[mirror_ubuntu-jammy-kernel.git] / drivers / devfreq / governor_userspace.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/devfreq/governor_userspace.c
 *
 *  Copyright (C) 2011 Samsung Electronics
 *	MyungJoo Ham <myungjoo.ham@samsung.com>
 */

#include <linux/slab.h>
#include <linux/device.h>
#include <linux/devfreq.h>
#include <linux/pm.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include "governor.h"

struct userspace_data {
	unsigned long user_frequency;
	bool valid;
};

static int devfreq_userspace_func(struct devfreq *df, unsigned long *freq)
{
	struct userspace_data *data = df->data;

	if (data->valid)
		*freq = data->user_frequency;
	else
		*freq = df->previous_freq; /* No user freq specified yet */

	return 0;
}

static ssize_t set_freq_store(struct device *dev, struct device_attribute *attr,
			      const char *buf, size_t count)
{
	struct devfreq *devfreq = to_devfreq(dev);
	struct userspace_data *data;
	unsigned long wanted;
	int err = 0;

	mutex_lock(&devfreq->lock);
	data = devfreq->data;

	sscanf(buf, "%lu", &wanted);
	data->user_frequency = wanted;
	data->valid = true;
	err = update_devfreq(devfreq);
	if (err == 0)
		err = count;
	mutex_unlock(&devfreq->lock);
	return err;
}

static ssize_t set_freq_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	struct devfreq *devfreq = to_devfreq(dev);
	struct userspace_data *data;
	int err = 0;

	mutex_lock(&devfreq->lock);
	data = devfreq->data;

	if (data->valid)
		err = sprintf(buf, "%lu\n", data->user_frequency);
	else
		err = sprintf(buf, "undefined\n");
	mutex_unlock(&devfreq->lock);
	return err;
}

static DEVICE_ATTR_RW(set_freq);
static struct attribute *dev_entries[] = {
	&dev_attr_set_freq.attr,
	NULL,
};
static const struct attribute_group dev_attr_group = {
	.name	= DEVFREQ_GOV_USERSPACE,
	.attrs	= dev_entries,
};

static int userspace_init(struct devfreq *devfreq)
{
	int err = 0;
	struct userspace_data *data = kzalloc(sizeof(struct userspace_data),
					      GFP_KERNEL);

	if (!data) {
		err = -ENOMEM;
		goto out;
	}
	data->valid = false;
	devfreq->data = data;

	err = sysfs_create_group(&devfreq->dev.kobj, &dev_attr_group);
out:
	return err;
}

static void userspace_exit(struct devfreq *devfreq)
{
	/*
	 * Remove the sysfs entry, unless this is being called after
	 * device_del(), which should have done this already via kobject_del().
	 */
	if (devfreq->dev.kobj.sd)
		sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group);

	kfree(devfreq->data);
	devfreq->data = NULL;
}

static int devfreq_userspace_handler(struct devfreq *devfreq,
			unsigned int event, void *data)
{
	int ret = 0;

	switch (event) {
	case DEVFREQ_GOV_START:
		ret = userspace_init(devfreq);
		break;
	case DEVFREQ_GOV_STOP:
		userspace_exit(devfreq);
		break;
	default:
		break;
	}

	return ret;
}

static struct devfreq_governor devfreq_userspace = {
	.name = DEVFREQ_GOV_USERSPACE,
	.get_target_freq = devfreq_userspace_func,
	.event_handler = devfreq_userspace_handler,
};

static int __init devfreq_userspace_init(void)
{
	return devfreq_add_governor(&devfreq_userspace);
}
subsys_initcall(devfreq_userspace_init);

static void __exit devfreq_userspace_exit(void)
{
	int ret;

	ret = devfreq_remove_governor(&devfreq_userspace);
	if (ret)
		pr_err("%s: failed remove governor %d\n", __func__, ret);

	return;
}
module_exit(devfreq_userspace_exit);
MODULE_LICENSE("GPL");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
ce26c5bb	2	/*
c701335e	3	* linux/drivers/devfreq/governor_userspace.c
ce26c5bb MH	4	*
	5	* Copyright (C) 2011 Samsung Electronics
	6	* MyungJoo Ham <myungjoo.ham@samsung.com>
ce26c5bb MH	7	*/
	8
	9	#include <linux/slab.h>
	10	#include <linux/device.h>
	11	#include <linux/devfreq.h>
	12	#include <linux/pm.h>
	13	#include <linux/mutex.h>
eff607fd	14	#include <linux/module.h>
ce26c5bb MH	15	#include "governor.h"
	16
	17	struct userspace_data {
	18	unsigned long user_frequency;
	19	bool valid;
	20	};
	21
	22	static int devfreq_userspace_func(struct devfreq df, unsigned long freq)
	23	{
	24	struct userspace_data *data = df->data;
	25
6ff66e2a MK	26	if (data->valid)
	27	*freq = data->user_frequency;
	28	else
ce26c5bb	29	freq = df->previous_freq; / No user freq specified yet */
6ff66e2a	30
ce26c5bb MH	31	return 0;
	32	}
	33
1ad4f329 Y	34	static ssize_t set_freq_store(struct device dev, struct device_attribute attr,
1ad4f329 Y	35	const char *buf, size_t count)
ce26c5bb MH	36	{
	37	struct devfreq *devfreq = to_devfreq(dev);
	38	struct userspace_data *data;
	39	unsigned long wanted;
	40	int err = 0;
	41
ce26c5bb MH	42	mutex_lock(&devfreq->lock);
	43	data = devfreq->data;
	44
	45	sscanf(buf, "%lu", &wanted);
	46	data->user_frequency = wanted;
	47	data->valid = true;
	48	err = update_devfreq(devfreq);
	49	if (err == 0)
	50	err = count;
	51	mutex_unlock(&devfreq->lock);
	52	return err;
	53	}
	54
1ad4f329 Y	55	static ssize_t set_freq_show(struct device *dev,
1ad4f329 Y	56	struct device_attribute attr, char buf)
ce26c5bb MH	57	{
	58	struct devfreq *devfreq = to_devfreq(dev);
	59	struct userspace_data *data;
	60	int err = 0;
	61
	62	mutex_lock(&devfreq->lock);
	63	data = devfreq->data;
	64
	65	if (data->valid)
	66	err = sprintf(buf, "%lu\n", data->user_frequency);
	67	else
	68	err = sprintf(buf, "undefined\n");
	69	mutex_unlock(&devfreq->lock);
	70	return err;
	71	}
	72
1ad4f329	73	static DEVICE_ATTR_RW(set_freq);
ce26c5bb MH	74	static struct attribute *dev_entries[] = {
	75	&dev_attr_set_freq.attr,
	76	NULL,
	77	};
37d644aa	78	static const struct attribute_group dev_attr_group = {
aa7c352f	79	.name = DEVFREQ_GOV_USERSPACE,
ce26c5bb MH	80	.attrs = dev_entries,
	81	};
	82
	83	static int userspace_init(struct devfreq *devfreq)
	84	{
	85	int err = 0;
	86	struct userspace_data *data = kzalloc(sizeof(struct userspace_data),
	87	GFP_KERNEL);
	88
	89	if (!data) {
	90	err = -ENOMEM;
	91	goto out;
	92	}
	93	data->valid = false;
	94	devfreq->data = data;
	95
	96	err = sysfs_create_group(&devfreq->dev.kobj, &dev_attr_group);
	97	out:
	98	return err;
	99	}
	100
	101	static void userspace_exit(struct devfreq *devfreq)
	102	{
924b9111 CD	103	/*
	104	* Remove the sysfs entry, unless this is being called after
	105	* device_del(), which should have done this already via kobject_del().
	106	*/
	107	if (devfreq->dev.kobj.sd)
	108	sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group);
	109
ce26c5bb MH	110	kfree(devfreq->data);
	111	devfreq->data = NULL;
	112	}
	113
7e6fdd4b RV	114	static int devfreq_userspace_handler(struct devfreq *devfreq,
	115	unsigned int event, void *data)
	116	{
	117	int ret = 0;
	118
	119	switch (event) {
	120	case DEVFREQ_GOV_START:
	121	ret = userspace_init(devfreq);
	122	break;
	123	case DEVFREQ_GOV_STOP:
	124	userspace_exit(devfreq);
	125	break;
	126	default:
	127	break;
	128	}
	129
	130	return ret;
	131	}
	132
1b5c1be2	133	static struct devfreq_governor devfreq_userspace = {
4bb1faac	134	.name = DEVFREQ_GOV_USERSPACE,
ce26c5bb	135	.get_target_freq = devfreq_userspace_func,
7e6fdd4b	136	.event_handler = devfreq_userspace_handler,
ce26c5bb	137	};
83116e66 NM	138
	139	static int __init devfreq_userspace_init(void)
	140	{
	141	return devfreq_add_governor(&devfreq_userspace);
	142	}
	143	subsys_initcall(devfreq_userspace_init);
	144
	145	static void __exit devfreq_userspace_exit(void)
	146	{
	147	int ret;
	148
	149	ret = devfreq_remove_governor(&devfreq_userspace);
	150	if (ret)
	151	pr_err("%s: failed remove governor %d\n", __func__, ret);
	152
	153	return;
	154	}
	155	module_exit(devfreq_userspace_exit);
eff607fd	156	MODULE_LICENSE("GPL");