i3c.yaml (5978B)
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2%YAML 1.2 3--- 4$id: http://devicetree.org/schemas/i3c/i3c.yaml# 5$schema: http://devicetree.org/meta-schemas/core.yaml# 6 7title: I3C bus binding 8 9maintainers: 10 - Alexandre Belloni <alexandre.belloni@bootlin.com> 11 - Miquel Raynal <miquel.raynal@bootlin.com> 12 13description: | 14 I3C busses can be described with a node for the primary I3C controller device 15 and a set of child nodes for each I2C or I3C slave on the bus. Each of them 16 may, during the life of the bus, request mastership. 17 18properties: 19 $nodename: 20 pattern: "^i3c-master@[0-9a-f]+$" 21 22 "#address-cells": 23 const: 3 24 description: | 25 Each I2C device connected to the bus should be described in a subnode. 26 27 All I3C devices are supposed to support DAA (Dynamic Address Assignment), 28 and are thus discoverable. So, by default, I3C devices do not have to be 29 described in the device tree. This being said, one might want to attach 30 extra resources to these devices, and those resources may have to be 31 described in the device tree, which in turn means we have to describe 32 I3C devices. 33 34 Another use case for describing an I3C device in the device tree is when 35 this I3C device has a static I2C address and we want to assign it a 36 specific I3C dynamic address before the DAA takes place (so that other 37 devices on the bus can't take this dynamic address). 38 39 "#size-cells": 40 const: 0 41 42 i3c-scl-hz: 43 description: | 44 Frequency of the SCL signal used for I3C transfers. When undefined, the 45 default value should be 12.5MHz. 46 47 May not be supported by all controllers. 48 49 i2c-scl-hz: 50 description: | 51 Frequency of the SCL signal used for I2C transfers. When undefined, the 52 default should be to look at LVR (Legacy Virtual Register) values of 53 I2C devices described in the device tree to determine the maximum I2C 54 frequency. 55 56 May not be supported by all controllers. 57 58required: 59 - "#address-cells" 60 - "#size-cells" 61 62patternProperties: 63 "@[0-9a-f]+$": 64 type: object 65 description: | 66 I2C child, should be named: <device-type>@<i2c-address> 67 68 All properties described in Documentation/devicetree/bindings/i2c/i2c.txt 69 are valid here, except the reg property whose content is changed. 70 71 properties: 72 compatible: 73 description: 74 Compatible of the I2C device. 75 76 reg: 77 items: 78 - items: 79 - description: | 80 I2C address. 10 bit addressing is not supported. Devices with 81 10-bit address can't be properly passed through DEFSLVS 82 command. 83 minimum: 0 84 maximum: 0x7f 85 - const: 0 86 - description: | 87 Shall encode the I3C LVR (Legacy Virtual Register): 88 bit[31:8]: unused/ignored 89 bit[7:5]: I2C device index. Possible values: 90 * 0: I2C device has a 50 ns spike filter 91 * 1: I2C device does not have a 50 ns spike filter but 92 supports high frequency on SCL 93 * 2: I2C device does not have a 50 ns spike filter and is 94 not tolerant to high frequencies 95 * 3-7: reserved 96 bit[4]: tell whether the device operates in FM (Fast Mode) 97 or FM+ mode: 98 * 0: FM+ mode 99 * 1: FM mode 100 bit[3:0]: device type 101 * 0-15: reserved 102 103 required: 104 - compatible 105 - reg 106 107 "@[0-9a-f]+,[0-9a-f]+$": 108 type: object 109 description: | 110 I3C child, should be named: <device-type>@<static-i2c-address>,<i3c-pid> 111 112 properties: 113 reg: 114 items: 115 - items: 116 - description: | 117 Encodes the static I2C address. Should be 0 if the device does 118 not have one (0 is not a valid I2C address). 119 minimum: 0 120 maximum: 0x7f 121 - description: | 122 First half of the Provisional ID (following the PID 123 definition provided by the I3C specification). 124 125 Contains the manufacturer ID left-shifted by 1. 126 - description: | 127 Second half of the Provisional ID (following the PID 128 definition provided by the I3C specification). 129 130 Contains the ORing of the part ID left-shifted by 16, 131 the instance ID left-shifted by 12 and extra information. 132 133 assigned-address: 134 $ref: /schemas/types.yaml#/definitions/uint32 135 minimum: 0x1 136 maximum: 0xff 137 description: | 138 Dynamic address to be assigned to this device. This property is only 139 valid if the I3C device has a static address (first cell of the reg 140 property != 0). 141 142 required: 143 - reg 144 145additionalProperties: true 146 147examples: 148 - | 149 i3c-master@d040000 { 150 compatible = "cdns,i3c-master"; 151 clocks = <&coreclock>, <&i3csysclock>; 152 clock-names = "pclk", "sysclk"; 153 interrupts = <3 0>; 154 reg = <0x0d040000 0x1000>; 155 #address-cells = <3>; 156 #size-cells = <0>; 157 i2c-scl-hz = <100000>; 158 159 /* I2C device. */ 160 eeprom@57 { 161 compatible = "atmel,24c01"; 162 reg = <0x57 0x0 0x10>; 163 pagesize = <0x8>; 164 }; 165 166 /* I3C device with a static I2C address. */ 167 thermal_sensor: sensor@68,39200144004 { 168 reg = <0x68 0x392 0x144004>; 169 assigned-address = <0xa>; 170 }; 171 172 /* 173 * I3C device without a static I2C address but requiring 174 * resources described in the DT. 175 */ 176 sensor@0,39200154004 { 177 reg = <0x0 0x392 0x154004>; 178 clocks = <&clock_provider 0>; 179 }; 180 };