Version:  2.0.40 2.2.26 2.4.37 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2

Linux/drivers/cpufreq/exynos-cpufreq.c

  1 /*
  2  * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
  3  *              http://www.samsung.com
  4  *
  5  * EXYNOS - CPU frequency scaling support for EXYNOS series
  6  *
  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.
 10 */
 11 
 12 #include <linux/kernel.h>
 13 #include <linux/module.h>
 14 #include <linux/err.h>
 15 #include <linux/clk.h>
 16 #include <linux/io.h>
 17 #include <linux/slab.h>
 18 #include <linux/regulator/consumer.h>
 19 #include <linux/cpufreq.h>
 20 #include <linux/platform_device.h>
 21 #include <linux/of.h>
 22 #include <linux/cpu_cooling.h>
 23 #include <linux/cpu.h>
 24 
 25 #include "exynos-cpufreq.h"
 26 
 27 static struct exynos_dvfs_info *exynos_info;
 28 static struct thermal_cooling_device *cdev;
 29 static struct regulator *arm_regulator;
 30 static unsigned int locking_frequency;
 31 
 32 static int exynos_cpufreq_get_index(unsigned int freq)
 33 {
 34         struct cpufreq_frequency_table *freq_table = exynos_info->freq_table;
 35         struct cpufreq_frequency_table *pos;
 36 
 37         cpufreq_for_each_entry(pos, freq_table)
 38                 if (pos->frequency == freq)
 39                         break;
 40 
 41         if (pos->frequency == CPUFREQ_TABLE_END)
 42                 return -EINVAL;
 43 
 44         return pos - freq_table;
 45 }
 46 
 47 static int exynos_cpufreq_scale(unsigned int target_freq)
 48 {
 49         struct cpufreq_frequency_table *freq_table = exynos_info->freq_table;
 50         unsigned int *volt_table = exynos_info->volt_table;
 51         struct cpufreq_policy *policy = cpufreq_cpu_get(0);
 52         unsigned int arm_volt, safe_arm_volt = 0;
 53         unsigned int mpll_freq_khz = exynos_info->mpll_freq_khz;
 54         struct device *dev = exynos_info->dev;
 55         unsigned int old_freq;
 56         int index, old_index;
 57         int ret = 0;
 58 
 59         old_freq = policy->cur;
 60 
 61         /*
 62          * The policy max have been changed so that we cannot get proper
 63          * old_index with cpufreq_frequency_table_target(). Thus, ignore
 64          * policy and get the index from the raw frequency table.
 65          */
 66         old_index = exynos_cpufreq_get_index(old_freq);
 67         if (old_index < 0) {
 68                 ret = old_index;
 69                 goto out;
 70         }
 71 
 72         index = exynos_cpufreq_get_index(target_freq);
 73         if (index < 0) {
 74                 ret = index;
 75                 goto out;
 76         }
 77 
 78         /*
 79          * ARM clock source will be changed APLL to MPLL temporary
 80          * To support this level, need to control regulator for
 81          * required voltage level
 82          */
 83         if (exynos_info->need_apll_change != NULL) {
 84                 if (exynos_info->need_apll_change(old_index, index) &&
 85                    (freq_table[index].frequency < mpll_freq_khz) &&
 86                    (freq_table[old_index].frequency < mpll_freq_khz))
 87                         safe_arm_volt = volt_table[exynos_info->pll_safe_idx];
 88         }
 89         arm_volt = volt_table[index];
 90 
 91         /* When the new frequency is higher than current frequency */
 92         if ((target_freq > old_freq) && !safe_arm_volt) {
 93                 /* Firstly, voltage up to increase frequency */
 94                 ret = regulator_set_voltage(arm_regulator, arm_volt, arm_volt);
 95                 if (ret) {
 96                         dev_err(dev, "failed to set cpu voltage to %d\n",
 97                                 arm_volt);
 98                         return ret;
 99                 }
100         }
101 
102         if (safe_arm_volt) {
103                 ret = regulator_set_voltage(arm_regulator, safe_arm_volt,
104                                       safe_arm_volt);
105                 if (ret) {
106                         dev_err(dev, "failed to set cpu voltage to %d\n",
107                                 safe_arm_volt);
108                         return ret;
109                 }
110         }
111 
112         exynos_info->set_freq(old_index, index);
113 
114         /* When the new frequency is lower than current frequency */
115         if ((target_freq < old_freq) ||
116            ((target_freq > old_freq) && safe_arm_volt)) {
117                 /* down the voltage after frequency change */
118                 ret = regulator_set_voltage(arm_regulator, arm_volt,
119                                 arm_volt);
120                 if (ret) {
121                         dev_err(dev, "failed to set cpu voltage to %d\n",
122                                 arm_volt);
123                         goto out;
124                 }
125         }
126 
127 out:
128         cpufreq_cpu_put(policy);
129 
130         return ret;
131 }
132 
133 static int exynos_target(struct cpufreq_policy *policy, unsigned int index)
134 {
135         return exynos_cpufreq_scale(exynos_info->freq_table[index].frequency);
136 }
137 
138 static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
139 {
140         policy->clk = exynos_info->cpu_clk;
141         policy->suspend_freq = locking_frequency;
142         return cpufreq_generic_init(policy, exynos_info->freq_table, 100000);
143 }
144 
145 static struct cpufreq_driver exynos_driver = {
146         .flags          = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
147         .verify         = cpufreq_generic_frequency_table_verify,
148         .target_index   = exynos_target,
149         .get            = cpufreq_generic_get,
150         .init           = exynos_cpufreq_cpu_init,
151         .name           = "exynos_cpufreq",
152         .attr           = cpufreq_generic_attr,
153 #ifdef CONFIG_ARM_EXYNOS_CPU_FREQ_BOOST_SW
154         .boost_supported = true,
155 #endif
156 #ifdef CONFIG_PM
157         .suspend        = cpufreq_generic_suspend,
158 #endif
159 };
160 
161 static int exynos_cpufreq_probe(struct platform_device *pdev)
162 {
163         struct device_node *cpu0;
164         int ret = -EINVAL;
165 
166         exynos_info = kzalloc(sizeof(*exynos_info), GFP_KERNEL);
167         if (!exynos_info)
168                 return -ENOMEM;
169 
170         exynos_info->dev = &pdev->dev;
171 
172         if (of_machine_is_compatible("samsung,exynos4212")) {
173                 exynos_info->type = EXYNOS_SOC_4212;
174                 ret = exynos4x12_cpufreq_init(exynos_info);
175         } else if (of_machine_is_compatible("samsung,exynos4412")) {
176                 exynos_info->type = EXYNOS_SOC_4412;
177                 ret = exynos4x12_cpufreq_init(exynos_info);
178         } else if (of_machine_is_compatible("samsung,exynos5250")) {
179                 exynos_info->type = EXYNOS_SOC_5250;
180                 ret = exynos5250_cpufreq_init(exynos_info);
181         } else {
182                 pr_err("%s: Unknown SoC type\n", __func__);
183                 ret = -ENODEV;
184         }
185 
186         if (ret)
187                 goto err_vdd_arm;
188 
189         if (exynos_info->set_freq == NULL) {
190                 dev_err(&pdev->dev, "No set_freq function (ERR)\n");
191                 ret = -EINVAL;
192                 goto err_vdd_arm;
193         }
194 
195         arm_regulator = regulator_get(NULL, "vdd_arm");
196         if (IS_ERR(arm_regulator)) {
197                 dev_err(&pdev->dev, "failed to get resource vdd_arm\n");
198                 ret = -EINVAL;
199                 goto err_vdd_arm;
200         }
201 
202         /* Done here as we want to capture boot frequency */
203         locking_frequency = clk_get_rate(exynos_info->cpu_clk) / 1000;
204 
205         ret = cpufreq_register_driver(&exynos_driver);
206         if (ret)
207                 goto err_cpufreq_reg;
208 
209         cpu0 = of_get_cpu_node(0, NULL);
210         if (!cpu0) {
211                 pr_err("failed to find cpu0 node\n");
212                 return 0;
213         }
214 
215         if (of_find_property(cpu0, "#cooling-cells", NULL)) {
216                 cdev = of_cpufreq_cooling_register(cpu0,
217                                                    cpu_present_mask);
218                 if (IS_ERR(cdev))
219                         pr_err("running cpufreq without cooling device: %ld\n",
220                                PTR_ERR(cdev));
221         }
222 
223         return 0;
224 
225 err_cpufreq_reg:
226         dev_err(&pdev->dev, "failed to register cpufreq driver\n");
227         regulator_put(arm_regulator);
228 err_vdd_arm:
229         kfree(exynos_info);
230         return ret;
231 }
232 
233 static struct platform_driver exynos_cpufreq_platdrv = {
234         .driver = {
235                 .name   = "exynos-cpufreq",
236         },
237         .probe = exynos_cpufreq_probe,
238 };
239 module_platform_driver(exynos_cpufreq_platdrv);
240 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us