# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2 --- $id: http://devicetree.org/schemas/i3c/i3c.yaml# $schema: http://devicetree.org/meta-schemas/core.yaml# title: I3C bus maintainers: - Alexandre Belloni - Miquel Raynal description: | I3C busses can be described with a node for the primary I3C controller device and a set of child nodes for each I2C or I3C slave on the bus. Each of them may, during the life of the bus, request mastership. properties: $nodename: pattern: "^i3c@[0-9a-f]+$" "#address-cells": const: 3 description: | Each I2C device connected to the bus should be described in a subnode. All I3C devices are supposed to support DAA (Dynamic Address Assignment), and are thus discoverable. So, by default, I3C devices do not have to be described in the device tree. This being said, one might want to attach extra resources to these devices, and those resources may have to be described in the device tree, which in turn means we have to describe I3C devices. Other use-cases for describing an I3C device in the device tree are: - When the I3C device has a static I2C address and we want to assign it a specific I3C dynamic address before the DAA takes place (so that other devices on the bus can't take this dynamic address). - When the I3C device requires SETAASA for its discovery and uses a pre-defined static address. "#size-cells": const: 0 i3c-scl-hz: description: | Frequency of the SCL signal used for I3C transfers. When undefined, the default value should be 12.5MHz. May not be supported by all controllers. i2c-scl-hz: description: | Frequency of the SCL signal used for I2C transfers. When undefined, the default should be to look at LVR (Legacy Virtual Register) values of I2C devices described in the device tree to determine the maximum I2C frequency. May not be supported by all controllers. mctp-controller: type: boolean description: | Indicates that the system is accessible via this bus as an endpoint for MCTP over I3C transport. required: - "#address-cells" - "#size-cells" patternProperties: "@[0-9a-f]+$": type: object description: | I2C child, should be named: @ All properties described in dtschema schemas/i2c/i2c-controller.yaml are valid here, except the reg property whose content is changed. properties: compatible: description: Compatible of the I2C device. reg: items: - items: - description: | I2C address. 10 bit addressing is not supported. Devices with 10-bit address can't be properly passed through DEFSLVS command. minimum: 0 maximum: 0x7f - const: 0 - description: | Shall encode the I3C LVR (Legacy Virtual Register): See include/dt-bindings/i3c/i3c.h bit[31:8]: unused/ignored bit[7:5]: I2C device index. Possible values: * 0: I2C device has a 50 ns spike filter * 1: I2C device does not have a 50 ns spike filter but supports high frequency on SCL * 2: I2C device does not have a 50 ns spike filter and is not tolerant to high frequencies * 3-7: reserved bit[4]: tell whether the device operates in FM (Fast Mode) or FM+ mode: * 0: FM+ mode * 1: FM mode bit[3:0]: device type * 0-15: reserved required: - compatible - reg "@[0-9a-f]+,[0-9a-f]+$": type: object description: | I3C child, should be named: @, properties: reg: items: - items: - description: | Encodes the static I2C address. Should be 0 if the device does not have one (0 is not a valid I2C address). minimum: 0 maximum: 0x7f - description: | First half of the Provisioned ID (following the PID definition provided by the I3C specification). Contains the manufacturer ID left-shifted by 1. - description: | Second half of the Provisioned ID (following the PID definition provided by the I3C specification). Contains the ORing of the part ID left-shifted by 16, the instance ID left-shifted by 12 and extra information. assigned-address: $ref: /schemas/types.yaml#/definitions/uint32 minimum: 0x1 maximum: 0xff description: | Dynamic address to be assigned to this device. In case static address is present (first cell of the reg property != 0), this address is assigned through SETDASA. If static address is not present, this address is assigned through SETNEWDA after assigning a temporary address via ENTDAA. If SETAASA is used, this property is not used, and the static address itself becomes the dynamic address. mipi-i3c-static-method: $ref: /schemas/types.yaml#/definitions/uint32 minimum: 0x1 maximum: 0x7 default: 1 description: | Bitmap describing which methods of Dynamic Address Assignment from a static address are supported by this I3C Target. For each defined bit position, a set bit indicates support for that method and a cleared bit indicates lack of support. Bit 0: SETDASA CCC (Direct) Bit 1: SETAASA CCC (Broadcast) Bit 2: Other CCC (vendor / standards extension) All other bits are reserved. This property follows the MIPI I3C specification. The primary use of this property is to indicate support for SETAASA, i.e Bit 1, but will allow other values mentioned in the specification so that it mirrors the specification. SETDASA will remain as the default method even if this property is not present. required: - reg additionalProperties: true examples: - | #include i3c@d040000 { compatible = "cdns,i3c-master"; clocks = <&coreclock>, <&i3csysclock>; clock-names = "pclk", "sysclk"; interrupts = <3 0>; reg = <0x0d040000 0x1000>; #address-cells = <3>; #size-cells = <0>; i2c-scl-hz = <100000>; /* I2C device. */ eeprom@57 { compatible = "atmel,24c01"; reg = <0x57 0x0 (I2C_FM | I2C_FILTER)>; pagesize = <0x8>; }; /* I3C device with a static I2C address and assigned address. */ thermal_sensor: sensor@68,39200144004 { reg = <0x68 0x392 0x144004>; assigned-address = <0xa>; }; /* I3C device with only assigned address. */ pressure_sensor: sensor@0,39200124004 { reg = <0x0 0x392 0x124000>; assigned-address = <0xc>; }; /* * I3C device without a static I2C address but requiring * resources described in the DT. */ sensor@0,39200154004 { reg = <0x0 0x392 0x154004>; clocks = <&clock_provider 0>; }; };