[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>
#include <linux/slab.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;
	unsigned int *setspeed = policy->governor_data;

	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;

	*setspeed = freq;

	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_userspace_policy_init(struct cpufreq_policy *policy)
{
	unsigned int *setspeed;

	setspeed = kzalloc(sizeof(*setspeed), GFP_KERNEL);
	if (!setspeed)
		return -ENOMEM;

	policy->governor_data = setspeed;
	return 0;
}

static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
				   unsigned int event)
{
	unsigned int *setspeed = policy->governor_data;
	unsigned int cpu = policy->cpu;
	int rc = 0;

	if (event == CPUFREQ_GOV_POLICY_INIT)
		return cpufreq_userspace_policy_init(policy);

	if (!setspeed)
		return -EINVAL;

	switch (event) {
	case CPUFREQ_GOV_POLICY_EXIT:
		mutex_lock(&userspace_mutex);
		policy->governor_data = NULL;
		kfree(setspeed);
		mutex_unlock(&userspace_mutex);
		break;
	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;
		*setspeed = policy->cur;
		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;
		*setspeed = 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, last set to %u kHz\n",
			cpu, policy->min, policy->max, policy->cur, *setspeed);

		if (policy->max < *setspeed)
			__cpufreq_driver_target(policy, policy->max,
						CPUFREQ_RELATION_H);
		else if (policy->min > *setspeed)
			__cpufreq_driver_target(policy, policy->min,
						CPUFREQ_RELATION_L);
		else
			__cpufreq_driver_target(policy, *setspeed,
						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>
e43e94c1	20	#include <linux/slab.h>
1da177e4	21
b38868aa	22	static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
1bceb8d1	23	static DEFINE_MUTEX(userspace_mutex);
1da177e4	24
32ee8c3e	25	/**
1da177e4	26	* cpufreq_set - set the CPU frequency
9e76988e	27	* @policy: pointer to policy struct where freq is being set
1da177e4	28	* @freq: target frequency in kHz
1da177e4 LT	29	*
	30	* Sets the CPU frequency to freq.
	31	*/
9e76988e	32	static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
1da177e4 LT	33	{
1da177e4 LT	34	int ret = -EINVAL;
e43e94c1	35	unsigned int *setspeed = policy->governor_data;
1da177e4	36
2d06d8c4	37	pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
1da177e4	38
3fc54d37	39	mutex_lock(&userspace_mutex);
b38868aa	40	if (!per_cpu(cpu_is_managed, policy->cpu))
1da177e4 LT	41	goto err;
1da177e4 LT	42
e43e94c1 SG	43	*setspeed = freq;
e43e94c1 SG	44
c0672860	45	ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L);
1da177e4	46	err:
3fc54d37	47	mutex_unlock(&userspace_mutex);
1da177e4 LT	48	return ret;
	49	}
	50
9e76988e	51	static ssize_t show_speed(struct cpufreq_policy policy, char buf)
1da177e4	52	{
d1922f02	53	return sprintf(buf, "%u\n", policy->cur);
1da177e4 LT	54	}
1da177e4 LT	55
e43e94c1 SG	56	static int cpufreq_userspace_policy_init(struct cpufreq_policy *policy)
	57	{
	58	unsigned int *setspeed;
	59
	60	setspeed = kzalloc(sizeof(*setspeed), GFP_KERNEL);
	61	if (!setspeed)
	62	return -ENOMEM;
	63
	64	policy->governor_data = setspeed;
	65	return 0;
	66	}
	67
1da177e4 LT	68	static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
	69	unsigned int event)
	70	{
e43e94c1	71	unsigned int *setspeed = policy->governor_data;
1da177e4	72	unsigned int cpu = policy->cpu;
914f7c31 JG	73	int rc = 0;
914f7c31 JG	74
e43e94c1 SG	75	if (event == CPUFREQ_GOV_POLICY_INIT)
	76	return cpufreq_userspace_policy_init(policy);
	77
	78	if (!setspeed)
	79	return -EINVAL;
	80
1da177e4	81	switch (event) {
e43e94c1 SG	82	case CPUFREQ_GOV_POLICY_EXIT:
	83	mutex_lock(&userspace_mutex);
	84	policy->governor_data = NULL;
	85	kfree(setspeed);
	86	mutex_unlock(&userspace_mutex);
	87	break;
1da177e4	88	case CPUFREQ_GOV_START:
1da177e4	89	BUG_ON(!policy->cur);
d1922f02	90	pr_debug("started managing cpu %u\n", cpu);
c7f652e0	91
d1922f02	92	mutex_lock(&userspace_mutex);
b38868aa	93	per_cpu(cpu_is_managed, cpu) = 1;
e43e94c1	94	*setspeed = policy->cur;
3fc54d37	95	mutex_unlock(&userspace_mutex);
1da177e4 LT	96	break;
1da177e4 LT	97	case CPUFREQ_GOV_STOP:
d1922f02	98	pr_debug("managing cpu %u stopped\n", cpu);
c7f652e0	99
d1922f02	100	mutex_lock(&userspace_mutex);
b38868aa	101	per_cpu(cpu_is_managed, cpu) = 0;
e43e94c1	102	*setspeed = 0;
3fc54d37	103	mutex_unlock(&userspace_mutex);
1da177e4 LT	104	break;
1da177e4 LT	105	case CPUFREQ_GOV_LIMITS:
3fc54d37	106	mutex_lock(&userspace_mutex);
e43e94c1 SG	107	pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz, last set to %u kHz\n",
e43e94c1 SG	108	cpu, policy->min, policy->max, policy->cur, *setspeed);
d1922f02	109
e43e94c1	110	if (policy->max < *setspeed)
c0672860 TR	111	__cpufreq_driver_target(policy, policy->max,
c0672860 TR	112	CPUFREQ_RELATION_H);
e43e94c1	113	else if (policy->min > *setspeed)
c0672860 TR	114	__cpufreq_driver_target(policy, policy->min,
c0672860 TR	115	CPUFREQ_RELATION_L);
e43e94c1 SG	116	else
	117	__cpufreq_driver_target(policy, *setspeed,
	118	CPUFREQ_RELATION_L);
3fc54d37	119	mutex_unlock(&userspace_mutex);
1da177e4 LT	120	break;
1da177e4 LT	121	}
914f7c31	122	return rc;
1da177e4 LT	123	}
1da177e4 LT	124
de1df26b	125	static struct cpufreq_governor cpufreq_gov_userspace = {
1da177e4 LT	126	.name = "userspace",
1da177e4 LT	127	.governor = cpufreq_governor_userspace,
9e76988e VP	128	.store_setspeed = cpufreq_set,
9e76988e VP	129	.show_setspeed = show_speed,
1da177e4 LT	130	.owner = THIS_MODULE,
1da177e4 LT	131	};
1da177e4 LT	132
	133	static int __init cpufreq_gov_userspace_init(void)
	134	{
1da177e4 LT	135	return cpufreq_register_governor(&cpufreq_gov_userspace);
	136	}
	137
1da177e4 LT	138	static void __exit cpufreq_gov_userspace_exit(void)
	139	{
	140	cpufreq_unregister_governor(&cpufreq_gov_userspace);
1da177e4 LT	141	}
1da177e4 LT	142
1bceb8d1 DJ	143	MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>, "
	144	"Russell King <rmk@arm.linux.org.uk>");
	145	MODULE_DESCRIPTION("CPUfreq policy governor 'userspace'");
	146	MODULE_LICENSE("GPL");
1da177e4	147
6915719b	148	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
de1df26b RW	149	struct cpufreq_governor *cpufreq_default_governor(void)
	150	{
	151	return &cpufreq_gov_userspace;
	152	}
	153
1da177e4	154	fs_initcall(cpufreq_gov_userspace_init);
6915719b JW	155	#else
	156	module_init(cpufreq_gov_userspace_init);
	157	#endif
1da177e4	158	module_exit(cpufreq_gov_userspace_exit);