- - clock-names : List of clock names corresponding to the clocks specified in
- the "clocks" property (above).
- Should be "smmu_pclk" for specifying the interface clock
- required for iommu's register accesses.
- Should be "smmu_clk" for specifying the functional clock
- required by iommu for bus accesses.
-
-Each bus master connected to an IOMMU must reference the IOMMU in its device
-node with the following property:
-
- - iommus: A reference to the IOMMU in multiple cells. The first cell is a
- phandle to the IOMMU and the second cell is the stream id.
- A single master device can be connected to more than one iommu
- and multiple contexts in each of the iommu. So multiple entries
- are required to list all the iommus and the stream ids that the
- master is connected to.
-
-Example: mdp iommu and its bus master
-
- mdp_port0: iommu@7500000 {
- compatible = "qcom,apq8064-iommu";
- #iommu-cells = <1>;
- clock-names =
- "smmu_pclk",
- "smmu_clk";
- clocks =
- <&mmcc SMMU_AHB_CLK>,
- <&mmcc MDP_AXI_CLK>;
- reg = <0x07500000 0x100000>;
- interrupts =
- <GIC_SPI 63 0>,
- <GIC_SPI 64 0>;
- qcom,ncb = <2>;
- };
-
- mdp: qcom,mdp@5100000 {
- compatible = "qcom,mdp";
- ...
- iommus = <&mdp_port0 0
- &mdp_port0 2>;
- };
diff --git a/Documentation/devicetree/bindings/iommu/qcom,apq8064-iommu.yaml b/Documentation/devicetree/bindings/iommu/qcom,apq8064-iommu.yaml
new file mode 100644
index 000000000000..b9a2d02ed2e6
--- /dev/null
+++ b/Documentation/devicetree/bindings/iommu/qcom,apq8064-iommu.yaml
@@ -0,0 +1,76 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+
+$id: http://devicetree.org/schemas/iommu/qcom,apq8064-iommu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm APQ8064 IOMMU
+
+maintainers:
+ - Will Deacon <will@xxxxxxxxxx>
This should be someone from QCom or that otherwise cares about this
device.
Can I put Sricharan Ramabadhran <quic_srichara@xxxxxxxxxxx> here (CCed)?
+
+description:
+ The MSM IOMMU is an implementation compatible with the ARM VMSA short
+ descriptor page tables. It provides address translation for bus masters
+ outside of the CPU, each connected to the IOMMU through a port called micro-TLB.
+
+properties:
+ compatible:
+ const: qcom,apq8064-iommu
+
+ clocks:
+ items:
+ - description: interface clock for register accesses
+ - description: functional clock for bus accesses
+
+ clock-names:
+ items:
+ - const: smmu_pclk
+ - const: iommu_clk
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ description: Specifiers for the MMU fault interrupts.
+ minItems: 1
+ items:
+ - description: non-secure mode interrupt
+ - description: secure mode interrupt (for instances which supports it)
+
+ "#iommu-cells":
+ const: 1
+ description: Each IOMMU specifier describes a single Stream ID.
+
+ qcom,ncb:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: The total number of context banks in the IOMMU.
Is there a maximum? I assume it is not 2^32.
It's signed 32-bit int (because of armv7), haven't seen any limit in the
code . In dts there are only values 2 or 3.
Should I set min to 1 and max to (2^31)-1?
+
+required:
+ - reg
+ - interrupts
+ - clocks
+ - clock-names
+ - qcom,ncb
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/clock/qcom,mmcc-msm8960.h>
+ #include <dt-bindings/interrupt-controller/irq.h>
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+ iommu@7500000 {
+ compatible = "qcom,apq8064-iommu";
+ reg = <0x07500000 0x100000>;
+ interrupts = <GIC_SPI 63 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 64 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&clk SMMU_AHB_CLK>,
+ <&clk MDP_AXI_CLK>;
+ clock-names = "smmu_pclk",
+ "iommu_clk";
+ #iommu-cells = <1>;
+ qcom,ncb = <2>;
+ };
--
2.43.0
--
David Heidelberg