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Diffstat (limited to '')
-rw-r--r-- | drivers/arm/css/scp/css_pm_scpi.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/drivers/arm/css/scp/css_pm_scpi.c b/drivers/arm/css/scp/css_pm_scpi.c new file mode 100644 index 0000000..b4019ce --- /dev/null +++ b/drivers/arm/css/scp/css_pm_scpi.c @@ -0,0 +1,165 @@ +/* + * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <assert.h> + +#include <arch_helpers.h> +#include <common/debug.h> +#include <drivers/arm/css/css_scp.h> +#include <drivers/arm/css/css_scpi.h> +#include <plat/arm/common/plat_arm.h> +#include <plat/arm/css/common/css_pm.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(); +} |