0001 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
0002 %YAML 1.2
0003 ---
0004 $id: http://devicetree.org/schemas/i2c/opencores,i2c-ocores.yaml#
0005 $schema: http://devicetree.org/meta-schemas/core.yaml#
0006
0007 title: OpenCores I2C controller
0008
0009 maintainers:
0010 - Peter Korsgaard <peter@korsgaard.com>
0011 - Andrew Lunn <andrew@lunn.ch>
0012
0013 allOf:
0014 - $ref: /schemas/i2c/i2c-controller.yaml#
0015
0016 properties:
0017 compatible:
0018 oneOf:
0019 - items:
0020 - enum:
0021 - sifive,fu740-c000-i2c # Opencore based IP block FU740-C000 SoC
0022 - sifive,fu540-c000-i2c # Opencore based IP block FU540-C000 SoC
0023 - const: sifive,i2c0
0024 - enum:
0025 - opencores,i2c-ocores
0026 - aeroflexgaisler,i2cmst
0027
0028 reg:
0029 maxItems: 1
0030
0031 interrupts:
0032 maxItems: 1
0033
0034 clocks:
0035 maxItems: 1
0036
0037 clock-frequency:
0038 description: |
0039 clock-frequency property is meant to control the bus frequency for i2c bus
0040 drivers, but it was incorrectly used to specify i2c controller input clock
0041 frequency. So the following rules are set to fix this situation:
0042 - if clock-frequency is present and neither opencores,ip-clock-frequency nor
0043 clocks are, then clock-frequency specifies i2c controller clock frequency.
0044 This is to keep backwards compatibility with setups using old DTB. i2c bus
0045 frequency is fixed at 100 KHz.
0046 - if clocks is present it specifies i2c controller clock. clock-frequency
0047 property specifies i2c bus frequency.
0048 - if opencores,ip-clock-frequency is present it specifies i2c controller
0049 clock frequency. clock-frequency property specifies i2c bus frequency.
0050 default: 100000
0051
0052 reg-io-width:
0053 description: |
0054 io register width in bytes
0055 enum: [1, 2, 4]
0056
0057 reg-shift:
0058 description: |
0059 device register offsets are shifted by this value
0060 default: 0
0061
0062 regstep:
0063 description: |
0064 deprecated, use reg-shift above
0065 deprecated: true
0066
0067 opencores,ip-clock-frequency:
0068 $ref: /schemas/types.yaml#/definitions/uint32
0069 description: |
0070 Frequency of the controller clock in Hz. Mutually exclusive with clocks.
0071 See the note above.
0072
0073 required:
0074 - compatible
0075 - reg
0076 - "#address-cells"
0077 - "#size-cells"
0078
0079 oneOf:
0080 - required:
0081 - opencores,ip-clock-frequency
0082 - required:
0083 - clocks
0084
0085 unevaluatedProperties: false
0086
0087 examples:
0088 - |
0089 i2c@a0000000 {
0090 compatible = "opencores,i2c-ocores";
0091 reg = <0xa0000000 0x8>;
0092 #address-cells = <1>;
0093 #size-cells = <0>;
0094 interrupts = <10>;
0095 opencores,ip-clock-frequency = <20000000>;
0096
0097 reg-shift = <0>; /* 8 bit registers */
0098 reg-io-width = <1>; /* 8 bit read/write */
0099 };
0100
0101 i2c@b0000000 {
0102 compatible = "opencores,i2c-ocores";
0103 reg = <0xa0000000 0x8>;
0104 #address-cells = <1>;
0105 #size-cells = <0>;
0106 interrupts = <10>;
0107 clocks = <&osc>;
0108 clock-frequency = <400000>; /* i2c bus frequency 400 KHz */
0109
0110 reg-shift = <0>; /* 8 bit registers */
0111 reg-io-width = <1>; /* 8 bit read/write */
0112 };
0113 ...
