From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/cpufreq/cpufreq_userspace.c | 123 ++++++++++++++++++++++++++++++++++++ 1 file changed, 123 insertions(+) create mode 100644 drivers/cpufreq/cpufreq_userspace.c (limited to 'drivers/cpufreq/cpufreq_userspace.c') diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c new file mode 100644 index 000000000..4dbf1db16 --- /dev/null +++ b/drivers/cpufreq/cpufreq_userspace.c @@ -0,0 +1,123 @@ + +/* + * linux/drivers/cpufreq/cpufreq_userspace.c + * + * Copyright (C) 2001 Russell King + * (C) 2002 - 2004 Dominik Brodowski + * + * 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 +#include +#include +#include + +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 , " + "Russell King "); +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); -- cgit v1.2.3-54-g00ecf