PSCI

Table of Contents

• Features Supported
• SysConfig Features
• Features NOT Supported
• Example Usage
• API

Power State Coordination Interface (PSCI) is a standard interface for power management between ARM processors. It provides a standardized way for software running on an ARM system to communicate with power management firmware (Trusted Firmware-A).

Features Supported

• CPU Power Management
  • CPU_ON
  • CPU_OFF
• System Power Management
  • SYSTEM_RESET
• Power State Query and Configuration
  • PSCI Version Query
  • PSCI Features

SysConfig Features

• PSCI init and open is done by default through sysconfig generated code.
• No other specific configuration required for power management through PSCI.

Features NOT Supported

NA

Example Usage

Include the below file to access the APIs

#include <drivers/psci.h>

Instance Open Example

    PSCI_Handle handle = PSCI_open(CONFIG_PSCI_INSTANCE);
    DebugP_assert(handle != NULL);

Instance Close Example

    PSCI_Handle handle = PSCI_getHandle(CONFIG_PSCI_INSTANCE);
    PSCI_close(handle);

CPU Power On Example

    int32_t status;
    PSCI_Handle handle = PSCI_getHandle(CONFIG_PSCI_INSTANCE);
    status = PSCI_cpuOn(handle, cpuId, gPSCICpuEntryPoint[cpuId]);
    DebugP_assert(status == SystemP_SUCCESS);

System Reset Example

    int32_t status;
    PSCI_Handle handle = PSCI_getHandle(CONFIG_PSCI_INSTANCE);
    status = PSCI_systemReset(handle);
    /* We should not reach this point. */
    DebugP_assert(status == SystemP_SUCCESS);

API

APIs for PSCI