[PATCH v2] dt-bindings: arm: samsung: Convert Samsung Exynos IOMMU H/W, System MMU to dt-schema
From: Maciej Falkowski
Date: Tue Sep 10 2019 - 11:52:45 EST
Convert Samsung Exynos IOMMU H/W, System Memory Management Unit
to newer dt-schema format.
Update clock description.
Signed-off-by: Maciej Falkowski <m.falkowski@xxxxxxxxxxx>
Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
---
Hi Krzysztof,
Thank you for feedback.
New changes:
- style fixes including missing empty lines,
deletion of unneeded descriptions
- fix mistake where one example was split
into two separete ones.
There are some updates with clock description. I have spoken with
Marek Szyprowski and the right setup for clocks seems to be two pairs:
"sysmmu" with optional "master" or a pair of "aclk" + "pclk".
The option: "aclk" + "pclk" + "master" was never used in any
of device bindings and there are none compilation problems with that.
In so, clock-names are rewritten to handle this version
and maximal clock number is set to two.
Best regards,
Maciej Falkowski
---
.../bindings/iommu/samsung,sysmmu.txt | 67 -----------
.../bindings/iommu/samsung,sysmmu.yaml | 112 ++++++++++++++++++
2 files changed, 112 insertions(+), 67 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt
create mode 100644 Documentation/devicetree/bindings/iommu/samsung,sysmmu.yaml
diff --git a/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt b/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt
deleted file mode 100644
index 525ec82615a6..000000000000
--- a/Documentation/devicetree/bindings/iommu/samsung,sysmmu.txt
+++ /dev/null
@@ -1,67 +0,0 @@
-Samsung Exynos IOMMU H/W, System MMU (System Memory Management Unit)
-
-Samsung's Exynos architecture contains System MMUs that enables scattered
-physical memory chunks visible as a contiguous region to DMA-capable peripheral
-devices like MFC, FIMC, FIMD, GScaler, FIMC-IS and so forth.
-
-System MMU is an IOMMU and supports identical translation table format to
-ARMv7 translation tables with minimum set of page properties including access
-permissions, shareability and security protection. In addition, System MMU has
-another capabilities like L2 TLB or block-fetch buffers to minimize translation
-latency.
-
-System MMUs are in many to one relation with peripheral devices, i.e. single
-peripheral device might have multiple System MMUs (usually one for each bus
-master), but one System MMU can handle transactions from only one peripheral
-device. The relation between a System MMU and the peripheral device needs to be
-defined in device node of the peripheral device.
-
-MFC in all Exynos SoCs and FIMD, M2M Scalers and G2D in Exynos5420 has 2 System
-MMUs.
-* MFC has one System MMU on its left and right bus.
-* FIMD in Exynos5420 has one System MMU for window 0 and 4, the other system MMU
- for window 1, 2 and 3.
-* M2M Scalers and G2D in Exynos5420 has one System MMU on the read channel and
- the other System MMU on the write channel.
-
-For information on assigning System MMU controller to its peripheral devices,
-see generic IOMMU bindings.
-
-Required properties:
-- compatible: Should be "samsung,exynos-sysmmu"
-- reg: A tuple of base address and size of System MMU registers.
-- #iommu-cells: Should be <0>.
-- interrupts: An interrupt specifier for interrupt signal of System MMU,
- according to the format defined by a particular interrupt
- controller.
-- clock-names: Should be "sysmmu" or a pair of "aclk" and "pclk" to gate
- SYSMMU core clocks.
- Optional "master" if the clock to the System MMU is gated by
- another gate clock other core (usually main gate clock
- of peripheral device this SYSMMU belongs to).
-- clocks: Phandles for respective clocks described by clock-names.
-- power-domains: Required if the System MMU is needed to gate its power.
- Please refer to the following document:
- Documentation/devicetree/bindings/power/pd-samsung.txt
-
-Examples:
- gsc_0: gsc@13e00000 {
- compatible = "samsung,exynos5-gsc";
- reg = <0x13e00000 0x1000>;
- interrupts = <0 85 0>;
- power-domains = <&pd_gsc>;
- clocks = <&clock CLK_GSCL0>;
- clock-names = "gscl";
- iommus = <&sysmmu_gsc0>;
- };
-
- sysmmu_gsc0: sysmmu@13e80000 {
- compatible = "samsung,exynos-sysmmu";
- reg = <0x13E80000 0x1000>;
- interrupt-parent = <&combiner>;
- interrupts = <2 0>;
- clock-names = "sysmmu", "master";
- clocks = <&clock CLK_SMMU_GSCL0>, <&clock CLK_GSCL0>;
- power-domains = <&pd_gsc>;
- #iommu-cells = <0>;
- };
diff --git a/Documentation/devicetree/bindings/iommu/samsung,sysmmu.yaml b/Documentation/devicetree/bindings/iommu/samsung,sysmmu.yaml
new file mode 100644
index 000000000000..85d1a251f2ff
--- /dev/null
+++ b/Documentation/devicetree/bindings/iommu/samsung,sysmmu.yaml
@@ -0,0 +1,112 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iommu/samsung,sysmmu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung Exynos IOMMU H/W, System MMU (System Memory Management Unit)
+
+maintainers:
+ - Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
+
+description: |+
+ Samsung's Exynos architecture contains System MMUs that enables scattered
+ physical memory chunks visible as a contiguous region to DMA-capable peripheral
+ devices like MFC, FIMC, FIMD, GScaler, FIMC-IS and so forth.
+
+ System MMU is an IOMMU and supports identical translation table format to
+ ARMv7 translation tables with minimum set of page properties including access
+ permissions, shareability and security protection. In addition, System MMU has
+ another capabilities like L2 TLB or block-fetch buffers to minimize translation
+ latency.
+
+ System MMUs are in many to one relation with peripheral devices, i.e. single
+ peripheral device might have multiple System MMUs (usually one for each bus
+ master), but one System MMU can handle transactions from only one peripheral
+ device. The relation between a System MMU and the peripheral device needs to be
+ defined in device node of the peripheral device.
+
+ MFC in all Exynos SoCs and FIMD, M2M Scalers and G2D in Exynos5420 has 2 System
+ MMUs.
+ * MFC has one System MMU on its left and right bus.
+ * FIMD in Exynos5420 has one System MMU for window 0 and 4, the other system MMU
+ for window 1, 2 and 3.
+ * M2M Scalers and G2D in Exynos5420 has one System MMU on the read channel and
+ the other System MMU on the write channel.
+
+ For information on assigning System MMU controller to its peripheral devices,
+ see generic IOMMU bindings.
+
+properties:
+ compatible:
+ const: samsung,exynos-sysmmu
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ description: |
+ An interrupt specifier for interrupt signal of System MMU,
+ according to the format defined by a particular interrupt
+ controller.
+
+ clocks:
+ minItems: 1
+ maxItems: 2
+
+ clock-names:
+ oneOf:
+ - contains:
+ enum:
+ - sysmmu
+ - master
+ - contains:
+ enum:
+ - aclk
+ - pclk
+ description: |
+ Should be "sysmmu" with optional "master"
+ or a pair "aclk" with "pclk".
+
+ "#iommu-cells":
+ const: 0
+
+ power-domains:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description: |
+ Required if the System MMU is needed to gate its power.
+ Please refer to the following document:
+ Documentation/devicetree/bindings/power/pd-samsung.txt
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - clocks
+ - clock-names
+ - "#iommu-cells"
+
+examples:
+ - |
+ gsc_0: gsc@13e00000 {
+ compatible = "samsung,exynos5-gsc";
+ reg = <0x13e00000 0x1000>;
+ interrupts = <0 85 0>;
+ power-domains = <&pd_gsc>;
+ clocks = <&clock 0>; // CLK_GSCL0
+ clock-names = "gscl";
+ iommus = <&sysmmu_gsc0>;
+ };
+
+ sysmmu_gsc0: sysmmu@13e80000 {
+ compatible = "samsung,exynos-sysmmu";
+ reg = <0x13E80000 0x1000>;
+ interrupt-parent = <&combiner>;
+ interrupts = <2 0>;
+ clock-names = "sysmmu", "master";
+ clocks = <&clock 0>, // CLK_SMMU_GSCL0
+ <&clock 0>; // CLK_GSCL0
+ power-domains = <&pd_gsc>;
+ #iommu-cells = <0>;
+ };
+
--
2.17.1