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/*
* Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* EXYNOS - CPU frequency scaling support for EXYNOS series
*
* 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/module.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/regulator/consumer.h>
#include <linux/cpufreq.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/cpu_cooling.h>
#include <linux/cpu.h>
#include "exynos-cpufreq.h"
static struct exynos_dvfs_info *exynos_info;
static struct thermal_cooling_device *cdev;
static struct regulator *arm_regulator;
static unsigned int locking_frequency;
static int exynos_cpufreq_get_index(unsigned int freq)
{
struct cpufreq_frequency_table *freq_table = exynos_info->freq_table;
struct cpufreq_frequency_table *pos;
cpufreq_for_each_entry(pos, freq_table)
if (pos->frequency == freq)
break;
if (pos->frequency == CPUFREQ_TABLE_END)
return -EINVAL;
return pos - freq_table;
}
static int exynos_cpufreq_scale(unsigned int target_freq)
{
struct cpufreq_frequency_table *freq_table = exynos_info->freq_table;
unsigned int *volt_table = exynos_info->volt_table;
struct cpufreq_policy *policy = cpufreq_cpu_get(0);
unsigned int arm_volt, safe_arm_volt = 0;
unsigned int mpll_freq_khz = exynos_info->mpll_freq_khz;
struct device *dev = exynos_info->dev;
unsigned int old_freq;
int index, old_index;
int ret = 0;
old_freq = policy->cur;
/*
* The policy max have been changed so that we cannot get proper
* old_index with cpufreq_frequency_table_target(). Thus, ignore
* policy and get the index from the raw frequency table.
*/
old_index = exynos_cpufreq_get_index(old_freq);
if (old_index < 0) {
ret = old_index;
goto out;
}
index = exynos_cpufreq_get_index(target_freq);
if (index < 0) {
ret = index;
goto out;
}
/*
* ARM clock source will be changed APLL to MPLL temporary
* To support this level, need to control regulator for
* required voltage level
*/
if (exynos_info->need_apll_change != NULL) {
if (exynos_info->need_apll_change(old_index, index) &&
(freq_table[index].frequency < mpll_freq_khz) &&
(freq_table[old_index].frequency < mpll_freq_khz))
safe_arm_volt = volt_table[exynos_info->pll_safe_idx];
}
arm_volt = volt_table[index];
/* When the new frequency is higher than current frequency */
if ((target_freq > old_freq) && !safe_arm_volt) {
/* Firstly, voltage up to increase frequency */
ret = regulator_set_voltage(arm_regulator, arm_volt, arm_volt);
if (ret) {
dev_err(dev, "failed to set cpu voltage to %d\n",
arm_volt);
return ret;
}
}
if (safe_arm_volt) {
ret = regulator_set_voltage(arm_regulator, safe_arm_volt,
safe_arm_volt);
if (ret) {
dev_err(dev, "failed to set cpu voltage to %d\n",
safe_arm_volt);
return ret;
}
}
exynos_info->set_freq(old_index, index);
/* When the new frequency is lower than current frequency */
if ((target_freq < old_freq) ||
((target_freq > old_freq) && safe_arm_volt)) {
/* down the voltage after frequency change */
ret = regulator_set_voltage(arm_regulator, arm_volt,
arm_volt);
if (ret) {
dev_err(dev, "failed to set cpu voltage to %d\n",
arm_volt);
goto out;
}
}
out:
cpufreq_cpu_put(policy);
return ret;
}
static int exynos_target(struct cpufreq_policy *policy, unsigned int index)
{
return exynos_cpufreq_scale(exynos_info->freq_table[index].frequency);
}
static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
policy->clk = exynos_info->cpu_clk;
policy->suspend_freq = locking_frequency;
return cpufreq_generic_init(policy, exynos_info->freq_table, 100000);
}
static struct cpufreq_driver exynos_driver = {
.flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = exynos_target,
.get = cpufreq_generic_get,
.init = exynos_cpufreq_cpu_init,
.name = "exynos_cpufreq",
.attr = cpufreq_generic_attr,
#ifdef CONFIG_ARM_EXYNOS_CPU_FREQ_BOOST_SW
.boost_supported = true,
#endif
#ifdef CONFIG_PM
.suspend = cpufreq_generic_suspend,
#endif
};
static int exynos_cpufreq_probe(struct platform_device *pdev)
{
struct device_node *cpu0;
int ret = -EINVAL;
exynos_info = kzalloc(sizeof(*exynos_info), GFP_KERNEL);
if (!exynos_info)
return -ENOMEM;
exynos_info->dev = &pdev->dev;
if (of_machine_is_compatible("samsung,exynos4212")) {
exynos_info->type = EXYNOS_SOC_4212;
ret = exynos4x12_cpufreq_init(exynos_info);
} else if (of_machine_is_compatible("samsung,exynos4412")) {
exynos_info->type = EXYNOS_SOC_4412;
ret = exynos4x12_cpufreq_init(exynos_info);
} else {
pr_err("%s: Unknown SoC type\n", __func__);
return -ENODEV;
}
if (ret)
goto err_vdd_arm;
if (exynos_info->set_freq == NULL) {
dev_err(&pdev->dev, "No set_freq function (ERR)\n");
goto err_vdd_arm;
}
arm_regulator = regulator_get(NULL, "vdd_arm");
if (IS_ERR(arm_regulator)) {
dev_err(&pdev->dev, "failed to get resource vdd_arm\n");
goto err_vdd_arm;
}
/* Done here as we want to capture boot frequency */
locking_frequency = clk_get_rate(exynos_info->cpu_clk) / 1000;
ret = cpufreq_register_driver(&exynos_driver);
if (ret)
goto err_cpufreq_reg;
cpu0 = of_get_cpu_node(0, NULL);
if (!cpu0) {
pr_err("failed to find cpu0 node\n");
return 0;
}
if (of_find_property(cpu0, "#cooling-cells", NULL)) {
cdev = of_cpufreq_cooling_register(cpu0,
cpu_present_mask);
if (IS_ERR(cdev))
pr_err("running cpufreq without cooling device: %ld\n",
PTR_ERR(cdev));
}
return 0;
err_cpufreq_reg:
dev_err(&pdev->dev, "failed to register cpufreq driver\n");
regulator_put(arm_regulator);
err_vdd_arm:
kfree(exynos_info);
return -EINVAL;
}
static struct platform_driver exynos_cpufreq_platdrv = {
.driver = {
.name = "exynos-cpufreq",
},
.probe = exynos_cpufreq_probe,
};
module_platform_driver(exynos_cpufreq_platdrv);
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