Configuring the PMIC Setting

During system boot, MB1 enables system power rails such as CPU, SRAM, and CORE as well as some system PMIC configurations. The typical configurations are:

  • Enabling rails
  • Setting rail voltages
  • FPS configurations

Enabling and setting of voltages of rails may require:

  • I2C command to devices
  • MMIO access to Tegra registers, either read-modify-write or write-only
  • Delay after the commands

Rail-specific configurations, such as I2C commands, MMIO access, and delays, are platform-specific. The MB1 BCT configuration file must provide configuration information.

The MB1-CFG format supports:

  • I2C commands and MMIO commands on any sequence.
  • Any I2C controller instance.
  • Any 7-bit secondary address of the device.
  • MMIO commands on read-modify-write format to support read only and Read-modify-write format.
  • I2C commands are read-modify-write format to support read only and Read-modify-write format.
  • Any amount of delay between commands.
  • Write only commands for I2C/MMIO.
  • Any size of device registers address and data size for i2c commands.
  • I2c command on the 400 KHz.
  • The sequence may be
    • 1 MMIO, 1 I2C
    • 1 I2C, 1 MMIO
    • 2 MMIO, 1 I2C
    • 1 MMIO, 2 I2C

The typical rail/configurations are divided into these PMIC command domains:

  • Generic: General PMIC configurations
  • GPU: Command related to CPU rails
  • GPU: Commands related to GPU
  • SRAM: Commands related to SRAM
  • CORE: Commands related to CORE
  • MEM: Commands related to Memory

If the configuration for given rail is NOT specified, it is not necessary to provide the command sequence of that rail. MB1 device side code ignores the configuration of that rail.

Each rail is defined with a unique ID to enable the parsing and BCT binary. The unique IDs are as follows:

Rail Name

ID

GENERIC

1

CPU

2

CORE

3

SRAM

4

GPU

5

MEM

6

The PMIC configuration file is available at:

<top>/drive-foundation/platform-config/t23x/
automotive/bct/<board>/pmic/tegra194-mb1-bct-pmic-
<board>-<sku_id>-<rev>-t<a|b|c>.cfg

For example:

tegra194-mb1-bct-pmic-e3550-0001-b01-ta.cfg

For definitions of the <board>-<sku_id>-<rev>-t<a|b|c>, see the Release Notes.