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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 | |
6c523c61 | 21 | #include <plat/cpu.h> |
a125a17f | 22 | |
c4aaa295 KK |
23 | #include "exynos-cpufreq.h" |
24 | ||
a125a17f JL |
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 | ||
5542721a | 34 | static unsigned int exynos_getspeed(unsigned int cpu) |
a125a17f JL |
35 | { |
36 | return clk_get_rate(exynos_info->cpu_clk) / 1000; | |
37 | } | |
38 | ||
0e0e425f JC |
39 | static int exynos_cpufreq_get_index(unsigned int freq) |
40 | { | |
41 | struct cpufreq_frequency_table *freq_table = exynos_info->freq_table; | |
42 | int index; | |
43 | ||
44 | for (index = 0; | |
45 | freq_table[index].frequency != CPUFREQ_TABLE_END; index++) | |
46 | if (freq_table[index].frequency == freq) | |
47 | break; | |
48 | ||
49 | if (freq_table[index].frequency == CPUFREQ_TABLE_END) | |
50 | return -EINVAL; | |
51 | ||
52 | return index; | |
53 | } | |
54 | ||
55 | static int exynos_cpufreq_scale(unsigned int target_freq) | |
a125a17f | 56 | { |
a125a17f JL |
57 | struct cpufreq_frequency_table *freq_table = exynos_info->freq_table; |
58 | unsigned int *volt_table = exynos_info->volt_table; | |
0e0e425f JC |
59 | struct cpufreq_policy *policy = cpufreq_cpu_get(0); |
60 | unsigned int arm_volt, safe_arm_volt = 0; | |
a125a17f | 61 | unsigned int mpll_freq_khz = exynos_info->mpll_freq_khz; |
d271d077 | 62 | int index, old_index; |
0e0e425f | 63 | int ret = 0; |
a125a17f JL |
64 | |
65 | freqs.old = policy->cur; | |
c098ea74 | 66 | freqs.new = target_freq; |
a125a17f | 67 | |
c098ea74 | 68 | if (freqs.new == freqs.old) |
a125a17f | 69 | goto out; |
a125a17f | 70 | |
53df1ad5 JL |
71 | /* |
72 | * The policy max have been changed so that we cannot get proper | |
73 | * old_index with cpufreq_frequency_table_target(). Thus, ignore | |
74 | * policy and get the index from the raw freqeuncy table. | |
75 | */ | |
0e0e425f JC |
76 | old_index = exynos_cpufreq_get_index(freqs.old); |
77 | if (old_index < 0) { | |
78 | ret = old_index; | |
a125a17f JL |
79 | goto out; |
80 | } | |
81 | ||
0e0e425f JC |
82 | index = exynos_cpufreq_get_index(target_freq); |
83 | if (index < 0) { | |
84 | ret = index; | |
a125a17f JL |
85 | goto out; |
86 | } | |
87 | ||
a125a17f JL |
88 | /* |
89 | * ARM clock source will be changed APLL to MPLL temporary | |
90 | * To support this level, need to control regulator for | |
91 | * required voltage level | |
92 | */ | |
93 | if (exynos_info->need_apll_change != NULL) { | |
94 | if (exynos_info->need_apll_change(old_index, index) && | |
95 | (freq_table[index].frequency < mpll_freq_khz) && | |
96 | (freq_table[old_index].frequency < mpll_freq_khz)) | |
97 | safe_arm_volt = volt_table[exynos_info->pll_safe_idx]; | |
98 | } | |
99 | arm_volt = volt_table[index]; | |
100 | ||
b43a7ffb | 101 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); |
a125a17f JL |
102 | |
103 | /* When the new frequency is higher than current frequency */ | |
104 | if ((freqs.new > freqs.old) && !safe_arm_volt) { | |
105 | /* Firstly, voltage up to increase frequency */ | |
0e0e425f JC |
106 | ret = regulator_set_voltage(arm_regulator, arm_volt, arm_volt); |
107 | if (ret) { | |
108 | pr_err("%s: failed to set cpu voltage to %d\n", | |
109 | __func__, arm_volt); | |
c3aca6b1 VK |
110 | freqs.new = freqs.old; |
111 | goto post_notify; | |
0e0e425f | 112 | } |
a125a17f JL |
113 | } |
114 | ||
0e0e425f JC |
115 | if (safe_arm_volt) { |
116 | ret = regulator_set_voltage(arm_regulator, safe_arm_volt, | |
a125a17f | 117 | safe_arm_volt); |
0e0e425f JC |
118 | if (ret) { |
119 | pr_err("%s: failed to set cpu voltage to %d\n", | |
120 | __func__, safe_arm_volt); | |
c3aca6b1 VK |
121 | freqs.new = freqs.old; |
122 | goto post_notify; | |
0e0e425f JC |
123 | } |
124 | } | |
857d90f7 JC |
125 | |
126 | exynos_info->set_freq(old_index, index); | |
a125a17f | 127 | |
c3aca6b1 | 128 | post_notify: |
b43a7ffb | 129 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); |
a125a17f | 130 | |
c3aca6b1 VK |
131 | if (ret) |
132 | goto out; | |
133 | ||
a125a17f JL |
134 | /* When the new frequency is lower than current frequency */ |
135 | if ((freqs.new < freqs.old) || | |
136 | ((freqs.new > freqs.old) && safe_arm_volt)) { | |
137 | /* down the voltage after frequency change */ | |
138 | regulator_set_voltage(arm_regulator, arm_volt, | |
139 | arm_volt); | |
0e0e425f JC |
140 | if (ret) { |
141 | pr_err("%s: failed to set cpu voltage to %d\n", | |
142 | __func__, arm_volt); | |
143 | goto out; | |
144 | } | |
a125a17f JL |
145 | } |
146 | ||
0e0e425f JC |
147 | out: |
148 | ||
149 | cpufreq_cpu_put(policy); | |
150 | ||
151 | return ret; | |
152 | } | |
153 | ||
154 | static int exynos_target(struct cpufreq_policy *policy, | |
155 | unsigned int target_freq, | |
156 | unsigned int relation) | |
157 | { | |
158 | struct cpufreq_frequency_table *freq_table = exynos_info->freq_table; | |
159 | unsigned int index; | |
c098ea74 | 160 | unsigned int new_freq; |
229b21e2 | 161 | int ret = 0; |
0e0e425f JC |
162 | |
163 | mutex_lock(&cpufreq_lock); | |
164 | ||
165 | if (frequency_locked) | |
166 | goto out; | |
167 | ||
168 | if (cpufreq_frequency_table_target(policy, freq_table, | |
169 | target_freq, relation, &index)) { | |
170 | ret = -EINVAL; | |
171 | goto out; | |
a125a17f JL |
172 | } |
173 | ||
c098ea74 | 174 | new_freq = freq_table[index].frequency; |
0e0e425f | 175 | |
c098ea74 | 176 | ret = exynos_cpufreq_scale(new_freq); |
0e0e425f | 177 | |
a125a17f JL |
178 | out: |
179 | mutex_unlock(&cpufreq_lock); | |
180 | ||
181 | return ret; | |
182 | } | |
183 | ||
184 | #ifdef CONFIG_PM | |
185 | static int exynos_cpufreq_suspend(struct cpufreq_policy *policy) | |
186 | { | |
187 | return 0; | |
188 | } | |
189 | ||
190 | static int exynos_cpufreq_resume(struct cpufreq_policy *policy) | |
191 | { | |
192 | return 0; | |
193 | } | |
194 | #endif | |
195 | ||
196 | /** | |
197 | * exynos_cpufreq_pm_notifier - block CPUFREQ's activities in suspend-resume | |
198 | * context | |
199 | * @notifier | |
200 | * @pm_event | |
201 | * @v | |
202 | * | |
203 | * While frequency_locked == true, target() ignores every frequency but | |
204 | * locking_frequency. The locking_frequency value is the initial frequency, | |
205 | * which is set by the bootloader. In order to eliminate possible | |
206 | * inconsistency in clock values, we save and restore frequencies during | |
207 | * suspend and resume and block CPUFREQ activities. Note that the standard | |
208 | * suspend/resume cannot be used as they are too deep (syscore_ops) for | |
209 | * regulator actions. | |
210 | */ | |
211 | static int exynos_cpufreq_pm_notifier(struct notifier_block *notifier, | |
212 | unsigned long pm_event, void *v) | |
213 | { | |
0e0e425f | 214 | int ret; |
a125a17f | 215 | |
a125a17f JL |
216 | switch (pm_event) { |
217 | case PM_SUSPEND_PREPARE: | |
0e0e425f | 218 | mutex_lock(&cpufreq_lock); |
a125a17f | 219 | frequency_locked = true; |
0e0e425f | 220 | mutex_unlock(&cpufreq_lock); |
a125a17f | 221 | |
0e0e425f JC |
222 | ret = exynos_cpufreq_scale(locking_frequency); |
223 | if (ret < 0) | |
224 | return NOTIFY_BAD; | |
a125a17f | 225 | |
a125a17f JL |
226 | break; |
227 | ||
228 | case PM_POST_SUSPEND: | |
0e0e425f | 229 | mutex_lock(&cpufreq_lock); |
a125a17f | 230 | frequency_locked = false; |
0e0e425f | 231 | mutex_unlock(&cpufreq_lock); |
a125a17f JL |
232 | break; |
233 | } | |
a125a17f JL |
234 | |
235 | return NOTIFY_OK; | |
236 | } | |
237 | ||
238 | static struct notifier_block exynos_cpufreq_nb = { | |
239 | .notifier_call = exynos_cpufreq_pm_notifier, | |
240 | }; | |
241 | ||
242 | static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy) | |
243 | { | |
b249abae | 244 | return cpufreq_generic_init(policy, exynos_info->freq_table, 100000); |
a125a17f JL |
245 | } |
246 | ||
247 | static struct cpufreq_driver exynos_driver = { | |
248 | .flags = CPUFREQ_STICKY, | |
eea6181e | 249 | .verify = cpufreq_generic_frequency_table_verify, |
a125a17f JL |
250 | .target = exynos_target, |
251 | .get = exynos_getspeed, | |
252 | .init = exynos_cpufreq_cpu_init, | |
eea6181e | 253 | .exit = cpufreq_generic_exit, |
a125a17f | 254 | .name = "exynos_cpufreq", |
eea6181e | 255 | .attr = cpufreq_generic_attr, |
a125a17f JL |
256 | #ifdef CONFIG_PM |
257 | .suspend = exynos_cpufreq_suspend, | |
258 | .resume = exynos_cpufreq_resume, | |
259 | #endif | |
260 | }; | |
261 | ||
262 | static int __init exynos_cpufreq_init(void) | |
263 | { | |
264 | int ret = -EINVAL; | |
265 | ||
d5b73cd8 | 266 | exynos_info = kzalloc(sizeof(*exynos_info), GFP_KERNEL); |
a125a17f JL |
267 | if (!exynos_info) |
268 | return -ENOMEM; | |
269 | ||
270 | if (soc_is_exynos4210()) | |
271 | ret = exynos4210_cpufreq_init(exynos_info); | |
a35c5051 JL |
272 | else if (soc_is_exynos4212() || soc_is_exynos4412()) |
273 | ret = exynos4x12_cpufreq_init(exynos_info); | |
562a6cbe JL |
274 | else if (soc_is_exynos5250()) |
275 | ret = exynos5250_cpufreq_init(exynos_info); | |
a125a17f | 276 | else |
c1585207 | 277 | return 0; |
a125a17f JL |
278 | |
279 | if (ret) | |
280 | goto err_vdd_arm; | |
281 | ||
282 | if (exynos_info->set_freq == NULL) { | |
283 | pr_err("%s: No set_freq function (ERR)\n", __func__); | |
284 | goto err_vdd_arm; | |
285 | } | |
286 | ||
287 | arm_regulator = regulator_get(NULL, "vdd_arm"); | |
288 | if (IS_ERR(arm_regulator)) { | |
289 | pr_err("%s: failed to get resource vdd_arm\n", __func__); | |
290 | goto err_vdd_arm; | |
291 | } | |
292 | ||
6e45eb12 JC |
293 | locking_frequency = exynos_getspeed(0); |
294 | ||
a125a17f JL |
295 | register_pm_notifier(&exynos_cpufreq_nb); |
296 | ||
297 | if (cpufreq_register_driver(&exynos_driver)) { | |
298 | pr_err("%s: failed to register cpufreq driver\n", __func__); | |
299 | goto err_cpufreq; | |
300 | } | |
301 | ||
302 | return 0; | |
303 | err_cpufreq: | |
304 | unregister_pm_notifier(&exynos_cpufreq_nb); | |
305 | ||
184cddd1 | 306 | regulator_put(arm_regulator); |
a125a17f JL |
307 | err_vdd_arm: |
308 | kfree(exynos_info); | |
a125a17f JL |
309 | return -EINVAL; |
310 | } | |
311 | late_initcall(exynos_cpufreq_init); |