1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2012 Freescale Semiconductor, Inc.
4 *
5 * Copyright (C) 2014 Linaro.
6 * Viresh Kumar <viresh.kumar@linaro.org>
7 */
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/list.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/pm_opp.h>
20 #include <linux/platform_device.h>
21 #include <linux/regulator/consumer.h>
22 #include <linux/slab.h>
23 #include <linux/thermal.h>
24
25 #include "cpufreq-dt.h"
26
27 struct private_data {
28 struct list_head node;
29
30 cpumask_var_t cpus;
31 struct device *cpu_dev;
32 struct opp_table *opp_table;
33 struct opp_table *reg_opp_table;
34 bool have_static_opps;
35 };
36
37 static LIST_HEAD(priv_list);
38
39 static struct freq_attr *cpufreq_dt_attr[] = {
40 &cpufreq_freq_attr_scaling_available_freqs,
41 NULL, /* Extra space for boost-attr if required */
42 NULL,
43 };
44
cpufreq_dt_find_data(int cpu)45 static struct private_data *cpufreq_dt_find_data(int cpu)
46 {
47 struct private_data *priv;
48
49 list_for_each_entry(priv, &priv_list, node) {
50 if (cpumask_test_cpu(cpu, priv->cpus))
51 return priv;
52 }
53
54 return NULL;
55 }
56
set_target(struct cpufreq_policy * policy,unsigned int index)57 static int set_target(struct cpufreq_policy *policy, unsigned int index)
58 {
59 struct private_data *priv = policy->driver_data;
60 unsigned long freq = policy->freq_table[index].frequency;
61
62 return dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000);
63 }
64
65 /*
66 * An earlier version of opp-v1 bindings used to name the regulator
67 * "cpu0-supply", we still need to handle that for backwards compatibility.
68 */
find_supply_name(struct device * dev)69 static const char *find_supply_name(struct device *dev)
70 {
71 struct device_node *np;
72 struct property *pp;
73 int cpu = dev->id;
74 const char *name = NULL;
75
76 np = of_node_get(dev->of_node);
77
78 /* This must be valid for sure */
79 if (WARN_ON(!np))
80 return NULL;
81
82 /* Try "cpu0" for older DTs */
83 if (!cpu) {
84 pp = of_find_property(np, "cpu0-supply", NULL);
85 if (pp) {
86 name = "cpu0";
87 goto node_put;
88 }
89 }
90
91 pp = of_find_property(np, "cpu-supply", NULL);
92 if (pp) {
93 name = "cpu";
94 goto node_put;
95 }
96
97 dev_dbg(dev, "no regulator for cpu%d\n", cpu);
98 node_put:
99 of_node_put(np);
100 return name;
101 }
102
cpufreq_init(struct cpufreq_policy * policy)103 static int cpufreq_init(struct cpufreq_policy *policy)
104 {
105 struct cpufreq_frequency_table *freq_table;
106 struct private_data *priv;
107 struct device *cpu_dev;
108 struct clk *cpu_clk;
109 unsigned int transition_latency;
110 int ret;
111
112 priv = cpufreq_dt_find_data(policy->cpu);
113 if (!priv) {
114 pr_err("failed to find data for cpu%d\n", policy->cpu);
115 return -ENODEV;
116 }
117
118 cpu_dev = priv->cpu_dev;
119 cpumask_copy(policy->cpus, priv->cpus);
120
121 cpu_clk = clk_get(cpu_dev, NULL);
122 if (IS_ERR(cpu_clk)) {
123 ret = PTR_ERR(cpu_clk);
124 dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret);
125 return ret;
126 }
127
128 /*
129 * Initialize OPP tables for all policy->cpus. They will be shared by
130 * all CPUs which have marked their CPUs shared with OPP bindings.
131 *
132 * For platforms not using operating-points-v2 bindings, we do this
133 * before updating policy->cpus. Otherwise, we will end up creating
134 * duplicate OPPs for policy->cpus.
135 *
136 * OPPs might be populated at runtime, don't check for error here
137 */
138 if (!dev_pm_opp_of_cpumask_add_table(policy->cpus))
139 priv->have_static_opps = true;
140
141 /*
142 * But we need OPP table to function so if it is not there let's
143 * give platform code chance to provide it for us.
144 */
145 ret = dev_pm_opp_get_opp_count(cpu_dev);
146 if (ret <= 0) {
147 dev_err(cpu_dev, "OPP table can't be empty\n");
148 ret = -ENODEV;
149 goto out_free_opp;
150 }
151
152 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
153 if (ret) {
154 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
155 goto out_free_opp;
156 }
157
158 policy->driver_data = priv;
159 policy->clk = cpu_clk;
160 policy->freq_table = freq_table;
161
162 policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000;
163
164 /* Support turbo/boost mode */
165 if (policy_has_boost_freq(policy)) {
166 /* This gets disabled by core on driver unregister */
167 ret = cpufreq_enable_boost_support();
168 if (ret)
169 goto out_free_cpufreq_table;
170 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
171 }
172
173 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
174 if (!transition_latency)
175 transition_latency = CPUFREQ_ETERNAL;
176
177 policy->cpuinfo.transition_latency = transition_latency;
178 policy->dvfs_possible_from_any_cpu = true;
179
180 dev_pm_opp_of_register_em(cpu_dev, policy->cpus);
181
182 return 0;
183
184 out_free_cpufreq_table:
185 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
186 out_free_opp:
187 if (priv->have_static_opps)
188 dev_pm_opp_of_cpumask_remove_table(policy->cpus);
189 clk_put(cpu_clk);
190
191 return ret;
192 }
193
cpufreq_online(struct cpufreq_policy * policy)194 static int cpufreq_online(struct cpufreq_policy *policy)
195 {
196 /* We did light-weight tear down earlier, nothing to do here */
197 return 0;
198 }
199
cpufreq_offline(struct cpufreq_policy * policy)200 static int cpufreq_offline(struct cpufreq_policy *policy)
201 {
202 /*
203 * Preserve policy->driver_data and don't free resources on light-weight
204 * tear down.
205 */
206 return 0;
207 }
208
cpufreq_exit(struct cpufreq_policy * policy)209 static int cpufreq_exit(struct cpufreq_policy *policy)
210 {
211 struct private_data *priv = policy->driver_data;
212
213 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
214 if (priv->have_static_opps)
215 dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
216 clk_put(policy->clk);
217 return 0;
218 }
219
220 static struct cpufreq_driver dt_cpufreq_driver = {
221 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK |
222 CPUFREQ_IS_COOLING_DEV,
223 .verify = cpufreq_generic_frequency_table_verify,
224 .target_index = set_target,
225 .get = cpufreq_generic_get,
226 .init = cpufreq_init,
227 .exit = cpufreq_exit,
228 .online = cpufreq_online,
229 .offline = cpufreq_offline,
230 .name = "cpufreq-dt",
231 .attr = cpufreq_dt_attr,
232 .suspend = cpufreq_generic_suspend,
233 };
234
dt_cpufreq_early_init(struct device * dev,int cpu)235 static int dt_cpufreq_early_init(struct device *dev, int cpu)
236 {
237 struct private_data *priv;
238 struct device *cpu_dev;
239 const char *reg_name;
240 int ret;
241
242 /* Check if this CPU is already covered by some other policy */
243 if (cpufreq_dt_find_data(cpu))
244 return 0;
245
246 cpu_dev = get_cpu_device(cpu);
247 if (!cpu_dev)
248 return -EPROBE_DEFER;
249
250 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
251 if (!priv)
252 return -ENOMEM;
253
254 if (!alloc_cpumask_var(&priv->cpus, GFP_KERNEL))
255 return -ENOMEM;
256
257 priv->cpu_dev = cpu_dev;
258
259 /* Try to get OPP table early to ensure resources are available */
260 priv->opp_table = dev_pm_opp_get_opp_table(cpu_dev);
261 if (IS_ERR(priv->opp_table)) {
262 ret = PTR_ERR(priv->opp_table);
263 if (ret != -EPROBE_DEFER)
264 dev_err(cpu_dev, "failed to get OPP table: %d\n", ret);
265 goto free_cpumask;
266 }
267
268 /*
269 * OPP layer will be taking care of regulators now, but it needs to know
270 * the name of the regulator first.
271 */
272 reg_name = find_supply_name(cpu_dev);
273 if (reg_name) {
274 priv->reg_opp_table = dev_pm_opp_set_regulators(cpu_dev,
275 ®_name, 1);
276 if (IS_ERR(priv->reg_opp_table)) {
277 ret = PTR_ERR(priv->reg_opp_table);
278 if (ret != -EPROBE_DEFER)
279 dev_err(cpu_dev, "failed to set regulators: %d\n",
280 ret);
281 goto put_table;
282 }
283 }
284
285 /* Find OPP sharing information so we can fill pri->cpus here */
286 /* Get OPP-sharing information from "operating-points-v2" bindings */
287 ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, priv->cpus);
288 if (ret) {
289 if (ret != -ENOENT)
290 goto put_reg;
291
292 /*
293 * operating-points-v2 not supported, fallback to all CPUs share
294 * OPP for backward compatibility if the platform hasn't set
295 * sharing CPUs.
296 */
297 if (dev_pm_opp_get_sharing_cpus(cpu_dev, priv->cpus)) {
298 cpumask_setall(priv->cpus);
299
300 /*
301 * OPP tables are initialized only for cpu, do it for
302 * others as well.
303 */
304 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, priv->cpus);
305 if (ret)
306 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
307 __func__, ret);
308 }
309 }
310
311 list_add(&priv->node, &priv_list);
312 return 0;
313
314 put_reg:
315 if (priv->reg_opp_table)
316 dev_pm_opp_put_regulators(priv->reg_opp_table);
317 put_table:
318 dev_pm_opp_put_opp_table(priv->opp_table);
319 free_cpumask:
320 free_cpumask_var(priv->cpus);
321 return ret;
322 }
323
dt_cpufreq_release(void)324 static void dt_cpufreq_release(void)
325 {
326 struct private_data *priv, *tmp;
327
328 list_for_each_entry_safe(priv, tmp, &priv_list, node) {
329 if (priv->reg_opp_table)
330 dev_pm_opp_put_regulators(priv->reg_opp_table);
331 dev_pm_opp_put_opp_table(priv->opp_table);
332 free_cpumask_var(priv->cpus);
333 list_del(&priv->node);
334 }
335 }
336
dt_cpufreq_probe(struct platform_device * pdev)337 static int dt_cpufreq_probe(struct platform_device *pdev)
338 {
339 struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev);
340 int ret, cpu;
341
342 /* Request resources early so we can return in case of -EPROBE_DEFER */
343 for_each_possible_cpu(cpu) {
344 ret = dt_cpufreq_early_init(&pdev->dev, cpu);
345 if (ret)
346 goto err;
347 }
348
349 if (data) {
350 if (data->have_governor_per_policy)
351 dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY;
352
353 dt_cpufreq_driver.resume = data->resume;
354 if (data->suspend)
355 dt_cpufreq_driver.suspend = data->suspend;
356 if (data->get_intermediate) {
357 dt_cpufreq_driver.target_intermediate = data->target_intermediate;
358 dt_cpufreq_driver.get_intermediate = data->get_intermediate;
359 }
360 }
361
362 ret = cpufreq_register_driver(&dt_cpufreq_driver);
363 if (ret) {
364 dev_err(&pdev->dev, "failed register driver: %d\n", ret);
365 goto err;
366 }
367
368 return 0;
369 err:
370 dt_cpufreq_release();
371 return ret;
372 }
373
dt_cpufreq_remove(struct platform_device * pdev)374 static int dt_cpufreq_remove(struct platform_device *pdev)
375 {
376 cpufreq_unregister_driver(&dt_cpufreq_driver);
377 dt_cpufreq_release();
378 return 0;
379 }
380
381 static struct platform_driver dt_cpufreq_platdrv = {
382 .driver = {
383 .name = "cpufreq-dt",
384 },
385 .probe = dt_cpufreq_probe,
386 .remove = dt_cpufreq_remove,
387 };
388 module_platform_driver(dt_cpufreq_platdrv);
389
390 MODULE_ALIAS("platform:cpufreq-dt");
391 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
392 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
393 MODULE_DESCRIPTION("Generic cpufreq driver");
394 MODULE_LICENSE("GPL");
395