2 * Copyright (C) 2012 Freescale Semiconductor, Inc.
4 * Copyright (C) 2014 Linaro.
5 * Viresh Kumar <viresh.kumar@linaro.org>
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.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
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>
28 #include "cpufreq-dt.h"
31 struct opp_table *opp_table;
32 struct device *cpu_dev;
33 struct thermal_cooling_device *cdev;
35 bool have_static_opps;
38 static struct freq_attr *cpufreq_dt_attr[] = {
39 &cpufreq_freq_attr_scaling_available_freqs,
40 NULL, /* Extra space for boost-attr if required */
44 static int set_target(struct cpufreq_policy *policy, unsigned int index)
46 struct private_data *priv = policy->driver_data;
48 return dev_pm_opp_set_rate(priv->cpu_dev,
49 policy->freq_table[index].frequency * 1000);
53 * An earlier version of opp-v1 bindings used to name the regulator
54 * "cpu0-supply", we still need to handle that for backwards compatibility.
56 static const char *find_supply_name(struct device *dev)
58 struct device_node *np;
61 const char *name = NULL;
63 np = of_node_get(dev->of_node);
65 /* This must be valid for sure */
69 /* Try "cpu0" for older DTs */
71 pp = of_find_property(np, "cpu0-supply", NULL);
78 pp = of_find_property(np, "cpu-supply", NULL);
84 dev_dbg(dev, "no regulator for cpu%d\n", cpu);
90 static int resources_available(void)
92 struct device *cpu_dev;
93 struct regulator *cpu_reg;
98 cpu_dev = get_cpu_device(0);
100 pr_err("failed to get cpu0 device\n");
104 cpu_clk = clk_get(cpu_dev, NULL);
105 ret = PTR_ERR_OR_ZERO(cpu_clk);
108 * If cpu's clk node is present, but clock is not yet
109 * registered, we should try defering probe.
111 if (ret == -EPROBE_DEFER)
112 dev_dbg(cpu_dev, "clock not ready, retry\n");
114 dev_err(cpu_dev, "failed to get clock: %d\n", ret);
121 name = find_supply_name(cpu_dev);
122 /* Platform doesn't require regulator */
126 cpu_reg = regulator_get_optional(cpu_dev, name);
127 ret = PTR_ERR_OR_ZERO(cpu_reg);
130 * If cpu's regulator supply node is present, but regulator is
131 * not yet registered, we should try defering probe.
133 if (ret == -EPROBE_DEFER)
134 dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n");
136 dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret);
141 regulator_put(cpu_reg);
145 static int cpufreq_init(struct cpufreq_policy *policy)
147 struct cpufreq_frequency_table *freq_table;
148 struct opp_table *opp_table = NULL;
149 struct private_data *priv;
150 struct device *cpu_dev;
152 unsigned int transition_latency;
153 bool fallback = false;
157 cpu_dev = get_cpu_device(policy->cpu);
159 pr_err("failed to get cpu%d device\n", policy->cpu);
163 cpu_clk = clk_get(cpu_dev, NULL);
164 if (IS_ERR(cpu_clk)) {
165 ret = PTR_ERR(cpu_clk);
166 dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret);
170 /* Get OPP-sharing information from "operating-points-v2" bindings */
171 ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus);
177 * operating-points-v2 not supported, fallback to old method of
178 * finding shared-OPPs for backward compatibility if the
179 * platform hasn't set sharing CPUs.
181 if (dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus))
186 * OPP layer will be taking care of regulators now, but it needs to know
187 * the name of the regulator first.
189 name = find_supply_name(cpu_dev);
191 opp_table = dev_pm_opp_set_regulators(cpu_dev, &name, 1);
192 if (IS_ERR(opp_table)) {
193 ret = PTR_ERR(opp_table);
194 dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n",
200 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
203 goto out_put_regulator;
206 priv->reg_name = name;
207 priv->opp_table = opp_table;
210 * Initialize OPP tables for all policy->cpus. They will be shared by
211 * all CPUs which have marked their CPUs shared with OPP bindings.
213 * For platforms not using operating-points-v2 bindings, we do this
214 * before updating policy->cpus. Otherwise, we will end up creating
215 * duplicate OPPs for policy->cpus.
217 * OPPs might be populated at runtime, don't check for error here
219 if (!dev_pm_opp_of_cpumask_add_table(policy->cpus))
220 priv->have_static_opps = true;
223 * But we need OPP table to function so if it is not there let's
224 * give platform code chance to provide it for us.
226 ret = dev_pm_opp_get_opp_count(cpu_dev);
228 dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n");
234 cpumask_setall(policy->cpus);
237 * OPP tables are initialized only for policy->cpu, do it for
240 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
242 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
246 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
248 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
252 priv->cpu_dev = cpu_dev;
253 policy->driver_data = priv;
254 policy->clk = cpu_clk;
256 policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000;
258 ret = cpufreq_table_validate_and_show(policy, freq_table);
260 dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__,
262 goto out_free_cpufreq_table;
265 /* Support turbo/boost mode */
266 if (policy_has_boost_freq(policy)) {
267 /* This gets disabled by core on driver unregister */
268 ret = cpufreq_enable_boost_support();
270 goto out_free_cpufreq_table;
271 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
274 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
275 if (!transition_latency)
276 transition_latency = CPUFREQ_ETERNAL;
278 policy->cpuinfo.transition_latency = transition_latency;
279 policy->dvfs_possible_from_any_cpu = true;
283 out_free_cpufreq_table:
284 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
286 if (priv->have_static_opps)
287 dev_pm_opp_of_cpumask_remove_table(policy->cpus);
291 dev_pm_opp_put_regulators(opp_table);
298 static int cpufreq_exit(struct cpufreq_policy *policy)
300 struct private_data *priv = policy->driver_data;
302 cpufreq_cooling_unregister(priv->cdev);
303 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
304 if (priv->have_static_opps)
305 dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
307 dev_pm_opp_put_regulators(priv->opp_table);
309 clk_put(policy->clk);
315 static void cpufreq_ready(struct cpufreq_policy *policy)
317 struct private_data *priv = policy->driver_data;
318 struct device_node *np = of_node_get(priv->cpu_dev->of_node);
324 * For now, just loading the cooling device;
325 * thermal DT code takes care of matching them.
327 if (of_find_property(np, "#cooling-cells", NULL)) {
328 u32 power_coefficient = 0;
330 of_property_read_u32(np, "dynamic-power-coefficient",
333 priv->cdev = of_cpufreq_power_cooling_register(np,
334 policy, power_coefficient, NULL);
335 if (IS_ERR(priv->cdev)) {
336 dev_err(priv->cpu_dev,
337 "running cpufreq without cooling device: %ld\n",
338 PTR_ERR(priv->cdev));
347 static struct cpufreq_driver dt_cpufreq_driver = {
348 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
349 .verify = cpufreq_generic_frequency_table_verify,
350 .target_index = set_target,
351 .get = cpufreq_generic_get,
352 .init = cpufreq_init,
353 .exit = cpufreq_exit,
354 .ready = cpufreq_ready,
355 .name = "cpufreq-dt",
356 .attr = cpufreq_dt_attr,
357 .suspend = cpufreq_generic_suspend,
360 static int dt_cpufreq_probe(struct platform_device *pdev)
362 struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev);
366 * All per-cluster (CPUs sharing clock/voltages) initialization is done
367 * from ->init(). In probe(), we just need to make sure that clk and
368 * regulators are available. Else defer probe and retry.
370 * FIXME: Is checking this only for CPU0 sufficient ?
372 ret = resources_available();
376 if (data && data->have_governor_per_policy)
377 dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY;
379 ret = cpufreq_register_driver(&dt_cpufreq_driver);
381 dev_err(&pdev->dev, "failed register driver: %d\n", ret);
386 static int dt_cpufreq_remove(struct platform_device *pdev)
388 cpufreq_unregister_driver(&dt_cpufreq_driver);
392 static struct platform_driver dt_cpufreq_platdrv = {
394 .name = "cpufreq-dt",
396 .probe = dt_cpufreq_probe,
397 .remove = dt_cpufreq_remove,
399 module_platform_driver(dt_cpufreq_platdrv);
401 MODULE_ALIAS("platform:cpufreq-dt");
402 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
403 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
404 MODULE_DESCRIPTION("Generic cpufreq driver");
405 MODULE_LICENSE("GPL");