--- /dev/null
+/*
+ * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
+ * for Non-CPU Devices.
+ *
+ * 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/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/pm_opp.h>
+#include <linux/devfreq.h>
+#include <linux/workqueue.h>
+#include <linux/platform_device.h>
+#include <linux/list.h>
+#include <linux/printk.h>
+#include <linux/hrtimer.h>
+#include "governor.h"
+
+static struct class *devfreq_class;
+
+/*
+ * devfreq core provides delayed work based load monitoring helper
+ * functions. Governors can use these or can implement their own
+ * monitoring mechanism.
+ */
+static struct workqueue_struct *devfreq_wq;
+
+/* The list of all device-devfreq governors */
+static LIST_HEAD(devfreq_governor_list);
+/* The list of all device-devfreq */
+static LIST_HEAD(devfreq_list);
+static DEFINE_MUTEX(devfreq_list_lock);
+
+/**
+ * find_device_devfreq() - find devfreq struct using device pointer
+ * @dev: device pointer used to lookup device devfreq.
+ *
+ * Search the list of device devfreqs and return the matched device's
+ * devfreq info. devfreq_list_lock should be held by the caller.
+ */
+static struct devfreq *find_device_devfreq(struct device *dev)
+{
+ struct devfreq *tmp_devfreq;
+
+ if (unlikely(IS_ERR_OR_NULL(dev))) {
+ pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
+ return ERR_PTR(-EINVAL);
+ }
+ WARN(!mutex_is_locked(&devfreq_list_lock),
+ "devfreq_list_lock must be locked.");
+
+ list_for_each_entry(tmp_devfreq, &devfreq_list, node) {
+ if (tmp_devfreq->dev.parent == dev)
+ return tmp_devfreq;
+ }
+
+ return ERR_PTR(-ENODEV);
+}
+
+/**
+ * devfreq_get_freq_level() - Lookup freq_table for the frequency
+ * @devfreq: the devfreq instance
+ * @freq: the target frequency
+ */
+static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
+{
+ int lev;
+
+ for (lev = 0; lev < devfreq->profile->max_state; lev++)
+ if (freq == devfreq->profile->freq_table[lev])
+ return lev;
+
+ return -EINVAL;
+}
+
+/**
+ * devfreq_update_status() - Update statistics of devfreq behavior
+ * @devfreq: the devfreq instance
+ * @freq: the update target frequency
+ */
+static int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
+{
+ int lev, prev_lev, ret = 0;
+ unsigned long cur_time;
+
+ cur_time = jiffies;
+
+ prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);
+ if (prev_lev < 0) {
+ ret = prev_lev;
+ goto out;
+ }
+
+ devfreq->time_in_state[prev_lev] +=
+ cur_time - devfreq->last_stat_updated;
+
+ lev = devfreq_get_freq_level(devfreq, freq);
+ if (lev < 0) {
+ ret = lev;
+ goto out;
+ }
+
+ if (lev != prev_lev) {
+ devfreq->trans_table[(prev_lev *
+ devfreq->profile->max_state) + lev]++;
+ devfreq->total_trans++;
+ }
+
+out:
+ devfreq->last_stat_updated = cur_time;
+ return ret;
+}
+
+/**
+ * find_devfreq_governor() - find devfreq governor from name
+ * @name: name of the governor
+ *
+ * Search the list of devfreq governors and return the matched
+ * governor's pointer. devfreq_list_lock should be held by the caller.
+ */
+static struct devfreq_governor *find_devfreq_governor(const char *name)
+{
+ struct devfreq_governor *tmp_governor;
+
+ if (unlikely(IS_ERR_OR_NULL(name))) {
+ pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
+ return ERR_PTR(-EINVAL);
+ }
+ WARN(!mutex_is_locked(&devfreq_list_lock),
+ "devfreq_list_lock must be locked.");
+
+ list_for_each_entry(tmp_governor, &devfreq_governor_list, node) {
+ if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN))
+ return tmp_governor;
+ }
+
+ return ERR_PTR(-ENODEV);
+}
+
+/* Load monitoring helper functions for governors use */
+
+/**
+ * update_devfreq() - Reevaluate the device and configure frequency.
+ * @devfreq: the devfreq instance.
+ *
+ * Note: Lock devfreq->lock before calling update_devfreq
+ * This function is exported for governors.
+ */
+int update_devfreq(struct devfreq *devfreq)
+{
+ unsigned long freq;
+ int err = 0;
+ u32 flags = 0;
+
+ if (!mutex_is_locked(&devfreq->lock)) {
+ WARN(true, "devfreq->lock must be locked by the caller.\n");
+ return -EINVAL;
+ }
+
+ if (!devfreq->governor)
+ return -EINVAL;
+
+ /* Reevaluate the proper frequency */
+ err = devfreq->governor->get_target_freq(devfreq, &freq);
+ if (err)
+ return err;
+
+ /*
+ * Adjust the freuqency with user freq and QoS.
+ *
+ * List from the highest proiority
+ * max_freq (probably called by thermal when it's too hot)
+ * min_freq
+ */
+
+ if (devfreq->min_freq && freq < devfreq->min_freq) {
+ freq = devfreq->min_freq;
+ flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */
+ }
+ if (devfreq->max_freq && freq > devfreq->max_freq) {
+ freq = devfreq->max_freq;
+ flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
+ }
+
+ err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);
+ if (err)
+ return err;
+
+ if (devfreq->profile->freq_table)
+ if (devfreq_update_status(devfreq, freq))
+ dev_err(&devfreq->dev,
+ "Couldn't update frequency transition information.\n");
+
+ devfreq->previous_freq = freq;
+ return err;
+}
+EXPORT_SYMBOL(update_devfreq);
+
+/**
+ * devfreq_monitor() - Periodically poll devfreq objects.
+ * @work: the work struct used to run devfreq_monitor periodically.
+ *
+ */
+static void devfreq_monitor(struct work_struct *work)
+{
+ int err;
+ struct devfreq *devfreq = container_of(work,
+ struct devfreq, work.work);
+
+ mutex_lock(&devfreq->lock);
+ err = update_devfreq(devfreq);
+ if (err)
+ dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err);
+
+ queue_delayed_work(devfreq_wq, &devfreq->work,
+ msecs_to_jiffies(devfreq->profile->polling_ms));
+ mutex_unlock(&devfreq->lock);
+}
+
+/**
+ * devfreq_monitor_start() - Start load monitoring of devfreq instance
+ * @devfreq: the devfreq instance.
+ *
+ * Helper function for starting devfreq device load monitoing. By
+ * default delayed work based monitoring is supported. Function
+ * to be called from governor in response to DEVFREQ_GOV_START
+ * event when device is added to devfreq framework.
+ */
+void devfreq_monitor_start(struct devfreq *devfreq)
+{
+ INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);
+ if (devfreq->profile->polling_ms)
+ queue_delayed_work(devfreq_wq, &devfreq->work,
+ msecs_to_jiffies(devfreq->profile->polling_ms));
+}
+EXPORT_SYMBOL(devfreq_monitor_start);
+
+/**
+ * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance
+ * @devfreq: the devfreq instance.
+ *
+ * Helper function to stop devfreq device load monitoing. Function
+ * to be called from governor in response to DEVFREQ_GOV_STOP
+ * event when device is removed from devfreq framework.
+ */
+void devfreq_monitor_stop(struct devfreq *devfreq)
+{
+ cancel_delayed_work_sync(&devfreq->work);
+}
+EXPORT_SYMBOL(devfreq_monitor_stop);
+
+/**
+ * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance
+ * @devfreq: the devfreq instance.
+ *
+ * Helper function to suspend devfreq device load monitoing. Function
+ * to be called from governor in response to DEVFREQ_GOV_SUSPEND
+ * event or when polling interval is set to zero.
+ *
+ * Note: Though this function is same as devfreq_monitor_stop(),
+ * intentionally kept separate to provide hooks for collecting
+ * transition statistics.
+ */
+void devfreq_monitor_suspend(struct devfreq *devfreq)
+{
+ mutex_lock(&devfreq->lock);
+ if (devfreq->stop_polling) {
+ mutex_unlock(&devfreq->lock);
+ return;
+ }
+
+ devfreq_update_status(devfreq, devfreq->previous_freq);
+ devfreq->stop_polling = true;
+ mutex_unlock(&devfreq->lock);
+ cancel_delayed_work_sync(&devfreq->work);
+}
+EXPORT_SYMBOL(devfreq_monitor_suspend);
+
+/**
+ * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance
+ * @devfreq: the devfreq instance.
+ *
+ * Helper function to resume devfreq device load monitoing. Function
+ * to be called from governor in response to DEVFREQ_GOV_RESUME
+ * event or when polling interval is set to non-zero.
+ */
+void devfreq_monitor_resume(struct devfreq *devfreq)
+{
+ unsigned long freq;
+
+ mutex_lock(&devfreq->lock);
+ if (!devfreq->stop_polling)
+ goto out;
+
+ if (!delayed_work_pending(&devfreq->work) &&
+ devfreq->profile->polling_ms)
+ queue_delayed_work(devfreq_wq, &devfreq->work,
+ msecs_to_jiffies(devfreq->profile->polling_ms));
+
+ devfreq->last_stat_updated = jiffies;
+ devfreq->stop_polling = false;
+
+ if (devfreq->profile->get_cur_freq &&
+ !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
+ devfreq->previous_freq = freq;
+
+out:
+ mutex_unlock(&devfreq->lock);
+}
+EXPORT_SYMBOL(devfreq_monitor_resume);
+
+/**
+ * devfreq_interval_update() - Update device devfreq monitoring interval
+ * @devfreq: the devfreq instance.
+ * @delay: new polling interval to be set.
+ *
+ * Helper function to set new load monitoring polling interval. Function
+ * to be called from governor in response to DEVFREQ_GOV_INTERVAL event.
+ */
+void devfreq_interval_update(struct devfreq *devfreq, unsigned int *delay)
+{
+ unsigned int cur_delay = devfreq->profile->polling_ms;
+ unsigned int new_delay = *delay;
+
+ mutex_lock(&devfreq->lock);
+ devfreq->profile->polling_ms = new_delay;
+
+ if (devfreq->stop_polling)
+ goto out;
+
+ /* if new delay is zero, stop polling */
+ if (!new_delay) {
+ mutex_unlock(&devfreq->lock);
+ cancel_delayed_work_sync(&devfreq->work);
+ return;
+ }
+
+ /* if current delay is zero, start polling with new delay */
+ if (!cur_delay) {
+ queue_delayed_work(devfreq_wq, &devfreq->work,
+ msecs_to_jiffies(devfreq->profile->polling_ms));
+ goto out;
+ }
+
+ /* if current delay is greater than new delay, restart polling */
+ if (cur_delay > new_delay) {
+ mutex_unlock(&devfreq->lock);
+ cancel_delayed_work_sync(&devfreq->work);
+ mutex_lock(&devfreq->lock);
+ if (!devfreq->stop_polling)
+ queue_delayed_work(devfreq_wq, &devfreq->work,
+ msecs_to_jiffies(devfreq->profile->polling_ms));
+ }
+out:
+ mutex_unlock(&devfreq->lock);
+}
+EXPORT_SYMBOL(devfreq_interval_update);
+
+/**
+ * devfreq_notifier_call() - Notify that the device frequency requirements
+ * has been changed out of devfreq framework.
+ * @nb: the notifier_block (supposed to be devfreq->nb)
+ * @type: not used
+ * @devp: not used
+ *
+ * Called by a notifier that uses devfreq->nb.
+ */
+static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
+ void *devp)
+{
+ struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
+ int ret;
+
+ mutex_lock(&devfreq->lock);
+ ret = update_devfreq(devfreq);
+ mutex_unlock(&devfreq->lock);
+
+ return ret;
+}
+
+/**
+ * _remove_devfreq() - Remove devfreq from the list and release its resources.
+ * @devfreq: the devfreq struct
+ */
+static void _remove_devfreq(struct devfreq *devfreq)
+{
+ mutex_lock(&devfreq_list_lock);
+ if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) {
+ mutex_unlock(&devfreq_list_lock);
+ dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n");
+ return;
+ }
+ list_del(&devfreq->node);
+ mutex_unlock(&devfreq_list_lock);
+
+ if (devfreq->governor)
+ devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_STOP, NULL);
+
+ if (devfreq->profile->exit)
+ devfreq->profile->exit(devfreq->dev.parent);
+
+ mutex_destroy(&devfreq->lock);
+ kfree(devfreq);
+}
+
+/**
+ * devfreq_dev_release() - Callback for struct device to release the device.
+ * @dev: the devfreq device
+ *
+ * This calls _remove_devfreq() if _remove_devfreq() is not called.
+ */
+static void devfreq_dev_release(struct device *dev)
+{
+ struct devfreq *devfreq = to_devfreq(dev);
+
+ _remove_devfreq(devfreq);
+}
+
+/**
+ * devfreq_add_device() - Add devfreq feature to the device
+ * @dev: the device to add devfreq feature.
+ * @profile: device-specific profile to run devfreq.
+ * @governor_name: name of the policy to choose frequency.
+ * @data: private data for the governor. The devfreq framework does not
+ * touch this value.
+ */
+struct devfreq *devfreq_add_device(struct device *dev,
+ struct devfreq_dev_profile *profile,
+ const char *governor_name,
+ void *data)
+{
+ struct devfreq *devfreq;
+ struct devfreq_governor *governor;
+ int err = 0;
+
+ if (!dev || !profile || !governor_name) {
+ dev_err(dev, "%s: Invalid parameters.\n", __func__);
+ return ERR_PTR(-EINVAL);
+ }
+
+ mutex_lock(&devfreq_list_lock);
+ devfreq = find_device_devfreq(dev);
+ mutex_unlock(&devfreq_list_lock);
+ if (!IS_ERR(devfreq)) {
+ dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__);
+ err = -EINVAL;
+ goto err_out;
+ }
+
+ devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL);
+ if (!devfreq) {
+ dev_err(dev, "%s: Unable to create devfreq for the device\n",
+ __func__);
+ err = -ENOMEM;
+ goto err_out;
+ }
+
+ mutex_init(&devfreq->lock);
+ mutex_lock(&devfreq->lock);
+ devfreq->dev.parent = dev;
+ devfreq->dev.class = devfreq_class;
+ devfreq->dev.release = devfreq_dev_release;
+ devfreq->profile = profile;
+ strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);
+ devfreq->previous_freq = profile->initial_freq;
+ devfreq->data = data;
+ devfreq->nb.notifier_call = devfreq_notifier_call;
+
+ devfreq->trans_table = devm_kzalloc(dev, sizeof(unsigned int) *
+ devfreq->profile->max_state *
+ devfreq->profile->max_state,
+ GFP_KERNEL);
+ devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned int) *
+ devfreq->profile->max_state,
+ GFP_KERNEL);
+ devfreq->last_stat_updated = jiffies;
+
+ dev_set_name(&devfreq->dev, "%s", dev_name(dev));
+ err = device_register(&devfreq->dev);
+ if (err) {
+ put_device(&devfreq->dev);
+ mutex_unlock(&devfreq->lock);
+ goto err_dev;
+ }
+
+ mutex_unlock(&devfreq->lock);
+
+ mutex_lock(&devfreq_list_lock);
+ list_add(&devfreq->node, &devfreq_list);
+
+ governor = find_devfreq_governor(devfreq->governor_name);
+ if (!IS_ERR(governor))
+ devfreq->governor = governor;
+ if (devfreq->governor)
+ err = devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_START, NULL);
+ mutex_unlock(&devfreq_list_lock);
+ if (err) {
+ dev_err(dev, "%s: Unable to start governor for the device\n",
+ __func__);
+ goto err_init;
+ }
+
+ return devfreq;
+
+err_init:
+ list_del(&devfreq->node);
+ device_unregister(&devfreq->dev);
+err_dev:
+ kfree(devfreq);
+err_out:
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL(devfreq_add_device);
+
+/**
+ * devfreq_remove_device() - Remove devfreq feature from a device.
+ * @devfreq: the devfreq instance to be removed
+ *
+ * The opposite of devfreq_add_device().
+ */
+int devfreq_remove_device(struct devfreq *devfreq)
+{
+ if (!devfreq)
+ return -EINVAL;
+
+ device_unregister(&devfreq->dev);
+ put_device(&devfreq->dev);
+
+ return 0;
+}
+EXPORT_SYMBOL(devfreq_remove_device);
+
+static int devm_devfreq_dev_match(struct device *dev, void *res, void *data)
+{
+ struct devfreq **r = res;
+
+ if (WARN_ON(!r || !*r))
+ return 0;
+
+ return *r == data;
+}
+
+static void devm_devfreq_dev_release(struct device *dev, void *res)
+{
+ devfreq_remove_device(*(struct devfreq **)res);
+}
+
+/**
+ * devm_devfreq_add_device() - Resource-managed devfreq_add_device()
+ * @dev: the device to add devfreq feature.
+ * @profile: device-specific profile to run devfreq.
+ * @governor_name: name of the policy to choose frequency.
+ * @data: private data for the governor. The devfreq framework does not
+ * touch this value.
+ *
+ * This function manages automatically the memory of devfreq device using device
+ * resource management and simplify the free operation for memory of devfreq
+ * device.
+ */
+struct devfreq *devm_devfreq_add_device(struct device *dev,
+ struct devfreq_dev_profile *profile,
+ const char *governor_name,
+ void *data)
+{
+ struct devfreq **ptr, *devfreq;
+
+ ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ devfreq = devfreq_add_device(dev, profile, governor_name, data);
+ if (IS_ERR(devfreq)) {
+ devres_free(ptr);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ *ptr = devfreq;
+ devres_add(dev, ptr);
+
+ return devfreq;
+}
+EXPORT_SYMBOL(devm_devfreq_add_device);
+
+/**
+ * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
+ * @dev: the device to add devfreq feature.
+ * @devfreq: the devfreq instance to be removed
+ */
+void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq)
+{
+ WARN_ON(devres_release(dev, devm_devfreq_dev_release,
+ devm_devfreq_dev_match, devfreq));
+}
+EXPORT_SYMBOL(devm_devfreq_remove_device);
+
+/**
+ * devfreq_suspend_device() - Suspend devfreq of a device.
+ * @devfreq: the devfreq instance to be suspended
+ *
+ * This function is intended to be called by the pm callbacks
+ * (e.g., runtime_suspend, suspend) of the device driver that
+ * holds the devfreq.
+ */
+int devfreq_suspend_device(struct devfreq *devfreq)
+{
+ if (!devfreq)
+ return -EINVAL;
+
+ if (!devfreq->governor)
+ return 0;
+
+ return devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_SUSPEND, NULL);
+}
+EXPORT_SYMBOL(devfreq_suspend_device);
+
+/**
+ * devfreq_resume_device() - Resume devfreq of a device.
+ * @devfreq: the devfreq instance to be resumed
+ *
+ * This function is intended to be called by the pm callbacks
+ * (e.g., runtime_resume, resume) of the device driver that
+ * holds the devfreq.
+ */
+int devfreq_resume_device(struct devfreq *devfreq)
+{
+ if (!devfreq)
+ return -EINVAL;
+
+ if (!devfreq->governor)
+ return 0;
+
+ return devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_RESUME, NULL);
+}
+EXPORT_SYMBOL(devfreq_resume_device);
+
+/**
+ * devfreq_add_governor() - Add devfreq governor
+ * @governor: the devfreq governor to be added
+ */
+int devfreq_add_governor(struct devfreq_governor *governor)
+{
+ struct devfreq_governor *g;
+ struct devfreq *devfreq;
+ int err = 0;
+
+ if (!governor) {
+ pr_err("%s: Invalid parameters.\n", __func__);
+ return -EINVAL;
+ }
+
+ mutex_lock(&devfreq_list_lock);
+ g = find_devfreq_governor(governor->name);
+ if (!IS_ERR(g)) {
+ pr_err("%s: governor %s already registered\n", __func__,
+ g->name);
+ err = -EINVAL;
+ goto err_out;
+ }
+
+ list_add(&governor->node, &devfreq_governor_list);
+
+ list_for_each_entry(devfreq, &devfreq_list, node) {
+ int ret = 0;
+ struct device *dev = devfreq->dev.parent;
+
+ if (!strncmp(devfreq->governor_name, governor->name,
+ DEVFREQ_NAME_LEN)) {
+ /* The following should never occur */
+ if (devfreq->governor) {
+ dev_warn(dev,
+ "%s: Governor %s already present\n",
+ __func__, devfreq->governor->name);
+ ret = devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_STOP, NULL);
+ if (ret) {
+ dev_warn(dev,
+ "%s: Governor %s stop = %d\n",
+ __func__,
+ devfreq->governor->name, ret);
+ }
+ /* Fall through */
+ }
+ devfreq->governor = governor;
+ ret = devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_START, NULL);
+ if (ret) {
+ dev_warn(dev, "%s: Governor %s start=%d\n",
+ __func__, devfreq->governor->name,
+ ret);
+ }
+ }
+ }
+
+err_out:
+ mutex_unlock(&devfreq_list_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(devfreq_add_governor);
+
+/**
+ * devfreq_remove_device() - Remove devfreq feature from a device.
+ * @governor: the devfreq governor to be removed
+ */
+int devfreq_remove_governor(struct devfreq_governor *governor)
+{
+ struct devfreq_governor *g;
+ struct devfreq *devfreq;
+ int err = 0;
+
+ if (!governor) {
+ pr_err("%s: Invalid parameters.\n", __func__);
+ return -EINVAL;
+ }
+
+ mutex_lock(&devfreq_list_lock);
+ g = find_devfreq_governor(governor->name);
+ if (IS_ERR(g)) {
+ pr_err("%s: governor %s not registered\n", __func__,
+ governor->name);
+ err = PTR_ERR(g);
+ goto err_out;
+ }
+ list_for_each_entry(devfreq, &devfreq_list, node) {
+ int ret;
+ struct device *dev = devfreq->dev.parent;
+
+ if (!strncmp(devfreq->governor_name, governor->name,
+ DEVFREQ_NAME_LEN)) {
+ /* we should have a devfreq governor! */
+ if (!devfreq->governor) {
+ dev_warn(dev, "%s: Governor %s NOT present\n",
+ __func__, governor->name);
+ continue;
+ /* Fall through */
+ }
+ ret = devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_STOP, NULL);
+ if (ret) {
+ dev_warn(dev, "%s: Governor %s stop=%d\n",
+ __func__, devfreq->governor->name,
+ ret);
+ }
+ devfreq->governor = NULL;
+ }
+ }
+
+ list_del(&governor->node);
+err_out:
+ mutex_unlock(&devfreq_list_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(devfreq_remove_governor);
+
+static ssize_t governor_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ if (!to_devfreq(dev)->governor)
+ return -EINVAL;
+
+ return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name);
+}
+
+static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct devfreq *df = to_devfreq(dev);
+ int ret;
+ char str_governor[DEVFREQ_NAME_LEN + 1];
+ struct devfreq_governor *governor;
+
+ ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);
+ if (ret != 1)
+ return -EINVAL;
+
+ mutex_lock(&devfreq_list_lock);
+ governor = find_devfreq_governor(str_governor);
+ if (IS_ERR(governor)) {
+ ret = PTR_ERR(governor);
+ goto out;
+ }
+ if (df->governor == governor)
+ goto out;
+
+ if (df->governor) {
+ ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
+ if (ret) {
+ dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
+ __func__, df->governor->name, ret);
+ goto out;
+ }
+ }
+ df->governor = governor;
+ strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN);
+ ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
+ if (ret)
+ dev_warn(dev, "%s: Governor %s not started(%d)\n",
+ __func__, df->governor->name, ret);
+out:
+ mutex_unlock(&devfreq_list_lock);
+
+ if (!ret)
+ ret = count;
+ return ret;
+}
+static DEVICE_ATTR_RW(governor);
+
+static ssize_t available_governors_show(struct device *d,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct devfreq_governor *tmp_governor;
+ ssize_t count = 0;
+
+ mutex_lock(&devfreq_list_lock);
+ list_for_each_entry(tmp_governor, &devfreq_governor_list, node)
+ count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
+ "%s ", tmp_governor->name);
+ mutex_unlock(&devfreq_list_lock);
+
+ /* Truncate the trailing space */
+ if (count)
+ count--;
+
+ count += sprintf(&buf[count], "\n");
+
+ return count;
+}
+static DEVICE_ATTR_RO(available_governors);
+
+static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ unsigned long freq;
+ struct devfreq *devfreq = to_devfreq(dev);
+
+ if (devfreq->profile->get_cur_freq &&
+ !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
+ return sprintf(buf, "%lu\n", freq);
+
+ return sprintf(buf, "%lu\n", devfreq->previous_freq);
+}
+static DEVICE_ATTR_RO(cur_freq);
+
+static ssize_t target_freq_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq);
+}
+static DEVICE_ATTR_RO(target_freq);
+
+static ssize_t polling_interval_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms);
+}
+
+static ssize_t polling_interval_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct devfreq *df = to_devfreq(dev);
+ unsigned int value;
+ int ret;
+
+ if (!df->governor)
+ return -EINVAL;
+
+ ret = sscanf(buf, "%u", &value);
+ if (ret != 1)
+ return -EINVAL;
+
+ df->governor->event_handler(df, DEVFREQ_GOV_INTERVAL, &value);
+ ret = count;
+
+ return ret;
+}
+static DEVICE_ATTR_RW(polling_interval);
+
+static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct devfreq *df = to_devfreq(dev);
+ unsigned long value;
+ int ret;
+ unsigned long max;
+
+ ret = sscanf(buf, "%lu", &value);
+ if (ret != 1)
+ return -EINVAL;
+
+ mutex_lock(&df->lock);
+ max = df->max_freq;
+ if (value && max && value > max) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ df->min_freq = value;
+ update_devfreq(df);
+ ret = count;
+unlock:
+ mutex_unlock(&df->lock);
+ return ret;
+}
+
+static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq);
+}
+
+static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct devfreq *df = to_devfreq(dev);
+ unsigned long value;
+ int ret;
+ unsigned long min;
+
+ ret = sscanf(buf, "%lu", &value);
+ if (ret != 1)
+ return -EINVAL;
+
+ mutex_lock(&df->lock);
+ min = df->min_freq;
+ if (value && min && value < min) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ df->max_freq = value;
+ update_devfreq(df);
+ ret = count;
+unlock:
+ mutex_unlock(&df->lock);
+ return ret;
+}
+static DEVICE_ATTR_RW(min_freq);
+
+static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq);
+}
+static DEVICE_ATTR_RW(max_freq);
+
+static ssize_t available_frequencies_show(struct device *d,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct devfreq *df = to_devfreq(d);
+ struct device *dev = df->dev.parent;
+ struct dev_pm_opp *opp;
+ ssize_t count = 0;
+ unsigned long freq = 0;
+
+ rcu_read_lock();
+ do {
+ opp = dev_pm_opp_find_freq_ceil(dev, &freq);
+ if (IS_ERR(opp))
+ break;
+
+ count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
+ "%lu ", freq);
+ freq++;
+ } while (1);
+ rcu_read_unlock();
+
+ /* Truncate the trailing space */
+ if (count)
+ count--;
+
+ count += sprintf(&buf[count], "\n");
+
+ return count;
+}
+static DEVICE_ATTR_RO(available_frequencies);
+
+static ssize_t trans_stat_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct devfreq *devfreq = to_devfreq(dev);
+ ssize_t len;
+ int i, j;
+ unsigned int max_state = devfreq->profile->max_state;
+
+ if (!devfreq->stop_polling &&
+ devfreq_update_status(devfreq, devfreq->previous_freq))
+ return 0;
+
+ len = sprintf(buf, " From : To\n");
+ len += sprintf(buf + len, " :");
+ for (i = 0; i < max_state; i++)
+ len += sprintf(buf + len, "%8u",
+ devfreq->profile->freq_table[i]);
+
+ len += sprintf(buf + len, " time(ms)\n");
+
+ for (i = 0; i < max_state; i++) {
+ if (devfreq->profile->freq_table[i]
+ == devfreq->previous_freq) {
+ len += sprintf(buf + len, "*");
+ } else {
+ len += sprintf(buf + len, " ");
+ }
+ len += sprintf(buf + len, "%8u:",
+ devfreq->profile->freq_table[i]);
+ for (j = 0; j < max_state; j++)
+ len += sprintf(buf + len, "%8u",
+ devfreq->trans_table[(i * max_state) + j]);
+ len += sprintf(buf + len, "%10u\n",
+ jiffies_to_msecs(devfreq->time_in_state[i]));
+ }
+
+ len += sprintf(buf + len, "Total transition : %u\n",
+ devfreq->total_trans);
+ return len;
+}
+static DEVICE_ATTR_RO(trans_stat);
+
+static struct attribute *devfreq_attrs[] = {
+ &dev_attr_governor.attr,
+ &dev_attr_available_governors.attr,
+ &dev_attr_cur_freq.attr,
+ &dev_attr_available_frequencies.attr,
+ &dev_attr_target_freq.attr,
+ &dev_attr_polling_interval.attr,
+ &dev_attr_min_freq.attr,
+ &dev_attr_max_freq.attr,
+ &dev_attr_trans_stat.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(devfreq);
+
+static int __init devfreq_init(void)
+{
+ devfreq_class = class_create(THIS_MODULE, "devfreq");
+ if (IS_ERR(devfreq_class)) {
+ pr_err("%s: couldn't create class\n", __FILE__);
+ return PTR_ERR(devfreq_class);
+ }
+
+ devfreq_wq = create_freezable_workqueue("devfreq_wq");
+ if (!devfreq_wq) {
+ class_destroy(devfreq_class);
+ pr_err("%s: couldn't create workqueue\n", __FILE__);
+ return -ENOMEM;
+ }
+ devfreq_class->dev_groups = devfreq_groups;
+
+ return 0;
+}
+subsys_initcall(devfreq_init);
+
+static void __exit devfreq_exit(void)
+{
+ class_destroy(devfreq_class);
+ destroy_workqueue(devfreq_wq);
+}
+module_exit(devfreq_exit);
+
+/*
+ * The followings are helper functions for devfreq user device drivers with
+ * OPP framework.
+ */
+
+/**
+ * devfreq_recommended_opp() - Helper function to get proper OPP for the
+ * freq value given to target callback.
+ * @dev: The devfreq user device. (parent of devfreq)
+ * @freq: The frequency given to target function
+ * @flags: Flags handed from devfreq framework.
+ *
+ * Locking: This function must be called under rcu_read_lock(). opp is a rcu
+ * protected pointer. The reason for the same is that the opp pointer which is
+ * returned will remain valid for use with opp_get_{voltage, freq} only while
+ * under the locked area. The pointer returned must be used prior to unlocking
+ * with rcu_read_unlock() to maintain the integrity of the pointer.
+ */
+struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
+ unsigned long *freq,
+ u32 flags)
+{
+ struct dev_pm_opp *opp;
+
+ if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {
+ /* The freq is an upper bound. opp should be lower */
+ opp = dev_pm_opp_find_freq_floor(dev, freq);
+
+ /* If not available, use the closest opp */
+ if (opp == ERR_PTR(-ERANGE))
+ opp = dev_pm_opp_find_freq_ceil(dev, freq);
+ } else {
+ /* The freq is an lower bound. opp should be higher */
+ opp = dev_pm_opp_find_freq_ceil(dev, freq);
+
+ /* If not available, use the closest opp */
+ if (opp == ERR_PTR(-ERANGE))
+ opp = dev_pm_opp_find_freq_floor(dev, freq);
+ }
+
+ return opp;
+}
+EXPORT_SYMBOL(devfreq_recommended_opp);
+
+/**
+ * devfreq_register_opp_notifier() - Helper function to get devfreq notified
+ * for any changes in the OPP availability
+ * changes
+ * @dev: The devfreq user device. (parent of devfreq)
+ * @devfreq: The devfreq object.
+ */
+int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
+{
+ struct srcu_notifier_head *nh;
+ int ret = 0;
+
+ rcu_read_lock();
+ nh = dev_pm_opp_get_notifier(dev);
+ if (IS_ERR(nh))
+ ret = PTR_ERR(nh);
+ rcu_read_unlock();
+ if (!ret)
+ ret = srcu_notifier_chain_register(nh, &devfreq->nb);
+
+ return ret;
+}
+EXPORT_SYMBOL(devfreq_register_opp_notifier);
+
+/**
+ * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq
+ * notified for any changes in the OPP
+ * availability changes anymore.
+ * @dev: The devfreq user device. (parent of devfreq)
+ * @devfreq: The devfreq object.
+ *
+ * At exit() callback of devfreq_dev_profile, this must be included if
+ * devfreq_recommended_opp is used.
+ */
+int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
+{
+ struct srcu_notifier_head *nh;
+ int ret = 0;
+
+ rcu_read_lock();
+ nh = dev_pm_opp_get_notifier(dev);
+ if (IS_ERR(nh))
+ ret = PTR_ERR(nh);
+ rcu_read_unlock();
+ if (!ret)
+ ret = srcu_notifier_chain_unregister(nh, &devfreq->nb);
+
+ return ret;
+}
+EXPORT_SYMBOL(devfreq_unregister_opp_notifier);
+
+static void devm_devfreq_opp_release(struct device *dev, void *res)
+{
+ devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res);
+}
+
+/**
+ * devm_ devfreq_register_opp_notifier()
+ * - Resource-managed devfreq_register_opp_notifier()
+ * @dev: The devfreq user device. (parent of devfreq)
+ * @devfreq: The devfreq object.
+ */
+int devm_devfreq_register_opp_notifier(struct device *dev,
+ struct devfreq *devfreq)
+{
+ struct devfreq **ptr;
+ int ret;
+
+ ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
+ ret = devfreq_register_opp_notifier(dev, devfreq);
+ if (ret) {
+ devres_free(ptr);
+ return ret;
+ }
+
+ *ptr = devfreq;
+ devres_add(dev, ptr);
+
+ return 0;
+}
+EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);
+
+/**
+ * devm_devfreq_unregister_opp_notifier()
+ * - Resource-managed devfreq_unregister_opp_notifier()
+ * @dev: The devfreq user device. (parent of devfreq)
+ * @devfreq: The devfreq object.
+ */
+void devm_devfreq_unregister_opp_notifier(struct device *dev,
+ struct devfreq *devfreq)
+{
+ WARN_ON(devres_release(dev, devm_devfreq_opp_release,
+ devm_devfreq_dev_match, devfreq));
+}
+EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);
+
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
+MODULE_DESCRIPTION("devfreq class support");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff