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a125a17f JL |
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 | ||
a125a17f JL |
12 | #include <linux/kernel.h> |
13 | #include <linux/err.h> | |
14 | #include <linux/clk.h> | |
15 | #include <linux/io.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/regulator/consumer.h> | |
18 | #include <linux/cpufreq.h> | |
19 | #include <linux/suspend.h> | |
a125a17f | 20 | |
a125a17f JL |
21 | #include <mach/cpufreq.h> |
22 | ||
6c523c61 | 23 | #include <plat/cpu.h> |
a125a17f JL |
24 | |
25 | static struct exynos_dvfs_info *exynos_info; | |
26 | ||
27 | static struct regulator *arm_regulator; | |
28 | static struct cpufreq_freqs freqs; | |
29 | ||
30 | static unsigned int locking_frequency; | |
31 | static bool frequency_locked; | |
32 | static DEFINE_MUTEX(cpufreq_lock); | |
33 | ||
34 | int exynos_verify_speed(struct cpufreq_policy *policy) | |
35 | { | |
36 | return cpufreq_frequency_table_verify(policy, | |
37 | exynos_info->freq_table); | |
38 | } | |
39 | ||
40 | unsigned int exynos_getspeed(unsigned int cpu) | |
41 | { | |
42 | return clk_get_rate(exynos_info->cpu_clk) / 1000; | |
43 | } | |
44 | ||
45 | static int exynos_target(struct cpufreq_policy *policy, | |
46 | unsigned int target_freq, | |
47 | unsigned int relation) | |
48 | { | |
49 | unsigned int index, old_index; | |
50 | unsigned int arm_volt, safe_arm_volt = 0; | |
51 | int ret = 0; | |
52 | struct cpufreq_frequency_table *freq_table = exynos_info->freq_table; | |
53 | unsigned int *volt_table = exynos_info->volt_table; | |
54 | unsigned int mpll_freq_khz = exynos_info->mpll_freq_khz; | |
55 | ||
56 | mutex_lock(&cpufreq_lock); | |
57 | ||
58 | freqs.old = policy->cur; | |
59 | ||
60 | if (frequency_locked && target_freq != locking_frequency) { | |
61 | ret = -EAGAIN; | |
62 | goto out; | |
63 | } | |
64 | ||
53df1ad5 JL |
65 | /* |
66 | * The policy max have been changed so that we cannot get proper | |
67 | * old_index with cpufreq_frequency_table_target(). Thus, ignore | |
68 | * policy and get the index from the raw freqeuncy table. | |
69 | */ | |
70 | for (old_index = 0; | |
71 | freq_table[old_index].frequency != CPUFREQ_TABLE_END; | |
72 | old_index++) | |
73 | if (freq_table[old_index].frequency == freqs.old) | |
74 | break; | |
75 | ||
76 | if (freq_table[old_index].frequency == CPUFREQ_TABLE_END) { | |
a125a17f JL |
77 | ret = -EINVAL; |
78 | goto out; | |
79 | } | |
80 | ||
81 | if (cpufreq_frequency_table_target(policy, freq_table, | |
82 | target_freq, relation, &index)) { | |
83 | ret = -EINVAL; | |
84 | goto out; | |
85 | } | |
86 | ||
87 | freqs.new = freq_table[index].frequency; | |
88 | freqs.cpu = policy->cpu; | |
89 | ||
90 | /* | |
91 | * ARM clock source will be changed APLL to MPLL temporary | |
92 | * To support this level, need to control regulator for | |
93 | * required voltage level | |
94 | */ | |
95 | if (exynos_info->need_apll_change != NULL) { | |
96 | if (exynos_info->need_apll_change(old_index, index) && | |
97 | (freq_table[index].frequency < mpll_freq_khz) && | |
98 | (freq_table[old_index].frequency < mpll_freq_khz)) | |
99 | safe_arm_volt = volt_table[exynos_info->pll_safe_idx]; | |
100 | } | |
101 | arm_volt = volt_table[index]; | |
102 | ||
103 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
104 | ||
105 | /* When the new frequency is higher than current frequency */ | |
106 | if ((freqs.new > freqs.old) && !safe_arm_volt) { | |
107 | /* Firstly, voltage up to increase frequency */ | |
108 | regulator_set_voltage(arm_regulator, arm_volt, | |
109 | arm_volt); | |
110 | } | |
111 | ||
112 | if (safe_arm_volt) | |
113 | regulator_set_voltage(arm_regulator, safe_arm_volt, | |
114 | safe_arm_volt); | |
115 | if (freqs.new != freqs.old) | |
116 | exynos_info->set_freq(old_index, index); | |
117 | ||
118 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
119 | ||
120 | /* When the new frequency is lower than current frequency */ | |
121 | if ((freqs.new < freqs.old) || | |
122 | ((freqs.new > freqs.old) && safe_arm_volt)) { | |
123 | /* down the voltage after frequency change */ | |
124 | regulator_set_voltage(arm_regulator, arm_volt, | |
125 | arm_volt); | |
126 | } | |
127 | ||
128 | out: | |
129 | mutex_unlock(&cpufreq_lock); | |
130 | ||
131 | return ret; | |
132 | } | |
133 | ||
134 | #ifdef CONFIG_PM | |
135 | static int exynos_cpufreq_suspend(struct cpufreq_policy *policy) | |
136 | { | |
137 | return 0; | |
138 | } | |
139 | ||
140 | static int exynos_cpufreq_resume(struct cpufreq_policy *policy) | |
141 | { | |
142 | return 0; | |
143 | } | |
144 | #endif | |
145 | ||
146 | /** | |
147 | * exynos_cpufreq_pm_notifier - block CPUFREQ's activities in suspend-resume | |
148 | * context | |
149 | * @notifier | |
150 | * @pm_event | |
151 | * @v | |
152 | * | |
153 | * While frequency_locked == true, target() ignores every frequency but | |
154 | * locking_frequency. The locking_frequency value is the initial frequency, | |
155 | * which is set by the bootloader. In order to eliminate possible | |
156 | * inconsistency in clock values, we save and restore frequencies during | |
157 | * suspend and resume and block CPUFREQ activities. Note that the standard | |
158 | * suspend/resume cannot be used as they are too deep (syscore_ops) for | |
159 | * regulator actions. | |
160 | */ | |
161 | static int exynos_cpufreq_pm_notifier(struct notifier_block *notifier, | |
162 | unsigned long pm_event, void *v) | |
163 | { | |
164 | struct cpufreq_policy *policy = cpufreq_cpu_get(0); /* boot CPU */ | |
165 | static unsigned int saved_frequency; | |
166 | unsigned int temp; | |
167 | ||
168 | mutex_lock(&cpufreq_lock); | |
169 | switch (pm_event) { | |
170 | case PM_SUSPEND_PREPARE: | |
171 | if (frequency_locked) | |
172 | goto out; | |
173 | ||
174 | frequency_locked = true; | |
175 | ||
176 | if (locking_frequency) { | |
177 | saved_frequency = exynos_getspeed(0); | |
178 | ||
179 | mutex_unlock(&cpufreq_lock); | |
180 | exynos_target(policy, locking_frequency, | |
181 | CPUFREQ_RELATION_H); | |
182 | mutex_lock(&cpufreq_lock); | |
183 | } | |
184 | break; | |
185 | ||
186 | case PM_POST_SUSPEND: | |
187 | if (saved_frequency) { | |
188 | /* | |
189 | * While frequency_locked, only locking_frequency | |
190 | * is valid for target(). In order to use | |
191 | * saved_frequency while keeping frequency_locked, | |
192 | * we temporarly overwrite locking_frequency. | |
193 | */ | |
194 | temp = locking_frequency; | |
195 | locking_frequency = saved_frequency; | |
196 | ||
197 | mutex_unlock(&cpufreq_lock); | |
198 | exynos_target(policy, locking_frequency, | |
199 | CPUFREQ_RELATION_H); | |
200 | mutex_lock(&cpufreq_lock); | |
201 | ||
202 | locking_frequency = temp; | |
203 | } | |
204 | frequency_locked = false; | |
205 | break; | |
206 | } | |
207 | out: | |
208 | mutex_unlock(&cpufreq_lock); | |
209 | ||
210 | return NOTIFY_OK; | |
211 | } | |
212 | ||
213 | static struct notifier_block exynos_cpufreq_nb = { | |
214 | .notifier_call = exynos_cpufreq_pm_notifier, | |
215 | }; | |
216 | ||
217 | static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy) | |
218 | { | |
219 | policy->cur = policy->min = policy->max = exynos_getspeed(policy->cpu); | |
220 | ||
221 | cpufreq_frequency_table_get_attr(exynos_info->freq_table, policy->cpu); | |
222 | ||
60d2725d TB |
223 | locking_frequency = exynos_getspeed(0); |
224 | ||
a125a17f JL |
225 | /* set the transition latency value */ |
226 | policy->cpuinfo.transition_latency = 100000; | |
227 | ||
228 | /* | |
229 | * EXYNOS4 multi-core processors has 2 cores | |
230 | * that the frequency cannot be set independently. | |
231 | * Each cpu is bound to the same speed. | |
232 | * So the affected cpu is all of the cpus. | |
233 | */ | |
234 | if (num_online_cpus() == 1) { | |
235 | cpumask_copy(policy->related_cpus, cpu_possible_mask); | |
236 | cpumask_copy(policy->cpus, cpu_online_mask); | |
237 | } else { | |
238 | cpumask_setall(policy->cpus); | |
239 | } | |
240 | ||
241 | return cpufreq_frequency_table_cpuinfo(policy, exynos_info->freq_table); | |
242 | } | |
243 | ||
244 | static struct cpufreq_driver exynos_driver = { | |
245 | .flags = CPUFREQ_STICKY, | |
246 | .verify = exynos_verify_speed, | |
247 | .target = exynos_target, | |
248 | .get = exynos_getspeed, | |
249 | .init = exynos_cpufreq_cpu_init, | |
250 | .name = "exynos_cpufreq", | |
251 | #ifdef CONFIG_PM | |
252 | .suspend = exynos_cpufreq_suspend, | |
253 | .resume = exynos_cpufreq_resume, | |
254 | #endif | |
255 | }; | |
256 | ||
257 | static int __init exynos_cpufreq_init(void) | |
258 | { | |
259 | int ret = -EINVAL; | |
260 | ||
261 | exynos_info = kzalloc(sizeof(struct exynos_dvfs_info), GFP_KERNEL); | |
262 | if (!exynos_info) | |
263 | return -ENOMEM; | |
264 | ||
265 | if (soc_is_exynos4210()) | |
266 | ret = exynos4210_cpufreq_init(exynos_info); | |
a35c5051 JL |
267 | else if (soc_is_exynos4212() || soc_is_exynos4412()) |
268 | ret = exynos4x12_cpufreq_init(exynos_info); | |
562a6cbe JL |
269 | else if (soc_is_exynos5250()) |
270 | ret = exynos5250_cpufreq_init(exynos_info); | |
a125a17f JL |
271 | else |
272 | pr_err("%s: CPU type not found\n", __func__); | |
273 | ||
274 | if (ret) | |
275 | goto err_vdd_arm; | |
276 | ||
277 | if (exynos_info->set_freq == NULL) { | |
278 | pr_err("%s: No set_freq function (ERR)\n", __func__); | |
279 | goto err_vdd_arm; | |
280 | } | |
281 | ||
282 | arm_regulator = regulator_get(NULL, "vdd_arm"); | |
283 | if (IS_ERR(arm_regulator)) { | |
284 | pr_err("%s: failed to get resource vdd_arm\n", __func__); | |
285 | goto err_vdd_arm; | |
286 | } | |
287 | ||
288 | register_pm_notifier(&exynos_cpufreq_nb); | |
289 | ||
290 | if (cpufreq_register_driver(&exynos_driver)) { | |
291 | pr_err("%s: failed to register cpufreq driver\n", __func__); | |
292 | goto err_cpufreq; | |
293 | } | |
294 | ||
295 | return 0; | |
296 | err_cpufreq: | |
297 | unregister_pm_notifier(&exynos_cpufreq_nb); | |
298 | ||
299 | if (!IS_ERR(arm_regulator)) | |
300 | regulator_put(arm_regulator); | |
301 | err_vdd_arm: | |
302 | kfree(exynos_info); | |
303 | pr_debug("%s: failed initialization\n", __func__); | |
304 | return -EINVAL; | |
305 | } | |
306 | late_initcall(exynos_cpufreq_init); |