249 lines
6.5 KiB
C
249 lines
6.5 KiB
C
/*
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* Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
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* http://www.samsung.com
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*
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* EXYNOS - CPU frequency scaling support for EXYNOS series
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/err.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#include <linux/regulator/consumer.h>
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#include <linux/cpufreq.h>
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#include <linux/platform_device.h>
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#include <linux/of.h>
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#include <linux/cpu_cooling.h>
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#include <linux/cpu.h>
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#include "exynos-cpufreq.h"
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static struct exynos_dvfs_info *exynos_info;
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static struct thermal_cooling_device *cdev;
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static struct regulator *arm_regulator;
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static unsigned int locking_frequency;
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static int exynos_cpufreq_get_index(unsigned int freq)
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{
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struct cpufreq_frequency_table *freq_table = exynos_info->freq_table;
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struct cpufreq_frequency_table *pos;
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cpufreq_for_each_entry(pos, freq_table)
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if (pos->frequency == freq)
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break;
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if (pos->frequency == CPUFREQ_TABLE_END)
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return -EINVAL;
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return pos - freq_table;
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}
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static int exynos_cpufreq_scale(unsigned int target_freq)
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{
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struct cpufreq_frequency_table *freq_table = exynos_info->freq_table;
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unsigned int *volt_table = exynos_info->volt_table;
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struct cpufreq_policy *policy = cpufreq_cpu_get(0);
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unsigned int arm_volt, safe_arm_volt = 0;
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unsigned int mpll_freq_khz = exynos_info->mpll_freq_khz;
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struct device *dev = exynos_info->dev;
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unsigned int old_freq;
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int index, old_index;
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int ret = 0;
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old_freq = policy->cur;
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/*
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* The policy max have been changed so that we cannot get proper
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* old_index with cpufreq_frequency_table_target(). Thus, ignore
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* policy and get the index from the raw frequency table.
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*/
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old_index = exynos_cpufreq_get_index(old_freq);
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if (old_index < 0) {
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ret = old_index;
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goto out;
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}
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index = exynos_cpufreq_get_index(target_freq);
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if (index < 0) {
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ret = index;
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goto out;
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}
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/*
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* ARM clock source will be changed APLL to MPLL temporary
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* To support this level, need to control regulator for
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* required voltage level
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*/
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if (exynos_info->need_apll_change != NULL) {
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if (exynos_info->need_apll_change(old_index, index) &&
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(freq_table[index].frequency < mpll_freq_khz) &&
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(freq_table[old_index].frequency < mpll_freq_khz))
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safe_arm_volt = volt_table[exynos_info->pll_safe_idx];
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}
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arm_volt = volt_table[index];
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/* When the new frequency is higher than current frequency */
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if ((target_freq > old_freq) && !safe_arm_volt) {
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/* Firstly, voltage up to increase frequency */
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ret = regulator_set_voltage(arm_regulator, arm_volt, arm_volt);
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if (ret) {
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dev_err(dev, "failed to set cpu voltage to %d\n",
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arm_volt);
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return ret;
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}
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}
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if (safe_arm_volt) {
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ret = regulator_set_voltage(arm_regulator, safe_arm_volt,
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safe_arm_volt);
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if (ret) {
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dev_err(dev, "failed to set cpu voltage to %d\n",
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safe_arm_volt);
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return ret;
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}
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}
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exynos_info->set_freq(old_index, index);
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/* When the new frequency is lower than current frequency */
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if ((target_freq < old_freq) ||
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((target_freq > old_freq) && safe_arm_volt)) {
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/* down the voltage after frequency change */
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ret = regulator_set_voltage(arm_regulator, arm_volt,
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arm_volt);
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if (ret) {
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dev_err(dev, "failed to set cpu voltage to %d\n",
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arm_volt);
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goto out;
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}
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}
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out:
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cpufreq_cpu_put(policy);
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return ret;
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}
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static int exynos_target(struct cpufreq_policy *policy, unsigned int index)
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{
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return exynos_cpufreq_scale(exynos_info->freq_table[index].frequency);
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}
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static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
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{
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policy->clk = exynos_info->cpu_clk;
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policy->suspend_freq = locking_frequency;
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return cpufreq_generic_init(policy, exynos_info->freq_table, 100000);
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}
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static struct cpufreq_driver exynos_driver = {
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.flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
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.verify = cpufreq_generic_frequency_table_verify,
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.target_index = exynos_target,
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.get = cpufreq_generic_get,
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.init = exynos_cpufreq_cpu_init,
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.name = "exynos_cpufreq",
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.attr = cpufreq_generic_attr,
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#ifdef CONFIG_ARM_EXYNOS_CPU_FREQ_BOOST_SW
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.boost_supported = true,
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#endif
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#ifdef CONFIG_PM
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.suspend = cpufreq_generic_suspend,
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#endif
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};
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static int exynos_cpufreq_probe(struct platform_device *pdev)
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{
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struct device_node *cpus, *np;
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int ret = -EINVAL;
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exynos_info = kzalloc(sizeof(*exynos_info), GFP_KERNEL);
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if (!exynos_info)
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return -ENOMEM;
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exynos_info->dev = &pdev->dev;
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if (of_machine_is_compatible("samsung,exynos4210")) {
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exynos_info->type = EXYNOS_SOC_4210;
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ret = exynos4210_cpufreq_init(exynos_info);
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} else if (of_machine_is_compatible("samsung,exynos4212")) {
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exynos_info->type = EXYNOS_SOC_4212;
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ret = exynos4x12_cpufreq_init(exynos_info);
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} else if (of_machine_is_compatible("samsung,exynos4412")) {
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exynos_info->type = EXYNOS_SOC_4412;
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ret = exynos4x12_cpufreq_init(exynos_info);
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} else if (of_machine_is_compatible("samsung,exynos5250")) {
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exynos_info->type = EXYNOS_SOC_5250;
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ret = exynos5250_cpufreq_init(exynos_info);
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} else {
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pr_err("%s: Unknown SoC type\n", __func__);
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return -ENODEV;
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}
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if (ret)
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goto err_vdd_arm;
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if (exynos_info->set_freq == NULL) {
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dev_err(&pdev->dev, "No set_freq function (ERR)\n");
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goto err_vdd_arm;
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}
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arm_regulator = regulator_get(NULL, "vdd_arm");
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if (IS_ERR(arm_regulator)) {
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dev_err(&pdev->dev, "failed to get resource vdd_arm\n");
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goto err_vdd_arm;
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}
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/* Done here as we want to capture boot frequency */
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locking_frequency = clk_get_rate(exynos_info->cpu_clk) / 1000;
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ret = cpufreq_register_driver(&exynos_driver);
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if (ret)
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goto err_cpufreq_reg;
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cpus = of_find_node_by_path("/cpus");
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if (!cpus) {
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pr_err("failed to find cpus node\n");
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return 0;
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}
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np = of_get_next_child(cpus, NULL);
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if (!np) {
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pr_err("failed to find cpus child node\n");
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of_node_put(cpus);
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return 0;
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}
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if (of_find_property(np, "#cooling-cells", NULL)) {
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cdev = of_cpufreq_cooling_register(np,
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cpu_present_mask);
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if (IS_ERR(cdev))
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pr_err("running cpufreq without cooling device: %ld\n",
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PTR_ERR(cdev));
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}
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of_node_put(np);
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of_node_put(cpus);
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return 0;
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err_cpufreq_reg:
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dev_err(&pdev->dev, "failed to register cpufreq driver\n");
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regulator_put(arm_regulator);
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err_vdd_arm:
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kfree(exynos_info);
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return -EINVAL;
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}
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static struct platform_driver exynos_cpufreq_platdrv = {
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.driver = {
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.name = "exynos-cpufreq",
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},
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.probe = exynos_cpufreq_probe,
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};
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module_platform_driver(exynos_cpufreq_platdrv);
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