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 arm_cpuidle_init(unsigned int cpu) 19 { 20 int ret = -EOPNOTSUPP; 21 struct device_node *cpu_node = of_cpu_device_node_get(cpu); 22 23 if (!cpu_node) 24 return -ENODEV; 25 26 if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_init_idle) 27 ret = cpu_ops[cpu]->cpu_init_idle(cpu_node, cpu); 28 29 of_node_put(cpu_node); 30 return ret; 31 } 32 33 /** 34 * cpu_suspend() - function to enter a low-power idle state 35 * @arg: argument to pass to CPU suspend operations 36 * 37 * Return: 0 on success, -EOPNOTSUPP if CPU suspend hook not initialized, CPU 38 * operations back-end error code otherwise. 39 */ 40 int cpu_suspend(unsigned long arg) 41 { 42 int cpu = smp_processor_id(); 43 44 /* 45 * If cpu_ops have not been registered or suspend 46 * has not been initialized, cpu_suspend call fails early. 47 */ 48 if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_suspend) 49 return -EOPNOTSUPP; 50 return cpu_ops[cpu]->cpu_suspend(arg); 51 } 52