1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2012 Freescale Semiconductor, Inc.
5 * Copyright (C) 2014 Linaro.
6 * Viresh Kumar <viresh.kumar@linaro.org>
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
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>
24 #include "cpufreq-dt.h"
27 struct opp_table *opp_table;
28 struct device *cpu_dev;
30 bool have_static_opps;
33 static struct freq_attr *cpufreq_dt_attr[] = {
34 &cpufreq_freq_attr_scaling_available_freqs,
35 NULL, /* Extra space for boost-attr if required */
39 static int set_target(struct cpufreq_policy *policy, unsigned int index)
41 struct private_data *priv = policy->driver_data;
42 unsigned long freq = policy->freq_table[index].frequency;
45 ret = dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000);
48 arch_set_freq_scale(policy->related_cpus, freq,
49 policy->cpuinfo.max_freq);
56 * An earlier version of opp-v1 bindings used to name the regulator
57 * "cpu0-supply", we still need to handle that for backwards compatibility.
59 static const char *find_supply_name(struct device *dev)
61 struct device_node *np;
64 const char *name = NULL;
66 np = of_node_get(dev->of_node);
68 /* This must be valid for sure */
72 /* Try "cpu0" for older DTs */
74 pp = of_find_property(np, "cpu0-supply", NULL);
81 pp = of_find_property(np, "cpu-supply", NULL);
87 dev_dbg(dev, "no regulator for cpu%d\n", cpu);
93 static int resources_available(void)
95 struct device *cpu_dev;
96 struct regulator *cpu_reg;
101 cpu_dev = get_cpu_device(0);
103 pr_err("failed to get cpu0 device\n");
107 cpu_clk = clk_get(cpu_dev, NULL);
108 ret = PTR_ERR_OR_ZERO(cpu_clk);
111 * If cpu's clk node is present, but clock is not yet
112 * registered, we should try defering probe.
114 if (ret == -EPROBE_DEFER)
115 dev_dbg(cpu_dev, "clock not ready, retry\n");
117 dev_err(cpu_dev, "failed to get clock: %d\n", ret);
124 name = find_supply_name(cpu_dev);
125 /* Platform doesn't require regulator */
129 cpu_reg = regulator_get_optional(cpu_dev, name);
130 ret = PTR_ERR_OR_ZERO(cpu_reg);
133 * If cpu's regulator supply node is present, but regulator is
134 * not yet registered, we should try defering probe.
136 if (ret == -EPROBE_DEFER)
137 dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n");
139 dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret);
144 regulator_put(cpu_reg);
148 static int cpufreq_init(struct cpufreq_policy *policy)
150 struct cpufreq_frequency_table *freq_table;
151 struct opp_table *opp_table = NULL;
152 struct private_data *priv;
153 struct device *cpu_dev;
155 unsigned int transition_latency;
156 bool fallback = false;
160 cpu_dev = get_cpu_device(policy->cpu);
162 pr_err("failed to get cpu%d device\n", policy->cpu);
166 cpu_clk = clk_get(cpu_dev, NULL);
167 if (IS_ERR(cpu_clk)) {
168 ret = PTR_ERR(cpu_clk);
169 dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret);
173 /* Get OPP-sharing information from "operating-points-v2" bindings */
174 ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus);
180 * operating-points-v2 not supported, fallback to old method of
181 * finding shared-OPPs for backward compatibility if the
182 * platform hasn't set sharing CPUs.
184 if (dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus))
189 * OPP layer will be taking care of regulators now, but it needs to know
190 * the name of the regulator first.
192 name = find_supply_name(cpu_dev);
194 opp_table = dev_pm_opp_set_regulators(cpu_dev, &name, 1);
195 if (IS_ERR(opp_table)) {
196 ret = PTR_ERR(opp_table);
197 dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n",
203 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
206 goto out_put_regulator;
209 priv->reg_name = name;
210 priv->opp_table = opp_table;
213 * Initialize OPP tables for all policy->cpus. They will be shared by
214 * all CPUs which have marked their CPUs shared with OPP bindings.
216 * For platforms not using operating-points-v2 bindings, we do this
217 * before updating policy->cpus. Otherwise, we will end up creating
218 * duplicate OPPs for policy->cpus.
220 * OPPs might be populated at runtime, don't check for error here
222 if (!dev_pm_opp_of_cpumask_add_table(policy->cpus))
223 priv->have_static_opps = true;
226 * But we need OPP table to function so if it is not there let's
227 * give platform code chance to provide it for us.
229 ret = dev_pm_opp_get_opp_count(cpu_dev);
231 dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n");
237 cpumask_setall(policy->cpus);
240 * OPP tables are initialized only for policy->cpu, do it for
243 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
245 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
249 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
251 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
255 priv->cpu_dev = cpu_dev;
256 policy->driver_data = priv;
257 policy->clk = cpu_clk;
258 policy->freq_table = freq_table;
260 policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000;
262 /* Support turbo/boost mode */
263 if (policy_has_boost_freq(policy)) {
264 /* This gets disabled by core on driver unregister */
265 ret = cpufreq_enable_boost_support();
267 goto out_free_cpufreq_table;
268 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
271 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
272 if (!transition_latency)
273 transition_latency = CPUFREQ_ETERNAL;
275 policy->cpuinfo.transition_latency = transition_latency;
276 policy->dvfs_possible_from_any_cpu = true;
278 dev_pm_opp_of_register_em(policy->cpus);
282 out_free_cpufreq_table:
283 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
285 if (priv->have_static_opps)
286 dev_pm_opp_of_cpumask_remove_table(policy->cpus);
290 dev_pm_opp_put_regulators(opp_table);
297 static int cpufreq_online(struct cpufreq_policy *policy)
299 /* We did light-weight tear down earlier, nothing to do here */
303 static int cpufreq_offline(struct cpufreq_policy *policy)
306 * Preserve policy->driver_data and don't free resources on light-weight
312 static int cpufreq_exit(struct cpufreq_policy *policy)
314 struct private_data *priv = policy->driver_data;
316 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
317 if (priv->have_static_opps)
318 dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
320 dev_pm_opp_put_regulators(priv->opp_table);
322 clk_put(policy->clk);
328 static struct cpufreq_driver dt_cpufreq_driver = {
329 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK |
330 CPUFREQ_IS_COOLING_DEV,
331 .verify = cpufreq_generic_frequency_table_verify,
332 .target_index = set_target,
333 .get = cpufreq_generic_get,
334 .init = cpufreq_init,
335 .exit = cpufreq_exit,
336 .online = cpufreq_online,
337 .offline = cpufreq_offline,
338 .name = "cpufreq-dt",
339 .attr = cpufreq_dt_attr,
340 .suspend = cpufreq_generic_suspend,
343 static int dt_cpufreq_probe(struct platform_device *pdev)
345 struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev);
349 * All per-cluster (CPUs sharing clock/voltages) initialization is done
350 * from ->init(). In probe(), we just need to make sure that clk and
351 * regulators are available. Else defer probe and retry.
353 * FIXME: Is checking this only for CPU0 sufficient ?
355 ret = resources_available();
360 if (data->have_governor_per_policy)
361 dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY;
363 dt_cpufreq_driver.resume = data->resume;
365 dt_cpufreq_driver.suspend = data->suspend;
368 ret = cpufreq_register_driver(&dt_cpufreq_driver);
370 dev_err(&pdev->dev, "failed register driver: %d\n", ret);
375 static int dt_cpufreq_remove(struct platform_device *pdev)
377 cpufreq_unregister_driver(&dt_cpufreq_driver);
381 static struct platform_driver dt_cpufreq_platdrv = {
383 .name = "cpufreq-dt",
385 .probe = dt_cpufreq_probe,
386 .remove = dt_cpufreq_remove,
388 module_platform_driver(dt_cpufreq_platdrv);
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");