xref: /linux/Documentation/devicetree/bindings/iommu/samsung,sysmmu.yaml (revision ae22a94997b8a03dcb3c922857c203246711f9d4) 
1# SPDX-License-Identifier: GPL-2.0
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/iommu/samsung,sysmmu.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Samsung Exynos IOMMU H/W, System MMU (System Memory Management Unit)
8
9maintainers:
10  - Marek Szyprowski <m.szyprowski@samsung.com>
11
12description: |+
13  Samsung's Exynos architecture contains System MMUs that enables scattered
14  physical memory chunks visible as a contiguous region to DMA-capable peripheral
15  devices like MFC, FIMC, FIMD, GScaler, FIMC-IS and so forth.
16
17  System MMU is an IOMMU and supports identical translation table format to
18  ARMv7 translation tables with minimum set of page properties including access
19  permissions, shareability and security protection. In addition, System MMU has
20  another capabilities like L2 TLB or block-fetch buffers to minimize translation
21  latency.
22
23  System MMUs are in many to one relation with peripheral devices, i.e. single
24  peripheral device might have multiple System MMUs (usually one for each bus
25  master), but one System MMU can handle transactions from only one peripheral
26  device. The relation between a System MMU and the peripheral device needs to be
27  defined in device node of the peripheral device.
28
29  MFC in all Exynos SoCs and FIMD, M2M Scalers and G2D in Exynos5420 has 2 System
30  MMUs.
31  * MFC has one System MMU on its left and right bus.
32  * FIMD in Exynos5420 has one System MMU for window 0 and 4, the other system MMU
33    for window 1, 2 and 3.
34  * M2M Scalers and G2D in Exynos5420 has one System MMU on the read channel and
35    the other System MMU on the write channel.
36
37  For information on assigning System MMU controller to its peripheral devices,
38  see generic IOMMU bindings.
39
40properties:
41  compatible:
42    const: samsung,exynos-sysmmu
43
44  reg:
45    maxItems: 1
46
47  interrupts:
48    maxItems: 1
49
50  clocks:
51    minItems: 1
52    maxItems: 2
53
54  clock-names:
55    oneOf:
56      - items:
57          - const: sysmmu
58      - items:
59          - const: sysmmu
60          - const: master
61      - items:
62          - const: aclk
63          - const: pclk
64
65  "#iommu-cells":
66    const: 0
67
68  power-domains:
69    description: |
70      Required if the System MMU is needed to gate its power.
71      Please refer to the following document:
72      Documentation/devicetree/bindings/power/pd-samsung.yaml
73    maxItems: 1
74
75required:
76  - compatible
77  - reg
78  - interrupts
79  - clocks
80  - clock-names
81  - "#iommu-cells"
82
83additionalProperties: false
84
85examples:
86  - |
87    #include <dt-bindings/clock/exynos5250.h>
88
89    sysmmu_gsc0: iommu@13e80000 {
90      compatible = "samsung,exynos-sysmmu";
91      reg = <0x13E80000 0x1000>;
92      interrupt-parent = <&combiner>;
93      interrupts = <2 0>;
94      clock-names = "sysmmu", "master";
95      clocks = <&clock CLK_SMMU_GSCL0>,
96               <&clock CLK_GSCL0>;
97      power-domains = <&pd_gsc>;
98      #iommu-cells = <0>;
99    };
100