1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ARM64 CPU idle arch support 4 * 5 * Copyright (C) 2014 ARM Ltd. 6 * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> 7 */ 8 9 #include <linux/acpi.h> 10 #include <linux/cpuidle.h> 11 #include <linux/cpu_pm.h> 12 #include <linux/of.h> 13 #include <linux/of_device.h> 14 15 #include <asm/cpuidle.h> 16 #include <asm/cpu_ops.h> 17 18 int arm_cpuidle_init(unsigned int cpu) 19 { 20 int ret = -EOPNOTSUPP; 21 22 if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_suspend && 23 cpu_ops[cpu]->cpu_init_idle) 24 ret = cpu_ops[cpu]->cpu_init_idle(cpu); 25 26 return ret; 27 } 28 29 /** 30 * arm_cpuidle_suspend() - function to enter a low-power idle state 31 * @arg: argument to pass to CPU suspend operations 32 * 33 * Return: 0 on success, -EOPNOTSUPP if CPU suspend hook not initialized, CPU 34 * operations back-end error code otherwise. 35 */ 36 int arm_cpuidle_suspend(int index) 37 { 38 int cpu = smp_processor_id(); 39 40 return cpu_ops[cpu]->cpu_suspend(index); 41 } 42 43 #ifdef CONFIG_ACPI 44 45 #include <acpi/processor.h> 46 47 #define ARM64_LPI_IS_RETENTION_STATE(arch_flags) (!(arch_flags)) 48 49 int acpi_processor_ffh_lpi_probe(unsigned int cpu) 50 { 51 return arm_cpuidle_init(cpu); 52 } 53 54 int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) 55 { 56 if (ARM64_LPI_IS_RETENTION_STATE(lpi->arch_flags)) 57 return CPU_PM_CPU_IDLE_ENTER_RETENTION(arm_cpuidle_suspend, 58 lpi->index); 59 else 60 return CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, lpi->index); 61 } 62 #endif 63