/*
* 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 (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_set_freq_table() - Initialize freq_table for the frequency
* @devfreq: the devfreq instance
*/
static void devfreq_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;
profile->max_state = count;
profile->freq_table = devm_kcalloc(devfreq->dev.parent,
profile->max_state,
sizeof(*profile->freq_table),
GFP_KERNEL