1 /* 2 * ARM64 CPU idle arch support 3 * 4 * Copyright (C) 2014 ARM Ltd. 5 * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <linux/acpi.h> 13 #include <linux/cpuidle.h> 14 #include <linux/cpu_pm.h> 15 #include <linux/of.h> 16 #include <linux/of_device.h> 17 18 #include <asm/cpuidle.h> 19 #include <asm/cpu_ops.h> 20 21 int arm_cpuidle_init(unsigned int cpu) 22 { 23 int ret = -EOPNOTSUPP; 24 25 if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_suspend && 26 cpu_ops[cpu]->cpu_init_idle) 27 ret = cpu_ops[cpu]->cpu_init_idle(cpu); 28 29 return ret; 30 } 31 32 /** 33 * arm_cpuidle_suspend() - function to enter a low-power idle state 34 * @arg: argument to pass to CPU suspend operations 35 * 36 * Return: 0 on success, -EOPNOTSUPP if CPU suspend hook not initialized, CPU 37 * operations back-end error code otherwise. 38 */ 39 int arm_cpuidle_suspend(int index) 40 { 41 int cpu = smp_processor_id(); 42 43 return cpu_ops[cpu]->cpu_suspend(index); 44 } 45 46 #ifdef CONFIG_ACPI 47 48 #include <acpi/processor.h> 49 50 int acpi_processor_ffh_lpi_probe(unsigned int cpu) 51 { 52 return arm_cpuidle_init(cpu); 53 } 54 55 int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) 56 { 57 return CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, lpi->index); 58 } 59 #endif 60