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| 1 | +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) |
| 2 | +%YAML 1.2 |
| 3 | +--- |
| 4 | +$id: http://devicetree.org/schemas/iommu/mediatek,iommu.yaml# |
| 5 | +$schema: http://devicetree.org/meta-schemas/core.yaml# |
| 6 | + |
| 7 | +title: MediaTek IOMMU Architecture Implementation |
| 8 | + |
| 9 | +maintainers: |
| 10 | + |
| 11 | + |
| 12 | +description: |+ |
| 13 | + Some MediaTek SOCs contain a Multimedia Memory Management Unit (M4U), and |
| 14 | + this M4U have two generations of HW architecture. Generation one uses flat |
| 15 | + pagetable, and only supports 4K size page mapping. Generation two uses the |
| 16 | + ARM Short-Descriptor translation table format for address translation. |
| 17 | +
|
| 18 | + About the M4U Hardware Block Diagram, please check below: |
| 19 | +
|
| 20 | + EMI (External Memory Interface) |
| 21 | + | |
| 22 | + m4u (Multimedia Memory Management Unit) |
| 23 | + | |
| 24 | + +--------+ |
| 25 | + | | |
| 26 | + gals0-rx gals1-rx (Global Async Local Sync rx) |
| 27 | + | | |
| 28 | + | | |
| 29 | + gals0-tx gals1-tx (Global Async Local Sync tx) |
| 30 | + | | Some SoCs may have GALS. |
| 31 | + +--------+ |
| 32 | + | |
| 33 | + SMI Common(Smart Multimedia Interface Common) |
| 34 | + | |
| 35 | + +----------------+------- |
| 36 | + | | |
| 37 | + | gals-rx There may be GALS in some larbs. |
| 38 | + | | |
| 39 | + | | |
| 40 | + | gals-tx |
| 41 | + | | |
| 42 | + SMI larb0 SMI larb1 ... SoCs have several SMI local arbiter(larb). |
| 43 | + (display) (vdec) |
| 44 | + | | |
| 45 | + | | |
| 46 | + +-----+-----+ +----+----+ |
| 47 | + | | | | | | |
| 48 | + | | |... | | | ... There are different ports in each larb. |
| 49 | + | | | | | | |
| 50 | + OVL0 RDMA0 WDMA0 MC PP VLD |
| 51 | +
|
| 52 | + As above, The Multimedia HW will go through SMI and M4U while it |
| 53 | + access EMI. SMI is a bridge between m4u and the Multimedia HW. It contain |
| 54 | + smi local arbiter and smi common. It will control whether the Multimedia |
| 55 | + HW should go though the m4u for translation or bypass it and talk |
| 56 | + directly with EMI. And also SMI help control the power domain and clocks for |
| 57 | + each local arbiter. |
| 58 | +
|
| 59 | + Normally we specify a local arbiter(larb) for each multimedia HW |
| 60 | + like display, video decode, and camera. And there are different ports |
| 61 | + in each larb. Take a example, There are many ports like MC, PP, VLD in the |
| 62 | + video decode local arbiter, all these ports are according to the video HW. |
| 63 | +
|
| 64 | + In some SoCs, there may be a GALS(Global Async Local Sync) module between |
| 65 | + smi-common and m4u, and additional GALS module between smi-larb and |
| 66 | + smi-common. GALS can been seen as a "asynchronous fifo" which could help |
| 67 | + synchronize for the modules in different clock frequency. |
| 68 | +
|
| 69 | +properties: |
| 70 | + compatible: |
| 71 | + oneOf: |
| 72 | + - enum: |
| 73 | + - mediatek,mt2701-m4u # generation one |
| 74 | + - mediatek,mt2712-m4u # generation two |
| 75 | + - mediatek,mt6779-m4u # generation two |
| 76 | + - mediatek,mt8167-m4u # generation two |
| 77 | + - mediatek,mt8173-m4u # generation two |
| 78 | + - mediatek,mt8183-m4u # generation two |
| 79 | + - mediatek,mt8192-m4u # generation two |
| 80 | + |
| 81 | + - description: mt7623 generation one |
| 82 | + items: |
| 83 | + - const: mediatek,mt7623-m4u |
| 84 | + - const: mediatek,mt2701-m4u |
| 85 | + |
| 86 | + reg: |
| 87 | + maxItems: 1 |
| 88 | + |
| 89 | + interrupts: |
| 90 | + maxItems: 1 |
| 91 | + |
| 92 | + clocks: |
| 93 | + items: |
| 94 | + - description: bclk is the block clock. |
| 95 | + |
| 96 | + clock-names: |
| 97 | + items: |
| 98 | + - const: bclk |
| 99 | + |
| 100 | + mediatek,larbs: |
| 101 | + $ref: /schemas/types.yaml#/definitions/phandle-array |
| 102 | + minItems: 1 |
| 103 | + maxItems: 32 |
| 104 | + description: | |
| 105 | + List of phandle to the local arbiters in the current Socs. |
| 106 | + Refer to bindings/memory-controllers/mediatek,smi-larb.yaml. It must sort |
| 107 | + according to the local arbiter index, like larb0, larb1, larb2... |
| 108 | +
|
| 109 | + '#iommu-cells': |
| 110 | + const: 1 |
| 111 | + description: | |
| 112 | + This is the mtk_m4u_id according to the HW. Specifies the mtk_m4u_id as |
| 113 | + defined in |
| 114 | + dt-binding/memory/mt2701-larb-port.h for mt2701 and mt7623, |
| 115 | + dt-binding/memory/mt2712-larb-port.h for mt2712, |
| 116 | + dt-binding/memory/mt6779-larb-port.h for mt6779, |
| 117 | + dt-binding/memory/mt8167-larb-port.h for mt8167, |
| 118 | + dt-binding/memory/mt8173-larb-port.h for mt8173, |
| 119 | + dt-binding/memory/mt8183-larb-port.h for mt8183, |
| 120 | + dt-binding/memory/mt8192-larb-port.h for mt8192. |
| 121 | +
|
| 122 | + power-domains: |
| 123 | + maxItems: 1 |
| 124 | + |
| 125 | +required: |
| 126 | + - compatible |
| 127 | + - reg |
| 128 | + - interrupts |
| 129 | + - mediatek,larbs |
| 130 | + - '#iommu-cells' |
| 131 | + |
| 132 | +allOf: |
| 133 | + - if: |
| 134 | + properties: |
| 135 | + compatible: |
| 136 | + contains: |
| 137 | + enum: |
| 138 | + - mediatek,mt2701-m4u |
| 139 | + - mediatek,mt2712-m4u |
| 140 | + - mediatek,mt8173-m4u |
| 141 | + - mediatek,mt8192-m4u |
| 142 | + |
| 143 | + then: |
| 144 | + required: |
| 145 | + - clocks |
| 146 | + |
| 147 | + - if: |
| 148 | + properties: |
| 149 | + compatible: |
| 150 | + enum: |
| 151 | + - mediatek,mt8192-m4u |
| 152 | + |
| 153 | + then: |
| 154 | + required: |
| 155 | + - power-domains |
| 156 | + |
| 157 | +additionalProperties: false |
| 158 | + |
| 159 | +examples: |
| 160 | + - | |
| 161 | + #include <dt-bindings/clock/mt8173-clk.h> |
| 162 | + #include <dt-bindings/interrupt-controller/arm-gic.h> |
| 163 | +
|
| 164 | + iommu: iommu@10205000 { |
| 165 | + compatible = "mediatek,mt8173-m4u"; |
| 166 | + reg = <0x10205000 0x1000>; |
| 167 | + interrupts = <GIC_SPI 139 IRQ_TYPE_LEVEL_LOW>; |
| 168 | + clocks = <&infracfg CLK_INFRA_M4U>; |
| 169 | + clock-names = "bclk"; |
| 170 | + mediatek,larbs = <&larb0 &larb1 &larb2 |
| 171 | + &larb3 &larb4 &larb5>; |
| 172 | + #iommu-cells = <1>; |
| 173 | + }; |
| 174 | +
|
| 175 | + - | |
| 176 | + #include <dt-bindings/memory/mt8173-larb-port.h> |
| 177 | +
|
| 178 | + /* Example for a client device */ |
| 179 | + display { |
| 180 | + compatible = "mediatek,mt8173-disp"; |
| 181 | + iommus = <&iommu M4U_PORT_DISP_OVL0>, |
| 182 | + <&iommu M4U_PORT_DISP_RDMA0>; |
| 183 | + }; |
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