2 * Copyright (C) 2012 Freescale Semiconductor, Inc.
4 * Copyright (C) 2014 Linaro.
5 * Viresh Kumar <viresh.kumar@linaro.org>
7 * The OPP code in function set_target() is reused from
8 * drivers/cpufreq/omap-cpufreq.c
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 #include <linux/clk.h>
18 #include <linux/cpu.h>
19 #include <linux/cpu_cooling.h>
20 #include <linux/cpufreq.h>
21 #include <linux/cpufreq-dt.h>
22 #include <linux/cpumask.h>
23 #include <linux/err.h>
24 #include <linux/module.h>
26 #include <linux/pm_opp.h>
27 #include <linux/platform_device.h>
28 #include <linux/regulator/consumer.h>
29 #include <linux/slab.h>
30 #include <linux/thermal.h>
33 struct device *cpu_dev;
34 struct thermal_cooling_device *cdev;
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 private_data *priv;
149 struct device *cpu_dev;
151 struct dev_pm_opp *suspend_opp;
152 #ifdef CONFIG_ARCH_ROCKCHIP
155 unsigned int transition_latency;
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);
177 * operating-points-v2 not supported, fallback to old method of
178 * finding shared-OPPs for backward compatibility.
187 * OPP layer will be taking care of regulators now, but it needs to know
188 * the name of the regulator first.
190 name = find_supply_name(cpu_dev);
192 ret = dev_pm_opp_set_regulator(cpu_dev, name);
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 #ifdef CONFIG_ARCH_ROCKCHIP
211 ret = dev_pm_opp_of_add_table(cpu_dev);
213 dev_err(cpu_dev, "couldn't find opp table for cpu:%d, %d\n",
216 cpumask_copy(&cpus, policy->cpus);
217 cpumask_clear_cpu(policy->cpu, &cpus);
218 if (!cpumask_empty(&cpus)) {
219 if (dev_pm_opp_of_cpumask_add_table(&cpus))
220 dev_pm_opp_of_remove_table(cpu_dev);
224 dev_pm_opp_of_cpumask_add_table(policy->cpus);
228 * But we need OPP table to function so if it is not there let's
229 * give platform code chance to provide it for us.
231 ret = dev_pm_opp_get_opp_count(cpu_dev);
233 dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n");
239 struct cpufreq_dt_platform_data *pd = cpufreq_get_driver_data();
241 if (!pd || !pd->independent_clocks)
242 cpumask_setall(policy->cpus);
245 * OPP tables are initialized only for policy->cpu, do it for
248 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
250 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
254 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
260 priv->reg_name = name;
262 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
264 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
268 priv->cpu_dev = cpu_dev;
269 policy->driver_data = priv;
270 policy->clk = cpu_clk;
273 suspend_opp = dev_pm_opp_get_suspend_opp(cpu_dev);
275 policy->suspend_freq = dev_pm_opp_get_freq(suspend_opp) / 1000;
278 ret = cpufreq_table_validate_and_show(policy, freq_table);
280 dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__,
282 goto out_free_cpufreq_table;
285 /* Support turbo/boost mode */
286 if (policy_has_boost_freq(policy)) {
287 /* This gets disabled by core on driver unregister */
288 ret = cpufreq_enable_boost_support();
290 goto out_free_cpufreq_table;
291 cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
294 transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
295 if (!transition_latency)
296 transition_latency = CPUFREQ_ETERNAL;
298 policy->cpuinfo.transition_latency = transition_latency;
302 out_free_cpufreq_table:
303 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
307 dev_pm_opp_of_cpumask_remove_table(policy->cpus);
309 dev_pm_opp_put_regulator(cpu_dev);
316 static int cpufreq_exit(struct cpufreq_policy *policy)
319 struct private_data *priv = policy->driver_data;
321 #ifdef CONFIG_ARCH_ROCKCHIP
322 cpumask_set_cpu(policy->cpu, policy->cpus);
323 if (cpufreq_generic_suspend(policy))
324 pr_err("%s: Failed to suspend driver: %p\n", __func__, policy);
325 cpumask_clear_cpu(policy->cpu, policy->cpus);
327 priv->cpu_dev = get_cpu_device(policy->cpu);
328 cpufreq_cooling_unregister(priv->cdev);
329 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
330 cpumask_copy(&cpus, policy->related_cpus);
331 cpumask_clear_cpu(policy->cpu, &cpus);
332 dev_pm_opp_of_cpumask_remove_table(&cpus);
333 dev_pm_opp_of_remove_table(priv->cpu_dev);
335 dev_pm_opp_put_regulator(priv->cpu_dev);
337 clk_put(policy->clk);
343 static void cpufreq_ready(struct cpufreq_policy *policy)
345 struct private_data *priv = policy->driver_data;
346 struct device_node *np = of_node_get(priv->cpu_dev->of_node);
352 * For now, just loading the cooling device;
353 * thermal DT code takes care of matching them.
355 if (of_find_property(np, "#cooling-cells", NULL)) {
356 u32 power_coefficient = 0;
358 of_property_read_u32(np, "dynamic-power-coefficient",
361 priv->cdev = of_cpufreq_power_cooling_register(np,
362 policy->related_cpus, power_coefficient, NULL);
363 if (IS_ERR(priv->cdev)) {
364 dev_err(priv->cpu_dev,
365 "running cpufreq without cooling device: %ld\n",
366 PTR_ERR(priv->cdev));
375 static struct cpufreq_driver dt_cpufreq_driver = {
376 #ifdef CONFIG_ARCH_ROCKCHIP
377 .flags = CPUFREQ_STICKY | CPUFREQ_HAVE_GOVERNOR_PER_POLICY,
379 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
381 .verify = cpufreq_generic_frequency_table_verify,
382 .target_index = set_target,
383 .get = cpufreq_generic_get,
384 .init = cpufreq_init,
385 .exit = cpufreq_exit,
386 .ready = cpufreq_ready,
387 .name = "cpufreq-dt",
388 .attr = cpufreq_dt_attr,
389 .suspend = cpufreq_generic_suspend,
392 static int dt_cpufreq_probe(struct platform_device *pdev)
397 * All per-cluster (CPUs sharing clock/voltages) initialization is done
398 * from ->init(). In probe(), we just need to make sure that clk and
399 * regulators are available. Else defer probe and retry.
401 * FIXME: Is checking this only for CPU0 sufficient ?
403 ret = resources_available();
407 dt_cpufreq_driver.driver_data = dev_get_platdata(&pdev->dev);
409 ret = cpufreq_register_driver(&dt_cpufreq_driver);
411 dev_err(&pdev->dev, "failed register driver: %d\n", ret);
416 static int dt_cpufreq_remove(struct platform_device *pdev)
418 cpufreq_unregister_driver(&dt_cpufreq_driver);
422 static struct platform_driver dt_cpufreq_platdrv = {
424 .name = "cpufreq-dt",
426 .probe = dt_cpufreq_probe,
427 .remove = dt_cpufreq_remove,
429 module_platform_driver(dt_cpufreq_platdrv);
431 MODULE_ALIAS("platform:cpufreq-dt");
432 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
433 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
434 MODULE_DESCRIPTION("Generic cpufreq driver");
435 MODULE_LICENSE("GPL");