1 files changed, 156 insertions, 0 deletions
diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c
new file mode 100644
index 000000000..8a9cf8220
--- /dev/null
+++ b/drivers/devfreq/governor_userspace.c
@@ -0,0 +1,156 @@
+// 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->governor_data;
+
+	if (data->valid)
+		*freq = data->user_frequency;
+	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->governor_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->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(set_freq, 0644, show_freq, store_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->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_LICENSE("GPL");