1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 %YAML 1.2
3 ---
4 $id: http://devicetree.org/schemas/dma/stm32/st,stm32-mdma.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: STMicroelectronics STM32 MDMA Controller
8
9 description: |
10 The STM32 MDMA is a general-purpose direct memory access controller capable of
11 supporting 64 independent DMA channels with 256 HW requests.
12 DMA clients connected to the STM32 MDMA controller must use the format
13 described in the dma.txt file, using a five-cell specifier for each channel:
14 a phandle to the MDMA controller plus the following five integer cells:
15 1. The request line number
16 2. The priority level
17 0x0: Low
18 0x1: Medium
19 0x2: High
20 0x3: Very high
21 3. A 32bit mask specifying the DMA channel configuration
22 -bit 0-1: Source increment mode
23 0x0: Source address pointer is fixed
24 0x2: Source address pointer is incremented after each data transfer
25 0x3: Source address pointer is decremented after each data transfer
26 -bit 2-3: Destination increment mode
27 0x0: Destination address pointer is fixed
28 0x2: Destination address pointer is incremented after each data transfer
29 0x3: Destination address pointer is decremented after each data transfer
30 -bit 8-9: Source increment offset size
31 0x0: byte (8bit)
32 0x1: half-word (16bit)
33 0x2: word (32bit)
34 0x3: double-word (64bit)
35 -bit 10-11: Destination increment offset size
36 0x0: byte (8bit)
37 0x1: half-word (16bit)
38 0x2: word (32bit)
39 0x3: double-word (64bit)
40 -bit 25-18: The number of bytes to be transferred in a single transfer
41 (min = 1 byte, max = 128 bytes)
42 -bit 29:28: Trigger Mode
43 0x00: Each MDMA request triggers a buffer transfer (max 128 bytes)
44 0x1: Each MDMA request triggers a block transfer (max 64K bytes)
45 0x2: Each MDMA request triggers a repeated block transfer
46 0x3: Each MDMA request triggers a linked list transfer
47 4. A 32bit value specifying the register to be used to acknowledge the request
48 if no HW ack signal is used by the MDMA client
49 5. A 32bit mask specifying the value to be written to acknowledge the request
50 if no HW ack signal is used by the MDMA client
51
52 maintainers:
53 - Amelie Delaunay <amelie.delaunay@foss.st.com>
54
55 allOf:
56 - $ref: /schemas/dma/dma-controller.yaml#
57
58 properties:
59 "#dma-cells":
60 const: 5
61
62 compatible:
63 const: st,stm32h7-mdma
64
65 reg:
66 maxItems: 1
67
68 clocks:
69 maxItems: 1
70
71 interrupts:
72 maxItems: 1
73
74 resets:
75 maxItems: 1
76
77 st,ahb-addr-masks:
78 $ref: /schemas/types.yaml#/definitions/uint32-array
79 description: Array of u32 mask to list memory devices addressed via AHB bus.
80
81 required:
82 - compatible
83 - reg
84 - clocks
85 - interrupts
86
87 unevaluatedProperties: false
88
89 examples:
90 - |
91 #include <dt-bindings/interrupt-controller/arm-gic.h>
92 #include <dt-bindings/clock/stm32mp1-clks.h>
93 #include <dt-bindings/reset/stm32mp1-resets.h>
94 dma-controller@52000000 {
95 compatible = "st,stm32h7-mdma";
96 reg = <0x52000000 0x1000>;
97 interrupts = <122>;
98 clocks = <&timer_clk>;
99 resets = <&rcc 992>;
100 #dma-cells = <5>;
101 dma-channels = <16>;
102 dma-requests = <32>;
103 st,ahb-addr-masks = <0x20000000>, <0x00000000>;
104 };
105
106 ...
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