You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
123 lines
3.1 KiB
123 lines
3.1 KiB
|
|
/* |
|
* linux/drivers/cpufreq/cpufreq_userspace.c |
|
* |
|
* Copyright (C) 2001 Russell King |
|
* (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de> |
|
* |
|
* 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. |
|
* |
|
*/ |
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
|
|
|
#include <linux/cpufreq.h> |
|
#include <linux/init.h> |
|
#include <linux/module.h> |
|
#include <linux/mutex.h> |
|
|
|
static DEFINE_PER_CPU(unsigned int, cpu_is_managed); |
|
static DEFINE_MUTEX(userspace_mutex); |
|
|
|
/** |
|
* cpufreq_set - set the CPU frequency |
|
* @policy: pointer to policy struct where freq is being set |
|
* @freq: target frequency in kHz |
|
* |
|
* Sets the CPU frequency to freq. |
|
*/ |
|
static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq) |
|
{ |
|
int ret = -EINVAL; |
|
|
|
pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq); |
|
|
|
mutex_lock(&userspace_mutex); |
|
if (!per_cpu(cpu_is_managed, policy->cpu)) |
|
goto err; |
|
|
|
ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L); |
|
err: |
|
mutex_unlock(&userspace_mutex); |
|
return ret; |
|
} |
|
|
|
static ssize_t show_speed(struct cpufreq_policy *policy, char *buf) |
|
{ |
|
return sprintf(buf, "%u\n", policy->cur); |
|
} |
|
|
|
static int cpufreq_governor_userspace(struct cpufreq_policy *policy, |
|
unsigned int event) |
|
{ |
|
unsigned int cpu = policy->cpu; |
|
int rc = 0; |
|
|
|
switch (event) { |
|
case CPUFREQ_GOV_START: |
|
BUG_ON(!policy->cur); |
|
pr_debug("started managing cpu %u\n", cpu); |
|
|
|
mutex_lock(&userspace_mutex); |
|
per_cpu(cpu_is_managed, cpu) = 1; |
|
mutex_unlock(&userspace_mutex); |
|
break; |
|
case CPUFREQ_GOV_STOP: |
|
pr_debug("managing cpu %u stopped\n", cpu); |
|
|
|
mutex_lock(&userspace_mutex); |
|
per_cpu(cpu_is_managed, cpu) = 0; |
|
mutex_unlock(&userspace_mutex); |
|
break; |
|
case CPUFREQ_GOV_LIMITS: |
|
mutex_lock(&userspace_mutex); |
|
pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz\n", |
|
cpu, policy->min, policy->max, |
|
policy->cur); |
|
|
|
if (policy->max < policy->cur) |
|
__cpufreq_driver_target(policy, policy->max, |
|
CPUFREQ_RELATION_H); |
|
else if (policy->min > policy->cur) |
|
__cpufreq_driver_target(policy, policy->min, |
|
CPUFREQ_RELATION_L); |
|
mutex_unlock(&userspace_mutex); |
|
break; |
|
} |
|
return rc; |
|
} |
|
|
|
#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE |
|
static |
|
#endif |
|
struct cpufreq_governor cpufreq_gov_userspace = { |
|
.name = "userspace", |
|
.governor = cpufreq_governor_userspace, |
|
.store_setspeed = cpufreq_set, |
|
.show_setspeed = show_speed, |
|
.owner = THIS_MODULE, |
|
}; |
|
|
|
static int __init cpufreq_gov_userspace_init(void) |
|
{ |
|
return cpufreq_register_governor(&cpufreq_gov_userspace); |
|
} |
|
|
|
static void __exit cpufreq_gov_userspace_exit(void) |
|
{ |
|
cpufreq_unregister_governor(&cpufreq_gov_userspace); |
|
} |
|
|
|
MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, " |
|
"Russell King <rmk@arm.linux.org.uk>"); |
|
MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'"); |
|
MODULE_LICENSE("GPL"); |
|
|
|
#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE |
|
fs_initcall(cpufreq_gov_userspace_init); |
|
#else |
|
module_init(cpufreq_gov_userspace_init); |
|
#endif |
|
module_exit(cpufreq_gov_userspace_exit);
|
|
|