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;
37 static struct freq_attr *cpufreq_dt_attr[] = {
38 &cpufreq_freq_attr_scaling_available_freqs,
39 NULL, /* Extra space for boost-attr if required */
43 static int set_target(struct cpufreq_policy *policy, unsigned int index)
45 struct private_data *priv = policy->driver_data;
47 return dev_pm_opp_set_rate(priv->cpu_dev,
48 policy->freq_table[index].frequency * 1000);
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.
55 static const char *find_supply_name(struct device *dev)
57 struct device_node *np;
60 const char *name = NULL;
62 np = of_node_get(dev->of_node);
64 /* This must be valid for sure */
68 /* Try "cpu0" for older DTs */
70 pp = of_find_property(np, "cpu0-supply", NULL);
77 pp = of_find_property(np, "cpu-supply", NULL);
83 dev_dbg(dev, "no regulator for cpu%d\n", cpu);
89 static int resources_available(void)
91 struct device *cpu_dev;
92 struct regulator *cpu_reg;
97 cpu_dev = get_cpu_device(0);
99 pr_err("failed to get cpu0 device\n");
103 cpu_clk = clk_get(cpu_dev, NULL);
104 ret = PTR_ERR_OR_ZERO(cpu_clk);
107 * If cpu's clk node is present, but clock is not yet
108 * registered, we should try defering probe.
110 if (ret == -EPROBE_DEFER)
111 dev_dbg(cpu_dev, "clock not ready, retry\n");
113 dev_err(cpu_dev, "failed to get clock: %d\n", ret);
120 name = find_supply_name(cpu_dev);
121 /* Platform doesn't require regulator */
125 cpu_reg = regulator_get_optional(cpu_dev, name);
126 ret = PTR_ERR_OR_ZERO(cpu_reg);
129 * If cpu's regulator supply node is present, but regulator is
130 * not yet registered, we should try defering probe.
132 if (ret == -EPROBE_DEFER)
133 dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n");
135 dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret);
140 regulator_put(cpu_reg);
144 static int cpufreq_init(struct cpufreq_policy *policy)
146 struct cpufreq_frequency_table *freq_table;
147 struct opp_table *opp_table = NULL;
148 struct private_data *priv;
149 struct device *cpu_dev;
151 struct dev_pm_opp *suspend_opp;
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",
201 * Initialize OPP tables for all policy->cpus. They will be shared by
202 * all CPUs which have marked their CPUs shared with OPP bindings.
204 * For platforms not using operating-points-v2 bindings, we do this
205 * before updating policy->cpus. Otherwise, we will end up creating
206 * duplicate OPPs for policy->cpus.
208 * OPPs might be populated at runtime, don't check for error here
210 dev_pm_opp_of_cpumask_add_table(policy->cpus);
213 * But we need OPP table to function so if it is not there let's
214 * give platform code chance to provide it for us.
216 ret = dev_pm_opp_get_opp_count(cpu_dev);
218 dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n");
224 cpumask_setall(policy->cpus);
227 * OPP tables are initialized only for policy->cpu, do it for
230 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
232 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
236 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
242 priv->reg_name = name;
243 priv->opp_table = opp_table;
245 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
247 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
251 priv->cpu_dev = cpu_dev;
252 policy->driver_data = priv;
253 policy->clk = cpu_clk;
256 suspend_opp = dev_pm_opp_get_suspend_opp(cpu_dev);
258 policy->suspend_freq = dev_pm_opp_get_freq(suspend_opp) / 1000;
261 ret = cpufreq_table_validate_and_show(policy, freq_table);
263 dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__,
265 goto out_free_cpufreq_table;
268 /* Support turbo/boost mode */
269 if (policy_has_boost_freq(policy)) {
270 /* This gets disabled by core on driver unregister */
271 ret = cpufreq_enable_boost_support();
273 goto out_free_cpufreq_table;
274 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
277 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
278 if (!transition_latency)
279 transition_latency = CPUFREQ_ETERNAL;
281 policy->cpuinfo.transition_latency = transition_latency;
285 out_free_cpufreq_table:
286 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
290 dev_pm_opp_of_cpumask_remove_table(policy->cpus);
292 dev_pm_opp_put_regulators(opp_table);
299 static int cpufreq_exit(struct cpufreq_policy *policy)
301 struct private_data *priv = policy->driver_data;
303 cpufreq_cooling_unregister(priv->cdev);
304 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
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->related_cpus, 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");