File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c
new file mode 100644
index 0000000..35de6e8
--- /dev/null
+++ b/drivers/devfreq/governor_userspace.c
@@ -0,0 +1,162 @@
+/*
+ * linux/drivers/devfreq/governor_simpleondemand.c
+ *
+ * Copyright (C) 2011 Samsung Electronics
+ * MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * 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.
+ */
+
+#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) {
+ unsigned long adjusted_freq = data->user_frequency;
+
+ if (df->max_freq && adjusted_freq > df->max_freq)
+ adjusted_freq = df->max_freq;
+
+ if (df->min_freq && adjusted_freq < df->min_freq)
+ adjusted_freq = df->min_freq;
+
+ *freq = adjusted_freq;
+ } else {
+ *freq = df->previous_freq; /* No user freq specified yet */
+ }
+ return 0;
+}
+
+static ssize_t store_freq(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 show_freq(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(set_freq, 0644, show_freq, store_freq);
+static struct attribute *dev_entries[] = {
+ &dev_attr_set_freq.attr,
+ NULL,
+};
+static struct attribute_group dev_attr_group = {
+ .name = "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)
+{
+ 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 = "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");