PlatformManager Block Configuration

Block configurations allow defining multiple similar FPGA sub-devices using offset calculation expressions. This reduces configuration verbosity when an FPGA has many identical controllers at regular address offsets.

Overview

Instead of listing each I2C adapter, LED controller, or transceiver controller individually, block configs define a pattern with:

• A name prefix
• An offset calculation expression
• The number of instances

Offset Calculation Expressions

Expressions support:

• Hexadecimal constants: 0x1000
• Arithmetic: +, -, *
• Variables in braces (context-dependent, e.g., {adapterIndex}, {busIndex})

Available variables depend on the block config type:

• I2C adapter blocks: {adapterIndex}, {startAdapterIndex}
• MDIO bus blocks: {busIndex}
• Port/LED configs: {portNum}, {startPort}, {ledNum}

The result is computed as a hexadecimal offset.

Example Calculation

For csrOffsetCalc: "0x1000 + ({adapterIndex} - {startAdapterIndex}) * 0x100" with startAdapterIndex=1:

adapterIndex	Calculation	Result
1	0x1000 + (1-1)*0x100	0x1000
2	0x1000 + (2-1)*0x100	0x1100
3	0x1000 + (3-1)*0x100	0x1200

I2C Adapter Block Config

Creates multiple I2C adapters from an FPGA:

{
  "i2cAdapterBlockConfigs": [
    {
      "pmUnitScopedNamePrefix": "SMB_I2C_ADAPTER",
      "deviceName": "fbiob_i2c",
      "csrOffsetCalc": "0x1000 + ({adapterIndex} - {startAdapterIndex}) * 0x100",
      "iobufOffsetCalc": "0x2000 + ({adapterIndex} - {startAdapterIndex}) * 0x100",
      "startAdapterIndex": 1,
      "numAdapters": 8,
      "numBusesPerAdapter": 1
    }
  ]
}

This creates devices named SMB_I2C_ADAPTER_1 through SMB_I2C_ADAPTER_8.

Field	Description
pmUnitScopedNamePrefix	Prefix for generated device names
deviceName	Kernel driver name
csrOffsetCalc	Expression for CSR register offset
iobufOffsetCalc	Expression for I/O buffer offset
startAdapterIndex	Starting index for numbering
numAdapters	Number of adapters to create
numBusesPerAdapter	I2C buses per adapter (default: 1)

Available variables:

Variable	Description
{adapterIndex}	Current adapter index (from startAdapterIndex to startAdapterIndex + numAdapters - 1)
{startAdapterIndex}	Value of startAdapterIndex field

Transceiver Controller Block Config

Creates multiple transceiver (QSFP/SFP) controllers:

{
  "xcvrCtrlBlockConfigs": [
    {
      "pmUnitScopedNamePrefix": "XCVR_CTRL",
      "deviceName": "fbiob_xcvr",
      "csrOffsetCalc": "0x3000 + ({portNum} - {startPort}) * 0x4",
      "iobufOffsetCalc": "0x4000 + ({portNum} - {startPort}) * 0x4",
      "startPort": 1,
      "numPorts": 32
    }
  ]
}

This creates devices named XCVR_CTRL_PORT_1 through XCVR_CTRL_PORT_32.

Field	Description
pmUnitScopedNamePrefix	Prefix for generated device names
deviceName	Kernel driver name
csrOffsetCalc	Expression for CSR register offset
iobufOffsetCalc	Expression for I/O buffer offset
startPort	Starting port number
numPorts	Number of ports

Available variables:

Variable	Description
{portNum}	Current port number (from startPort to startPort + numPorts - 1)
{startPort}	Value of startPort field

LED Controller Block Config

Creates multiple LED controllers (typically per-port):

{
  "ledCtrlBlockConfigs": [
    {
      "pmUnitScopedNamePrefix": "LED_CTRL",
      "deviceName": "fbiob_led",
      "csrOffsetCalc": "0x5000 + ({portNum} - {startPort}) * 0x8 + ({ledNum} - 1) * 0x4",
      "iobufOffsetCalc": "0x6000 + ({portNum} - {startPort}) * 0x8 + ({ledNum} - 1) * 0x4",
      "startPort": 1,
      "numPorts": 32,
      "ledPerPort": 2
    }
  ]
}

This creates devices named LED_CTRL_PORT_1_LED_1, LED_CTRL_PORT_1_LED_2, through LED_CTRL_PORT_32_LED_2.

Field	Description
pmUnitScopedNamePrefix	Prefix for generated device names
deviceName	Kernel driver name
csrOffsetCalc	Expression for CSR register offset
iobufOffsetCalc	Expression for I/O buffer offset
startPort	Starting port number
numPorts	Number of ports
ledPerPort	LEDs per port

Available variables:

Variable	Description
{portNum}	Current port number (from startPort to startPort + numPorts - 1)
{startPort}	Value of startPort field
{ledNum}	Current LED number (from 1 to ledPerPort)

MDIO Bus Block Config

Creates multiple MDIO bus controllers:

{
  "mdioBusBlockConfigs": [
    {
      "pmUnitScopedNamePrefix": "RTM_MDIO_BUS",
      "deviceName": "fbiob_mdio",
      "csrOffsetCalc": "0x200 + {busIndex} * 0x20",
      "iobufOffsetCalc": "0x300 + {busIndex} * 0x4",
      "numBuses": 4
    }
  ]
}

This creates devices named RTM_MDIO_BUS_0 through RTM_MDIO_BUS_3.

Field	Description
pmUnitScopedNamePrefix	Prefix for generated device names
deviceName	Kernel driver name
csrOffsetCalc	Expression for CSR register offset
iobufOffsetCalc	Expression for I/O buffer offset
numBuses	Number of MDIO buses

Available variables:

Variable	Description
{busIndex}	Current bus index (from 0 to numBuses - 1)

Legacy Configs

Block configs replace the deprecated individual configs:

• i2cAdapterConfigs -> i2cAdapterBlockConfigs
• xcvrCtrlConfigs -> xcvrCtrlBlockConfigs
• ledCtrlConfigs -> ledCtrlBlockConfigs
• mdioBusConfigs -> mdioBusBlockConfigs

The legacy configs are still supported but should not be used for new platforms.