1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 %YAML 1.2
3 ---
4 $id: http://devicetree.org/schemas/i2c/opencores,i2c-ocores.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: OpenCores I2C controller
8
9 maintainers:
10 - Peter Korsgaard <peter@korsgaard.com>
11 - Andrew Lunn <andrew@lunn.ch>
12
13 allOf:
14 - $ref: /schemas/i2c/i2c-controller.yaml#
15
16 properties:
17 compatible:
18 oneOf:
19 - items:
20 - enum:
21 - sifive,fu740-c000-i2c # Opencore based IP block FU740-C000 SoC
22 - sifive,fu540-c000-i2c # Opencore based IP block FU540-C000 SoC
23 - const: sifive,i2c0
24 - enum:
25 - opencores,i2c-ocores
26 - aeroflexgaisler,i2cmst
27
28 reg:
29 maxItems: 1
30
31 interrupts:
32 maxItems: 1
33
34 clocks:
35 maxItems: 1
36
37 clock-frequency:
38 description: |
39 clock-frequency property is meant to control the bus frequency for i2c bus
40 drivers, but it was incorrectly used to specify i2c controller input clock
41 frequency. So the following rules are set to fix this situation:
42 - if clock-frequency is present and neither opencores,ip-clock-frequency nor
43 clocks are, then clock-frequency specifies i2c controller clock frequency.
44 This is to keep backwards compatibility with setups using old DTB. i2c bus
45 frequency is fixed at 100 KHz.
46 - if clocks is present it specifies i2c controller clock. clock-frequency
47 property specifies i2c bus frequency.
48 - if opencores,ip-clock-frequency is present it specifies i2c controller
49 clock frequency. clock-frequency property specifies i2c bus frequency.
50 default: 100000
51
52 reg-io-width:
53 description: |
54 io register width in bytes
55 enum: [1, 2, 4]
56
57 reg-shift:
58 description: |
59 device register offsets are shifted by this value
60 default: 0
61
62 regstep:
63 $ref: /schemas/types.yaml#/definitions/uint32
64 description: |
65 deprecated, use reg-shift above
66 deprecated: true
67
68 opencores,ip-clock-frequency:
69 $ref: /schemas/types.yaml#/definitions/uint32
70 description: |
71 Frequency of the controller clock in Hz. Mutually exclusive with clocks.
72 See the note above.
73
74 required:
75 - compatible
76 - reg
77 - "#address-cells"
78 - "#size-cells"
79
80 oneOf:
81 - required:
82 - opencores,ip-clock-frequency
83 - required:
84 - clocks
85
86 unevaluatedProperties: false
87
88 examples:
89 - |
90 i2c@a0000000 {
91 compatible = "opencores,i2c-ocores";
92 reg = <0xa0000000 0x8>;
93 #address-cells = <1>;
94 #size-cells = <0>;
95 interrupts = <10>;
96 opencores,ip-clock-frequency = <20000000>;
97
98 reg-shift = <0>; /* 8 bit registers */
99 reg-io-width = <1>; /* 8 bit read/write */
100 };
101
102 i2c@b0000000 {
103 compatible = "opencores,i2c-ocores";
104 reg = <0xa0000000 0x8>;
105 #address-cells = <1>;
106 #size-cells = <0>;
107 interrupts = <10>;
108 clocks = <&osc>;
109 clock-frequency = <400000>; /* i2c bus frequency 400 KHz */
110
111 reg-shift = <0>; /* 8 bit registers */
112 reg-io-width = <1>; /* 8 bit read/write */
113 };
114 ...
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