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/*
* Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define pr_fmt(fmt) "devfreq-simple-dev: " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/ktime.h>
#include <linux/time.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/devfreq.h>
#include <linux/of.h>
#include <linux/clk.h>
#include <trace/events/power.h>
struct dev_data {
struct clk *clk;
struct devfreq *df;
struct devfreq_dev_profile profile;
};
static void find_freq(struct devfreq_dev_profile *p, unsigned long *freq,
u32 flags)
{
int i;
unsigned long atmost, atleast, f;
atmost = p->freq_table[0];
atleast = p->freq_table[p->max_state-1];
for (i = 0; i < p->max_state; i++) {
f = p->freq_table[i];
if (f <= *freq)
atmost = max(f, atmost);
if (f >= *freq)
atleast = min(f, atleast);
}
if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND)
*freq = atmost;
else
*freq = atleast;
}
static int dev_target(struct device *dev, unsigned long *freq, u32 flags)
{
struct dev_data *d = dev_get_drvdata(dev);
unsigned long rfreq;
find_freq(&d->profile, freq, flags);
rfreq = clk_round_rate(d->clk, *freq * 1000);
if (IS_ERR_VALUE(rfreq)) {
dev_err(dev, "devfreq: Cannot find matching frequency for %lu\n",
*freq);
return rfreq;
}
return clk_set_rate(d->clk, rfreq);
}
static int dev_get_cur_freq(struct device *dev, unsigned long *freq)
{
struct dev_data *d = dev_get_drvdata(dev);
unsigned long f;
f = clk_get_rate(d->clk);
if (IS_ERR_VALUE(f))
return f;
*freq = f / 1000;
return 0;
}
#define PROP_TBL "freq-tbl-khz"
static int devfreq_clock_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct dev_data *d;
struct devfreq_dev_profile *p;
u32 *data, poll;
const char *gov_name;
int ret, len, i, j;
unsigned long f;
d = devm_kzalloc(dev, sizeof(*d), GFP_KERNEL);
if (!d)
return -ENOMEM;
platform_set_drvdata(pdev, d);
d->clk = devm_clk_get(dev, "devfreq_clk");
if (IS_ERR(d->clk))
return PTR_ERR(d->clk);
if (!of_find_property(dev->of_node, PROP_TBL, &len))
return -EINVAL;
len /= sizeof(*data);
data = devm_kzalloc(dev, len * sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
p = &d->profile;
p->freq_table = devm_kzalloc(dev, len * sizeof(*p->freq_table),
GFP_KERNEL);
if (!p->freq_table)
return -ENOMEM;
ret = of_property_read_u32_array(dev->of_node, PROP_TBL, data, len);
if (ret)
return ret;
j = 0;
for (i = 0; i < len; i++) {
f = clk_round_rate(d->clk, data[i] * 1000);
if (IS_ERR_VALUE(f))
dev_warn(dev, "Unable to find dev rate for %d KHz",
data[i]);
else
p->freq_table[j++] = f / 1000;
}
p->max_state = j;
devm_kfree(dev, data);
if (p->max_state == 0) {
dev_err(dev, "Error parsing property %s!\n", PROP_TBL);
return -EINVAL;
}
p->target = dev_target;
p->get_cur_freq = dev_get_cur_freq;
ret = dev_get_cur_freq(dev, &p->initial_freq);
if (ret)
return ret;
p->polling_ms = 50;
if (!of_property_read_u32(dev->of_node, "polling-ms", &poll))
p->polling_ms = poll;
if (of_property_read_string(dev->of_node, "governor", &gov_name))
gov_name = "performance";
if (of_property_read_bool(dev->of_node, "qcom,prepare-clk")) {
ret = clk_prepare(d->clk);
if (ret)
return ret;
}
d->df = devfreq_add_device(dev, p, gov_name, NULL);
if (IS_ERR(d->df)) {
ret = PTR_ERR(d->df);
goto add_err;
}
return 0;
add_err:
if (of_property_read_bool(dev->of_node, "qcom,prepare-clk"))
clk_unprepare(d->clk);
return ret;
}
static int devfreq_clock_remove(struct platform_device *pdev)
{
struct dev_data *d = platform_get_drvdata(pdev);
devfreq_remove_device(d->df);
return 0;
}
static struct of_device_id match_table[] = {
{ .compatible = "devfreq-simple-dev" },
{}
};
static struct platform_driver devfreq_clock_driver = {
.probe = devfreq_clock_probe,
.remove = devfreq_clock_remove,
.driver = {
.name = "devfreq-simple-dev",
.of_match_table = match_table,
.owner = THIS_MODULE,
},
};
static int __init devfreq_clock_init(void)
{
platform_driver_register(&devfreq_clock_driver);
return 0;
}
device_initcall(devfreq_clock_init);
static void __exit devfreq_clock_exit(void)
{
platform_driver_unregister(&devfreq_clock_driver);
}
module_exit(devfreq_clock_exit);
MODULE_DESCRIPTION("Devfreq driver for setting generic device clock frequency");
MODULE_LICENSE("GPL v2");
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