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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161// 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/devfreq-governor.h>#include <linux/kstrtox.h>#include <linux/pm.h>#include <linux/mutex.h>#include <linux/module.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->governor_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;
err = kstrtoul(buf, 0, &wanted); if (err) return err;
mutex_lock(&devfreq->lock); data = devfreq->governor_data;
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->governor_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_obj(struct userspace_data);
if (!data) { err = -ENOMEM; goto out; } data->valid = false; devfreq->governor_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->governor_data); devfreq->governor_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_DESCRIPTION("DEVFREQ Userspace governor");MODULE_LICENSE("GPL");