Files
thead-kernel/drivers/cpuidle/cpuidle-light.c
2022-09-13 11:05:52 +08:00

74 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2021 Alibaba Group Holding Limited.
* CPU idle support for Thead LIGHT SoC
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/cpuidle.h>
#include <linux/io.h>
#include <linux/export.h>
#include <asm/cpuidle.h>
#define LIGHT_MAX_STATES 1
extern void arch_cpu_idle(void);
/* Actual code that puts the SoC in different idle states */
static int light_enter_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
arch_cpu_idle();
return index;
}
static struct cpuidle_driver light_idle_driver = {
.name = "light_idle",
.owner = THIS_MODULE,
.states[0] = {
.enter = light_enter_idle,
.exit_latency = 1,
.power_usage = UINT_MAX,
.target_residency = 1,
.name = "WFI",
.desc = "RISC-V WFI",
},
.state_count = LIGHT_MAX_STATES,
};
/* Initialize CPU idle by registering the idle states */
static int light_cpuidle_probe(struct platform_device *dev)
{
return cpuidle_register(&light_idle_driver, NULL);
}
static struct platform_driver light_cpuidle_driver = {
.driver = {
.name = "cpuidle-light",
},
.probe = light_cpuidle_probe,
};
static int __init light_cpuidle_init(void)
{
int ret;
struct platform_device *pdev;
ret = platform_driver_register(&light_cpuidle_driver);
if (ret)
return ret;
pdev = platform_device_register_simple("cpuidle-light",
-1, NULL, 0);
if (IS_ERR(pdev)) {
platform_driver_unregister(&light_cpuidle_driver);
return PTR_ERR(pdev);
}
return 0;
}
device_initcall(light_cpuidle_init);