linux/arch/arm64/kernel/cpuidle.c

52 lines
1.2 KiB
C

/*
* ARM64 CPU idle arch support
*
* Copyright (C) 2014 ARM Ltd.
* Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/of.h>
#include <linux/of_device.h>
#include <asm/cpuidle.h>
#include <asm/cpu_ops.h>
int arm_cpuidle_init(unsigned int cpu)
{
int ret = -EOPNOTSUPP;
struct device_node *cpu_node = of_cpu_device_node_get(cpu);
if (!cpu_node)
return -ENODEV;
if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_init_idle)
ret = cpu_ops[cpu]->cpu_init_idle(cpu_node, cpu);
of_node_put(cpu_node);
return ret;
}
/**
* cpu_suspend() - function to enter a low-power idle state
* @arg: argument to pass to CPU suspend operations
*
* Return: 0 on success, -EOPNOTSUPP if CPU suspend hook not initialized, CPU
* operations back-end error code otherwise.
*/
int cpu_suspend(unsigned long arg)
{
int cpu = smp_processor_id();
/*
* If cpu_ops have not been registered or suspend
* has not been initialized, cpu_suspend call fails early.
*/
if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_suspend)
return -EOPNOTSUPP;
return cpu_ops[cpu]->cpu_suspend(arg);
}