blob: 123d54f4e5140b6f9266cd750c40e8c146fa8bc4 [file] [log] [blame]
/*
* Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch_helpers.h>
#include <assert.h>
#include <css_pm.h>
#include <debug.h>
#include <plat_arm.h>
#include "../scpi/css_scpi.h"
#include "css_scp.h"
/*
* This file implements the SCP power management functions using SCPI protocol.
*/
/*
* Helper function to inform power down state to SCP.
*/
void css_scp_suspend(const struct psci_power_state *target_state)
{
uint32_t cluster_state = scpi_power_on;
uint32_t system_state = scpi_power_on;
/* Check if power down at system power domain level is requested */
if (css_system_pwr_state(target_state) == ARM_LOCAL_STATE_OFF)
system_state = scpi_power_retention;
/* Cluster is to be turned off, so disable coherency */
if (CSS_CLUSTER_PWR_STATE(target_state) == ARM_LOCAL_STATE_OFF)
cluster_state = scpi_power_off;
/*
* Ask the SCP to power down the appropriate components depending upon
* their state.
*/
scpi_set_css_power_state(read_mpidr_el1(),
scpi_power_off,
cluster_state,
system_state);
}
/*
* Helper function to turn off a CPU power domain and its parent power domains
* if applicable. Since SCPI doesn't differentiate between OFF and suspend, we
* call the suspend helper here.
*/
void css_scp_off(const struct psci_power_state *target_state)
{
css_scp_suspend(target_state);
}
/*
* Helper function to turn ON a CPU power domain and its parent power domains
* if applicable.
*/
void css_scp_on(u_register_t mpidr)
{
/*
* SCP takes care of powering up parent power domains so we
* only need to care about level 0
*/
scpi_set_css_power_state(mpidr, scpi_power_on, scpi_power_on,
scpi_power_on);
}
/*
* Helper function to get the power state of a power domain node as reported
* by the SCP.
*/
int css_scp_get_power_state(u_register_t mpidr, unsigned int power_level)
{
int rc, element;
unsigned int cpu_state, cluster_state;
/*
* The format of 'power_level' is implementation-defined, but 0 must
* mean a CPU. We also allow 1 to denote the cluster
*/
if (power_level != ARM_PWR_LVL0 && power_level != ARM_PWR_LVL1)
return PSCI_E_INVALID_PARAMS;
/* Query SCP */
rc = scpi_get_css_power_state(mpidr, &cpu_state, &cluster_state);
if (rc != 0)
return PSCI_E_INVALID_PARAMS;
/* Map power states of CPU and cluster to expected PSCI return codes */
if (power_level == ARM_PWR_LVL0) {
/*
* The CPU state returned by SCP is an 8-bit bit mask
* corresponding to each CPU in the cluster
*/
#if ARM_PLAT_MT
/*
* The current SCPI driver only caters for single-threaded
* platforms. Hence we ignore the thread ID (which is always 0)
* for such platforms.
*/
element = (mpidr >> MPIDR_AFF1_SHIFT) & MPIDR_AFFLVL_MASK;
#else
element = mpidr & MPIDR_AFFLVL_MASK;
#endif /* ARM_PLAT_MT */
return CSS_CPU_PWR_STATE(cpu_state, element) ==
CSS_CPU_PWR_STATE_ON ? HW_ON : HW_OFF;
} else {
assert(cluster_state == CSS_CLUSTER_PWR_STATE_ON ||
cluster_state == CSS_CLUSTER_PWR_STATE_OFF);
return cluster_state == CSS_CLUSTER_PWR_STATE_ON ? HW_ON :
HW_OFF;
}
}
/*
* Helper function to shutdown the system via SCPI.
*/
void __dead2 css_scp_sys_shutdown(void)
{
uint32_t response;
/*
* Disable GIC CPU interface to prevent pending interrupt
* from waking up the AP from WFI.
*/
plat_arm_gic_cpuif_disable();
/* Send the power down request to the SCP */
response = scpi_sys_power_state(scpi_system_shutdown);
if (response != SCP_OK) {
ERROR("CSS System Off: SCP error %u.\n", response);
panic();
}
wfi();
ERROR("CSS System Off: operation not handled.\n");
panic();
}
/*
* Helper function to reset the system via SCPI.
*/
void __dead2 css_scp_sys_reboot(void)
{
uint32_t response;
/*
* Disable GIC CPU interface to prevent pending interrupt
* from waking up the AP from WFI.
*/
plat_arm_gic_cpuif_disable();
/* Send the system reset request to the SCP */
response = scpi_sys_power_state(scpi_system_reboot);
if (response != SCP_OK) {
ERROR("CSS System Reset: SCP error %u.\n", response);
panic();
}
wfi();
ERROR("CSS System Reset: operation not handled.\n");
panic();
}