[linux-2.6-block.git] / drivers / cpufreq / cpufreq_userspace.c


/*
 *  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;
}

static 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
struct cpufreq_governor *cpufreq_default_governor(void)
{
	return &cpufreq_gov_userspace;
}

fs_initcall(cpufreq_gov_userspace_init);
#else
module_init(cpufreq_gov_userspace_init);
#endif
module_exit(cpufreq_gov_userspace_exit);
Commit	Line	Data
c0672860	1
1da177e4 LT	2	/*
	3	* linux/drivers/cpufreq/cpufreq_userspace.c
	4	*
	5	* Copyright (C) 2001 Russell King
	6	* (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	*/
	13
db701151 VK	14	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
db701151 VK	15
1da177e4	16	#include <linux/cpufreq.h>
d1922f02 VK	17	#include <linux/init.h>
d1922f02 VK	18	#include <linux/module.h>
3fc54d37	19	#include <linux/mutex.h>
1da177e4	20
b38868aa	21	static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
1bceb8d1	22	static DEFINE_MUTEX(userspace_mutex);
1da177e4	23
32ee8c3e	24	/**
1da177e4	25	* cpufreq_set - set the CPU frequency
9e76988e	26	* @policy: pointer to policy struct where freq is being set
1da177e4	27	* @freq: target frequency in kHz
1da177e4 LT	28	*
	29	* Sets the CPU frequency to freq.
	30	*/
9e76988e	31	static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
1da177e4 LT	32	{
	33	int ret = -EINVAL;
	34
2d06d8c4	35	pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
1da177e4	36
3fc54d37	37	mutex_lock(&userspace_mutex);
b38868aa	38	if (!per_cpu(cpu_is_managed, policy->cpu))
1da177e4 LT	39	goto err;
1da177e4 LT	40
c0672860	41	ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L);
1da177e4	42	err:
3fc54d37	43	mutex_unlock(&userspace_mutex);
1da177e4 LT	44	return ret;
	45	}
	46
9e76988e	47	static ssize_t show_speed(struct cpufreq_policy policy, char buf)
1da177e4	48	{
d1922f02	49	return sprintf(buf, "%u\n", policy->cur);
1da177e4 LT	50	}
1da177e4 LT	51
1da177e4 LT	52	static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
	53	unsigned int event)
	54	{
	55	unsigned int cpu = policy->cpu;
914f7c31 JG	56	int rc = 0;
914f7c31 JG	57
1da177e4 LT	58	switch (event) {
1da177e4 LT	59	case CPUFREQ_GOV_START:
1da177e4	60	BUG_ON(!policy->cur);
d1922f02	61	pr_debug("started managing cpu %u\n", cpu);
c7f652e0	62
d1922f02	63	mutex_lock(&userspace_mutex);
b38868aa	64	per_cpu(cpu_is_managed, cpu) = 1;
3fc54d37	65	mutex_unlock(&userspace_mutex);
1da177e4 LT	66	break;
1da177e4 LT	67	case CPUFREQ_GOV_STOP:
d1922f02	68	pr_debug("managing cpu %u stopped\n", cpu);
c7f652e0	69
d1922f02	70	mutex_lock(&userspace_mutex);
b38868aa	71	per_cpu(cpu_is_managed, cpu) = 0;
3fc54d37	72	mutex_unlock(&userspace_mutex);
1da177e4 LT	73	break;
1da177e4 LT	74	case CPUFREQ_GOV_LIMITS:
3fc54d37	75	mutex_lock(&userspace_mutex);
d1922f02	76	pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz\n",
c0672860	77	cpu, policy->min, policy->max,
d1922f02 VK	78	policy->cur);
	79
	80	if (policy->max < policy->cur)
c0672860 TR	81	__cpufreq_driver_target(policy, policy->max,
c0672860 TR	82	CPUFREQ_RELATION_H);
d1922f02	83	else if (policy->min > policy->cur)
c0672860 TR	84	__cpufreq_driver_target(policy, policy->min,
c0672860 TR	85	CPUFREQ_RELATION_L);
3fc54d37	86	mutex_unlock(&userspace_mutex);
1da177e4 LT	87	break;
1da177e4 LT	88	}
914f7c31	89	return rc;
1da177e4 LT	90	}
1da177e4 LT	91
de1df26b	92	static struct cpufreq_governor cpufreq_gov_userspace = {
1da177e4 LT	93	.name = "userspace",
1da177e4 LT	94	.governor = cpufreq_governor_userspace,
9e76988e VP	95	.store_setspeed = cpufreq_set,
9e76988e VP	96	.show_setspeed = show_speed,
1da177e4 LT	97	.owner = THIS_MODULE,
1da177e4 LT	98	};
1da177e4 LT	99
	100	static int __init cpufreq_gov_userspace_init(void)
	101	{
1da177e4 LT	102	return cpufreq_register_governor(&cpufreq_gov_userspace);
	103	}
	104
1da177e4 LT	105	static void __exit cpufreq_gov_userspace_exit(void)
	106	{
	107	cpufreq_unregister_governor(&cpufreq_gov_userspace);
1da177e4 LT	108	}
1da177e4 LT	109
1bceb8d1 DJ	110	MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, "
	111	"Russell King <rmk@arm.linux.org.uk>");
	112	MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'");
	113	MODULE_LICENSE("GPL");
1da177e4	114
6915719b	115	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
de1df26b RW	116	struct cpufreq_governor *cpufreq_default_governor(void)
	117	{
	118	return &cpufreq_gov_userspace;
	119	}
	120
1da177e4	121	fs_initcall(cpufreq_gov_userspace_init);
6915719b JW	122	#else
	123	module_init(cpufreq_gov_userspace_init);
	124	#endif
1da177e4	125	module_exit(cpufreq_gov_userspace_exit);