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1 | /* | |
2 | * Copyright (C) 2012 Freescale Semiconductor, Inc. | |
3 | * | |
4 | * Copyright (C) 2014 Linaro. | |
5 | * Viresh Kumar <viresh.kumar@linaro.org> | |
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 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
13 | ||
14 | #include <linux/clk.h> | |
15 | #include <linux/cpu.h> | |
16 | #include <linux/cpu_cooling.h> | |
17 | #include <linux/cpufreq.h> | |
18 | #include <linux/cpumask.h> | |
19 | #include <linux/err.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/of.h> | |
22 | #include <linux/pm_opp.h> | |
23 | #include <linux/platform_device.h> | |
24 | #include <linux/regulator/consumer.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/thermal.h> | |
27 | ||
28 | #include "cpufreq-dt.h" | |
29 | ||
30 | struct private_data { | |
31 | struct opp_table *opp_table; | |
32 | struct device *cpu_dev; | |
33 | struct thermal_cooling_device *cdev; | |
34 | const char *reg_name; | |
35 | }; | |
36 | ||
37 | static struct freq_attr *cpufreq_dt_attr[] = { | |
38 | &cpufreq_freq_attr_scaling_available_freqs, | |
39 | NULL, /* Extra space for boost-attr if required */ | |
40 | NULL, | |
41 | }; | |
42 | ||
43 | static int set_target(struct cpufreq_policy *policy, unsigned int index) | |
44 | { | |
45 | struct private_data *priv = policy->driver_data; | |
46 | ||
47 | return dev_pm_opp_set_rate(priv->cpu_dev, | |
48 | policy->freq_table[index].frequency * 1000); | |
49 | } | |
50 | ||
51 | /* | |
52 | * An earlier version of opp-v1 bindings used to name the regulator | |
53 | * "cpu0-supply", we still need to handle that for backwards compatibility. | |
54 | */ | |
55 | static const char *find_supply_name(struct device *dev) | |
56 | { | |
57 | struct device_node *np; | |
58 | struct property *pp; | |
59 | int cpu = dev->id; | |
60 | const char *name = NULL; | |
61 | ||
62 | np = of_node_get(dev->of_node); | |
63 | ||
64 | /* This must be valid for sure */ | |
65 | if (WARN_ON(!np)) | |
66 | return NULL; | |
67 | ||
68 | /* Try "cpu0" for older DTs */ | |
69 | if (!cpu) { | |
70 | pp = of_find_property(np, "cpu0-supply", NULL); | |
71 | if (pp) { | |
72 | name = "cpu0"; | |
73 | goto node_put; | |
74 | } | |
75 | } | |
76 | ||
77 | pp = of_find_property(np, "cpu-supply", NULL); | |
78 | if (pp) { | |
79 | name = "cpu"; | |
80 | goto node_put; | |
81 | } | |
82 | ||
83 | dev_dbg(dev, "no regulator for cpu%d\n", cpu); | |
84 | node_put: | |
85 | of_node_put(np); | |
86 | return name; | |
87 | } | |
88 | ||
89 | static int resources_available(void) | |
90 | { | |
91 | struct device *cpu_dev; | |
92 | struct regulator *cpu_reg; | |
93 | struct clk *cpu_clk; | |
94 | int ret = 0; | |
95 | const char *name; | |
96 | ||
97 | cpu_dev = get_cpu_device(0); | |
98 | if (!cpu_dev) { | |
99 | pr_err("failed to get cpu0 device\n"); | |
100 | return -ENODEV; | |
101 | } | |
102 | ||
103 | cpu_clk = clk_get(cpu_dev, NULL); | |
104 | ret = PTR_ERR_OR_ZERO(cpu_clk); | |
105 | if (ret) { | |
106 | /* | |
107 | * If cpu's clk node is present, but clock is not yet | |
108 | * registered, we should try defering probe. | |
109 | */ | |
110 | if (ret == -EPROBE_DEFER) | |
111 | dev_dbg(cpu_dev, "clock not ready, retry\n"); | |
112 | else | |
113 | dev_err(cpu_dev, "failed to get clock: %d\n", ret); | |
114 | ||
115 | return ret; | |
116 | } | |
117 | ||
118 | clk_put(cpu_clk); | |
119 | ||
120 | name = find_supply_name(cpu_dev); | |
121 | /* Platform doesn't require regulator */ | |
122 | if (!name) | |
123 | return 0; | |
124 | ||
125 | cpu_reg = regulator_get_optional(cpu_dev, name); | |
126 | ret = PTR_ERR_OR_ZERO(cpu_reg); | |
127 | if (ret) { | |
128 | /* | |
129 | * If cpu's regulator supply node is present, but regulator is | |
130 | * not yet registered, we should try defering probe. | |
131 | */ | |
132 | if (ret == -EPROBE_DEFER) | |
133 | dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n"); | |
134 | else | |
135 | dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret); | |
136 | ||
137 | return ret; | |
138 | } | |
139 | ||
140 | regulator_put(cpu_reg); | |
141 | return 0; | |
142 | } | |
143 | ||
144 | static int cpufreq_init(struct cpufreq_policy *policy) | |
145 | { | |
146 | struct cpufreq_frequency_table *freq_table; | |
147 | struct opp_table *opp_table = NULL; | |
148 | struct private_data *priv; | |
149 | struct device *cpu_dev; | |
150 | struct clk *cpu_clk; | |
151 | unsigned int transition_latency; | |
152 | bool fallback = false; | |
153 | const char *name; | |
154 | int ret; | |
155 | ||
156 | cpu_dev = get_cpu_device(policy->cpu); | |
157 | if (!cpu_dev) { | |
158 | pr_err("failed to get cpu%d device\n", policy->cpu); | |
159 | return -ENODEV; | |
160 | } | |
161 | ||
162 | cpu_clk = clk_get(cpu_dev, NULL); | |
163 | if (IS_ERR(cpu_clk)) { | |
164 | ret = PTR_ERR(cpu_clk); | |
165 | dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret); | |
166 | return ret; | |
167 | } | |
168 | ||
169 | /* Get OPP-sharing information from "operating-points-v2" bindings */ | |
170 | ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus); | |
171 | if (ret) { | |
172 | if (ret != -ENOENT) | |
173 | goto out_put_clk; | |
174 | ||
175 | /* | |
176 | * operating-points-v2 not supported, fallback to old method of | |
177 | * finding shared-OPPs for backward compatibility if the | |
178 | * platform hasn't set sharing CPUs. | |
179 | */ | |
180 | if (dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus)) | |
181 | fallback = true; | |
182 | } | |
183 | ||
184 | /* | |
185 | * OPP layer will be taking care of regulators now, but it needs to know | |
186 | * the name of the regulator first. | |
187 | */ | |
188 | name = find_supply_name(cpu_dev); | |
189 | if (name) { | |
190 | opp_table = dev_pm_opp_set_regulators(cpu_dev, &name, 1); | |
191 | if (IS_ERR(opp_table)) { | |
192 | ret = PTR_ERR(opp_table); | |
193 | dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n", | |
194 | policy->cpu, ret); | |
195 | goto out_put_clk; | |
196 | } | |
197 | } | |
198 | ||
199 | /* | |
200 | * Initialize OPP tables for all policy->cpus. They will be shared by | |
201 | * all CPUs which have marked their CPUs shared with OPP bindings. | |
202 | * | |
203 | * For platforms not using operating-points-v2 bindings, we do this | |
204 | * before updating policy->cpus. Otherwise, we will end up creating | |
205 | * duplicate OPPs for policy->cpus. | |
206 | * | |
207 | * OPPs might be populated at runtime, don't check for error here | |
208 | */ | |
209 | dev_pm_opp_of_cpumask_add_table(policy->cpus); | |
210 | ||
211 | /* | |
212 | * But we need OPP table to function so if it is not there let's | |
213 | * give platform code chance to provide it for us. | |
214 | */ | |
215 | ret = dev_pm_opp_get_opp_count(cpu_dev); | |
216 | if (ret <= 0) { | |
217 | dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n"); | |
218 | ret = -EPROBE_DEFER; | |
219 | goto out_free_opp; | |
220 | } | |
221 | ||
222 | if (fallback) { | |
223 | cpumask_setall(policy->cpus); | |
224 | ||
225 | /* | |
226 | * OPP tables are initialized only for policy->cpu, do it for | |
227 | * others as well. | |
228 | */ | |
229 | ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus); | |
230 | if (ret) | |
231 | dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", | |
232 | __func__, ret); | |
233 | } | |
234 | ||
235 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
236 | if (!priv) { | |
237 | ret = -ENOMEM; | |
238 | goto out_free_opp; | |
239 | } | |
240 | ||
241 | priv->reg_name = name; | |
242 | priv->opp_table = opp_table; | |
243 | ||
244 | ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); | |
245 | if (ret) { | |
246 | dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); | |
247 | goto out_free_priv; | |
248 | } | |
249 | ||
250 | priv->cpu_dev = cpu_dev; | |
251 | policy->driver_data = priv; | |
252 | policy->clk = cpu_clk; | |
253 | ||
254 | policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000; | |
255 | ||
256 | ret = cpufreq_table_validate_and_show(policy, freq_table); | |
257 | if (ret) { | |
258 | dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__, | |
259 | ret); | |
260 | goto out_free_cpufreq_table; | |
261 | } | |
262 | ||
263 | /* Support turbo/boost mode */ | |
264 | if (policy_has_boost_freq(policy)) { | |
265 | /* This gets disabled by core on driver unregister */ | |
266 | ret = cpufreq_enable_boost_support(); | |
267 | if (ret) | |
268 | goto out_free_cpufreq_table; | |
269 | cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs; | |
270 | } | |
271 | ||
272 | transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev); | |
273 | if (!transition_latency) | |
274 | transition_latency = CPUFREQ_ETERNAL; | |
275 | ||
276 | policy->cpuinfo.transition_latency = transition_latency; | |
277 | ||
278 | return 0; | |
279 | ||
280 | out_free_cpufreq_table: | |
281 | dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); | |
282 | out_free_priv: | |
283 | kfree(priv); | |
284 | out_free_opp: | |
285 | dev_pm_opp_of_cpumask_remove_table(policy->cpus); | |
286 | if (name) | |
287 | dev_pm_opp_put_regulators(opp_table); | |
288 | out_put_clk: | |
289 | clk_put(cpu_clk); | |
290 | ||
291 | return ret; | |
292 | } | |
293 | ||
294 | static int cpufreq_exit(struct cpufreq_policy *policy) | |
295 | { | |
296 | struct private_data *priv = policy->driver_data; | |
297 | ||
298 | cpufreq_cooling_unregister(priv->cdev); | |
299 | dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); | |
300 | dev_pm_opp_of_cpumask_remove_table(policy->related_cpus); | |
301 | if (priv->reg_name) | |
302 | dev_pm_opp_put_regulators(priv->opp_table); | |
303 | ||
304 | clk_put(policy->clk); | |
305 | kfree(priv); | |
306 | ||
307 | return 0; | |
308 | } | |
309 | ||
310 | static void cpufreq_ready(struct cpufreq_policy *policy) | |
311 | { | |
312 | struct private_data *priv = policy->driver_data; | |
313 | struct device_node *np = of_node_get(priv->cpu_dev->of_node); | |
314 | ||
315 | if (WARN_ON(!np)) | |
316 | return; | |
317 | ||
318 | /* | |
319 | * For now, just loading the cooling device; | |
320 | * thermal DT code takes care of matching them. | |
321 | */ | |
322 | if (of_find_property(np, "#cooling-cells", NULL)) { | |
323 | u32 power_coefficient = 0; | |
324 | ||
325 | of_property_read_u32(np, "dynamic-power-coefficient", | |
326 | &power_coefficient); | |
327 | ||
328 | priv->cdev = of_cpufreq_power_cooling_register(np, | |
329 | policy, power_coefficient, NULL); | |
330 | if (IS_ERR(priv->cdev)) { | |
331 | dev_err(priv->cpu_dev, | |
332 | "running cpufreq without cooling device: %ld\n", | |
333 | PTR_ERR(priv->cdev)); | |
334 | ||
335 | priv->cdev = NULL; | |
336 | } | |
337 | } | |
338 | ||
339 | of_node_put(np); | |
340 | } | |
341 | ||
342 | static struct cpufreq_driver dt_cpufreq_driver = { | |
343 | .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, | |
344 | .verify = cpufreq_generic_frequency_table_verify, | |
345 | .target_index = set_target, | |
346 | .get = cpufreq_generic_get, | |
347 | .init = cpufreq_init, | |
348 | .exit = cpufreq_exit, | |
349 | .ready = cpufreq_ready, | |
350 | .name = "cpufreq-dt", | |
351 | .attr = cpufreq_dt_attr, | |
352 | .suspend = cpufreq_generic_suspend, | |
353 | }; | |
354 | ||
355 | static int dt_cpufreq_probe(struct platform_device *pdev) | |
356 | { | |
357 | struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev); | |
358 | int ret; | |
359 | ||
360 | /* | |
361 | * All per-cluster (CPUs sharing clock/voltages) initialization is done | |
362 | * from ->init(). In probe(), we just need to make sure that clk and | |
363 | * regulators are available. Else defer probe and retry. | |
364 | * | |
365 | * FIXME: Is checking this only for CPU0 sufficient ? | |
366 | */ | |
367 | ret = resources_available(); | |
368 | if (ret) | |
369 | return ret; | |
370 | ||
371 | if (data && data->have_governor_per_policy) | |
372 | dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY; | |
373 | ||
374 | ret = cpufreq_register_driver(&dt_cpufreq_driver); | |
375 | if (ret) | |
376 | dev_err(&pdev->dev, "failed register driver: %d\n", ret); | |
377 | ||
378 | return ret; | |
379 | } | |
380 | ||
381 | static int dt_cpufreq_remove(struct platform_device *pdev) | |
382 | { | |
383 | cpufreq_unregister_driver(&dt_cpufreq_driver); | |
384 | return 0; | |
385 | } | |
386 | ||
387 | static struct platform_driver dt_cpufreq_platdrv = { | |
388 | .driver = { | |
389 | .name = "cpufreq-dt", | |
390 | }, | |
391 | .probe = dt_cpufreq_probe, | |
392 | .remove = dt_cpufreq_remove, | |
393 | }; | |
394 | module_platform_driver(dt_cpufreq_platdrv); | |
395 | ||
396 | MODULE_ALIAS("platform:cpufreq-dt"); | |
397 | MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); | |
398 | MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); | |
399 | MODULE_DESCRIPTION("Generic cpufreq driver"); | |
400 | MODULE_LICENSE("GPL"); |