1# SPDX-License-Identifier: GPL-2.0-only 2%YAML 1.2 3--- 4$id: http://devicetree.org/schemas/dma/snps,dma-spear1340.yaml# 5$schema: http://devicetree.org/meta-schemas/core.yaml# 6 7title: Synopsys Designware DMA Controller 8 9maintainers: 10 - Viresh Kumar <vireshk@kernel.org> 11 - Andy Shevchenko <andriy.shevchenko@linux.intel.com> 12 13allOf: 14 - $ref: "dma-controller.yaml#" 15 16properties: 17 compatible: 18 const: snps,dma-spear1340 19 20 "#dma-cells": 21 minimum: 3 22 maximum: 4 23 description: | 24 First cell is a phandle pointing to the DMA controller. Second one is 25 the DMA request line number. Third cell is the memory master identifier 26 for transfers on dynamically allocated channel. Fourth cell is the 27 peripheral master identifier for transfers on an allocated channel. Fifth 28 cell is an optional mask of the DMA channels permitted to be allocated 29 for the corresponding client device. 30 31 reg: 32 maxItems: 1 33 34 interrupts: 35 maxItems: 1 36 37 clocks: 38 maxItems: 1 39 40 clock-names: 41 description: AHB interface reference clock. 42 const: hclk 43 44 dma-channels: 45 description: | 46 Number of DMA channels supported by the controller. In case if 47 not specified the driver will try to auto-detect this and 48 the rest of the optional parameters. 49 minimum: 1 50 maximum: 8 51 52 dma-requests: 53 minimum: 1 54 maximum: 16 55 56 dma-masters: 57 $ref: /schemas/types.yaml#definitions/uint32 58 description: | 59 Number of DMA masters supported by the controller. In case if 60 not specified the driver will try to auto-detect this and 61 the rest of the optional parameters. 62 minimum: 1 63 maximum: 4 64 65 chan_allocation_order: 66 $ref: /schemas/types.yaml#definitions/uint32 67 description: | 68 DMA channels allocation order specifier. Zero means ascending order 69 (first free allocated), while one - descending (last free allocated). 70 default: 0 71 enum: [0, 1] 72 73 chan_priority: 74 $ref: /schemas/types.yaml#definitions/uint32 75 description: | 76 DMA channels priority order. Zero means ascending channels priority 77 so the very first channel has the highest priority. While 1 means 78 descending priority (the last channel has the highest priority). 79 default: 0 80 enum: [0, 1] 81 82 block_size: 83 $ref: /schemas/types.yaml#definitions/uint32 84 description: Maximum block size supported by the DMA controller. 85 enum: [3, 7, 15, 31, 63, 127, 255, 511, 1023, 2047, 4095] 86 87 data-width: 88 $ref: /schemas/types.yaml#/definitions/uint32-array 89 description: Data bus width per each DMA master in bytes. 90 items: 91 maxItems: 4 92 items: 93 enum: [4, 8, 16, 32] 94 95 data_width: 96 $ref: /schemas/types.yaml#/definitions/uint32-array 97 deprecated: true 98 description: | 99 Data bus width per each DMA master in (2^n * 8) bits. This property is 100 deprecated. It' usage is discouraged in favor of data-width one. Moreover 101 the property incorrectly permits to define data-bus width of 8 and 16 102 bits, which is impossible in accordance with DW DMAC IP-core data book. 103 items: 104 maxItems: 4 105 items: 106 enum: 107 - 0 # 8 bits 108 - 1 # 16 bits 109 - 2 # 32 bits 110 - 3 # 64 bits 111 - 4 # 128 bits 112 - 5 # 256 bits 113 default: 0 114 115 multi-block: 116 $ref: /schemas/types.yaml#/definitions/uint32-array 117 description: | 118 LLP-based multi-block transfer supported by hardware per 119 each DMA channel. 120 items: 121 maxItems: 8 122 items: 123 enum: [0, 1] 124 default: 1 125 126 snps,max-burst-len: 127 $ref: /schemas/types.yaml#/definitions/uint32-array 128 description: | 129 Maximum length of the burst transactions supported by the controller. 130 This property defines the upper limit of the run-time burst setting 131 (CTLx.SRC_MSIZE/CTLx.DST_MSIZE fields) so the allowed burst length 132 will be from 1 to max-burst-len words. It's an array property with one 133 cell per channel in the units determined by the value set in the 134 CTLx.SRC_TR_WIDTH/CTLx.DST_TR_WIDTH fields (data width). 135 items: 136 maxItems: 8 137 items: 138 enum: [4, 8, 16, 32, 64, 128, 256] 139 default: 256 140 141 snps,dma-protection-control: 142 $ref: /schemas/types.yaml#definitions/uint32 143 description: | 144 Bits one-to-one passed to the AHB HPROT[3:1] bus. Each bit setting 145 indicates the following features: bit 0 - privileged mode, 146 bit 1 - DMA is bufferable, bit 2 - DMA is cacheable. 147 default: 0 148 minimum: 0 149 maximum: 7 150 151unevaluatedProperties: false 152 153required: 154 - compatible 155 - "#dma-cells" 156 - reg 157 - interrupts 158 159examples: 160 - | 161 dma-controller@fc000000 { 162 compatible = "snps,dma-spear1340"; 163 reg = <0xfc000000 0x1000>; 164 interrupt-parent = <&vic1>; 165 interrupts = <12>; 166 167 dma-channels = <8>; 168 dma-requests = <16>; 169 dma-masters = <4>; 170 #dma-cells = <3>; 171 172 chan_allocation_order = <1>; 173 chan_priority = <1>; 174 block_size = <0xfff>; 175 data-width = <8 8>; 176 multi-block = <0 0 0 0 0 0 0 0>; 177 snps,max-burst-len = <16 16 4 4 4 4 4 4>; 178 }; 179... 180