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8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/clk.h>
12#include <linux/cpu.h>
13#include <linux/cpufreq.h>
14#include <linux/cpumask.h>
15#include <linux/err.h>
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/pm_opp.h>
19#include <linux/platform_device.h>
20#include <linux/regulator/consumer.h>
21#include <linux/slab.h>
22#include <linux/thermal.h>
23
24#include "cpufreq-dt.h"
25
26struct private_data {
27 struct opp_table *opp_table;
28 struct device *cpu_dev;
29 const char *reg_name;
30 bool have_static_opps;
31};
32
33static struct freq_attr *cpufreq_dt_attr[] = {
34 &cpufreq_freq_attr_scaling_available_freqs,
35 NULL,
36 NULL,
37};
38
39static int set_target(struct cpufreq_policy *policy, unsigned int index)
40{
41 struct private_data *priv = policy->driver_data;
42 unsigned long freq = policy->freq_table[index].frequency;
43 int ret;
44
45 ret = dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000);
46
47 if (!ret) {
48 arch_set_freq_scale(policy->related_cpus, freq,
49 policy->cpuinfo.max_freq);
50 }
51
52 return ret;
53}
54
55
56
57
58
59static const char *find_supply_name(struct device *dev)
60{
61 struct device_node *np;
62 struct property *pp;
63 int cpu = dev->id;
64 const char *name = NULL;
65
66 np = of_node_get(dev->of_node);
67
68
69 if (WARN_ON(!np))
70 return NULL;
71
72
73 if (!cpu) {
74 pp = of_find_property(np, "cpu0-supply", NULL);
75 if (pp) {
76 name = "cpu0";
77 goto node_put;
78 }
79 }
80
81 pp = of_find_property(np, "cpu-supply", NULL);
82 if (pp) {
83 name = "cpu";
84 goto node_put;
85 }
86
87 dev_dbg(dev, "no regulator for cpu%d\n", cpu);
88node_put:
89 of_node_put(np);
90 return name;
91}
92
93static int resources_available(void)
94{
95 struct device *cpu_dev;
96 struct regulator *cpu_reg;
97 struct clk *cpu_clk;
98 int ret = 0;
99 const char *name;
100
101 cpu_dev = get_cpu_device(0);
102 if (!cpu_dev) {
103 pr_err("failed to get cpu0 device\n");
104 return -ENODEV;
105 }
106
107 cpu_clk = clk_get(cpu_dev, NULL);
108 ret = PTR_ERR_OR_ZERO(cpu_clk);
109 if (ret) {
110
111
112
113
114 if (ret == -EPROBE_DEFER)
115 dev_dbg(cpu_dev, "clock not ready, retry\n");
116 else
117 dev_err(cpu_dev, "failed to get clock: %d\n", ret);
118
119 return ret;
120 }
121
122 clk_put(cpu_clk);
123
124 ret = dev_pm_opp_of_find_icc_paths(cpu_dev, NULL);
125 if (ret)
126 return ret;
127
128 name = find_supply_name(cpu_dev);
129
130 if (!name)
131 return 0;
132
133 cpu_reg = regulator_get_optional(cpu_dev, name);
134 ret = PTR_ERR_OR_ZERO(cpu_reg);
135 if (ret) {
136
137
138
139
140 if (ret == -EPROBE_DEFER)
141 dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n");
142 else
143 dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret);
144
145 return ret;
146 }
147
148 regulator_put(cpu_reg);
149 return 0;
150}
151
152static int cpufreq_init(struct cpufreq_policy *policy)
153{
154 struct cpufreq_frequency_table *freq_table;
155 struct opp_table *opp_table = NULL;
156 struct private_data *priv;
157 struct device *cpu_dev;
158 struct clk *cpu_clk;
159 unsigned int transition_latency;
160 bool fallback = false;
161 const char *name;
162 int ret;
163
164 cpu_dev = get_cpu_device(policy->cpu);
165 if (!cpu_dev) {
166 pr_err("failed to get cpu%d device\n", policy->cpu);
167 return -ENODEV;
168 }
169
170 cpu_clk = clk_get(cpu_dev, NULL);
171 if (IS_ERR(cpu_clk)) {
172 ret = PTR_ERR(cpu_clk);
173 dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret);
174 return ret;
175 }
176
177
178 ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus);
179 if (ret) {
180 if (ret != -ENOENT)
181 goto out_put_clk;
182
183
184
185
186
187
188 if (dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus))
189 fallback = true;
190 }
191
192
193
194
195
196 name = find_supply_name(cpu_dev);
197 if (name) {
198 opp_table = dev_pm_opp_set_regulators(cpu_dev, &name, 1);
199 if (IS_ERR(opp_table)) {
200 ret = PTR_ERR(opp_table);
201 dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n",
202 policy->cpu, ret);
203 goto out_put_clk;
204 }
205 }
206
207 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
208 if (!priv) {
209 ret = -ENOMEM;
210 goto out_put_regulator;
211 }
212
213 priv->reg_name = name;
214 priv->opp_table = opp_table;
215
216
217
218
219
220
221
222
223
224
225
226 if (!dev_pm_opp_of_cpumask_add_table(policy->cpus))
227 priv->have_static_opps = true;
228
229
230
231
232
233 ret = dev_pm_opp_get_opp_count(cpu_dev);
234 if (ret <= 0) {
235 dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n");
236 ret = -EPROBE_DEFER;
237 goto out_free_opp;
238 }
239
240 if (fallback) {
241 cpumask_setall(policy->cpus);
242
243
244
245
246
247 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
248 if (ret)
249 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
250 __func__, ret);
251 }
252
253 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
254 if (ret) {
255 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
256 goto out_free_opp;
257 }
258
259 priv->cpu_dev = cpu_dev;
260 policy->driver_data = priv;
261 policy->clk = cpu_clk;
262 policy->freq_table = freq_table;
263
264 policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000;
265
266
267 if (policy_has_boost_freq(policy)) {
268
269 ret = cpufreq_enable_boost_support();
270 if (ret)
271 goto out_free_cpufreq_table;
272 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
273 }
274
275 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
276 if (!transition_latency)
277 transition_latency = CPUFREQ_ETERNAL;
278
279 policy->cpuinfo.transition_latency = transition_latency;
280 policy->dvfs_possible_from_any_cpu = true;
281
282 dev_pm_opp_of_register_em(cpu_dev, policy->cpus);
283
284 return 0;
285
286out_free_cpufreq_table:
287 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
288out_free_opp:
289 if (priv->have_static_opps)
290 dev_pm_opp_of_cpumask_remove_table(policy->cpus);
291 kfree(priv);
292out_put_regulator:
293 if (name)
294 dev_pm_opp_put_regulators(opp_table);
295out_put_clk:
296 clk_put(cpu_clk);
297
298 return ret;
299}
300
301static int cpufreq_online(struct cpufreq_policy *policy)
302{
303
304 return 0;
305}
306
307static int cpufreq_offline(struct cpufreq_policy *policy)
308{
309
310
311
312
313 return 0;
314}
315
316static int cpufreq_exit(struct cpufreq_policy *policy)
317{
318 struct private_data *priv = policy->driver_data;
319
320 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
321 if (priv->have_static_opps)
322 dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
323 if (priv->reg_name)
324 dev_pm_opp_put_regulators(priv->opp_table);
325
326 clk_put(policy->clk);
327 kfree(priv);
328
329 return 0;
330}
331
332static struct cpufreq_driver dt_cpufreq_driver = {
333 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK |
334 CPUFREQ_IS_COOLING_DEV,
335 .verify = cpufreq_generic_frequency_table_verify,
336 .target_index = set_target,
337 .get = cpufreq_generic_get,
338 .init = cpufreq_init,
339 .exit = cpufreq_exit,
340 .online = cpufreq_online,
341 .offline = cpufreq_offline,
342 .name = "cpufreq-dt",
343 .attr = cpufreq_dt_attr,
344 .suspend = cpufreq_generic_suspend,
345};
346
347static int dt_cpufreq_probe(struct platform_device *pdev)
348{
349 struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev);
350 int ret;
351
352
353
354
355
356
357
358
359 ret = resources_available();
360 if (ret)
361 return ret;
362
363 if (data) {
364 if (data->have_governor_per_policy)
365 dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY;
366
367 dt_cpufreq_driver.resume = data->resume;
368 if (data->suspend)
369 dt_cpufreq_driver.suspend = data->suspend;
370 if (data->get_intermediate) {
371 dt_cpufreq_driver.target_intermediate = data->target_intermediate;
372 dt_cpufreq_driver.get_intermediate = data->get_intermediate;
373 }
374 }
375
376 ret = cpufreq_register_driver(&dt_cpufreq_driver);
377 if (ret)
378 dev_err(&pdev->dev, "failed register driver: %d\n", ret);
379
380 return ret;
381}
382
383static int dt_cpufreq_remove(struct platform_device *pdev)
384{
385 cpufreq_unregister_driver(&dt_cpufreq_driver);
386 return 0;
387}
388
389static struct platform_driver dt_cpufreq_platdrv = {
390 .driver = {
391 .name = "cpufreq-dt",
392 },
393 .probe = dt_cpufreq_probe,
394 .remove = dt_cpufreq_remove,
395};
396module_platform_driver(dt_cpufreq_platdrv);
397
398MODULE_ALIAS("platform:cpufreq-dt");
399MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
400MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
401MODULE_DESCRIPTION("Generic cpufreq driver");
402MODULE_LICENSE("GPL");
403