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/of.h> 13 #include <linux/of_device.h> 14 15 #include <asm/cpuidle.h> 16 #include <asm/cpu_ops.h> 17 18 int __init arm_cpuidle_init(unsigned int cpu) 19 { 20 int ret = -EOPNOTSUPP; 21 22 if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_init_idle) 23 ret = cpu_ops[cpu]->cpu_init_idle(cpu); 24 25 return ret; 26 } 27 28 /** 29 * cpu_suspend() - function to enter a low-power idle state 30 * @arg: argument to pass to CPU suspend operations 31 * 32 * Return: 0 on success, -EOPNOTSUPP if CPU suspend hook not initialized, CPU 33 * operations back-end error code otherwise. 34 */ 35 int arm_cpuidle_suspend(int index) 36 { 37 int cpu = smp_processor_id(); 38 39 /* 40 * If cpu_ops have not been registered or suspend 41 * has not been initialized, cpu_suspend call fails early. 42 */ 43 if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_suspend) 44 return -EOPNOTSUPP; 45 return cpu_ops[cpu]->cpu_suspend(index); 46 } 47