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Source at commit 2604e7f9a98c27be50a0c3ff7503b6a5ea8f6cfe created 12 years 7 months ago. By Maarten ter Huurne, cpufreq_stats: Support runtime changes to frequency table | |
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1 | /* |
2 | * CPU frequency scaling for OMAP using OPP information |
3 | * |
4 | * Copyright (C) 2005 Nokia Corporation |
5 | * Written by Tony Lindgren <tony@atomide.com> |
6 | * |
7 | * Based on cpu-sa1110.c, Copyright (C) 2001 Russell King |
8 | * |
9 | * Copyright (C) 2007-2011 Texas Instruments, Inc. |
10 | * - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar |
11 | * |
12 | * This program is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License version 2 as |
14 | * published by the Free Software Foundation. |
15 | */ |
16 | #include <linux/types.h> |
17 | #include <linux/kernel.h> |
18 | #include <linux/sched.h> |
19 | #include <linux/cpufreq.h> |
20 | #include <linux/delay.h> |
21 | #include <linux/init.h> |
22 | #include <linux/err.h> |
23 | #include <linux/clk.h> |
24 | #include <linux/io.h> |
25 | #include <linux/opp.h> |
26 | #include <linux/cpu.h> |
27 | #include <linux/module.h> |
28 | #include <linux/regulator/consumer.h> |
29 | |
30 | #include <asm/smp_plat.h> |
31 | #include <asm/cpu.h> |
32 | |
33 | #include <plat/clock.h> |
34 | #include <plat/omap-pm.h> |
35 | #include <plat/common.h> |
36 | #include <plat/omap_device.h> |
37 | |
38 | #include <mach/hardware.h> |
39 | |
40 | /* OPP tolerance in percentage */ |
41 | #define OPP_TOLERANCE 4 |
42 | |
43 | #ifdef CONFIG_SMP |
44 | struct lpj_info { |
45 | unsigned long ref; |
46 | unsigned int freq; |
47 | }; |
48 | |
49 | static DEFINE_PER_CPU(struct lpj_info, lpj_ref); |
50 | static struct lpj_info global_lpj_ref; |
51 | #endif |
52 | |
53 | static struct cpufreq_frequency_table *freq_table; |
54 | static atomic_t freq_table_users = ATOMIC_INIT(0); |
55 | static struct clk *mpu_clk; |
56 | static char *mpu_clk_name; |
57 | static struct device *mpu_dev; |
58 | static struct regulator *mpu_reg; |
59 | |
60 | static int omap_verify_speed(struct cpufreq_policy *policy) |
61 | { |
62 | if (!freq_table) |
63 | return -EINVAL; |
64 | return cpufreq_frequency_table_verify(policy, freq_table); |
65 | } |
66 | |
67 | static unsigned int omap_getspeed(unsigned int cpu) |
68 | { |
69 | unsigned long rate; |
70 | |
71 | if (cpu >= NR_CPUS) |
72 | return 0; |
73 | |
74 | rate = clk_get_rate(mpu_clk) / 1000; |
75 | return rate; |
76 | } |
77 | |
78 | static int omap_target(struct cpufreq_policy *policy, |
79 | unsigned int target_freq, |
80 | unsigned int relation) |
81 | { |
82 | unsigned int i; |
83 | int r, ret = 0; |
84 | struct cpufreq_freqs freqs; |
85 | struct opp *opp; |
86 | unsigned long freq, volt = 0, volt_old = 0, tol = 0; |
87 | |
88 | if (!freq_table) { |
89 | dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__, |
90 | policy->cpu); |
91 | return -EINVAL; |
92 | } |
93 | |
94 | ret = cpufreq_frequency_table_target(policy, freq_table, target_freq, |
95 | relation, &i); |
96 | if (ret) { |
97 | dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n", |
98 | __func__, policy->cpu, target_freq, ret); |
99 | return ret; |
100 | } |
101 | freqs.new = freq_table[i].frequency; |
102 | if (!freqs.new) { |
103 | dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__, |
104 | policy->cpu, target_freq); |
105 | return -EINVAL; |
106 | } |
107 | |
108 | freqs.old = omap_getspeed(policy->cpu); |
109 | freqs.cpu = policy->cpu; |
110 | |
111 | if (freqs.old == freqs.new && policy->cur == freqs.new) |
112 | return ret; |
113 | |
114 | /* notifiers */ |
115 | for_each_cpu(i, policy->cpus) { |
116 | freqs.cpu = i; |
117 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); |
118 | } |
119 | |
120 | freq = freqs.new * 1000; |
121 | |
122 | if (mpu_reg) { |
123 | opp = opp_find_freq_ceil(mpu_dev, &freq); |
124 | if (IS_ERR(opp)) { |
125 | dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n", |
126 | __func__, freqs.new); |
127 | return -EINVAL; |
128 | } |
129 | volt = opp_get_voltage(opp); |
130 | tol = volt * OPP_TOLERANCE / 100; |
131 | volt_old = regulator_get_voltage(mpu_reg); |
132 | } |
133 | |
134 | dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n", |
135 | freqs.old / 1000, volt_old ? volt_old / 1000 : -1, |
136 | freqs.new / 1000, volt ? volt / 1000 : -1); |
137 | |
138 | /* scaling up? scale voltage before frequency */ |
139 | if (mpu_reg && (freqs.new > freqs.old)) { |
140 | r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol); |
141 | if (r < 0) { |
142 | dev_warn(mpu_dev, "%s: unable to scale voltage up.\n", |
143 | __func__); |
144 | freqs.new = freqs.old; |
145 | goto done; |
146 | } |
147 | } |
148 | |
149 | ret = clk_set_rate(mpu_clk, freqs.new * 1000); |
150 | |
151 | /* scaling down? scale voltage after frequency */ |
152 | if (mpu_reg && (freqs.new < freqs.old)) { |
153 | r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol); |
154 | if (r < 0) { |
155 | dev_warn(mpu_dev, "%s: unable to scale voltage down.\n", |
156 | __func__); |
157 | ret = clk_set_rate(mpu_clk, freqs.old * 1000); |
158 | freqs.new = freqs.old; |
159 | goto done; |
160 | } |
161 | } |
162 | |
163 | freqs.new = omap_getspeed(policy->cpu); |
164 | #ifdef CONFIG_SMP |
165 | /* |
166 | * Note that loops_per_jiffy is not updated on SMP systems in |
167 | * cpufreq driver. So, update the per-CPU loops_per_jiffy value |
168 | * on frequency transition. We need to update all dependent CPUs. |
169 | */ |
170 | for_each_cpu(i, policy->cpus) { |
171 | struct lpj_info *lpj = &per_cpu(lpj_ref, i); |
172 | if (!lpj->freq) { |
173 | lpj->ref = per_cpu(cpu_data, i).loops_per_jiffy; |
174 | lpj->freq = freqs.old; |
175 | } |
176 | |
177 | per_cpu(cpu_data, i).loops_per_jiffy = |
178 | cpufreq_scale(lpj->ref, lpj->freq, freqs.new); |
179 | } |
180 | |
181 | /* And don't forget to adjust the global one */ |
182 | if (!global_lpj_ref.freq) { |
183 | global_lpj_ref.ref = loops_per_jiffy; |
184 | global_lpj_ref.freq = freqs.old; |
185 | } |
186 | loops_per_jiffy = cpufreq_scale(global_lpj_ref.ref, global_lpj_ref.freq, |
187 | freqs.new); |
188 | #endif |
189 | |
190 | done: |
191 | /* notifiers */ |
192 | for_each_cpu(i, policy->cpus) { |
193 | freqs.cpu = i; |
194 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); |
195 | } |
196 | |
197 | return ret; |
198 | } |
199 | |
200 | static inline void freq_table_free(void) |
201 | { |
202 | if (atomic_dec_and_test(&freq_table_users)) |
203 | opp_free_cpufreq_table(mpu_dev, &freq_table); |
204 | } |
205 | |
206 | static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy) |
207 | { |
208 | int result = 0; |
209 | |
210 | mpu_clk = clk_get(NULL, mpu_clk_name); |
211 | if (IS_ERR(mpu_clk)) |
212 | return PTR_ERR(mpu_clk); |
213 | |
214 | if (policy->cpu >= NR_CPUS) { |
215 | result = -EINVAL; |
216 | goto fail_ck; |
217 | } |
218 | |
219 | policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu); |
220 | |
221 | if (!freq_table) |
222 | result = opp_init_cpufreq_table(mpu_dev, &freq_table); |
223 | |
224 | if (result) { |
225 | dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n", |
226 | __func__, policy->cpu, result); |
227 | goto fail_ck; |
228 | } |
229 | |
230 | atomic_inc_return(&freq_table_users); |
231 | |
232 | result = cpufreq_frequency_table_cpuinfo(policy, freq_table); |
233 | if (result) |
234 | goto fail_table; |
235 | |
236 | cpufreq_frequency_table_get_attr(freq_table, policy->cpu); |
237 | |
238 | policy->min = policy->cpuinfo.min_freq; |
239 | policy->max = policy->cpuinfo.max_freq; |
240 | policy->cur = omap_getspeed(policy->cpu); |
241 | |
242 | /* |
243 | * On OMAP SMP configuartion, both processors share the voltage |
244 | * and clock. So both CPUs needs to be scaled together and hence |
245 | * needs software co-ordination. Use cpufreq affected_cpus |
246 | * interface to handle this scenario. Additional is_smp() check |
247 | * is to keep SMP_ON_UP build working. |
248 | */ |
249 | if (is_smp()) { |
250 | policy->shared_type = CPUFREQ_SHARED_TYPE_ANY; |
251 | cpumask_setall(policy->cpus); |
252 | } |
253 | |
254 | /* FIXME: what's the actual transition time? */ |
255 | policy->cpuinfo.transition_latency = 300 * 1000; |
256 | |
257 | return 0; |
258 | |
259 | fail_table: |
260 | freq_table_free(); |
261 | fail_ck: |
262 | clk_put(mpu_clk); |
263 | return result; |
264 | } |
265 | |
266 | static int omap_cpu_exit(struct cpufreq_policy *policy) |
267 | { |
268 | freq_table_free(); |
269 | clk_put(mpu_clk); |
270 | return 0; |
271 | } |
272 | |
273 | static struct freq_attr *omap_cpufreq_attr[] = { |
274 | &cpufreq_freq_attr_scaling_available_freqs, |
275 | NULL, |
276 | }; |
277 | |
278 | static struct cpufreq_driver omap_driver = { |
279 | .flags = CPUFREQ_STICKY, |
280 | .verify = omap_verify_speed, |
281 | .target = omap_target, |
282 | .get = omap_getspeed, |
283 | .init = omap_cpu_init, |
284 | .exit = omap_cpu_exit, |
285 | .name = "omap", |
286 | .attr = omap_cpufreq_attr, |
287 | }; |
288 | |
289 | static int __init omap_cpufreq_init(void) |
290 | { |
291 | if (cpu_is_omap24xx()) |
292 | mpu_clk_name = "virt_prcm_set"; |
293 | else if (cpu_is_omap34xx()) |
294 | mpu_clk_name = "dpll1_ck"; |
295 | else if (cpu_is_omap44xx()) |
296 | mpu_clk_name = "dpll_mpu_ck"; |
297 | |
298 | if (!mpu_clk_name) { |
299 | pr_err("%s: unsupported Silicon?\n", __func__); |
300 | return -EINVAL; |
301 | } |
302 | |
303 | mpu_dev = omap_device_get_by_hwmod_name("mpu"); |
304 | if (!mpu_dev) { |
305 | pr_warning("%s: unable to get the mpu device\n", __func__); |
306 | return -EINVAL; |
307 | } |
308 | |
309 | mpu_reg = regulator_get(mpu_dev, "vcc"); |
310 | if (IS_ERR(mpu_reg)) { |
311 | pr_warning("%s: unable to get MPU regulator\n", __func__); |
312 | mpu_reg = NULL; |
313 | } else { |
314 | /* |
315 | * Ensure physical regulator is present. |
316 | * (e.g. could be dummy regulator.) |
317 | */ |
318 | if (regulator_get_voltage(mpu_reg) < 0) { |
319 | pr_warn("%s: physical regulator not present for MPU\n", |
320 | __func__); |
321 | regulator_put(mpu_reg); |
322 | mpu_reg = NULL; |
323 | } |
324 | } |
325 | |
326 | return cpufreq_register_driver(&omap_driver); |
327 | } |
328 | |
329 | static void __exit omap_cpufreq_exit(void) |
330 | { |
331 | cpufreq_unregister_driver(&omap_driver); |
332 | } |
333 | |
334 | MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs"); |
335 | MODULE_LICENSE("GPL"); |
336 | module_init(omap_cpufreq_init); |
337 | module_exit(omap_cpufreq_exit); |
338 |
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