[mirror_ubuntu-bionic-kernel.git] / drivers / cpufreq / cpufreq-dt.c

/*
 * Copyright (C) 2012 Freescale Semiconductor, Inc.
 *
 * Copyright (C) 2014 Linaro.
 * Viresh Kumar <viresh.kumar@linaro.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpu_cooling.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/thermal.h>

#include "cpufreq-dt.h"

struct private_data {
	struct opp_table *opp_table;
	struct device *cpu_dev;
	struct thermal_cooling_device *cdev;
	const char *reg_name;
	bool have_static_opps;
};

static struct freq_attr *cpufreq_dt_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,   /* Extra space for boost-attr if required */
	NULL,
};

static int set_target(struct cpufreq_policy *policy, unsigned int index)
{
	struct private_data *priv = policy->driver_data;
	unsigned long freq = policy->freq_table[index].frequency;
	int ret;

	ret = dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000);

	if (!ret) {
		arch_set_freq_scale(policy->related_cpus, freq,
				    policy->cpuinfo.max_freq);
	}

	return ret;
}

/*
 * An earlier version of opp-v1 bindings used to name the regulator
 * "cpu0-supply", we still need to handle that for backwards compatibility.
 */
static const char *find_supply_name(struct device *dev)
{
	struct device_node *np;
	struct property *pp;
	int cpu = dev->id;
	const char *name = NULL;

	np = of_node_get(dev->of_node);

	/* This must be valid for sure */
	if (WARN_ON(!np))
		return NULL;

	/* Try "cpu0" for older DTs */
	if (!cpu) {
		pp = of_find_property(np, "cpu0-supply", NULL);
		if (pp) {
			name = "cpu0";
			goto node_put;
		}
	}

	pp = of_find_property(np, "cpu-supply", NULL);
	if (pp) {
		name = "cpu";
		goto node_put;
	}

	dev_dbg(dev, "no regulator for cpu%d\n", cpu);
node_put:
	of_node_put(np);
	return name;
}

static int resources_available(void)
{
	struct device *cpu_dev;
	struct regulator *cpu_reg;
	struct clk *cpu_clk;
	int ret = 0;
	const char *name;

	cpu_dev = get_cpu_device(0);
	if (!cpu_dev) {
		pr_err("failed to get cpu0 device\n");
		return -ENODEV;
	}

	cpu_clk = clk_get(cpu_dev, NULL);
	ret = PTR_ERR_OR_ZERO(cpu_clk);
	if (ret) {
		/*
		 * If cpu's clk node is present, but clock is not yet
		 * registered, we should try defering probe.
		 */
		if (ret == -EPROBE_DEFER)
			dev_dbg(cpu_dev, "clock not ready, retry\n");
		else
			dev_err(cpu_dev, "failed to get clock: %d\n", ret);

		return ret;
	}

	clk_put(cpu_clk);

	name = find_supply_name(cpu_dev);
	/* Platform doesn't require regulator */
	if (!name)
		return 0;

	cpu_reg = regulator_get_optional(cpu_dev, name);
	ret = PTR_ERR_OR_ZERO(cpu_reg);
	if (ret) {
		/*
		 * If cpu's regulator supply node is present, but regulator is
		 * not yet registered, we should try defering probe.
		 */
		if (ret == -EPROBE_DEFER)
			dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n");
		else
			dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret);

		return ret;
	}

	regulator_put(cpu_reg);
	return 0;
}

static int cpufreq_init(struct cpufreq_policy *policy)
{
	struct cpufreq_frequency_table *freq_table;
	struct opp_table *opp_table = NULL;
	struct private_data *priv;
	struct device *cpu_dev;
	struct clk *cpu_clk;
	unsigned int transition_latency;
	bool fallback = false;
	const char *name;
	int ret;

	cpu_dev = get_cpu_device(policy->cpu);
	if (!cpu_dev) {
		pr_err("failed to get cpu%d device\n", policy->cpu);
		return -ENODEV;
	}

	cpu_clk = clk_get(cpu_dev, NULL);
	if (IS_ERR(cpu_clk)) {
		ret = PTR_ERR(cpu_clk);
		dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret);
		return ret;
	}

	/* Get OPP-sharing information from "operating-points-v2" bindings */
	ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus);
	if (ret) {
		if (ret != -ENOENT)
			goto out_put_clk;

		/*
		 * operating-points-v2 not supported, fallback to old method of
		 * finding shared-OPPs for backward compatibility if the
		 * platform hasn't set sharing CPUs.
		 */
		if (dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus))
			fallback = true;
	}

	/*
	 * OPP layer will be taking care of regulators now, but it needs to know
	 * the name of the regulator first.
	 */
	name = find_supply_name(cpu_dev);
	if (name) {
		opp_table = dev_pm_opp_set_regulators(cpu_dev, &name, 1);
		if (IS_ERR(opp_table)) {
			ret = PTR_ERR(opp_table);
			dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n",
				policy->cpu, ret);
			goto out_put_clk;
		}
	}

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv) {
		ret = -ENOMEM;
		goto out_put_regulator;
	}

	priv->reg_name = name;
	priv->opp_table = opp_table;

	/*
	 * Initialize OPP tables for all policy->cpus. They will be shared by
	 * all CPUs which have marked their CPUs shared with OPP bindings.
	 *
	 * For platforms not using operating-points-v2 bindings, we do this
	 * before updating policy->cpus. Otherwise, we will end up creating
	 * duplicate OPPs for policy->cpus.
	 *
	 * OPPs might be populated at runtime, don't check for error here
	 */
	if (!dev_pm_opp_of_cpumask_add_table(policy->cpus))
		priv->have_static_opps = true;

	/*
	 * But we need OPP table to function so if it is not there let's
	 * give platform code chance to provide it for us.
	 */
	ret = dev_pm_opp_get_opp_count(cpu_dev);
	if (ret <= 0) {
		dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n");
		ret = -EPROBE_DEFER;
		goto out_free_opp;
	}

	if (fallback) {
		cpumask_setall(policy->cpus);

		/*
		 * OPP tables are initialized only for policy->cpu, do it for
		 * others as well.
		 */
		ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
		if (ret)
			dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
				__func__, ret);
	}

	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
	if (ret) {
		dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
		goto out_free_opp;
	}

	priv->cpu_dev = cpu_dev;
	policy->driver_data = priv;
	policy->clk = cpu_clk;

	policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000;

	ret = cpufreq_table_validate_and_show(policy, freq_table);
	if (ret) {
		dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__,
			ret);
		goto out_free_cpufreq_table;
	}

	/* Support turbo/boost mode */
	if (policy_has_boost_freq(policy)) {
		/* This gets disabled by core on driver unregister */
		ret = cpufreq_enable_boost_support();
		if (ret)
			goto out_free_cpufreq_table;
		cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
	}

	transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
	if (!transition_latency)
		transition_latency = CPUFREQ_ETERNAL;

	policy->cpuinfo.transition_latency = transition_latency;
	policy->dvfs_possible_from_any_cpu = true;

	return 0;

out_free_cpufreq_table:
	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
out_free_opp:
	if (priv->have_static_opps)
		dev_pm_opp_of_cpumask_remove_table(policy->cpus);
	kfree(priv);
out_put_regulator:
	if (name)
		dev_pm_opp_put_regulators(opp_table);
out_put_clk:
	clk_put(cpu_clk);

	return ret;
}

static int cpufreq_exit(struct cpufreq_policy *policy)
{
	struct private_data *priv = policy->driver_data;

	cpufreq_cooling_unregister(priv->cdev);
	dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
	if (priv->have_static_opps)
		dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
	if (priv->reg_name)
		dev_pm_opp_put_regulators(priv->opp_table);

	clk_put(policy->clk);
	kfree(priv);

	return 0;
}

static void cpufreq_ready(struct cpufreq_policy *policy)
{
	struct private_data *priv = policy->driver_data;
	struct device_node *np = of_node_get(priv->cpu_dev->of_node);

	if (WARN_ON(!np))
		return;

	/*
	 * For now, just loading the cooling device;
	 * thermal DT code takes care of matching them.
	 */
	if (of_find_property(np, "#cooling-cells", NULL)) {
		u32 power_coefficient = 0;

		of_property_read_u32(np, "dynamic-power-coefficient",
				     &power_coefficient);

		priv->cdev = of_cpufreq_power_cooling_register(np,
				policy, power_coefficient, NULL);
		if (IS_ERR(priv->cdev)) {
			dev_err(priv->cpu_dev,
				"running cpufreq without cooling device: %ld\n",
				PTR_ERR(priv->cdev));

			priv->cdev = NULL;
		}
	}

	of_node_put(np);
}

static struct cpufreq_driver dt_cpufreq_driver = {
	.flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
	.verify = cpufreq_generic_frequency_table_verify,
	.target_index = set_target,
	.get = cpufreq_generic_get,
	.init = cpufreq_init,
	.exit = cpufreq_exit,
	.ready = cpufreq_ready,
	.name = "cpufreq-dt",
	.attr = cpufreq_dt_attr,
	.suspend = cpufreq_generic_suspend,
};

static int dt_cpufreq_probe(struct platform_device *pdev)
{
	struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev);
	int ret;

	/*
	 * All per-cluster (CPUs sharing clock/voltages) initialization is done
	 * from ->init(). In probe(), we just need to make sure that clk and
	 * regulators are available. Else defer probe and retry.
	 *
	 * FIXME: Is checking this only for CPU0 sufficient ?
	 */
	ret = resources_available();
	if (ret)
		return ret;

	if (data && data->have_governor_per_policy)
		dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY;

	ret = cpufreq_register_driver(&dt_cpufreq_driver);
	if (ret)
		dev_err(&pdev->dev, "failed register driver: %d\n", ret);

	return ret;
}

static int dt_cpufreq_remove(struct platform_device *pdev)
{
	cpufreq_unregister_driver(&dt_cpufreq_driver);
	return 0;
}

static struct platform_driver dt_cpufreq_platdrv = {
	.driver = {
		.name	= "cpufreq-dt",
	},
	.probe		= dt_cpufreq_probe,
	.remove		= dt_cpufreq_remove,
};
module_platform_driver(dt_cpufreq_platdrv);

MODULE_ALIAS("platform:cpufreq-dt");
MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
MODULE_DESCRIPTION("Generic cpufreq driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2012 Freescale Semiconductor, Inc.
	3	*
	4	* Copyright (C) 2014 Linaro.
	5	* Viresh Kumar <viresh.kumar@linaro.org>
	6	*
	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.
	10	*/
	11
	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	13
	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>
	21	#include <linux/of.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>
	27
	28	#include "cpufreq-dt.h"
	29
	30	struct private_data {
	31	struct opp_table *opp_table;
	32	struct device *cpu_dev;
	33	struct thermal_cooling_device *cdev;
	34	const char *reg_name;
	35	bool have_static_opps;
	36	};
	37
	38	static struct freq_attr *cpufreq_dt_attr[] = {
	39	&cpufreq_freq_attr_scaling_available_freqs,
	40	NULL, /* Extra space for boost-attr if required */
	41	NULL,
	42	};
	43
	44	static int set_target(struct cpufreq_policy *policy, unsigned int index)
	45	{
	46	struct private_data *priv = policy->driver_data;
	47	unsigned long freq = policy->freq_table[index].frequency;
	48	int ret;
	49
	50	ret = dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000);
	51
	52	if (!ret) {
	53	arch_set_freq_scale(policy->related_cpus, freq,
	54	policy->cpuinfo.max_freq);
	55	}
	56
	57	return ret;
	58	}
	59
	60	/*
	61	* An earlier version of opp-v1 bindings used to name the regulator
	62	* "cpu0-supply", we still need to handle that for backwards compatibility.
	63	*/
	64	static const char find_supply_name(struct device dev)
	65	{
	66	struct device_node *np;
	67	struct property *pp;
	68	int cpu = dev->id;
	69	const char *name = NULL;
	70
	71	np = of_node_get(dev->of_node);
	72
	73	/* This must be valid for sure */
	74	if (WARN_ON(!np))
	75	return NULL;
	76
	77	/* Try "cpu0" for older DTs */
	78	if (!cpu) {
	79	pp = of_find_property(np, "cpu0-supply", NULL);
	80	if (pp) {
	81	name = "cpu0";
	82	goto node_put;
	83	}
	84	}
	85
	86	pp = of_find_property(np, "cpu-supply", NULL);
	87	if (pp) {
	88	name = "cpu";
	89	goto node_put;
	90	}
	91
	92	dev_dbg(dev, "no regulator for cpu%d\n", cpu);
	93	node_put:
	94	of_node_put(np);
	95	return name;
	96	}
	97
	98	static int resources_available(void)
	99	{
	100	struct device *cpu_dev;
	101	struct regulator *cpu_reg;
	102	struct clk *cpu_clk;
	103	int ret = 0;
	104	const char *name;
	105
	106	cpu_dev = get_cpu_device(0);
	107	if (!cpu_dev) {
	108	pr_err("failed to get cpu0 device\n");
	109	return -ENODEV;
	110	}
	111
	112	cpu_clk = clk_get(cpu_dev, NULL);
	113	ret = PTR_ERR_OR_ZERO(cpu_clk);
	114	if (ret) {
	115	/*
	116	* If cpu's clk node is present, but clock is not yet
	117	* registered, we should try defering probe.
	118	*/
	119	if (ret == -EPROBE_DEFER)
	120	dev_dbg(cpu_dev, "clock not ready, retry\n");
	121	else
	122	dev_err(cpu_dev, "failed to get clock: %d\n", ret);
	123
	124	return ret;
	125	}
	126
	127	clk_put(cpu_clk);
	128
	129	name = find_supply_name(cpu_dev);
	130	/* Platform doesn't require regulator */
	131	if (!name)
	132	return 0;
	133
	134	cpu_reg = regulator_get_optional(cpu_dev, name);
	135	ret = PTR_ERR_OR_ZERO(cpu_reg);
	136	if (ret) {
	137	/*
	138	* If cpu's regulator supply node is present, but regulator is
	139	* not yet registered, we should try defering probe.
	140	*/
	141	if (ret == -EPROBE_DEFER)
	142	dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n");
	143	else
	144	dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret);
	145
	146	return ret;
	147	}
	148
	149	regulator_put(cpu_reg);
	150	return 0;
	151	}
	152
	153	static int cpufreq_init(struct cpufreq_policy *policy)
	154	{
	155	struct cpufreq_frequency_table *freq_table;
	156	struct opp_table *opp_table = NULL;
	157	struct private_data *priv;
	158	struct device *cpu_dev;
	159	struct clk *cpu_clk;
	160	unsigned int transition_latency;
	161	bool fallback = false;
	162	const char *name;
	163	int ret;
	164
	165	cpu_dev = get_cpu_device(policy->cpu);
	166	if (!cpu_dev) {
	167	pr_err("failed to get cpu%d device\n", policy->cpu);
	168	return -ENODEV;
	169	}
	170
	171	cpu_clk = clk_get(cpu_dev, NULL);
	172	if (IS_ERR(cpu_clk)) {
	173	ret = PTR_ERR(cpu_clk);
	174	dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret);
	175	return ret;
	176	}
	177
	178	/* Get OPP-sharing information from "operating-points-v2" bindings */
	179	ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus);
	180	if (ret) {
	181	if (ret != -ENOENT)
	182	goto out_put_clk;
	183
	184	/*
	185	* operating-points-v2 not supported, fallback to old method of
	186	* finding shared-OPPs for backward compatibility if the
	187	* platform hasn't set sharing CPUs.
	188	*/
	189	if (dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus))
	190	fallback = true;
	191	}
	192
	193	/*
	194	* OPP layer will be taking care of regulators now, but it needs to know
	195	* the name of the regulator first.
	196	*/
	197	name = find_supply_name(cpu_dev);
	198	if (name) {
	199	opp_table = dev_pm_opp_set_regulators(cpu_dev, &name, 1);
	200	if (IS_ERR(opp_table)) {
	201	ret = PTR_ERR(opp_table);
	202	dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n",
	203	policy->cpu, ret);
	204	goto out_put_clk;
	205	}
	206	}
	207
	208	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	209	if (!priv) {
	210	ret = -ENOMEM;
	211	goto out_put_regulator;
	212	}
	213
	214	priv->reg_name = name;
	215	priv->opp_table = opp_table;
	216
	217	/*
	218	* Initialize OPP tables for all policy->cpus. They will be shared by
	219	* all CPUs which have marked their CPUs shared with OPP bindings.
	220	*
	221	* For platforms not using operating-points-v2 bindings, we do this
	222	* before updating policy->cpus. Otherwise, we will end up creating
	223	* duplicate OPPs for policy->cpus.
	224	*
	225	* OPPs might be populated at runtime, don't check for error here
	226	*/
	227	if (!dev_pm_opp_of_cpumask_add_table(policy->cpus))
	228	priv->have_static_opps = true;
	229
	230	/*
	231	* But we need OPP table to function so if it is not there let's
	232	* give platform code chance to provide it for us.
	233	*/
	234	ret = dev_pm_opp_get_opp_count(cpu_dev);
	235	if (ret <= 0) {
	236	dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n");
	237	ret = -EPROBE_DEFER;
	238	goto out_free_opp;
	239	}
	240
	241	if (fallback) {
	242	cpumask_setall(policy->cpus);
	243
	244	/*
	245	* OPP tables are initialized only for policy->cpu, do it for
	246	* others as well.
	247	*/
	248	ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
	249	if (ret)
	250	dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
	251	__func__, ret);
	252	}
	253
	254	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
	255	if (ret) {
	256	dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
	257	goto out_free_opp;
	258	}
	259
	260	priv->cpu_dev = cpu_dev;
	261	policy->driver_data = priv;
	262	policy->clk = cpu_clk;
	263
	264	policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000;
	265
	266	ret = cpufreq_table_validate_and_show(policy, freq_table);
	267	if (ret) {
	268	dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__,
	269	ret);
	270	goto out_free_cpufreq_table;
	271	}
	272
	273	/* Support turbo/boost mode */
	274	if (policy_has_boost_freq(policy)) {
	275	/* This gets disabled by core on driver unregister */
	276	ret = cpufreq_enable_boost_support();
	277	if (ret)
	278	goto out_free_cpufreq_table;
	279	cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
	280	}
	281
	282	transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
	283	if (!transition_latency)
	284	transition_latency = CPUFREQ_ETERNAL;
	285
	286	policy->cpuinfo.transition_latency = transition_latency;
	287	policy->dvfs_possible_from_any_cpu = true;
	288
	289	return 0;
	290
	291	out_free_cpufreq_table:
	292	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
	293	out_free_opp:
	294	if (priv->have_static_opps)
	295	dev_pm_opp_of_cpumask_remove_table(policy->cpus);
	296	kfree(priv);
	297	out_put_regulator:
	298	if (name)
	299	dev_pm_opp_put_regulators(opp_table);
	300	out_put_clk:
	301	clk_put(cpu_clk);
	302
	303	return ret;
	304	}
	305
	306	static int cpufreq_exit(struct cpufreq_policy *policy)
	307	{
	308	struct private_data *priv = policy->driver_data;
	309
	310	cpufreq_cooling_unregister(priv->cdev);
	311	dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
	312	if (priv->have_static_opps)
	313	dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
	314	if (priv->reg_name)
	315	dev_pm_opp_put_regulators(priv->opp_table);
	316
	317	clk_put(policy->clk);
	318	kfree(priv);
	319
	320	return 0;
	321	}
	322
	323	static void cpufreq_ready(struct cpufreq_policy *policy)
	324	{
	325	struct private_data *priv = policy->driver_data;
	326	struct device_node *np = of_node_get(priv->cpu_dev->of_node);
	327
	328	if (WARN_ON(!np))
	329	return;
	330
	331	/*
	332	* For now, just loading the cooling device;
	333	* thermal DT code takes care of matching them.
	334	*/
	335	if (of_find_property(np, "#cooling-cells", NULL)) {
	336	u32 power_coefficient = 0;
	337
	338	of_property_read_u32(np, "dynamic-power-coefficient",
	339	&power_coefficient);
	340
	341	priv->cdev = of_cpufreq_power_cooling_register(np,
	342	policy, power_coefficient, NULL);
	343	if (IS_ERR(priv->cdev)) {
	344	dev_err(priv->cpu_dev,
	345	"running cpufreq without cooling device: %ld\n",
	346	PTR_ERR(priv->cdev));
	347
	348	priv->cdev = NULL;
	349	}
	350	}
	351
	352	of_node_put(np);
	353	}
	354
	355	static struct cpufreq_driver dt_cpufreq_driver = {
	356	.flags = CPUFREQ_STICKY \| CPUFREQ_NEED_INITIAL_FREQ_CHECK,
	357	.verify = cpufreq_generic_frequency_table_verify,
	358	.target_index = set_target,
	359	.get = cpufreq_generic_get,
	360	.init = cpufreq_init,
	361	.exit = cpufreq_exit,
	362	.ready = cpufreq_ready,
	363	.name = "cpufreq-dt",
	364	.attr = cpufreq_dt_attr,
	365	.suspend = cpufreq_generic_suspend,
	366	};
	367
	368	static int dt_cpufreq_probe(struct platform_device *pdev)
	369	{
	370	struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev);
	371	int ret;
	372
	373	/*
	374	* All per-cluster (CPUs sharing clock/voltages) initialization is done
	375	* from ->init(). In probe(), we just need to make sure that clk and
	376	* regulators are available. Else defer probe and retry.
	377	*
	378	* FIXME: Is checking this only for CPU0 sufficient ?
	379	*/
	380	ret = resources_available();
	381	if (ret)
	382	return ret;
	383
	384	if (data && data->have_governor_per_policy)
	385	dt_cpufreq_driver.flags \|= CPUFREQ_HAVE_GOVERNOR_PER_POLICY;
	386
	387	ret = cpufreq_register_driver(&dt_cpufreq_driver);
	388	if (ret)
	389	dev_err(&pdev->dev, "failed register driver: %d\n", ret);
	390
	391	return ret;
	392	}
	393
	394	static int dt_cpufreq_remove(struct platform_device *pdev)
	395	{
	396	cpufreq_unregister_driver(&dt_cpufreq_driver);
	397	return 0;
	398	}
	399
	400	static struct platform_driver dt_cpufreq_platdrv = {
	401	.driver = {
	402	.name = "cpufreq-dt",
	403	},
	404	.probe = dt_cpufreq_probe,
	405	.remove = dt_cpufreq_remove,
	406	};
	407	module_platform_driver(dt_cpufreq_platdrv);
	408
	409	MODULE_ALIAS("platform:cpufreq-dt");
	410	MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
	411	MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
	412	MODULE_DESCRIPTION("Generic cpufreq driver");
	413	MODULE_LICENSE("GPL");