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android-kvm / linux / 24327c478b2fc17a01b21a4721f35f22a51fe12b / . / drivers / devfreq / devfreq.c
blob: bf3047896e41ac770b9c67522d0995fbdbfc74aa [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
* for Non-CPU Devices.
*
* Copyright (C) 2011 Samsung Electronics
* MyungJoo Ham <myungjoo.ham@samsung.com>
*/
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/sched.h>
#include <linux/debugfs.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/export.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 <linux/of.h>
#include <linux/pm_qos.h>
#include "governor.h"
#define CREATE_TRACE_POINTS
#include <trace/events/devfreq.h>
#define IS_SUPPORTED_FLAG(f, name) ((f & DEVFREQ_GOV_FLAG_##name) ? true : false)
#define IS_SUPPORTED_ATTR(f, name) ((f & DEVFREQ_GOV_ATTR_##name) ? true : false)
#define HZ_PER_KHZ 1000
static struct class *devfreq_class;
static struct dentry *devfreq_debugfs;
/*
* 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);
static const char timer_name[][DEVFREQ_NAME_LEN] = {
[DEVFREQ_TIMER_DEFERRABLE] = { "deferrable" },
[DEVFREQ_TIMER_DELAYED] = { "delayed" },
};
/**
* 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;
lockdep_assert_held(&devfreq_list_lock);
if (IS_ERR_OR_NULL(dev)) {
pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
return ERR_PTR(-EINVAL);
}
list_for_each_entry(tmp_devfreq, &devfreq_list, node) {
if (tmp_devfreq->dev.parent == dev)
return tmp_devfreq;
}
return ERR_PTR(-ENODEV);
}
static unsigned long find_available_min_freq(struct devfreq *devfreq)
{
struct dev_pm_opp *opp;
unsigned long min_freq = 0;
opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &min_freq);
if (IS_ERR(opp))
min_freq = 0;
else
dev_pm_opp_put(opp);
return min_freq;
}
static unsigned long find_available_max_freq(struct devfreq *devfreq)
{
struct dev_pm_opp *opp;
unsigned long max_freq = ULONG_MAX;
opp = dev_pm_opp_find_freq_floor(devfreq->dev.parent, &max_freq);
if (IS_ERR(opp))
max_freq = 0;
else
dev_pm_opp_put(opp);
return max_freq;
}
/**
* get_freq_range() - Get the current freq range
* @devfreq: the devfreq instance
* @min_freq: the min frequency
* @max_freq: the max frequency
*
* This takes into consideration all constraints.
*/
static void get_freq_range(struct devfreq *devfreq,
unsigned long *min_freq,
unsigned long *max_freq)
{
unsigned long *freq_table = devfreq->profile->freq_table;
s32 qos_min_freq, qos_max_freq;
lockdep_assert_held(&devfreq->lock);
/*
* Initialize minimum/maximum frequency from freq table.
* The devfreq drivers can initialize this in either ascending or
* descending order and devfreq core supports both.
*/
if (freq_table[0] < freq_table[devfreq->profile->max_state - 1]) {
*min_freq = freq_table[0];
*max_freq = freq_table[devfreq->profile->max_state - 1];
} else {
*min_freq = freq_table[devfreq->profile->max_state - 1];
*max_freq = freq_table[0];
}
/* Apply constraints from PM QoS */
qos_min_freq = dev_pm_qos_read_value(devfreq->dev.parent,
DEV_PM_QOS_MIN_FREQUENCY);
qos_max_freq = dev_pm_qos_read_value(devfreq->dev.parent,
DEV_PM_QOS_MAX_FREQUENCY);
*min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq);
if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE)
*max_freq = min(*max_freq,
(unsigned long)HZ_PER_KHZ * qos_max_freq);
/* Apply constraints from OPP interface */
*min_freq = max(*min_freq, devfreq->scaling_min_freq);
*max_freq = min(*max_freq, devfreq->scaling_max_freq);
if (*min_freq > *max_freq)
*min_freq = *max_freq;
}
/**
* 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;
}
static int set_freq_table(struct devfreq *devfreq)
{
struct devfreq_dev_profile *profile = devfreq->profile;
struct dev_pm_opp *opp;
unsigned long freq;
int i, count;
/* Initialize the freq_table from OPP table */
count = dev_pm_opp_get_opp_count(devfreq->dev.parent);
if (count <= 0)
return -EINVAL;
profile->max_state = count;
profile->freq_table = devm_kcalloc(devfreq->dev.parent,
profile->max_state,
sizeof(*profile->freq_table),
GFP_KERNEL);
if (!profile->freq_table) {
profile->max_state = 0;
return -ENOMEM;
}
for (i = 0, freq = 0; i < profile->max_state; i++, freq++) {
opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq);
if (IS_ERR(opp)) {
devm_kfree(devfreq->dev.parent, profile->freq_table);
profile->max_state = 0;
return PTR_ERR(opp);
}
dev_pm_opp_put(opp);
profile->freq_table[i] = freq;
}
return 0;
}
/**
* devfreq_update_status() - Update statistics of devfreq behavior
* @devfreq: the devfreq instance
* @freq: the update target frequency
*/
int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
{
int lev, prev_lev, ret = 0;
u64 cur_time;
lockdep_assert_held(&devfreq->lock);
cur_time = get_jiffies_64();
/* Immediately exit if previous_freq is not initialized yet. */
if (!devfreq->previous_freq)
goto out;
prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);
if (prev_lev < 0) {
ret = prev_lev;
goto out;
}
devfreq->stats.time_in_state[prev_lev] +=
cur_time - devfreq->stats.last_update;
lev = devfreq_get_freq_level(devfreq, freq);
if (lev < 0) {
ret = lev;
goto out;
}
if (lev != prev_lev) {
devfreq->stats.trans_table[
(prev_lev * devfreq->profile->max_state) + lev]++;
devfreq->stats.total_trans++;
}
out:
devfreq->stats.last_update = cur_time;
return ret;
}
EXPORT_SYMBOL(devfreq_update_status);
/**
* 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;
lockdep_assert_held(&devfreq_list_lock);
if (IS_ERR_OR_NULL(name)) {
pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
return ERR_PTR(-EINVAL);
}
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);
}
/**
* try_then_request_governor() - Try to find the governor and request the
* module if is not found.
* @name: name of the governor
*
* Search the list of devfreq governors and request the module and try again
* if is not found. This can happen when both drivers (the governor driver
* and the driver that call devfreq_add_device) are built as modules.
* devfreq_list_lock should be held by the caller. Returns the matched
* governor's pointer or an error pointer.
*/
static struct devfreq_governor *try_then_request_governor(const char *name)
{
struct devfreq_governor *governor;
int err = 0;
lockdep_assert_held(&devfreq_list_lock);
if (IS_ERR_OR_NULL(name)) {
pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
return ERR_PTR(-EINVAL);
}
governor = find_devfreq_governor(name);
if (IS_ERR(governor)) {
mutex_unlock(&devfreq_list_lock);
if (!strncmp(name, DEVFREQ_GOV_SIMPLE_ONDEMAND,
DEVFREQ_NAME_LEN))
err = request_module("governor_%s", "simpleondemand");
else
err = request_module("governor_%s", name);
/* Restore previous state before return */
mutex_lock(&devfreq_list_lock);
if (err)
return (err < 0) ? ERR_PTR(err) : ERR_PTR(-EINVAL);
governor = find_devfreq_governor(name);
}
return governor;
}
static int devfreq_notify_transition(struct devfreq *devfreq,
struct devfreq_freqs *freqs, unsigned int state)
{
if (!devfreq)
return -EINVAL;
switch (state) {
case DEVFREQ_PRECHANGE:
srcu_notifier_call_chain(&devfreq->transition_notifier_list,
DEVFREQ_PRECHANGE, freqs);
break;
case DEVFREQ_POSTCHANGE:
srcu_notifier_call_chain(&devfreq->transition_notifier_list,
DEVFREQ_POSTCHANGE, freqs);
break;
default:
return -EINVAL;
}
return 0;
}
static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
u32 flags)
{
struct devfreq_freqs freqs;
unsigned long cur_freq;
int err = 0;
if (devfreq->profile->get_cur_freq)
devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
else
cur_freq = devfreq->previous_freq;
freqs.old = cur_freq;
freqs.new = new_freq;
devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);
err = devfreq->profile->target(devfreq->dev.parent, &new_freq, flags);
if (err) {
freqs.new = cur_freq;
devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
return err;
}
/*
* Print devfreq_frequency trace information between DEVFREQ_PRECHANGE
* and DEVFREQ_POSTCHANGE because for showing the correct frequency
* change order of between devfreq device and passive devfreq device.
*/
if (trace_devfreq_frequency_enabled() && new_freq != cur_freq)
trace_devfreq_frequency(devfreq, new_freq, cur_freq);
freqs.new = new_freq;
devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
if (devfreq_update_status(devfreq, new_freq))
dev_err(&devfreq->dev,
"Couldn't update frequency transition information.\n");
devfreq->previous_freq = new_freq;
if (devfreq->suspend_freq)
devfreq->resume_freq = cur_freq;
return err;
}
/**
* devfreq_update_target() - Reevaluate the device and configure frequency
* on the final stage.
* @devfreq: the devfreq instance.
* @freq: the new frequency of parent device. This argument
* is only used for devfreq device using passive governor.
*
* Note: Lock devfreq->lock before calling devfreq_update_target. This function
* should be only used by both update_devfreq() and devfreq governors.
*/
int devfreq_update_target(struct devfreq *devfreq, unsigned long freq)
{
unsigned long min_freq, max_freq;
int err = 0;
u32 flags = 0;
lockdep_assert_held(&devfreq->lock);
if (!devfreq->governor)
return -EINVAL;
/* Reevaluate the proper frequency */
err = devfreq->governor->get_target_freq(devfreq, &freq);
if (err)
return err;
get_freq_range(devfreq, &min_freq, &max_freq);
if (freq < min_freq) {
freq = min_freq;
flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */
}
if (freq > max_freq) {
freq = max_freq;
flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
}
return devfreq_set_target(devfreq, freq, flags);
}
EXPORT_SYMBOL(devfreq_update_target);
/* 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)
{
return devfreq_update_target(devfreq, 0L);
}
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);
trace_devfreq_monitor(devfreq);
}
/**
* devfreq_monitor_start() - Start load monitoring of devfreq instance
* @devfreq: the devfreq instance.
*
* Helper function for starting devfreq device load monitoring. 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)
{
if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
return;
switch (devfreq->profile->timer) {
case DEVFREQ_TIMER_DEFERRABLE:
INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);
break;
case DEVFREQ_TIMER_DELAYED:
INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor);
break;
default:
return;
}
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 monitoring. 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)
{
if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
return;
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 monitoring. 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);
if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
return;
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 monitoring. 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 (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
goto out_update;
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));
out_update:
devfreq->stats.last_update = get_jiffies_64();
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_update_interval() - 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_UPDATE_INTERVAL event.
*/
void devfreq_update_interval(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 (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
goto out;
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_update_interval);
/**
* 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 err = -EINVAL;
mutex_lock(&devfreq->lock);
devfreq->scaling_min_freq = find_available_min_freq(devfreq);
if (!devfreq->scaling_min_freq)
goto out;
devfreq->scaling_max_freq = find_available_max_freq(devfreq);
if (!devfreq->scaling_max_freq) {
devfreq->scaling_max_freq = ULONG_MAX;
goto out;
}
err = update_devfreq(devfreq);
out:
mutex_unlock(&devfreq->lock);
if (err)
dev_err(devfreq->dev.parent,
"failed to update frequency from OPP notifier (%d)\n",
err);
return NOTIFY_OK;
}
/**
* qos_notifier_call() - Common handler for QoS constraints.
* @devfreq: the devfreq instance.
*/
static int qos_notifier_call(struct devfreq *devfreq)
{
int err;
mutex_lock(&devfreq->lock);
err = update_devfreq(devfreq);
mutex_unlock(&devfreq->lock);
if (err)
dev_err(devfreq->dev.parent,
"failed to update frequency from PM QoS (%d)\n",
err);
return NOTIFY_OK;
}
/**
* qos_min_notifier_call() - Callback for QoS min_freq changes.
* @nb: Should be devfreq->nb_min
*/
static int qos_min_notifier_call(struct notifier_block *nb,
unsigned long val, void *ptr)
{
return qos_notifier_call(container_of(nb, struct devfreq, nb_min));
}
/**
* qos_max_notifier_call() - Callback for QoS max_freq changes.
* @nb: Should be devfreq->nb_max
*/
static int qos_max_notifier_call(struct notifier_block *nb,
unsigned long val, void *ptr)
{
return qos_notifier_call(container_of(nb, struct devfreq, nb_max));
}
/**
* devfreq_dev_release() - Callback for struct device to release the device.
* @dev: the devfreq device
*
* Remove devfreq from the list and release its resources.
*/
static void devfreq_dev_release(struct device *dev)
{
struct devfreq *devfreq = to_devfreq(dev);
int err;
mutex_lock(&devfreq_list_lock);
list_del(&devfreq->node);
mutex_unlock(&devfreq_list_lock);
err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max,
DEV_PM_QOS_MAX_FREQUENCY);
if (err && err != -ENOENT)
dev_warn(dev->parent,
"Failed to remove max_freq notifier: %d\n", err);
err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min,
DEV_PM_QOS_MIN_FREQUENCY);
if (err && err != -ENOENT)
dev_warn(dev->parent,
"Failed to remove min_freq notifier: %d\n", err);
if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) {
err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req);
if (err < 0)
dev_warn(dev->parent,
"Failed to remove max_freq request: %d\n", err);
}
if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) {
err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req);
if (err < 0)
dev_warn(dev->parent,
"Failed to remove min_freq request: %d\n", err);
}
if (devfreq->profile->exit)
devfreq->profile->exit(devfreq->dev.parent);
if (devfreq->opp_table)
dev_pm_opp_put_opp_table(devfreq->opp_table);
mutex_destroy(&devfreq->lock);
kfree(devfreq);
}
static void create_sysfs_files(struct devfreq *devfreq,
const struct devfreq_governor *gov);
static void remove_sysfs_files(struct devfreq *devfreq,
const struct devfreq_governor *gov);
/**
* 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: devfreq device already exists!\n",
__func__);
err = -EINVAL;
goto err_out;
}
devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL);
if (!devfreq) {
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;
INIT_LIST_HEAD(&devfreq->node);
devfreq->profile = profile;
devfreq->previous_freq = profile->initial_freq;
devfreq->last_status.current_frequency = profile->initial_freq;
devfreq->data = data;
devfreq->nb.notifier_call = devfreq_notifier_call;
if (devfreq->profile->timer < 0
|| devfreq->profile->timer >= DEVFREQ_TIMER_NUM) {
goto err_out;
}
if (!devfreq->profile->max_state && !devfreq->profile->freq_table) {
mutex_unlock(&devfreq->lock);
err = set_freq_table(devfreq);
if (err < 0)
goto err_dev;
mutex_lock(&devfreq->lock);
}
devfreq->scaling_min_freq = find_available_min_freq(devfreq);
if (!devfreq->scaling_min_freq) {
mutex_unlock(&devfreq->lock);
err = -EINVAL;
goto err_dev;
}
devfreq->scaling_max_freq = find_available_max_freq(devfreq);
if (!devfreq->scaling_max_freq) {
mutex_unlock(&devfreq->lock);
err = -EINVAL;
goto err_dev;
}
devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev);
devfreq->opp_table = dev_pm_opp_get_opp_table(dev);
if (IS_ERR(devfreq->opp_table))
devfreq->opp_table = NULL;
atomic_set(&devfreq->suspend_count, 0);
dev_set_name(&devfreq->dev, "%s", dev_name(dev));
err = device_register(&devfreq->dev);
if (err) {
mutex_unlock(&devfreq->lock);
put_device(&devfreq->dev);
goto err_out;
}
devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev,
array3_size(sizeof(unsigned int),
devfreq->profile->max_state,
devfreq->profile->max_state),
GFP_KERNEL);
if (!devfreq->stats.trans_table) {
mutex_unlock(&devfreq->lock);
err = -ENOMEM;
goto err_devfreq;
}
devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev,
devfreq->profile->max_state,
sizeof(*devfreq->stats.time_in_state),
GFP_KERNEL);
if (!devfreq->stats.time_in_state) {
mutex_unlock(&devfreq->lock);
err = -ENOMEM;
goto err_devfreq;
}
devfreq->stats.total_trans = 0;
devfreq->stats.last_update = get_jiffies_64();
srcu_init_notifier_head(&devfreq->transition_notifier_list);
mutex_unlock(&devfreq->lock);
err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req,
DEV_PM_QOS_MIN_FREQUENCY, 0);
if (err < 0)
goto err_devfreq;
err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req,
DEV_PM_QOS_MAX_FREQUENCY,
PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
if (err < 0)
goto err_devfreq;
devfreq->nb_min.notifier_call = qos_min_notifier_call;
err = dev_pm_qos_add_notifier(dev, &devfreq->nb_min,
DEV_PM_QOS_MIN_FREQUENCY);
if (err)
goto err_devfreq;
devfreq->nb_max.notifier_call = qos_max_notifier_call;
err = dev_pm_qos_add_notifier(dev, &devfreq->nb_max,
DEV_PM_QOS_MAX_FREQUENCY);
if (err)
goto err_devfreq;
mutex_lock(&devfreq_list_lock);
governor = try_then_request_governor(governor_name);
if (IS_ERR(governor)) {
dev_err(dev, "%s: Unable to find governor for the device\n",
__func__);
err = PTR_ERR(governor);
goto err_init;
}
devfreq->governor = governor;
err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START,
NULL);
if (err) {
dev_err(dev, "%s: Unable to start governor for the device\n",
__func__);
goto err_init;
}
create_sysfs_files(devfreq, devfreq->governor);
list_add(&devfreq->node, &devfreq_list);
mutex_unlock(&devfreq_list_lock);
return devfreq;
err_init:
mutex_unlock(&devfreq_list_lock);
err_devfreq:
devfreq_remove_device(devfreq);
devfreq = NULL;
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;
if (devfreq->governor) {
devfreq->governor->event_handler(devfreq,
DEVFREQ_GOV_STOP, NULL);
remove_sysfs_files(devfreq, devfreq->governor);
}
device_unregister(&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 devfreq;
}
*ptr = devfreq;
devres_add(dev, ptr);
return devfreq;
}
EXPORT_SYMBOL(devm_devfreq_add_device);
#ifdef CONFIG_OF
/*
* devfreq_get_devfreq_by_node - Get the devfreq device from devicetree
* @node - pointer to device_node
*
* return the instance of devfreq device
*/
struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
{
struct devfreq *devfreq;
if (!node)
return ERR_PTR(-EINVAL);
mutex_lock(&devfreq_list_lock);
list_for_each_entry(devfreq, &devfreq_list, node) {
if (devfreq->dev.parent
&& devfreq->dev.parent->of_node == node) {
mutex_unlock(&devfreq_list_lock);
return devfreq;
}
}
mutex_unlock(&devfreq_list_lock);
return ERR_PTR(-ENODEV);
}
/*
* devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree
* @dev - instance to the given device
* @phandle_name - name of property holding a phandle value
* @index - index into list of devfreq
*
* return the instance of devfreq device
*/
struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
const char *phandle_name, int index)
{
struct device_node *node;
struct devfreq *devfreq;
if (!dev || !phandle_name)
return ERR_PTR(-EINVAL);
if (!dev->of_node)
return ERR_PTR(-EINVAL);
node = of_parse_phandle(dev->of_node, phandle_name, index);
if (!node)
return ERR_PTR(-ENODEV);
devfreq = devfreq_get_devfreq_by_node(node);
of_node_put(node);
return devfreq;
}
#else
struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
{
return ERR_PTR(-ENODEV);
}
struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
const char *phandle_name, int index)
{
return ERR_PTR(-ENODEV);
}
#endif /* CONFIG_OF */
EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_node);
EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle);
/**
* devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
* @dev: the device from which to remove 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)
{
int ret;
if (!devfreq)
return -EINVAL;
if (atomic_inc_return(&devfreq->suspend_count) > 1)
return 0;
if (devfreq->governor) {
ret = devfreq->governor->event_handler(devfreq,
DEVFREQ_GOV_SUSPEND, NULL);
if (ret)
return ret;
}
if (devfreq->suspend_freq) {
mutex_lock(&devfreq->lock);
ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0);
mutex_unlock(&devfreq->lock);
if (ret)
return ret;
}
return 0;
}
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)
{
int ret;
if (!devfreq)
return -EINVAL;
if (atomic_dec_return(&devfreq->suspend_count) >= 1)
return 0;
if (devfreq->resume_freq) {
mutex_lock(&devfreq->lock);
ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0);
mutex_unlock(&devfreq->lock);
if (ret)
return ret;
}
if (devfreq->governor) {
ret = devfreq->governor->event_handler(devfreq,
DEVFREQ_GOV_RESUME, NULL);
if (ret)
return ret;
}
return 0;
}
EXPORT_SYMBOL(devfreq_resume_device);
/**
* devfreq_suspend() - Suspend devfreq governors and devices
*
* Called during system wide Suspend/Hibernate cycles for suspending governors
* and devices preserving the state for resume. On some platforms the devfreq
* device must have precise state (frequency) after resume in order to provide
* fully operating setup.
*/
void devfreq_suspend(void)
{
struct devfreq *devfreq;
int ret;
mutex_lock(&devfreq_list_lock);
list_for_each_entry(devfreq, &devfreq_list, node) {
ret = devfreq_suspend_device(devfreq);
if (ret)
dev_err(&devfreq->dev,
"failed to suspend devfreq device\n");
}
mutex_unlock(&devfreq_list_lock);
}
/**
* devfreq_resume() - Resume devfreq governors and devices
*
* Called during system wide Suspend/Hibernate cycle for resuming governors and
* devices that are suspended with devfreq_suspend().
*/
void devfreq_resume(void)
{
struct devfreq *devfreq;
int ret;
mutex_lock(&devfreq_list_lock);
list_for_each_entry(devfreq, &devfreq_list, node) {
ret = devfreq_resume_device(devfreq);
if (ret)
dev_warn(&devfreq->dev,
"failed to resume devfreq device\n");
}
mutex_unlock(&devfreq_list_lock);
}
/**
* 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_governor() - 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 name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct devfreq *df = to_devfreq(dev);
return sprintf(buf, "%s\n", dev_name(df->dev.parent));
}
static DEVICE_ATTR_RO(name);
static ssize_t governor_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct devfreq *df = to_devfreq(dev);
if (!df->governor)
return -EINVAL;
return sprintf(buf, "%s\n", df->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];
const struct devfreq_governor *governor, *prev_governor;
if (!df->governor)
return -EINVAL;
ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);
if (ret != 1)
return -EINVAL;
mutex_lock(&devfreq_list_lock);
governor = try_then_request_governor(str_governor);
if (IS_ERR(governor)) {
ret = PTR_ERR(governor);
goto out;
}
if (df->governor == governor) {
ret = 0;
goto out;
} else if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)
|| IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE)) {
ret = -EINVAL;
goto out;
}
/*
* Stop the current governor and remove the specific sysfs files
* which depend on current 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;
}
remove_sysfs_files(df, df->governor);
/*
* Start the new governor and create the specific sysfs files
* which depend on the new governor.
*/
prev_governor = df->governor;
df->governor = governor;
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);
/* Restore previous governor */
df->governor = prev_governor;
ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
if (ret) {
dev_err(dev,
"%s: reverting to Governor %s failed (%d)\n",
__func__, prev_governor->name, ret);
df->governor = NULL;
goto out;
}
}
/*
* Create the sysfs files for the new governor. But if failed to start
* the new governor, restore the sysfs files of previous governor.
*/
create_sysfs_files(df, df->governor);
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 *df = to_devfreq(d);
ssize_t count = 0;
if (!df->governor)
return -EINVAL;
mutex_lock(&devfreq_list_lock);
/*
* The devfreq with immutable governor (e.g., passive) shows
* only own governor.
*/
if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)) {
count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,
"%s ", df->governor->name);
/*
* The devfreq device shows the registered governor except for
* immutable governors such as passive governor .
*/
} else {
struct devfreq_governor *governor;
list_for_each_entry(governor, &devfreq_governor_list, node) {
if (IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE))
continue;
count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
"%s ", 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 *df = to_devfreq(dev);
if (!df->profile)
return -EINVAL;
if (df->profile->get_cur_freq &&
!df->profile->get_cur_freq(df->dev.parent, &freq))
return sprintf(buf, "%lu\n", freq);
return sprintf(buf, "%lu\n", df->previous_freq);
}
static DEVICE_ATTR_RO(cur_freq);
static ssize_t target_freq_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct devfreq *df = to_devfreq(dev);
return sprintf(buf, "%lu\n", df->previous_freq);
}
static DEVICE_ATTR_RO(target_freq);
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;
/*
* Protect against theoretical sysfs writes between
* device_add and dev_pm_qos_add_request
*/
if (!dev_pm_qos_request_active(&df->user_min_freq_req))
return -EAGAIN;
ret = sscanf(buf, "%lu", &value);
if (ret != 1)
return -EINVAL;
/* Round down to kHz for PM QoS */
ret = dev_pm_qos_update_request(&df->user_min_freq_req,
value / HZ_PER_KHZ);
if (ret < 0)
return ret;
return count;
}
static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct devfreq *df = to_devfreq(dev);
unsigned long min_freq, max_freq;
mutex_lock(&df->lock);
get_freq_range(df, &min_freq, &max_freq);
mutex_unlock(&df->lock);
return sprintf(buf, "%lu\n", min_freq);
}
static DEVICE_ATTR_RW(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;
/*
* Protect against theoretical sysfs writes between
* device_add and dev_pm_qos_add_request
*/
if (!dev_pm_qos_request_active(&df->user_max_freq_req))
return -EINVAL;
ret = sscanf(buf, "%lu", &value);
if (ret != 1)
return -EINVAL;
/*
* PM QoS frequencies are in kHz so we need to convert. Convert by
* rounding upwards so that the acceptable interval never shrinks.
*
* For example if the user writes "666666666" to sysfs this value will
* be converted to 666667 kHz and back to 666667000 Hz before an OPP
* lookup, this ensures that an OPP of 666666666Hz is still accepted.
*
* A value of zero means "no limit".
*/
if (value)
value = DIV_ROUND_UP(value, HZ_PER_KHZ);
else
value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
ret = dev_pm_qos_update_request(&df->user_max_freq_req, value);
if (ret < 0)
return ret;
return count;
}
static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct devfreq *df = to_devfreq(dev);
unsigned long min_freq, max_freq;
mutex_lock(&df->lock);
get_freq_range(df, &min_freq, &max_freq);
mutex_unlock(&df->lock);
return sprintf(buf, "%lu\n", 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);
ssize_t count = 0;
int i;
if (!df->profile)
return -EINVAL;
mutex_lock(&df->lock);
for (i = 0; i < df->profile->max_state; i++)
count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
"%lu ", df->profile->freq_table[i]);
mutex_unlock(&df->lock);
/* 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 *df = to_devfreq(dev);
ssize_t len;
int i, j;
unsigned int max_state;
if (!df->profile)
return -EINVAL;
max_state = df->profile->max_state;
if (max_state == 0)
return sprintf(buf, "Not Supported.\n");
mutex_lock(&df->lock);
if (!df->stop_polling &&
devfreq_update_status(df, df->previous_freq)) {
mutex_unlock(&df->lock);
return 0;
}
mutex_unlock(&df->lock);
len = sprintf(buf, " From : To\n");
len += sprintf(buf + len, " :");
for (i = 0; i < max_state; i++)
len += sprintf(buf + len, "%10lu",
df->profile->freq_table[i]);
len += sprintf(buf + len, " time(ms)\n");
for (i = 0; i < max_state; i++) {
if (df->profile->freq_table[i]
== df->previous_freq) {
len += sprintf(buf + len, "*");
} else {
len += sprintf(buf + len, " ");
}
len += sprintf(buf + len, "%10lu:",
df->profile->freq_table[i]);
for (j = 0; j < max_state; j++)
len += sprintf(buf + len, "%10u",
df->stats.trans_table[(i * max_state) + j]);
len += sprintf(buf + len, "%10llu\n", (u64)
jiffies64_to_msecs(df->stats.time_in_state[i]));
}
len += sprintf(buf + len, "Total transition : %u\n",
df->stats.total_trans);
return len;
}
static ssize_t trans_stat_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct devfreq *df = to_devfreq(dev);
int err, value;
if (!df->profile)
return -EINVAL;
if (df->profile->max_state == 0)
return count;
err = kstrtoint(buf, 10, &value);
if (err || value != 0)
return -EINVAL;
mutex_lock(&df->lock);
memset(df->stats.time_in_state, 0, (df->profile->max_state *
sizeof(*df->stats.time_in_state)));
memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int),
df->profile->max_state,
df->profile->max_state));
df->stats.total_trans = 0;
df->stats.last_update = get_jiffies_64();
mutex_unlock(&df->lock);
return count;
}
static DEVICE_ATTR_RW(trans_stat);
static struct attribute *devfreq_attrs[] = {
&dev_attr_name.attr,
&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_min_freq.attr,
&dev_attr_max_freq.attr,
&dev_attr_trans_stat.attr,
NULL,
};
ATTRIBUTE_GROUPS(devfreq);
static ssize_t polling_interval_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct devfreq *df = to_devfreq(dev);
if (!df->profile)
return -EINVAL;
return sprintf(buf, "%d\n", df->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_UPDATE_INTERVAL, &value);
ret = count;
return ret;
}
static DEVICE_ATTR_RW(polling_interval);
static ssize_t timer_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct devfreq *df = to_devfreq(dev);
if (!df->profile)
return -EINVAL;
return sprintf(buf, "%s\n", timer_name[df->profile->timer]);
}
static ssize_t timer_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct devfreq *df = to_devfreq(dev);
char str_timer[DEVFREQ_NAME_LEN + 1];
int timer = -1;
int ret = 0, i;
if (!df->governor || !df->profile)
return -EINVAL;
ret = sscanf(buf, "%16s", str_timer);
if (ret != 1)
return -EINVAL;
for (i = 0; i < DEVFREQ_TIMER_NUM; i++) {
if (!strncmp(timer_name[i], str_timer, DEVFREQ_NAME_LEN)) {
timer = i;
break;
}
}
if (timer < 0) {
ret = -EINVAL;
goto out;
}
if (df->profile->timer == timer) {
ret = 0;
goto out;
}
mutex_lock(&df->lock);
df->profile->timer = timer;
mutex_unlock(&df->lock);
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;
}
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:
return ret ? ret : count;
}
static DEVICE_ATTR_RW(timer);
#define CREATE_SYSFS_FILE(df, name) \
{ \
int ret; \
ret = sysfs_create_file(&df->dev.kobj, &dev_attr_##name.attr); \
if (ret < 0) { \
dev_warn(&df->dev, \
"Unable to create attr(%s)\n", "##name"); \
} \
} \
/* Create the specific sysfs files which depend on each governor. */
static void create_sysfs_files(struct devfreq *devfreq,
const struct devfreq_governor *gov)
{
if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))
CREATE_SYSFS_FILE(devfreq, polling_interval);
if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))
CREATE_SYSFS_FILE(devfreq, timer);
}
/* Remove the specific sysfs files which depend on each governor. */
static void remove_sysfs_files(struct devfreq *devfreq,
const struct devfreq_governor *gov)
{
if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))
sysfs_remove_file(&devfreq->dev.kobj,
&dev_attr_polling_interval.attr);
if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))
sysfs_remove_file(&devfreq->dev.kobj, &dev_attr_timer.attr);
}
/**
* devfreq_summary_show() - Show the summary of the devfreq devices
* @s: seq_file instance to show the summary of devfreq devices
* @data: not used
*
* Show the summary of the devfreq devices via 'devfreq_summary' debugfs file.
* It helps that user can know the detailed information of the devfreq devices.
*
* Return 0 always because it shows the information without any data change.
*/
static int devfreq_summary_show(struct seq_file *s, void *data)
{
struct devfreq *devfreq;
struct devfreq *p_devfreq = NULL;
unsigned long cur_freq, min_freq, max_freq;
unsigned int polling_ms;
unsigned int timer;
seq_printf(s, "%-30s %-30s %-15s %-10s %10s %12s %12s %12s\n",
"dev",
"parent_dev",
"governor",
"timer",
"polling_ms",
"cur_freq_Hz",
"min_freq_Hz",
"max_freq_Hz");
seq_printf(s, "%30s %30s %15s %10s %10s %12s %12s %12s\n",
"------------------------------",
"------------------------------",
"---------------",
"----------",
"----------",
"------------",
"------------",
"------------");
mutex_lock(&devfreq_list_lock);
list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
if (!strncmp(devfreq->governor->name, DEVFREQ_GOV_PASSIVE,
DEVFREQ_NAME_LEN)) {
struct devfreq_passive_data *data = devfreq->data;
if (data)
p_devfreq = data->parent;
} else {
p_devfreq = NULL;
}
#endif
mutex_lock(&devfreq->lock);
cur_freq = devfreq->previous_freq;
get_freq_range(devfreq, &min_freq, &max_freq);
timer = devfreq->profile->timer;
if (IS_SUPPORTED_ATTR(devfreq->governor->attrs, POLLING_INTERVAL))
polling_ms = devfreq->profile->polling_ms;
else
polling_ms = 0;
mutex_unlock(&devfreq->lock);
seq_printf(s,
"%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n",
dev_name(&devfreq->dev),
p_devfreq ? dev_name(&p_devfreq->dev) : "null",
devfreq->governor->name,
polling_ms ? timer_name[timer] : "null",
polling_ms,
cur_freq,
min_freq,
max_freq);
}
mutex_unlock(&devfreq_list_lock);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
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;
devfreq_debugfs = debugfs_create_dir("devfreq", NULL);
debugfs_create_file("devfreq_summary", 0444,
devfreq_debugfs, NULL,
&devfreq_summary_fops);
return 0;
}
subsys_initcall(devfreq_init);
/*
* The following 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.
*
* The callers are required to call dev_pm_opp_put() for the returned OPP after
* use.
*/
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)
{
return dev_pm_opp_register_notifier(dev, &devfreq->nb);
}
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)
{
return dev_pm_opp_unregister_notifier(dev, &devfreq->nb);
}
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);
/**
* devfreq_register_notifier() - Register a driver with devfreq
* @devfreq: The devfreq object.
* @nb: The notifier block to register.
* @list: DEVFREQ_TRANSITION_NOTIFIER.
*/
int devfreq_register_notifier(struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list)
{
int ret = 0;
if (!devfreq)
return -EINVAL;
switch (list) {
case DEVFREQ_TRANSITION_NOTIFIER:
ret = srcu_notifier_chain_register(
&devfreq->transition_notifier_list, nb);
break;
default:
ret = -EINVAL;
}
return ret;
}
EXPORT_SYMBOL(devfreq_register_notifier);
/*
* devfreq_unregister_notifier() - Unregister a driver with devfreq
* @devfreq: The devfreq object.
* @nb: The notifier block to be unregistered.
* @list: DEVFREQ_TRANSITION_NOTIFIER.
*/
int devfreq_unregister_notifier(struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list)
{
int ret = 0;
if (!devfreq)
return -EINVAL;
switch (list) {
case DEVFREQ_TRANSITION_NOTIFIER:
ret = srcu_notifier_chain_unregister(
&devfreq->transition_notifier_list, nb);
break;
default:
ret = -EINVAL;
}
return ret;
}
EXPORT_SYMBOL(devfreq_unregister_notifier);
struct devfreq_notifier_devres {
struct devfreq *devfreq;
struct notifier_block *nb;
unsigned int list;
};
static void devm_devfreq_notifier_release(struct device *dev, void *res)
{
struct devfreq_notifier_devres *this = res;
devfreq_unregister_notifier(this->devfreq, this->nb, this->list);
}
/**
* devm_devfreq_register_notifier()
* - Resource-managed devfreq_register_notifier()
* @dev: The devfreq user device. (parent of devfreq)
* @devfreq: The devfreq object.
* @nb: The notifier block to be unregistered.
* @list: DEVFREQ_TRANSITION_NOTIFIER.
*/
int devm_devfreq_register_notifier(struct device *dev,
struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list)
{
struct devfreq_notifier_devres *ptr;
int ret;
ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr),
GFP_KERNEL);
if (!ptr)
return -ENOMEM;
ret = devfreq_register_notifier(devfreq, nb, list);
if (ret) {
devres_free(ptr);
return ret;
}
ptr->devfreq = devfreq;
ptr->nb = nb;
ptr->list = list;
devres_add(dev, ptr);
return 0;
}
EXPORT_SYMBOL(devm_devfreq_register_notifier);
/**
* devm_devfreq_unregister_notifier()
* - Resource-managed devfreq_unregister_notifier()
* @dev: The devfreq user device. (parent of devfreq)
* @devfreq: The devfreq object.
* @nb: The notifier block to be unregistered.
* @list: DEVFREQ_TRANSITION_NOTIFIER.
*/
void devm_devfreq_unregister_notifier(struct device *dev,
struct devfreq *devfreq,
struct notifier_block *nb,
unsigned int list)
{
WARN_ON(devres_release(dev, devm_devfreq_notifier_release,
devm_devfreq_dev_match, devfreq));
}
EXPORT_SYMBOL(devm_devfreq_unregister_notifier);