/*
 *  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 <linux/debug-snapshot.h>

#include <trace/events/thermal.h>

#include <soc/samsung/tmu.h>
#include <soc/samsung/cal-if.h>
#include <soc/samsung/ect_parser.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;
};

static BLOCKING_NOTIFIER_HEAD(cpu_notifier);

static enum tmu_noti_state_t cpu_tstate = TMU_NORMAL;

/**
 * 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;
};

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_cooling_get_level - for a given cpu, return the cooling level.
 * @cpu: cpu for which the level is required
 * @freq: the frequency of interest
 *
 * This function will match the cooling level corresponding to the
 * requested @freq and return it.
 *
 * Return: The matched cooling level on success or THERMAL_CSTATE_INVALID
 * otherwise.
 */
unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
{
	struct cpufreq_cooling_device *cpufreq_cdev;

	mutex_lock(&cooling_list_lock);
	list_for_each_entry(cpufreq_cdev, &cpufreq_cdev_list, node) {
		if (cpumask_test_cpu(cpu, cpufreq_cdev->policy->related_cpus)) {
			unsigned long level = get_level(cpufreq_cdev, freq);

			mutex_unlock(&cooling_list_lock);
			return level;
		}
	}
	mutex_unlock(&cooling_list_lock);

	pr_err("%s: cpu:%d not part of any cooling device\n", __func__, cpu);
	return THERMAL_CSTATE_INVALID;
}
EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level);

/**
 * 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);
			dbg_snapshot_thermal(NULL, 0, cpufreq_cdev->cdev->type, 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 int build_static_power_table(struct device_node *np, struct cpufreq_cooling_device *cpufreq_cdev)
{
	int i, j;
	int ratio, asv_group, cal_id, ret = 0;

	void *gen_block;
	struct ect_gen_param_table *volt_temp_param, *asv_param;
	int ratio_table[16] = { 0, 18, 22, 27, 33, 40, 49, 60, 73, 89, 108, 131, 159, 194, 232, 250};

	ret = of_property_read_u32(np, "cal-id", &cal_id);
	if (ret) {
		pr_err("%s: Failed to get cal-id\n", __func__);
		return -EINVAL;
	}

	ratio = cal_asv_get_ids_info(cal_id);
	asv_group = cal_asv_get_grp(cal_id);

	if (asv_group < 0 || asv_group > 15)
		asv_group = 0;

	if (!ratio)
		ratio = ratio_table[asv_group];

	gen_block = ect_get_block("GEN");
	if (gen_block == NULL) {
		pr_err("%s: Failed to get gen block from ECT\n", __func__);
		return -EINVAL;
	}

	volt_temp_param = ect_gen_param_get_table(gen_block, "DTM_BIG_VOLT_TEMP");
	asv_param = ect_gen_param_get_table(gen_block, "DTM_BIG_ASV");

	if (volt_temp_param && asv_param) {
		cpufreq_cdev->var_volt_size = volt_temp_param->num_of_row - 1;
		cpufreq_cdev->var_temp_size = volt_temp_param->num_of_col - 1;

		cpufreq_cdev->var_coeff = kzalloc(sizeof(int) *
							volt_temp_param->num_of_row *
							volt_temp_param->num_of_col,
							GFP_KERNEL);
		if (!cpufreq_cdev->var_coeff)
			goto err_mem;

		cpufreq_cdev->asv_coeff = kzalloc(sizeof(int) *
							asv_param->num_of_row *
							asv_param->num_of_col,
							GFP_KERNEL);
		if (!cpufreq_cdev->asv_coeff)
			goto free_var_coeff;

		cpufreq_cdev->var_table = kzalloc(sizeof(int) *
							volt_temp_param->num_of_row *
							volt_temp_param->num_of_col,
							GFP_KERNEL);
		if (!cpufreq_cdev->var_table)
			goto free_asv_coeff;

		memcpy(cpufreq_cdev->var_coeff, volt_temp_param->parameter,
			sizeof(int) * volt_temp_param->num_of_row * volt_temp_param->num_of_col);
		memcpy(cpufreq_cdev->asv_coeff, asv_param->parameter,
			sizeof(int) * asv_param->num_of_row * asv_param->num_of_col);
		memcpy(cpufreq_cdev->var_table, volt_temp_param->parameter,
			sizeof(int) * volt_temp_param->num_of_row * volt_temp_param->num_of_col);
	} else {
		pr_err("%s: Failed to get param table from ECT\n", __func__);
		return -EINVAL;
	}

	for (i = 1; i <= cpufreq_cdev->var_volt_size; i++) {
		long asv_coeff = (long)cpufreq_cdev->asv_coeff[3 * i + 0] * asv_group * asv_group
				+ (long)cpufreq_cdev->asv_coeff[3 * i + 1] * asv_group
				+ (long)cpufreq_cdev->asv_coeff[3 * i + 2];
		asv_coeff = asv_coeff / 100;

		for (j = 1; j <= cpufreq_cdev->var_temp_size; j++) {
			long var_coeff = (long)cpufreq_cdev->var_coeff[i * (cpufreq_cdev->var_temp_size + 1) + j];
			var_coeff =  ratio * var_coeff * asv_coeff;
			var_coeff = var_coeff / 100000;
			cpufreq_cdev->var_table[i * (cpufreq_cdev->var_temp_size + 1) + j] = (int)var_coeff;
		}
	}

	return 0;

free_asv_coeff:
	kfree(cpufreq_cdev->asv_coeff);
free_var_coeff:
	kfree(cpufreq_cdev->var_coeff);
err_mem:
	return -ENOMEM;
}

static int lookup_static_power(struct cpufreq_cooling_device *cpufreq_cdev,
		unsigned long voltage, int temperature, u32 *power)
{
	int volt_index = 0, temp_index = 0;
	int index = 0;
	int num_cpus;
	int max_cpus;
	struct cpufreq_policy *policy = cpufreq_cdev->policy;
	cpumask_t tempmask;

	cpumask_and(&tempmask, policy->related_cpus, cpu_online_mask);
	max_cpus = cpumask_weight(policy->related_cpus);
	num_cpus = cpumask_weight(&tempmask);
	voltage = voltage / 1000;
	temperature  = temperature / 1000;

	for (volt_index = 0; volt_index <= cpufreq_cdev->var_volt_size; volt_index++) {
		if (voltage < cpufreq_cdev->var_table[volt_index * ((int)cpufreq_cdev->var_temp_size + 1)]) {
			volt_index = volt_index - 1;
			break;
		}
	}

	if (volt_index == 0)
		volt_index = 1;

	if (volt_index > cpufreq_cdev->var_volt_size)
		volt_index = cpufreq_cdev->var_volt_size;

	for (temp_index = 0; temp_index <= cpufreq_cdev->var_temp_size; temp_index++) {
		if (temperature < cpufreq_cdev->var_table[temp_index]) {
			temp_index = temp_index - 1;
			break;
		}
	}

	if (temp_index == 0)
		temp_index = 1;

	if (temp_index > cpufreq_cdev->var_temp_size)
		temp_index = cpufreq_cdev->var_temp_size;

	index = (int)(volt_index * (cpufreq_cdev->var_temp_size + 1) + temp_index);
	*power = (unsigned int)cpufreq_cdev->var_table[index];

	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_static_power() - calculate the static power consumed by the cpus
 * @cpufreq_cdev:	struct &cpufreq_cooling_device for this cpu cdev
 * @tz:		thermal zone device in which we're operating
 * @freq:	frequency in KHz
 * @power:	pointer in which to store the calculated static power
 *
 * Calculate the static power consumed by the cpus described by
 * @cpu_actor running at frequency @freq.  This function relies on a
 * platform specific function that should have been provided when the
 * actor was registered.  If it wasn't, the static power is assumed to
 * be negligible.  The calculated static power is stored in @power.
 *
 * Return: 0 on success, -E* on failure.
 */
static int get_static_power(struct cpufreq_cooling_device *cpufreq_cdev,
			    struct thermal_zone_device *tz, unsigned long freq,
			    u32 *power)
{
	struct dev_pm_opp *opp;
	unsigned long voltage;
	struct cpufreq_policy *policy = cpufreq_cdev->policy;
	unsigned long freq_hz = freq * 1000;
	struct device *dev;
	cpumask_t tempmask;
	int num_cpus, max_cpus;
	u32 raw_cpu_power;

	*power = 0;

	dev = get_cpu_device(policy->cpu);

	if (!dev)
		return 0;

	opp = dev_pm_opp_find_freq_exact(dev, freq_hz, true);
	if (IS_ERR(opp)) {
		dev_warn_ratelimited(dev, "Failed to find OPP for frequency %lu: %ld\n",
				     freq_hz, PTR_ERR(opp));
		return -EINVAL;
	}

	voltage = dev_pm_opp_get_voltage(opp);
	dev_pm_opp_put(opp);

	if (voltage == 0) {
		dev_err_ratelimited(dev, "Failed to get voltage for frequency %lu\n",
				    freq_hz);
		return -EINVAL;
	}

	lookup_static_power(cpufreq_cdev, voltage, tz->temperature, &raw_cpu_power);

	cpumask_and(&tempmask, policy->related_cpus, cpu_online_mask);
	num_cpus = cpumask_weight(&tempmask);
	max_cpus = cpumask_weight(policy->related_cpus);

	*power = (raw_cpu_power * (num_cpus + 1)) / (max_cpus + 1);

	return 0;
}

/**
 * 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;
}

static int exynos_cpufreq_cooling_get_level(struct thermal_cooling_device *cdev,
				 unsigned long value)
{
	struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;
	int level = get_level(cpufreq_cdev, value);

	if (level == THERMAL_CSTATE_INVALID && value > cpufreq_cdev->freq_table[0].frequency)
		level = 0;

	return level;
}

/**
 * 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, ret;
	u32 static_power, dynamic_power, 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 (freq == 0) {
		*power = 0;
		return 0;
	}

	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;

	dynamic_power = get_dynamic_power(cpufreq_cdev, freq);
	ret = get_static_power(cpufreq_cdev, tz, freq, &static_power);
	if (ret) {
		kfree(load_cpu);
		return ret;
	}

	if (load_cpu) {
		trace_thermal_power_cpu_get_power(tz->id, policy->related_cpus, freq,
						  load_cpu, i, dynamic_power,
						  static_power);

		kfree(load_cpu);
	}

	*power = static_power + dynamic_power;
	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;
	u32 static_power, dynamic_power;
	int ret;
	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;
	dynamic_power = cpu_freq_to_power(cpufreq_cdev, freq) * num_cpus;
	ret = get_static_power(cpufreq_cdev, tz, freq, &static_power);
	if (ret)
		return ret;

	*power = static_power + dynamic_power;
	return ret;
}

/**
 * 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 cpu, cur_freq, target_freq;
	int ret;
	s32 dyn_power;
	u32 normalised_power, static_power;
	struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;
	struct cpufreq_policy *policy = cpufreq_cdev->policy;
	cpumask_t tempmask;
	int num_cpus;

	cpumask_and(&tempmask, policy->related_cpus, cpu_online_mask);
	num_cpus = cpumask_weight(&tempmask);

	cpu = cpumask_any_and(policy->related_cpus, cpu_online_mask);

	/* None of our cpus are online */
	if (cpu >= nr_cpu_ids)
		return -ENODEV;

	cur_freq = cpufreq_quick_get(policy->cpu);
	ret = get_static_power(cpufreq_cdev, tz, cur_freq, &static_power);
	if (ret)
		return ret;

	dyn_power = power - static_power;
	dyn_power = dyn_power > 0 ? dyn_power : 0;
	normalised_power = dyn_power / num_cpus;
	target_freq = cpu_power_to_freq(cpufreq_cdev, normalised_power);

	*state = cpufreq_cooling_get_level(cpu, target_freq);
	if (*state == THERMAL_CSTATE_INVALID) {
		dev_warn_ratelimited(&cdev->device,
				     "Failed to convert %dKHz for cpu %d into a cdev state\n",
				     target_freq, cpu);
		return -EINVAL;
	}

	*state = get_level(cpufreq_cdev, target_freq);
	trace_thermal_power_cpu_limit(tz->id, policy->related_cpus, target_freq, *state,
				      power);
	return 0;
}

static int cpufreq_set_cur_temp(struct thermal_cooling_device *cdev,
				bool suspended, int temp)
{
	enum tmu_noti_state_t tstate;
	unsigned int on;

	if (suspended || temp < EXYNOS_COLD_TEMP) {
		tstate = TMU_COLD;
		on = 1;
	} else {
		tstate = TMU_NORMAL;
		on = 0;
	}

	if (cpu_tstate == tstate)
		return 0;

	cpu_tstate = tstate;

	blocking_notifier_call_chain(&cpu_notifier, TMU_COLD, &on);

	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,
	.get_cooling_level = exynos_cpufreq_cooling_get_level,
	.set_cur_temp = cpufreq_set_cur_temp,
};

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,
	.set_cur_temp = cpufreq_set_cur_temp,
};

/* Notifier for cpufreq policy change */
static struct notifier_block thermal_cpufreq_notifier_block = {
	.notifier_call = cpufreq_thermal_notifier,
};

int exynos_tmu_add_notifier(struct notifier_block *n)
{
	return blocking_notifier_chain_register(&cpu_notifier, n);
}

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
 * @plat_static_func: function to calculate the static power consumed by these
 *                    cpus (optional)
 *
 * 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,
			get_static_t plat_static_func)
{
	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", __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;
		}

		ret = build_static_power_table(np, cpufreq_cdev);
		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, NULL);
}
EXPORT_SYMBOL_GPL(cpufreq_cooling_register);

/**
 * of_cpufreq_cooling_register - function to create cpufreq cooling device.
 * @np: a valid struct device_node to the cooling device device tree node
 * @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.
 *
 * Return: a valid struct thermal_cooling_device pointer on success,
 * on failure, it returns a corresponding ERR_PTR().
 */
struct thermal_cooling_device *
of_cpufreq_cooling_register(struct device_node *np,
			    struct cpufreq_policy *policy)
{
	if (!np)
		return ERR_PTR(-EINVAL);

	return __cpufreq_cooling_register(np, policy, 0, NULL);
}
EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register);

/**
 * cpufreq_power_cooling_register() - create cpufreq cooling device with power extensions
 * @policy:		cpufreq policy
 * @capacitance:	dynamic power coefficient for these cpus
 * @plat_static_func:	function to calculate the static power consumed by these
 *			cpus (optional)
 *
 * 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 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.
 *
 * An optional @plat_static_func may be provided to calculate the
 * static power consumed by these cpus.  If the platform's static
 * power consumption is unknown or negligible, make it NULL.
 *
 * Return: a valid struct thermal_cooling_device pointer on success,
 * on failure, it returns a corresponding ERR_PTR().
 */
struct thermal_cooling_device *
cpufreq_power_cooling_register(struct cpufreq_policy *policy, u32 capacitance,
			       get_static_t plat_static_func)
{
	return __cpufreq_cooling_register(NULL, policy, capacitance,
				plat_static_func);
}
EXPORT_SYMBOL(cpufreq_power_cooling_register);

/**
 * of_cpufreq_power_cooling_register() - create cpufreq cooling device with power extensions
 * @np:	a valid struct device_node to the cooling device device tree node
 * @policy: cpufreq policy
 * @capacitance:	dynamic power coefficient for these cpus
 * @plat_static_func:	function to calculate the static power consumed by these
 *			cpus (optional)
 *
 * 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.
 *
 * An optional @plat_static_func may be provided to calculate the
 * static power consumed by these cpus.  If the platform's static
 * power consumption is unknown or negligible, make it NULL.
 *
 * Return: a valid struct thermal_cooling_device pointer on success,
 * on failure, it returns a corresponding ERR_PTR().
 */
struct thermal_cooling_device *
of_cpufreq_power_cooling_register(struct device_node *np,
				  struct cpufreq_policy *policy,
				  u32 capacitance,
				  get_static_t plat_static_func)
{
	if (!np)
		return ERR_PTR(-EINVAL);

	return __cpufreq_cooling_register(np, policy, capacitance,
				plat_static_func);
}
EXPORT_SYMBOL(of_cpufreq_power_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);

struct thermal_cooling_device *
exynos_cpufreq_cooling_register(struct device_node *np, struct cpufreq_policy *policy)
{
	struct thermal_zone_device *tz;
	void *gen_block;
	struct ect_gen_param_table *pwr_coeff;
	u32 capacitance = 0;

	if (!np)
		return ERR_PTR(-EINVAL);

	tz = thermal_zone_get_zone_by_cool_np(np);

	if (tz) {
		gen_block = ect_get_block("GEN");
		if (gen_block == NULL) {
			pr_err("%s: Failed to get gen block from ECT\n", __func__);
			goto regist;
		}
		pwr_coeff = ect_gen_param_get_table(gen_block, "DTM_PWR_Coeff");
		if (pwr_coeff == NULL) {
			pr_err("%s: Failed to get power coeff from ECT\n", __func__);
			goto regist;
		}
		capacitance = pwr_coeff->parameter[tz->id];
	} else {
		pr_err("%s: could not find thermal zone\n", __func__);
	}

regist:
	return __cpufreq_cooling_register(np, policy, capacitance,
				NULL);
}
EXPORT_SYMBOL_GPL(exynos_cpufreq_cooling_register);