tlbmc/bus_topology.proto

edition = "2023";

package uhmm;

option features.field_presence = EXPLICIT;
option java_multiple_files = true;
option java_package = "com.google.uhmm";
option java_outer_classname = "BusTopologyProto";

// Message to represent an address relative to a device connected to a bus
message I2CAddress {
  int32 address = 1;
  enum AddressLength {
    ADDRESS_LENGTH_UNSPECIFIED = 0;
    // 7 bit addressing.
    ADDRESS_LENGTH_BIT7 = 1;
    // 10 bit addressing.
    ADDRESS_LENGTH_BIT10 = 2;
  }
  AddressLength address_length = 2;
}

message Mux {
  // The PMBUS reported model number of this mux.
  string model = 1;
  I2CAddress address_identifier = 2;
  // The downstream buses that are connected to the mux.
  repeated Bus downstream_buses = 3;
}

message Eeprom {
  // The PMBUS reported model number of this EEPROM.
  string model = 1;
  // The barepath of the plugin that the EERPOM resides on.
  string barepath = 2;
  I2CAddress address_identifier = 3;
  // Addressing mode of the eeprom.
  enum AddressingMode {
    ADDRESSING_MODE_UNSPECIFIED = 0;
    ADDRESSING_MODE_BIT8 = 1;
    ADDRESSING_MODE_BIT16 = 2;
  }
  AddressingMode addressing_mode = 4;
  int32 size_bytes = 5;

  // Represents the different reporting areas of an EEPROM.
  enum ReportingArea {
    REPORTING_AREA_UNSPECIFIED = 0;
    REPORTING_AREA_CHASSIS = 1;
    REPORTING_AREA_BOARD = 2;
    REPORTING_AREA_PRODUCT = 3;
  }
  // The content expected to be written on the EEPROM in accordance with
  // go/fru-eeprom-specification and the associated reporting area.
  message FruDeviceInformation {
    // The area of the EEPROM's memory that contains this information.
    ReportingArea reporting_area = 1;
    string manufacturer = 2;
    string part_number = 3;
    string serial_number = 4;
  }
  repeated FruDeviceInformation part_information = 6;
}

message GpioController {
  // The PMBUS reported model number of this GPIO controller.
  string model = 1;
  I2CAddress address_identifier = 2;
  // The barepath of the plugin that the GPIO controller resides on.
  string barepath = 3;
}

message SensorController {
  // The PMBUS reported model number of this sensor controller.
  string model = 1;
  I2CAddress address_identifier = 2;
  // The barepath of the plugin that the sensor controller resides on.
  string barepath = 3;

  message MonitoredComponent {
    // The barepath of the FRU component that is being monitored by the sensor
    // controller.
    string barepath = 1;
    // The identifier of the probing sensor on the sensor controller that is
    // monitoring the component.
    string sensor_id = 2;
  }
  repeated MonitoredComponent monitored_components = 4;
}

message Bus {
  // Relative bus/channel id of the controller/muxes are upstream of this bus.
  int32 channel_id = 1;
  // Muxes connected to the bus and routing traffic to its downstream.
  repeated Mux muxes = 2;
  repeated Eeprom eeproms = 3;
  repeated GpioController gpio_controllers = 4;
  repeated SensorController sensor_controllers = 5;
}

message I2cRoot {
  // The node entity tag of the target node to be installed with this data.
  string node_entity_tag = 1;
  // The buses that are connected to the controller.
  repeated Bus buses = 2;
  // The chip model of the BMC as reported by the manufacturer.
  string chip_model = 3;
}

// Represents the overarching USB root of a node, containing all logical
// USB buses across all physical host controllers in the system.
// Since MC2 manages endpoints and devices without needing to track which
// logical buses map to which physical controller ASICs (e.g., xHCI vs EHCI),
// all logical USB buses are consolidated under a single UsbRoot.
message UsbRoot {
  repeated UsbBus buses = 1;
}

// Represents a logical USB Bus in the system.
// In USB topology, every bus originates from a Root Hub. A single physical
// controller (like XHCI) often registers multiple logical buses (Root Hubs)
// to separate traffic by speed/protocol (e.g., one for USB 2.0 and one for
// USB 3.0).
message UsbBus {
  // Alternative to hub_path, this is the bus number of the root hub which will
  // be static across reboots, which is guaranteed by the udev rules.
  int32 bus_number = 1;

  // Downstream ports on this root hub.
  repeated UsbPort ports = 2;
}

// Explicit port container isolates the port index and defines what is
// connected.
message UsbPort {
  // Physical port number on the parent hub.
  int32 port_id = 1;

  // A port can either branch into another chain of hubs or terminate at a
  // plugin (IOX), a generic USB device, or a UART device.
  // More downstream devices will be added in future revisions.
  oneof downstream_device {
    UsbHub hub = 2;
  }
}

message UsbHub {
  repeated UsbPort ports = 1;
}

message BmcMonitoredComponentsResponse {
  message MonitoredComponent {
    string barepath = 1;
    string plugin_id = 2;
    // Probe paths are encoding of the BMC software interface used to probe data
    // about a particular part.
    enum ProbePath {
      PROBE_PATH_UNSPECIFIED = 0;
      PROBE_PATH_I2C = 1;
      PROBE_PATH_NCSI = 2;
      PROBE_PATH_SMBIOS = 3;
      PROBE_PATH_ADC = 4;
    }
    ProbePath probe_path = 3;
  }
  repeated MonitoredComponent monitored_components = 1;
}