Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 820 insertions, 0 deletions

diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
new file mode 100644
index 000000000..8592ef694
--- /dev/null
+++ b/drivers/thermal/cpu_cooling.c
@@ -0,0 +1,820 @@
+/*
+ *  linux/drivers/thermal/cpu_cooling.c
+ *
+ *  Copyright (C) 2012	Samsung Electronics Co., Ltd(http://www.samsung.com)
+ *  Copyright (C) 2012  Amit Daniel <amit.kachhap@linaro.org>
+ *
+ *  Copyright (C) 2014  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 as published by
+ *  the Free Software Foundation; version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/module.h>
+#include <linux/thermal.h>
+#include <linux/cpufreq.h>
+#include <linux/err.h>
+#include <linux/idr.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/cpu_cooling.h>
+
+#include <trace/events/thermal.h>
+
+/*
+ * Cooling state <-> CPUFreq frequency
+ *
+ * Cooling states are translated to frequencies throughout this driver and this
+ * is the relation between them.
+ *
+ * Highest cooling state corresponds to lowest possible frequency.
+ *
+ * i.e.
+ *	level 0 --> 1st Max Freq
+ *	level 1 --> 2nd Max Freq
+ *	...
+ */
+
+/**
+ * struct freq_table - frequency table along with power entries
+ * @frequency:	frequency in KHz
+ * @power:	power in mW
+ *
+ * This structure is built when the cooling device registers and helps
+ * in translating frequency to power and vice versa.
+ */
+struct freq_table {
+	u32 frequency;
+	u32 power;
+};
+
+/**
+ * struct time_in_idle - Idle time stats
+ * @time: previous reading of the absolute time that this cpu was idle
+ * @timestamp: wall time of the last invocation of get_cpu_idle_time_us()
+ */
+struct time_in_idle {
+	u64 time;
+	u64 timestamp;
+};
+
+/**
+ * struct cpufreq_cooling_device - data for cooling device with cpufreq
+ * @id: unique integer value corresponding to each cpufreq_cooling_device
+ *	registered.
+ * @last_load: load measured by the latest call to cpufreq_get_requested_power()
+ * @cpufreq_state: integer value representing the current state of cpufreq
+ *	cooling	devices.
+ * @clipped_freq: integer value representing the absolute value of the clipped
+ *	frequency.
+ * @max_level: maximum cooling level. One less than total number of valid
+ *	cpufreq frequencies.
+ * @freq_table: Freq table in descending order of frequencies
+ * @cdev: thermal_cooling_device pointer to keep track of the
+ *	registered cooling device.
+ * @policy: cpufreq policy.
+ * @node: list_head to link all cpufreq_cooling_device together.
+ * @idle_time: idle time stats
+ *
+ * This structure is required for keeping information of each registered
+ * cpufreq_cooling_device.
+ */
+struct cpufreq_cooling_device {
+	int id;
+	u32 last_load;
+	unsigned int cpufreq_state;
+	unsigned int clipped_freq;
+	unsigned int max_level;
+	struct freq_table *freq_table;	/* In descending order */
+	struct thermal_cooling_device *cdev;
+	struct cpufreq_policy *policy;
+	struct list_head node;
+	struct time_in_idle *idle_time;
+};
+
+static DEFINE_IDA(cpufreq_ida);
+static DEFINE_MUTEX(cooling_list_lock);
+static LIST_HEAD(cpufreq_cdev_list);
+
+/* Below code defines functions to be used for cpufreq as cooling device */
+
+/**
+ * get_level: Find the level for a particular frequency
+ * @cpufreq_cdev: cpufreq_cdev for which the property is required
+ * @freq: Frequency
+ *
+ * Return: level corresponding to the frequency.
+ */
+static unsigned long get_level(struct cpufreq_cooling_device *cpufreq_cdev,
+			       unsigned int freq)
+{
+	struct freq_table *freq_table = cpufreq_cdev->freq_table;
+	unsigned long level;
+
+	for (level = 1; level <= cpufreq_cdev->max_level; level++)
+		if (freq > freq_table[level].frequency)
+			break;
+
+	return level - 1;
+}
+
+/**
+ * cpufreq_thermal_notifier - notifier callback for cpufreq policy change.
+ * @nb:	struct notifier_block * with callback info.
+ * @event: value showing cpufreq event for which this function invoked.
+ * @data: callback-specific data
+ *
+ * Callback to hijack the notification on cpufreq policy transition.
+ * Every time there is a change in policy, we will intercept and
+ * update the cpufreq policy with thermal constraints.
+ *
+ * Return: 0 (success)
+ */
+static int cpufreq_thermal_notifier(struct notifier_block *nb,
+				    unsigned long event, void *data)
+{
+	struct cpufreq_policy *policy = data;
+	unsigned long clipped_freq;
+	struct cpufreq_cooling_device *cpufreq_cdev;
+
+	if (event != CPUFREQ_ADJUST)
+		return NOTIFY_DONE;
+
+	mutex_lock(&cooling_list_lock);
+	list_for_each_entry(cpufreq_cdev, &cpufreq_cdev_list, node) {
+		/*
+		 * A new copy of the policy is sent to the notifier and can't
+		 * compare that directly.
+		 */
+		if (policy->cpu != cpufreq_cdev->policy->cpu)
+			continue;
+
+		/*
+		 * policy->max is the maximum allowed frequency defined by user
+		 * and clipped_freq is the maximum that thermal constraints
+		 * allow.
+		 *
+		 * If clipped_freq is lower than policy->max, then we need to
+		 * readjust policy->max.
+		 *
+		 * But, if clipped_freq is greater than policy->max, we don't
+		 * need to do anything.
+		 */
+		clipped_freq = cpufreq_cdev->clipped_freq;
+
+		if (policy->max > clipped_freq)
+			cpufreq_verify_within_limits(policy, 0, clipped_freq);
+		break;
+	}
+	mutex_unlock(&cooling_list_lock);
+
+	return NOTIFY_OK;
+}
+
+/**
+ * update_freq_table() - Update the freq table with power numbers
+ * @cpufreq_cdev:	the cpufreq cooling device in which to update the table
+ * @capacitance: dynamic power coefficient for these cpus
+ *
+ * Update the freq table with power numbers.  This table will be used in
+ * cpu_power_to_freq() and cpu_freq_to_power() to convert between power and
+ * frequency efficiently.  Power is stored in mW, frequency in KHz.  The
+ * resulting table is in descending order.
+ *
+ * Return: 0 on success, -EINVAL if there are no OPPs for any CPUs,
+ * or -ENOMEM if we run out of memory.
+ */
+static int update_freq_table(struct cpufreq_cooling_device *cpufreq_cdev,
+			     u32 capacitance)
+{
+	struct freq_table *freq_table = cpufreq_cdev->freq_table;
+	struct dev_pm_opp *opp;
+	struct device *dev = NULL;
+	int num_opps = 0, cpu = cpufreq_cdev->policy->cpu, i;
+
+	dev = get_cpu_device(cpu);
+	if (unlikely(!dev)) {
+		dev_warn(&cpufreq_cdev->cdev->device,
+			 "No cpu device for cpu %d\n", cpu);
+		return -ENODEV;
+	}
+
+	num_opps = dev_pm_opp_get_opp_count(dev);
+	if (num_opps < 0)
+		return num_opps;
+
+	/*
+	 * The cpufreq table is also built from the OPP table and so the count
+	 * should match.
+	 */
+	if (num_opps != cpufreq_cdev->max_level + 1) {
+		dev_warn(dev, "Number of OPPs not matching with max_levels\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i <= cpufreq_cdev->max_level; i++) {
+		unsigned long freq = freq_table[i].frequency * 1000;
+		u32 freq_mhz = freq_table[i].frequency / 1000;
+		u64 power;
+		u32 voltage_mv;
+
+		/*
+		 * Find ceil frequency as 'freq' may be slightly lower than OPP
+		 * freq due to truncation while converting to kHz.
+		 */
+		opp = dev_pm_opp_find_freq_ceil(dev, &freq);
+		if (IS_ERR(opp)) {
+			dev_err(dev, "failed to get opp for %lu frequency\n",
+				freq);
+			return -EINVAL;
+		}
+
+		voltage_mv = dev_pm_opp_get_voltage(opp) / 1000;
+		dev_pm_opp_put(opp);
+
+		/*
+		 * Do the multiplication with MHz and millivolt so as
+		 * to not overflow.
+		 */
+		power = (u64)capacitance * freq_mhz * voltage_mv * voltage_mv;
+		do_div(power, 1000000000);
+
+		/* power is stored in mW */
+		freq_table[i].power = power;
+	}
+
+	return 0;
+}
+
+static u32 cpu_freq_to_power(struct cpufreq_cooling_device *cpufreq_cdev,
+			     u32 freq)
+{
+	int i;
+	struct freq_table *freq_table = cpufreq_cdev->freq_table;
+
+	for (i = 1; i <= cpufreq_cdev->max_level; i++)
+		if (freq > freq_table[i].frequency)
+			break;
+
+	return freq_table[i - 1].power;
+}
+
+static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev,
+			     u32 power)
+{
+	int i;
+	struct freq_table *freq_table = cpufreq_cdev->freq_table;
+
+	for (i = 0; i < cpufreq_cdev->max_level; i++)
+		if (power >= freq_table[i].power)
+			break;
+
+	return freq_table[i].frequency;
+}
+
+/**
+ * get_load() - get load for a cpu since last updated
+ * @cpufreq_cdev:	&struct cpufreq_cooling_device for this cpu
+ * @cpu:	cpu number
+ * @cpu_idx:	index of the cpu in time_in_idle*
+ *
+ * Return: The average load of cpu @cpu in percentage since this
+ * function was last called.
+ */
+static u32 get_load(struct cpufreq_cooling_device *cpufreq_cdev, int cpu,
+		    int cpu_idx)
+{
+	u32 load;
+	u64 now, now_idle, delta_time, delta_idle;
+	struct time_in_idle *idle_time = &cpufreq_cdev->idle_time[cpu_idx];
+
+	now_idle = get_cpu_idle_time(cpu, &now, 0);
+	delta_idle = now_idle - idle_time->time;
+	delta_time = now - idle_time->timestamp;
+
+	if (delta_time <= delta_idle)
+		load = 0;
+	else
+		load = div64_u64(100 * (delta_time - delta_idle), delta_time);
+
+	idle_time->time = now_idle;
+	idle_time->timestamp = now;
+
+	return load;
+}
+
+/**
+ * get_dynamic_power() - calculate the dynamic power
+ * @cpufreq_cdev:	&cpufreq_cooling_device for this cdev
+ * @freq:	current frequency
+ *
+ * Return: the dynamic power consumed by the cpus described by
+ * @cpufreq_cdev.
+ */
+static u32 get_dynamic_power(struct cpufreq_cooling_device *cpufreq_cdev,
+			     unsigned long freq)
+{
+	u32 raw_cpu_power;
+
+	raw_cpu_power = cpu_freq_to_power(cpufreq_cdev, freq);
+	return (raw_cpu_power * cpufreq_cdev->last_load) / 100;
+}
+
+/* cpufreq cooling device callback functions are defined below */
+
+/**
+ * cpufreq_get_max_state - callback function to get the max cooling state.
+ * @cdev: thermal cooling device pointer.
+ * @state: fill this variable with the max cooling state.
+ *
+ * Callback for the thermal cooling device to return the cpufreq
+ * max cooling state.
+ *
+ * Return: 0 on success, an error code otherwise.
+ */
+static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;
+
+	*state = cpufreq_cdev->max_level;
+	return 0;
+}
+
+/**
+ * cpufreq_get_cur_state - callback function to get the current cooling state.
+ * @cdev: thermal cooling device pointer.
+ * @state: fill this variable with the current cooling state.
+ *
+ * Callback for the thermal cooling device to return the cpufreq
+ * current cooling state.
+ *
+ * Return: 0 on success, an error code otherwise.
+ */
+static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;
+
+	*state = cpufreq_cdev->cpufreq_state;
+
+	return 0;
+}
+
+/**
+ * cpufreq_set_cur_state - callback function to set the current cooling state.
+ * @cdev: thermal cooling device pointer.
+ * @state: set this variable to the current cooling state.
+ *
+ * Callback for the thermal cooling device to change the cpufreq
+ * current cooling state.
+ *
+ * Return: 0 on success, an error code otherwise.
+ */
+static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
+				 unsigned long state)
+{
+	struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;
+	unsigned int clip_freq;
+
+	/* Request state should be less than max_level */
+	if (WARN_ON(state > cpufreq_cdev->max_level))
+		return -EINVAL;
+
+	/* Check if the old cooling action is same as new cooling action */
+	if (cpufreq_cdev->cpufreq_state == state)
+		return 0;
+
+	clip_freq = cpufreq_cdev->freq_table[state].frequency;
+	cpufreq_cdev->cpufreq_state = state;
+	cpufreq_cdev->clipped_freq = clip_freq;
+
+	cpufreq_update_policy(cpufreq_cdev->policy->cpu);
+
+	return 0;
+}
+
+/**
+ * cpufreq_get_requested_power() - get the current power
+ * @cdev:	&thermal_cooling_device pointer
+ * @tz:		a valid thermal zone device pointer
+ * @power:	pointer in which to store the resulting power
+ *
+ * Calculate the current power consumption of the cpus in milliwatts
+ * and store it in @power.  This function should actually calculate
+ * the requested power, but it's hard to get the frequency that
+ * cpufreq would have assigned if there were no thermal limits.
+ * Instead, we calculate the current power on the assumption that the
+ * immediate future will look like the immediate past.
+ *
+ * We use the current frequency and the average load since this
+ * function was last called.  In reality, there could have been
+ * multiple opps since this function was last called and that affects
+ * the load calculation.  While it's not perfectly accurate, this
+ * simplification is good enough and works.  REVISIT this, as more
+ * complex code may be needed if experiments show that it's not
+ * accurate enough.
+ *
+ * Return: 0 on success, -E* if getting the static power failed.
+ */
+static int cpufreq_get_requested_power(struct thermal_cooling_device *cdev,
+				       struct thermal_zone_device *tz,
+				       u32 *power)
+{
+	unsigned long freq;
+	int i = 0, cpu;
+	u32 total_load = 0;
+	struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;
+	struct cpufreq_policy *policy = cpufreq_cdev->policy;
+	u32 *load_cpu = NULL;
+
+	freq = cpufreq_quick_get(policy->cpu);
+
+	if (trace_thermal_power_cpu_get_power_enabled()) {
+		u32 ncpus = cpumask_weight(policy->related_cpus);
+
+		load_cpu = kcalloc(ncpus, sizeof(*load_cpu), GFP_KERNEL);
+	}
+
+	for_each_cpu(cpu, policy->related_cpus) {
+		u32 load;
+
+		if (cpu_online(cpu))
+			load = get_load(cpufreq_cdev, cpu, i);
+		else
+			load = 0;
+
+		total_load += load;
+		if (load_cpu)
+			load_cpu[i] = load;
+
+		i++;
+	}
+
+	cpufreq_cdev->last_load = total_load;
+
+	*power = get_dynamic_power(cpufreq_cdev, freq);
+
+	if (load_cpu) {
+		trace_thermal_power_cpu_get_power(policy->related_cpus, freq,
+						  load_cpu, i, *power);
+
+		kfree(load_cpu);
+	}
+
+	return 0;
+}
+
+/**
+ * cpufreq_state2power() - convert a cpu cdev state to power consumed
+ * @cdev:	&thermal_cooling_device pointer
+ * @tz:		a valid thermal zone device pointer
+ * @state:	cooling device state to be converted
+ * @power:	pointer in which to store the resulting power
+ *
+ * Convert cooling device state @state into power consumption in
+ * milliwatts assuming 100% load.  Store the calculated power in
+ * @power.
+ *
+ * Return: 0 on success, -EINVAL if the cooling device state could not
+ * be converted into a frequency or other -E* if there was an error
+ * when calculating the static power.
+ */
+static int cpufreq_state2power(struct thermal_cooling_device *cdev,
+			       struct thermal_zone_device *tz,
+			       unsigned long state, u32 *power)
+{
+	unsigned int freq, num_cpus;
+	struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;
+
+	/* Request state should be less than max_level */
+	if (WARN_ON(state > cpufreq_cdev->max_level))
+		return -EINVAL;
+
+	num_cpus = cpumask_weight(cpufreq_cdev->policy->cpus);
+
+	freq = cpufreq_cdev->freq_table[state].frequency;
+	*power = cpu_freq_to_power(cpufreq_cdev, freq) * num_cpus;
+
+	return 0;
+}
+
+/**
+ * cpufreq_power2state() - convert power to a cooling device state
+ * @cdev:	&thermal_cooling_device pointer
+ * @tz:		a valid thermal zone device pointer
+ * @power:	power in milliwatts to be converted
+ * @state:	pointer in which to store the resulting state
+ *
+ * Calculate a cooling device state for the cpus described by @cdev
+ * that would allow them to consume at most @power mW and store it in
+ * @state.  Note that this calculation depends on external factors
+ * such as the cpu load or the current static power.  Calling this
+ * function with the same power as input can yield different cooling
+ * device states depending on those external factors.
+ *
+ * Return: 0 on success, -ENODEV if no cpus are online or -EINVAL if
+ * the calculated frequency could not be converted to a valid state.
+ * The latter should not happen unless the frequencies available to
+ * cpufreq have changed since the initialization of the cpu cooling
+ * device.
+ */
+static int cpufreq_power2state(struct thermal_cooling_device *cdev,
+			       struct thermal_zone_device *tz, u32 power,
+			       unsigned long *state)
+{
+	unsigned int cur_freq, target_freq;
+	u32 last_load, normalised_power;
+	struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;
+	struct cpufreq_policy *policy = cpufreq_cdev->policy;
+
+	cur_freq = cpufreq_quick_get(policy->cpu);
+	power = power > 0 ? power : 0;
+	last_load = cpufreq_cdev->last_load ?: 1;
+	normalised_power = (power * 100) / last_load;
+	target_freq = cpu_power_to_freq(cpufreq_cdev, normalised_power);
+
+	*state = get_level(cpufreq_cdev, target_freq);
+	trace_thermal_power_cpu_limit(policy->related_cpus, target_freq, *state,
+				      power);
+	return 0;
+}
+
+/* Bind cpufreq callbacks to thermal cooling device ops */
+
+static struct thermal_cooling_device_ops cpufreq_cooling_ops = {
+	.get_max_state = cpufreq_get_max_state,
+	.get_cur_state = cpufreq_get_cur_state,
+	.set_cur_state = cpufreq_set_cur_state,
+};
+
+static struct thermal_cooling_device_ops cpufreq_power_cooling_ops = {
+	.get_max_state		= cpufreq_get_max_state,
+	.get_cur_state		= cpufreq_get_cur_state,
+	.set_cur_state		= cpufreq_set_cur_state,
+	.get_requested_power	= cpufreq_get_requested_power,
+	.state2power		= cpufreq_state2power,
+	.power2state		= cpufreq_power2state,
+};
+
+/* Notifier for cpufreq policy change */
+static struct notifier_block thermal_cpufreq_notifier_block = {
+	.notifier_call = cpufreq_thermal_notifier,
+};
+
+static unsigned int find_next_max(struct cpufreq_frequency_table *table,
+				  unsigned int prev_max)
+{
+	struct cpufreq_frequency_table *pos;
+	unsigned int max = 0;
+
+	cpufreq_for_each_valid_entry(pos, table) {
+		if (pos->frequency > max && pos->frequency < prev_max)
+			max = pos->frequency;
+	}
+
+	return max;
+}
+
+/**
+ * __cpufreq_cooling_register - helper function to create cpufreq cooling device
+ * @np: a valid struct device_node to the cooling device device tree node
+ * @policy: cpufreq policy
+ * Normally this should be same as cpufreq policy->related_cpus.
+ * @capacitance: dynamic power coefficient for these cpus
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices. It also gives the opportunity to link the cooling device
+ * with a device tree node, in order to bind it via the thermal DT code.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * on failure, it returns a corresponding ERR_PTR().
+ */
+static struct thermal_cooling_device *
+__cpufreq_cooling_register(struct device_node *np,
+			struct cpufreq_policy *policy, u32 capacitance)
+{
+	struct thermal_cooling_device *cdev;
+	struct cpufreq_cooling_device *cpufreq_cdev;
+	char dev_name[THERMAL_NAME_LENGTH];
+	unsigned int freq, i, num_cpus;
+	int ret;
+	struct thermal_cooling_device_ops *cooling_ops;
+	bool first;
+
+	if (IS_ERR_OR_NULL(policy)) {
+		pr_err("%s: cpufreq policy isn't valid: %p\n", __func__, policy);
+		return ERR_PTR(-EINVAL);
+	}
+
+	i = cpufreq_table_count_valid_entries(policy);
+	if (!i) {
+		pr_debug("%s: CPUFreq table not found or has no valid entries\n",
+			 __func__);
+		return ERR_PTR(-ENODEV);
+	}
+
+	cpufreq_cdev = kzalloc(sizeof(*cpufreq_cdev), GFP_KERNEL);
+	if (!cpufreq_cdev)
+		return ERR_PTR(-ENOMEM);
+
+	cpufreq_cdev->policy = policy;
+	num_cpus = cpumask_weight(policy->related_cpus);
+	cpufreq_cdev->idle_time = kcalloc(num_cpus,
+					 sizeof(*cpufreq_cdev->idle_time),
+					 GFP_KERNEL);
+	if (!cpufreq_cdev->idle_time) {
+		cdev = ERR_PTR(-ENOMEM);
+		goto free_cdev;
+	}
+
+	/* max_level is an index, not a counter */
+	cpufreq_cdev->max_level = i - 1;
+
+	cpufreq_cdev->freq_table = kmalloc_array(i,
+					sizeof(*cpufreq_cdev->freq_table),
+					GFP_KERNEL);
+	if (!cpufreq_cdev->freq_table) {
+		cdev = ERR_PTR(-ENOMEM);
+		goto free_idle_time;
+	}
+
+	ret = ida_simple_get(&cpufreq_ida, 0, 0, GFP_KERNEL);
+	if (ret < 0) {
+		cdev = ERR_PTR(ret);
+		goto free_table;
+	}
+	cpufreq_cdev->id = ret;
+
+	snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
+		 cpufreq_cdev->id);
+
+	/* Fill freq-table in descending order of frequencies */
+	for (i = 0, freq = -1; i <= cpufreq_cdev->max_level; i++) {
+		freq = find_next_max(policy->freq_table, freq);
+		cpufreq_cdev->freq_table[i].frequency = freq;
+
+		/* Warn for duplicate entries */
+		if (!freq)
+			pr_warn("%s: table has duplicate entries\n", __func__);
+		else
+			pr_debug("%s: freq:%u KHz\n", __func__, freq);
+	}
+
+	if (capacitance) {
+		ret = update_freq_table(cpufreq_cdev, capacitance);
+		if (ret) {
+			cdev = ERR_PTR(ret);
+			goto remove_ida;
+		}
+
+		cooling_ops = &cpufreq_power_cooling_ops;
+	} else {
+		cooling_ops = &cpufreq_cooling_ops;
+	}
+
+	cdev = thermal_of_cooling_device_register(np, dev_name, cpufreq_cdev,
+						  cooling_ops);
+	if (IS_ERR(cdev))
+		goto remove_ida;
+
+	cpufreq_cdev->clipped_freq = cpufreq_cdev->freq_table[0].frequency;
+	cpufreq_cdev->cdev = cdev;
+
+	mutex_lock(&cooling_list_lock);
+	/* Register the notifier for first cpufreq cooling device */
+	first = list_empty(&cpufreq_cdev_list);
+	list_add(&cpufreq_cdev->node, &cpufreq_cdev_list);
+	mutex_unlock(&cooling_list_lock);
+
+	if (first)
+		cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
+					  CPUFREQ_POLICY_NOTIFIER);
+
+	return cdev;
+
+remove_ida:
+	ida_simple_remove(&cpufreq_ida, cpufreq_cdev->id);
+free_table:
+	kfree(cpufreq_cdev->freq_table);
+free_idle_time:
+	kfree(cpufreq_cdev->idle_time);
+free_cdev:
+	kfree(cpufreq_cdev);
+	return cdev;
+}
+
+/**
+ * cpufreq_cooling_register - function to create cpufreq cooling device.
+ * @policy: cpufreq policy
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * on failure, it returns a corresponding ERR_PTR().
+ */
+struct thermal_cooling_device *
+cpufreq_cooling_register(struct cpufreq_policy *policy)
+{
+	return __cpufreq_cooling_register(NULL, policy, 0);
+}
+EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
+
+/**
+ * of_cpufreq_cooling_register - function to create cpufreq cooling device.
+ * @policy: cpufreq policy
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices. Using this API, the cpufreq cooling device will be
+ * linked to the device tree node provided.
+ *
+ * Using this function, the cooling device will implement the power
+ * extensions by using a simple cpu power model.  The cpus must have
+ * registered their OPPs using the OPP library.
+ *
+ * It also takes into account, if property present in policy CPU node, the
+ * static power consumed by the cpu.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * and NULL on failure.
+ */
+struct thermal_cooling_device *
+of_cpufreq_cooling_register(struct cpufreq_policy *policy)
+{
+	struct device_node *np = of_get_cpu_node(policy->cpu, NULL);
+	struct thermal_cooling_device *cdev = NULL;
+	u32 capacitance = 0;
+
+	if (!np) {
+		pr_err("cpu_cooling: OF node not available for cpu%d\n",
+		       policy->cpu);
+		return NULL;
+	}
+
+	if (of_find_property(np, "#cooling-cells", NULL)) {
+		of_property_read_u32(np, "dynamic-power-coefficient",
+				     &capacitance);
+
+		cdev = __cpufreq_cooling_register(np, policy, capacitance);
+		if (IS_ERR(cdev)) {
+			pr_err("cpu_cooling: cpu%d is not running as cooling device: %ld\n",
+			       policy->cpu, PTR_ERR(cdev));
+			cdev = NULL;
+		}
+	}
+
+	of_node_put(np);
+	return cdev;
+}
+EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register);
+
+/**
+ * cpufreq_cooling_unregister - function to remove cpufreq cooling device.
+ * @cdev: thermal cooling device pointer.
+ *
+ * This interface function unregisters the "thermal-cpufreq-%x" cooling device.
+ */
+void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
+{
+	struct cpufreq_cooling_device *cpufreq_cdev;
+	bool last;
+
+	if (!cdev)
+		return;
+
+	cpufreq_cdev = cdev->devdata;
+
+	mutex_lock(&cooling_list_lock);
+	list_del(&cpufreq_cdev->node);
+	/* Unregister the notifier for the last cpufreq cooling device */
+	last = list_empty(&cpufreq_cdev_list);
+	mutex_unlock(&cooling_list_lock);
+
+	if (last)
+		cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
+					    CPUFREQ_POLICY_NOTIFIER);
+
+	thermal_cooling_device_unregister(cpufreq_cdev->cdev);
+	ida_simple_remove(&cpufreq_ida, cpufreq_cdev->id);
+	kfree(cpufreq_cdev->idle_time);
+	kfree(cpufreq_cdev->freq_table);
+	kfree(cpufreq_cdev);
+}
+EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);