Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / devfreq / governor_userspace.c

diff --git a/kernel/drivers/devfreq/governor_userspace.c b/kernel/drivers/devfreq/governor_userspace.c
new file mode 100644 (file)
index 0000000..35de6e8
--- /dev/null
+++ b/kernel/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");