2 * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
3 * http://www.samsung.com
5 * EXYNOS - CPU frequency scaling support for EXYNOS series
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/kernel.h>
13 #include <linux/err.h>
14 #include <linux/clk.h>
16 #include <linux/slab.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/cpufreq.h>
19 #include <linux/platform_device.h>
22 #include "exynos-cpufreq.h"
24 static struct exynos_dvfs_info *exynos_info;
25 static struct regulator *arm_regulator;
26 static unsigned int locking_frequency;
28 static int exynos_cpufreq_get_index(unsigned int freq)
30 struct cpufreq_frequency_table *freq_table = exynos_info->freq_table;
34 freq_table[index].frequency != CPUFREQ_TABLE_END; index++)
35 if (freq_table[index].frequency == freq)
38 if (freq_table[index].frequency == CPUFREQ_TABLE_END)
44 static int exynos_cpufreq_scale(unsigned int target_freq)
46 struct cpufreq_frequency_table *freq_table = exynos_info->freq_table;
47 unsigned int *volt_table = exynos_info->volt_table;
48 struct cpufreq_policy *policy = cpufreq_cpu_get(0);
49 unsigned int arm_volt, safe_arm_volt = 0;
50 unsigned int mpll_freq_khz = exynos_info->mpll_freq_khz;
51 unsigned int old_freq;
55 old_freq = policy->cur;
58 * The policy max have been changed so that we cannot get proper
59 * old_index with cpufreq_frequency_table_target(). Thus, ignore
60 * policy and get the index from the raw frequency table.
62 old_index = exynos_cpufreq_get_index(old_freq);
68 index = exynos_cpufreq_get_index(target_freq);
75 * ARM clock source will be changed APLL to MPLL temporary
76 * To support this level, need to control regulator for
77 * required voltage level
79 if (exynos_info->need_apll_change != NULL) {
80 if (exynos_info->need_apll_change(old_index, index) &&
81 (freq_table[index].frequency < mpll_freq_khz) &&
82 (freq_table[old_index].frequency < mpll_freq_khz))
83 safe_arm_volt = volt_table[exynos_info->pll_safe_idx];
85 arm_volt = volt_table[index];
87 /* When the new frequency is higher than current frequency */
88 if ((target_freq > old_freq) && !safe_arm_volt) {
89 /* Firstly, voltage up to increase frequency */
90 ret = regulator_set_voltage(arm_regulator, arm_volt, arm_volt);
92 pr_err("%s: failed to set cpu voltage to %d\n",
99 ret = regulator_set_voltage(arm_regulator, safe_arm_volt,
102 pr_err("%s: failed to set cpu voltage to %d\n",
103 __func__, safe_arm_volt);
108 exynos_info->set_freq(old_index, index);
110 /* When the new frequency is lower than current frequency */
111 if ((target_freq < old_freq) ||
112 ((target_freq > old_freq) && safe_arm_volt)) {
113 /* down the voltage after frequency change */
114 ret = regulator_set_voltage(arm_regulator, arm_volt,
117 pr_err("%s: failed to set cpu voltage to %d\n",
124 cpufreq_cpu_put(policy);
129 static int exynos_target(struct cpufreq_policy *policy, unsigned int index)
131 return exynos_cpufreq_scale(exynos_info->freq_table[index].frequency);
134 static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
136 policy->clk = exynos_info->cpu_clk;
137 policy->suspend_freq = locking_frequency;
138 return cpufreq_generic_init(policy, exynos_info->freq_table, 100000);
141 static struct cpufreq_driver exynos_driver = {
142 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
143 .verify = cpufreq_generic_frequency_table_verify,
144 .target_index = exynos_target,
145 .get = cpufreq_generic_get,
146 .init = exynos_cpufreq_cpu_init,
147 .name = "exynos_cpufreq",
148 .attr = cpufreq_generic_attr,
149 #ifdef CONFIG_ARM_EXYNOS_CPU_FREQ_BOOST_SW
150 .boost_supported = true,
153 .suspend = cpufreq_generic_suspend,
157 static int exynos_cpufreq_probe(struct platform_device *pdev)
161 exynos_info = kzalloc(sizeof(*exynos_info), GFP_KERNEL);
165 if (of_machine_is_compatible("samsung,exynos4210")) {
166 exynos_info->type = EXYNOS_SOC_4210;
167 ret = exynos4210_cpufreq_init(exynos_info);
168 } else if (of_machine_is_compatible("samsung,exynos4212")) {
169 exynos_info->type = EXYNOS_SOC_4212;
170 ret = exynos4x12_cpufreq_init(exynos_info);
171 } else if (of_machine_is_compatible("samsung,exynos4412")) {
172 exynos_info->type = EXYNOS_SOC_4412;
173 ret = exynos4x12_cpufreq_init(exynos_info);
174 } else if (of_machine_is_compatible("samsung,exynos5250")) {
175 exynos_info->type = EXYNOS_SOC_5250;
176 ret = exynos5250_cpufreq_init(exynos_info);
178 pr_err("%s: Unknown SoC type\n", __func__);
185 if (exynos_info->set_freq == NULL) {
186 pr_err("%s: No set_freq function (ERR)\n", __func__);
190 arm_regulator = regulator_get(NULL, "vdd_arm");
191 if (IS_ERR(arm_regulator)) {
192 pr_err("%s: failed to get resource vdd_arm\n", __func__);
196 /* Done here as we want to capture boot frequency */
197 locking_frequency = clk_get_rate(exynos_info->cpu_clk) / 1000;
199 if (!cpufreq_register_driver(&exynos_driver))
202 pr_err("%s: failed to register cpufreq driver\n", __func__);
203 regulator_put(arm_regulator);
209 static struct platform_driver exynos_cpufreq_platdrv = {
211 .name = "exynos-cpufreq",
212 .owner = THIS_MODULE,
214 .probe = exynos_cpufreq_probe,
216 module_platform_driver(exynos_cpufreq_platdrv);