diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-11 21:53:33 -0500 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-11 21:53:33 -0500 |
commit | 02d929502ce7b57f4835d8bb7c828d36e6d9e8ce (patch) | |
tree | 7bb0ca7a9bfe5c336c3125f823770934a2150ae4 /drivers/cpufreq/exynos-cpufreq.c | |
parent | b24ca57e7625bc304e77bc429693ad32a691eb16 (diff) | |
parent | 6c523c614c13b84a3dc64f7a56d6855b03e6b292 (diff) |
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: (23 commits)
[CPUFREQ] EXYNOS: Removed useless headers and codes
[CPUFREQ] EXYNOS: Make EXYNOS common cpufreq driver
[CPUFREQ] powernow-k8: Update copyright, maintainer and documentation information
[CPUFREQ] powernow-k8: Fix indexing issue
[CPUFREQ] powernow-k8: Avoid Pstate MSR accesses on systems supporting CPB
[CPUFREQ] update lpj only if frequency has changed
[CPUFREQ] cpufreq:userspace: fix cpu_cur_freq updation
[CPUFREQ] Remove wall variable from cpufreq_gov_dbs_init()
[CPUFREQ] EXYNOS4210: cpufreq code is changed for stable working
[CPUFREQ] EXYNOS4210: Update frequency table for cpu divider
[CPUFREQ] EXYNOS4210: Remove code about bus on cpufreq
[CPUFREQ] s3c64xx: Use pr_fmt() for consistent log messages
cpufreq: OMAP: fixup for omap_device changes, include <linux/module.h>
cpufreq: OMAP: fix freq_table leak
cpufreq: OMAP: put clk if cpu_init failed
cpufreq: OMAP: only supports OPP library
cpufreq: OMAP: dont support !freq_table
cpufreq: OMAP: deny initialization if no mpudev
cpufreq: OMAP: move clk name decision to init
cpufreq: OMAP: notify even with bad boot frequency
...
Diffstat (limited to 'drivers/cpufreq/exynos-cpufreq.c')
-rw-r--r-- | drivers/cpufreq/exynos-cpufreq.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/drivers/cpufreq/exynos-cpufreq.c b/drivers/cpufreq/exynos-cpufreq.c new file mode 100644 index 000000000000..5467879ea07d --- /dev/null +++ b/drivers/cpufreq/exynos-cpufreq.c | |||
@@ -0,0 +1,290 @@ | |||
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/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> | ||
20 | |||
21 | #include <mach/cpufreq.h> | ||
22 | |||
23 | #include <plat/cpu.h> | ||
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 | |||
65 | if (cpufreq_frequency_table_target(policy, freq_table, | ||
66 | freqs.old, relation, &old_index)) { | ||
67 | ret = -EINVAL; | ||
68 | goto out; | ||
69 | } | ||
70 | |||
71 | if (cpufreq_frequency_table_target(policy, freq_table, | ||
72 | target_freq, relation, &index)) { | ||
73 | ret = -EINVAL; | ||
74 | goto out; | ||
75 | } | ||
76 | |||
77 | freqs.new = freq_table[index].frequency; | ||
78 | freqs.cpu = policy->cpu; | ||
79 | |||
80 | /* | ||
81 | * ARM clock source will be changed APLL to MPLL temporary | ||
82 | * To support this level, need to control regulator for | ||
83 | * required voltage level | ||
84 | */ | ||
85 | if (exynos_info->need_apll_change != NULL) { | ||
86 | if (exynos_info->need_apll_change(old_index, index) && | ||
87 | (freq_table[index].frequency < mpll_freq_khz) && | ||
88 | (freq_table[old_index].frequency < mpll_freq_khz)) | ||
89 | safe_arm_volt = volt_table[exynos_info->pll_safe_idx]; | ||
90 | } | ||
91 | arm_volt = volt_table[index]; | ||
92 | |||
93 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | ||
94 | |||
95 | /* When the new frequency is higher than current frequency */ | ||
96 | if ((freqs.new > freqs.old) && !safe_arm_volt) { | ||
97 | /* Firstly, voltage up to increase frequency */ | ||
98 | regulator_set_voltage(arm_regulator, arm_volt, | ||
99 | arm_volt); | ||
100 | } | ||
101 | |||
102 | if (safe_arm_volt) | ||
103 | regulator_set_voltage(arm_regulator, safe_arm_volt, | ||
104 | safe_arm_volt); | ||
105 | if (freqs.new != freqs.old) | ||
106 | exynos_info->set_freq(old_index, index); | ||
107 | |||
108 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | ||
109 | |||
110 | /* When the new frequency is lower than current frequency */ | ||
111 | if ((freqs.new < freqs.old) || | ||
112 | ((freqs.new > freqs.old) && safe_arm_volt)) { | ||
113 | /* down the voltage after frequency change */ | ||
114 | regulator_set_voltage(arm_regulator, arm_volt, | ||
115 | arm_volt); | ||
116 | } | ||
117 | |||
118 | out: | ||
119 | mutex_unlock(&cpufreq_lock); | ||
120 | |||
121 | return ret; | ||
122 | } | ||
123 | |||
124 | #ifdef CONFIG_PM | ||
125 | static int exynos_cpufreq_suspend(struct cpufreq_policy *policy) | ||
126 | { | ||
127 | return 0; | ||
128 | } | ||
129 | |||
130 | static int exynos_cpufreq_resume(struct cpufreq_policy *policy) | ||
131 | { | ||
132 | return 0; | ||
133 | } | ||
134 | #endif | ||
135 | |||
136 | /** | ||
137 | * exynos_cpufreq_pm_notifier - block CPUFREQ's activities in suspend-resume | ||
138 | * context | ||
139 | * @notifier | ||
140 | * @pm_event | ||
141 | * @v | ||
142 | * | ||
143 | * While frequency_locked == true, target() ignores every frequency but | ||
144 | * locking_frequency. The locking_frequency value is the initial frequency, | ||
145 | * which is set by the bootloader. In order to eliminate possible | ||
146 | * inconsistency in clock values, we save and restore frequencies during | ||
147 | * suspend and resume and block CPUFREQ activities. Note that the standard | ||
148 | * suspend/resume cannot be used as they are too deep (syscore_ops) for | ||
149 | * regulator actions. | ||
150 | */ | ||
151 | static int exynos_cpufreq_pm_notifier(struct notifier_block *notifier, | ||
152 | unsigned long pm_event, void *v) | ||
153 | { | ||
154 | struct cpufreq_policy *policy = cpufreq_cpu_get(0); /* boot CPU */ | ||
155 | static unsigned int saved_frequency; | ||
156 | unsigned int temp; | ||
157 | |||
158 | mutex_lock(&cpufreq_lock); | ||
159 | switch (pm_event) { | ||
160 | case PM_SUSPEND_PREPARE: | ||
161 | if (frequency_locked) | ||
162 | goto out; | ||
163 | |||
164 | frequency_locked = true; | ||
165 | |||
166 | if (locking_frequency) { | ||
167 | saved_frequency = exynos_getspeed(0); | ||
168 | |||
169 | mutex_unlock(&cpufreq_lock); | ||
170 | exynos_target(policy, locking_frequency, | ||
171 | CPUFREQ_RELATION_H); | ||
172 | mutex_lock(&cpufreq_lock); | ||
173 | } | ||
174 | break; | ||
175 | |||
176 | case PM_POST_SUSPEND: | ||
177 | if (saved_frequency) { | ||
178 | /* | ||
179 | * While frequency_locked, only locking_frequency | ||
180 | * is valid for target(). In order to use | ||
181 | * saved_frequency while keeping frequency_locked, | ||
182 | * we temporarly overwrite locking_frequency. | ||
183 | */ | ||
184 | temp = locking_frequency; | ||
185 | locking_frequency = saved_frequency; | ||
186 | |||
187 | mutex_unlock(&cpufreq_lock); | ||
188 | exynos_target(policy, locking_frequency, | ||
189 | CPUFREQ_RELATION_H); | ||
190 | mutex_lock(&cpufreq_lock); | ||
191 | |||
192 | locking_frequency = temp; | ||
193 | } | ||
194 | frequency_locked = false; | ||
195 | break; | ||
196 | } | ||
197 | out: | ||
198 | mutex_unlock(&cpufreq_lock); | ||
199 | |||
200 | return NOTIFY_OK; | ||
201 | } | ||
202 | |||
203 | static struct notifier_block exynos_cpufreq_nb = { | ||
204 | .notifier_call = exynos_cpufreq_pm_notifier, | ||
205 | }; | ||
206 | |||
207 | static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy) | ||
208 | { | ||
209 | policy->cur = policy->min = policy->max = exynos_getspeed(policy->cpu); | ||
210 | |||
211 | cpufreq_frequency_table_get_attr(exynos_info->freq_table, policy->cpu); | ||
212 | |||
213 | /* set the transition latency value */ | ||
214 | policy->cpuinfo.transition_latency = 100000; | ||
215 | |||
216 | /* | ||
217 | * EXYNOS4 multi-core processors has 2 cores | ||
218 | * that the frequency cannot be set independently. | ||
219 | * Each cpu is bound to the same speed. | ||
220 | * So the affected cpu is all of the cpus. | ||
221 | */ | ||
222 | if (num_online_cpus() == 1) { | ||
223 | cpumask_copy(policy->related_cpus, cpu_possible_mask); | ||
224 | cpumask_copy(policy->cpus, cpu_online_mask); | ||
225 | } else { | ||
226 | cpumask_setall(policy->cpus); | ||
227 | } | ||
228 | |||
229 | return cpufreq_frequency_table_cpuinfo(policy, exynos_info->freq_table); | ||
230 | } | ||
231 | |||
232 | static struct cpufreq_driver exynos_driver = { | ||
233 | .flags = CPUFREQ_STICKY, | ||
234 | .verify = exynos_verify_speed, | ||
235 | .target = exynos_target, | ||
236 | .get = exynos_getspeed, | ||
237 | .init = exynos_cpufreq_cpu_init, | ||
238 | .name = "exynos_cpufreq", | ||
239 | #ifdef CONFIG_PM | ||
240 | .suspend = exynos_cpufreq_suspend, | ||
241 | .resume = exynos_cpufreq_resume, | ||
242 | #endif | ||
243 | }; | ||
244 | |||
245 | static int __init exynos_cpufreq_init(void) | ||
246 | { | ||
247 | int ret = -EINVAL; | ||
248 | |||
249 | exynos_info = kzalloc(sizeof(struct exynos_dvfs_info), GFP_KERNEL); | ||
250 | if (!exynos_info) | ||
251 | return -ENOMEM; | ||
252 | |||
253 | if (soc_is_exynos4210()) | ||
254 | ret = exynos4210_cpufreq_init(exynos_info); | ||
255 | else | ||
256 | pr_err("%s: CPU type not found\n", __func__); | ||
257 | |||
258 | if (ret) | ||
259 | goto err_vdd_arm; | ||
260 | |||
261 | if (exynos_info->set_freq == NULL) { | ||
262 | pr_err("%s: No set_freq function (ERR)\n", __func__); | ||
263 | goto err_vdd_arm; | ||
264 | } | ||
265 | |||
266 | arm_regulator = regulator_get(NULL, "vdd_arm"); | ||
267 | if (IS_ERR(arm_regulator)) { | ||
268 | pr_err("%s: failed to get resource vdd_arm\n", __func__); | ||
269 | goto err_vdd_arm; | ||
270 | } | ||
271 | |||
272 | register_pm_notifier(&exynos_cpufreq_nb); | ||
273 | |||
274 | if (cpufreq_register_driver(&exynos_driver)) { | ||
275 | pr_err("%s: failed to register cpufreq driver\n", __func__); | ||
276 | goto err_cpufreq; | ||
277 | } | ||
278 | |||
279 | return 0; | ||
280 | err_cpufreq: | ||
281 | unregister_pm_notifier(&exynos_cpufreq_nb); | ||
282 | |||
283 | if (!IS_ERR(arm_regulator)) | ||
284 | regulator_put(arm_regulator); | ||
285 | err_vdd_arm: | ||
286 | kfree(exynos_info); | ||
287 | pr_debug("%s: failed initialization\n", __func__); | ||
288 | return -EINVAL; | ||
289 | } | ||
290 | late_initcall(exynos_cpufreq_init); | ||