[deliverable/linux.git] / drivers / thermal / cpu_cooling.c

/*
 *  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>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *  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/slab.h>
#include <linux/cpu.h>
#include <linux/cpu_cooling.h>

/**
 * struct cpufreq_cooling_device - data for cooling device with cpufreq
 * @id: unique integer value corresponding to each cpufreq_cooling_device
 *	registered.
 * @cool_dev: thermal_cooling_device pointer to keep track of the
 *	registered cooling device.
 * @cpufreq_state: integer value representing the current state of cpufreq
 *	cooling	devices.
 * @cpufreq_val: integer value representing the absolute value of the clipped
 *	frequency.
 * @allowed_cpus: all the cpus involved for this cpufreq_cooling_device.
 * @node: list_head to link all cpufreq_cooling_device together.
 *
 * This structure is required for keeping information of each
 * cpufreq_cooling_device registered as a list whose head is represented by
 * cooling_cpufreq_list. In order to prevent corruption of this list a
 * mutex lock cooling_cpufreq_lock is used.
 */
struct cpufreq_cooling_device {
	int id;
	struct thermal_cooling_device *cool_dev;
	unsigned int cpufreq_state;
	unsigned int cpufreq_val;
	struct cpumask allowed_cpus;
	struct list_head node;
};
static LIST_HEAD(cooling_cpufreq_list);
static DEFINE_IDR(cpufreq_idr);
static DEFINE_MUTEX(cooling_cpufreq_lock);

static unsigned int cpufreq_dev_count;

/* notify_table passes value to the CPUFREQ_ADJUST callback function. */
#define NOTIFY_INVALID NULL
static struct cpufreq_cooling_device *notify_device;

/**
 * get_idr - function to get a unique id.
 * @idr: struct idr * handle used to create a id.
 * @id: int * value generated by this function.
 */
static int get_idr(struct idr *idr, int *id)
{
	int ret;

	mutex_lock(&cooling_cpufreq_lock);
	ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL);
	mutex_unlock(&cooling_cpufreq_lock);
	if (unlikely(ret < 0))
		return ret;
	*id = ret;
	return 0;
}

/**
 * release_idr - function to free the unique id.
 * @idr: struct idr * handle used for creating the id.
 * @id: int value representing the unique id.
 */
static void release_idr(struct idr *idr, int id)
{
	mutex_lock(&cooling_cpufreq_lock);
	idr_remove(idr, id);
	mutex_unlock(&cooling_cpufreq_lock);
}

/* Below code defines functions to be used for cpufreq as cooling device */

/**
 * is_cpufreq_valid - function to check if a cpu has frequency transition policy.
 * @cpu: cpu for which check is needed.
 */
static int is_cpufreq_valid(int cpu)
{
	struct cpufreq_policy policy;
	return !cpufreq_get_policy(&policy, cpu);
}

enum cpufreq_cooling_property {
	GET_LEVEL,
	GET_FREQ,
	GET_MAXL,
};

/*
 * this is the common function to
 * 1. get maximum cpu cooling states
 * 2. translate frequency to cooling state
 * 3. translate cooling state to frequency
 * Note that the code may be not in good shape
 * but it is written in this way in order to:
 * a) reduce duplicate code as most of the code can be shared.
 * b) make sure the logic is consistent when translating between
 *    cooling states and frequencies.
*/
static int get_property(unsigned int cpu, unsigned long input,
	unsigned int* output, enum cpufreq_cooling_property property)
{
	int i, j;
	unsigned long max_level = 0, level = 0;
	unsigned int freq = CPUFREQ_ENTRY_INVALID;
	int descend = -1;
	struct cpufreq_frequency_table *table =
					cpufreq_frequency_get_table(cpu);
	
	if (!output)
		return -EINVAL;

	if (!table)
		return -EINVAL;

	
	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
		/* ignore invalid entries */
		if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
			continue;

		/* ignore duplicate entry */
		if (freq == table[i].frequency)
			continue;

		/* get the frequency order */
		if (freq != CPUFREQ_ENTRY_INVALID && descend != -1)
			descend = !!(freq > table[i].frequency);

		freq = table[i].frequency;
		max_level++;
	}

	/* get max level */
	if (property == GET_MAXL) {
		*output = (unsigned int)max_level;
		return 0;
	}

	if (property == GET_FREQ)
		level = descend ? input : (max_level - input -1);


	for (i = 0, j = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
		/* ignore invalid entry */
		if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
			continue;

		/* ignore duplicate entry */
		if (freq == table[i].frequency)
			continue;

		/* now we have a valid frequency entry */
		freq = table[i].frequency;

		if (property == GET_LEVEL && (unsigned int)input == freq) {
			/* get level by frequency */
			*output = descend ? j : (max_level - j - 1);
			return 0;
		}
		if (property == GET_FREQ && level == j) {
			/* get frequency by level */
			*output = freq;
			return 0;
		}
		j++;
	}
	return -EINVAL;
}

unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
{
	unsigned int val;

	if (get_property(cpu, (unsigned long)freq, &val, GET_LEVEL))
		return THERMAL_CSTATE_INVALID;
	return (unsigned long)val;
}
EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level);

/**
 * get_cpu_frequency - get the absolute value of frequency from level.
 * @cpu: cpu for which frequency is fetched.
 * @level: level of frequency, equals cooling state of cpu cooling device
 *	e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc
 */
static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level)
{
	int ret = 0;
	unsigned int freq;

	ret = get_property(cpu, level, &freq, GET_FREQ);
	if (ret)
		return 0;
	return freq;
}

/**
 * cpufreq_apply_cooling - function to apply frequency clipping.
 * @cpufreq_device: cpufreq_cooling_device pointer containing frequency
 *	clipping data.
 * @cooling_state: value of the cooling state.
 */
static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device,
				unsigned long cooling_state)
{
	unsigned int cpuid, clip_freq;
	struct cpumask *mask = &cpufreq_device->allowed_cpus;
	unsigned int cpu = cpumask_any(mask);


	/* Check if the old cooling action is same as new cooling action */
	if (cpufreq_device->cpufreq_state == cooling_state)
		return 0;

	clip_freq = get_cpu_frequency(cpu, cooling_state);
	if (!clip_freq)
		return -EINVAL;

	cpufreq_device->cpufreq_state = cooling_state;
	cpufreq_device->cpufreq_val = clip_freq;
	notify_device = cpufreq_device;

	for_each_cpu(cpuid, mask) {
		if (is_cpufreq_valid(cpuid))
			cpufreq_update_policy(cpuid);
	}

	notify_device = NOTIFY_INVALID;

	return 0;
}

/**
 * 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
 */
static int cpufreq_thermal_notifier(struct notifier_block *nb,
					unsigned long event, void *data)
{
	struct cpufreq_policy *policy = data;
	unsigned long max_freq = 0;

	if (event != CPUFREQ_ADJUST || notify_device == NOTIFY_INVALID)
		return 0;

	if (cpumask_test_cpu(policy->cpu, &notify_device->allowed_cpus))
		max_freq = notify_device->cpufreq_val;

	/* Never exceed user_policy.max*/
	if (max_freq > policy->user_policy.max)
		max_freq = policy->user_policy.max;

	if (policy->max != max_freq)
		cpufreq_verify_within_limits(policy, 0, max_freq);

	return 0;
}

/*
 * 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.
 */
static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
				 unsigned long *state)
{
	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
	struct cpumask *mask = &cpufreq_device->allowed_cpus;
	unsigned int cpu;
	unsigned int count = 0;
	int ret;

	cpu = cpumask_any(mask);

	ret = get_property(cpu, 0, &count, GET_MAXL);

	if (count > 0)
		*state = count;

	return ret;
}

/**
 * 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.
 */
static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
				 unsigned long *state)
{
	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;

	*state = cpufreq_device->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.
 */
static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
				 unsigned long state)
{
	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;

	return cpufreq_apply_cooling(cpufreq_device, state);
}

/* Bind cpufreq callbacks to thermal cooling device ops */
static struct thermal_cooling_device_ops const cpufreq_cooling_ops = {
	.get_max_state = cpufreq_get_max_state,
	.get_cur_state = cpufreq_get_cur_state,
	.set_cur_state = cpufreq_set_cur_state,
};

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

/**
 * cpufreq_cooling_register - function to create cpufreq cooling device.
 * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
 */
struct thermal_cooling_device *cpufreq_cooling_register(
	const struct cpumask *clip_cpus)
{
	struct thermal_cooling_device *cool_dev;
	struct cpufreq_cooling_device *cpufreq_dev = NULL;
	unsigned int min = 0, max = 0;
	char dev_name[THERMAL_NAME_LENGTH];
	int ret = 0, i;
	struct cpufreq_policy policy;

	/*Verify that all the clip cpus have same freq_min, freq_max limit*/
	for_each_cpu(i, clip_cpus) {
		/*continue if cpufreq policy not found and not return error*/
		if (!cpufreq_get_policy(&policy, i))
			continue;
		if (min == 0 && max == 0) {
			min = policy.cpuinfo.min_freq;
			max = policy.cpuinfo.max_freq;
		} else {
			if (min != policy.cpuinfo.min_freq ||
				max != policy.cpuinfo.max_freq)
				return ERR_PTR(-EINVAL);
		}
	}
	cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device),
			GFP_KERNEL);
	if (!cpufreq_dev)
		return ERR_PTR(-ENOMEM);

	cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus);

	ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
	if (ret) {
		kfree(cpufreq_dev);
		return ERR_PTR(-EINVAL);
	}

	sprintf(dev_name, "thermal-cpufreq-%d", cpufreq_dev->id);

	cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev,
						&cpufreq_cooling_ops);
	if (!cool_dev) {
		release_idr(&cpufreq_idr, cpufreq_dev->id);
		kfree(cpufreq_dev);
		return ERR_PTR(-EINVAL);
	}
	cpufreq_dev->cool_dev = cool_dev;
	cpufreq_dev->cpufreq_state = 0;
	mutex_lock(&cooling_cpufreq_lock);

	/* Register the notifier for first cpufreq cooling device */
	if (cpufreq_dev_count == 0)
		cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
						CPUFREQ_POLICY_NOTIFIER);
	cpufreq_dev_count++;

	mutex_unlock(&cooling_cpufreq_lock);
	return cool_dev;
}
EXPORT_SYMBOL_GPL(cpufreq_cooling_register);

/**
 * cpufreq_cooling_unregister - function to remove cpufreq cooling device.
 * @cdev: thermal cooling device pointer.
 */
void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
{
	struct cpufreq_cooling_device *cpufreq_dev = cdev->devdata;

	mutex_lock(&cooling_cpufreq_lock);
	cpufreq_dev_count--;

	/* Unregister the notifier for the last cpufreq cooling device */
	if (cpufreq_dev_count == 0) {
		cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
					CPUFREQ_POLICY_NOTIFIER);
	}
	mutex_unlock(&cooling_cpufreq_lock);

	thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
	release_idr(&cpufreq_idr, cpufreq_dev->id);
	kfree(cpufreq_dev);
}
EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);
Commit	Line	Data
02361418 ADK	1	/*
	2	* linux/drivers/thermal/cpu_cooling.c
	3	*
	4	* Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com)
	5	* Copyright (C) 2012 Amit Daniel <amit.kachhap@linaro.org>
	6	*
	7	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; version 2 of the License.
	11	*
	12	* This program is distributed in the hope that it will be useful, but
	13	* WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	* General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License along
	18	* with this program; if not, write to the Free Software Foundation, Inc.,
	19	* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
	20	*
	21	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	22	*/
02361418 ADK	23	#include <linux/module.h>
02361418 ADK	24	#include <linux/thermal.h>
02361418 ADK	25	#include <linux/cpufreq.h>
	26	#include <linux/err.h>
	27	#include <linux/slab.h>
	28	#include <linux/cpu.h>
	29	#include <linux/cpu_cooling.h>
	30
	31	/**
3b3c0748	32	* struct cpufreq_cooling_device - data for cooling device with cpufreq
02361418 ADK	33	* @id: unique integer value corresponding to each cpufreq_cooling_device
02361418 ADK	34	* registered.
3b3c0748 EV	35	* @cool_dev: thermal_cooling_device pointer to keep track of the
3b3c0748 EV	36	* registered cooling device.
02361418 ADK	37	* @cpufreq_state: integer value representing the current state of cpufreq
	38	* cooling devices.
	39	* @cpufreq_val: integer value representing the absolute value of the clipped
	40	* frequency.
	41	* @allowed_cpus: all the cpus involved for this cpufreq_cooling_device.
	42	* @node: list_head to link all cpufreq_cooling_device together.
	43	*
	44	* This structure is required for keeping information of each
	45	* cpufreq_cooling_device registered as a list whose head is represented by
	46	* cooling_cpufreq_list. In order to prevent corruption of this list a
	47	* mutex lock cooling_cpufreq_lock is used.
	48	*/
	49	struct cpufreq_cooling_device {
	50	int id;
	51	struct thermal_cooling_device *cool_dev;
	52	unsigned int cpufreq_state;
	53	unsigned int cpufreq_val;
	54	struct cpumask allowed_cpus;
	55	struct list_head node;
	56	};
	57	static LIST_HEAD(cooling_cpufreq_list);
	58	static DEFINE_IDR(cpufreq_idr);
160b7d80	59	static DEFINE_MUTEX(cooling_cpufreq_lock);
02361418	60
160b7d80	61	static unsigned int cpufreq_dev_count;
02361418 ADK	62
	63	/* notify_table passes value to the CPUFREQ_ADJUST callback function. */
	64	#define NOTIFY_INVALID NULL
a0f846c2	65	static struct cpufreq_cooling_device *notify_device;
02361418 ADK	66
	67	/**
	68	* get_idr - function to get a unique id.
	69	* @idr: struct idr * handle used to create a id.
	70	* @id: int * value generated by this function.
	71	*/
	72	static int get_idr(struct idr idr, int id)
	73	{
6deb69fa	74	int ret;
02361418 ADK	75
02361418 ADK	76	mutex_lock(&cooling_cpufreq_lock);
6deb69fa	77	ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL);
02361418	78	mutex_unlock(&cooling_cpufreq_lock);
6deb69fa TH	79	if (unlikely(ret < 0))
	80	return ret;
	81	*id = ret;
02361418 ADK	82	return 0;
	83	}
	84
	85	/**
	86	* release_idr - function to free the unique id.
	87	* @idr: struct idr * handle used for creating the id.
	88	* @id: int value representing the unique id.
	89	*/
	90	static void release_idr(struct idr *idr, int id)
	91	{
	92	mutex_lock(&cooling_cpufreq_lock);
	93	idr_remove(idr, id);
	94	mutex_unlock(&cooling_cpufreq_lock);
	95	}
	96
	97	/* Below code defines functions to be used for cpufreq as cooling device */
	98
	99	/**
	100	* is_cpufreq_valid - function to check if a cpu has frequency transition policy.
	101	* @cpu: cpu for which check is needed.
	102	*/
	103	static int is_cpufreq_valid(int cpu)
	104	{
	105	struct cpufreq_policy policy;
	106	return !cpufreq_get_policy(&policy, cpu);
	107	}
	108
fc35b35c ZR	109	enum cpufreq_cooling_property {
	110	GET_LEVEL,
	111	GET_FREQ,
	112	GET_MAXL,
	113	};
	114
	115	/*
	116	* this is the common function to
	117	* 1. get maximum cpu cooling states
	118	* 2. translate frequency to cooling state
	119	* 3. translate cooling state to frequency
	120	* Note that the code may be not in good shape
	121	* but it is written in this way in order to:
	122	* a) reduce duplicate code as most of the code can be shared.
	123	* b) make sure the logic is consistent when translating between
	124	* cooling states and frequencies.
	125	*/
	126	static int get_property(unsigned int cpu, unsigned long input,
	127	unsigned int* output, enum cpufreq_cooling_property property)
02361418	128	{
fc35b35c	129	int i, j;
4469b997	130	unsigned long max_level = 0, level = 0;
fc35b35c ZR	131	unsigned int freq = CPUFREQ_ENTRY_INVALID;
fc35b35c ZR	132	int descend = -1;
02361418 ADK	133	struct cpufreq_frequency_table *table =
02361418 ADK	134	cpufreq_frequency_get_table(cpu);
fc35b35c ZR	135
	136	if (!output)
	137	return -EINVAL;
	138
02361418	139	if (!table)
fc35b35c	140	return -EINVAL;
02361418	141
fc35b35c ZR	142
	143	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
	144	/* ignore invalid entries */
02361418 ADK	145	if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
	146	continue;
	147
fc35b35c ZR	148	/* ignore duplicate entry */
	149	if (freq == table[i].frequency)
	150	continue;
	151
	152	/* get the frequency order */
	153	if (freq != CPUFREQ_ENTRY_INVALID && descend != -1)
	154	descend = !!(freq > table[i].frequency);
02361418	155
fc35b35c ZR	156	freq = table[i].frequency;
fc35b35c ZR	157	max_level++;
02361418	158	}
02361418	159
fc35b35c ZR	160	/* get max level */
	161	if (property == GET_MAXL) {
	162	*output = (unsigned int)max_level;
	163	return 0;
	164	}
02361418	165
fc35b35c ZR	166	if (property == GET_FREQ)
	167	level = descend ? input : (max_level - input -1);
	168
02361418	169
fc35b35c ZR	170	for (i = 0, j = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
fc35b35c ZR	171	/* ignore invalid entry */
02361418 ADK	172	if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
02361418 ADK	173	continue;
fc35b35c ZR	174
	175	/* ignore duplicate entry */
	176	if (freq == table[i].frequency)
	177	continue;
	178
	179	/* now we have a valid frequency entry */
	180	freq = table[i].frequency;
	181
	182	if (property == GET_LEVEL && (unsigned int)input == freq) {
	183	/* get level by frequency */
	184	*output = descend ? j : (max_level - j - 1);
	185	return 0;
	186	}
	187	if (property == GET_FREQ && level == j) {
	188	/* get frequency by level */
	189	*output = freq;
	190	return 0;
	191	}
	192	j++;
02361418	193	}
fc35b35c ZR	194	return -EINVAL;
	195	}
	196
57df8106 ZR	197	unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
	198	{
	199	unsigned int val;
	200
	201	if (get_property(cpu, (unsigned long)freq, &val, GET_LEVEL))
	202	return THERMAL_CSTATE_INVALID;
	203	return (unsigned long)val;
	204	}
243dbd9c	205	EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level);
57df8106	206
fc35b35c ZR	207	/**
	208	* get_cpu_frequency - get the absolute value of frequency from level.
	209	* @cpu: cpu for which frequency is fetched.
	210	* @level: level of frequency, equals cooling state of cpu cooling device
	211	* e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc
	212	*/
	213	static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level)
	214	{
	215	int ret = 0;
	216	unsigned int freq;
	217
	218	ret = get_property(cpu, level, &freq, GET_FREQ);
	219	if (ret)
	220	return 0;
	221	return freq;
02361418 ADK	222	}
	223
	224	/**
	225	* cpufreq_apply_cooling - function to apply frequency clipping.
	226	* @cpufreq_device: cpufreq_cooling_device pointer containing frequency
	227	* clipping data.
	228	* @cooling_state: value of the cooling state.
	229	*/
	230	static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device,
	231	unsigned long cooling_state)
	232	{
	233	unsigned int cpuid, clip_freq;
bde00663 LNM	234	struct cpumask *mask = &cpufreq_device->allowed_cpus;
bde00663 LNM	235	unsigned int cpu = cpumask_any(mask);
02361418 ADK	236
	237
	238	/* Check if the old cooling action is same as new cooling action */
	239	if (cpufreq_device->cpufreq_state == cooling_state)
	240	return 0;
	241
	242	clip_freq = get_cpu_frequency(cpu, cooling_state);
	243	if (!clip_freq)
	244	return -EINVAL;
	245
	246	cpufreq_device->cpufreq_state = cooling_state;
	247	cpufreq_device->cpufreq_val = clip_freq;
	248	notify_device = cpufreq_device;
	249
bde00663	250	for_each_cpu(cpuid, mask) {
02361418 ADK	251	if (is_cpufreq_valid(cpuid))
	252	cpufreq_update_policy(cpuid);
	253	}
	254
	255	notify_device = NOTIFY_INVALID;
	256
	257	return 0;
	258	}
	259
	260	/**
	261	* cpufreq_thermal_notifier - notifier callback for cpufreq policy change.
	262	* @nb: struct notifier_block * with callback info.
	263	* @event: value showing cpufreq event for which this function invoked.
	264	* @data: callback-specific data
	265	*/
	266	static int cpufreq_thermal_notifier(struct notifier_block *nb,
	267	unsigned long event, void *data)
	268	{
	269	struct cpufreq_policy *policy = data;
	270	unsigned long max_freq = 0;
	271
	272	if (event != CPUFREQ_ADJUST \|\| notify_device == NOTIFY_INVALID)
	273	return 0;
	274
	275	if (cpumask_test_cpu(policy->cpu, &notify_device->allowed_cpus))
	276	max_freq = notify_device->cpufreq_val;
	277
	278	/* Never exceed user_policy.max*/
	279	if (max_freq > policy->user_policy.max)
	280	max_freq = policy->user_policy.max;
	281
	282	if (policy->max != max_freq)
	283	cpufreq_verify_within_limits(policy, 0, max_freq);
	284
	285	return 0;
	286	}
	287
	288	/*
	289	* cpufreq cooling device callback functions are defined below
	290	*/
	291
	292	/**
	293	* cpufreq_get_max_state - callback function to get the max cooling state.
	294	* @cdev: thermal cooling device pointer.
	295	* @state: fill this variable with the max cooling state.
	296	*/
	297	static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
	298	unsigned long *state)
	299	{
160b7d80	300	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
bde00663	301	struct cpumask *mask = &cpufreq_device->allowed_cpus;
02361418	302	unsigned int cpu;
4f89038f	303	unsigned int count = 0;
fc35b35c	304	int ret;
02361418	305
bde00663	306	cpu = cpumask_any(mask);
02361418	307
4f89038f	308	ret = get_property(cpu, 0, &count, GET_MAXL);
9c51b05a	309
fc35b35c ZR	310	if (count > 0)
fc35b35c ZR	311	*state = count;
02361418	312
fc35b35c	313	return ret;
02361418 ADK	314	}
	315
	316	/**
	317	* cpufreq_get_cur_state - callback function to get the current cooling state.
	318	* @cdev: thermal cooling device pointer.
	319	* @state: fill this variable with the current cooling state.
	320	*/
	321	static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
	322	unsigned long *state)
	323	{
160b7d80	324	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
02361418	325
160b7d80	326	*state = cpufreq_device->cpufreq_state;
160b7d80	327	return 0;
02361418 ADK	328	}
	329
	330	/**
	331	* cpufreq_set_cur_state - callback function to set the current cooling state.
	332	* @cdev: thermal cooling device pointer.
	333	* @state: set this variable to the current cooling state.
	334	*/
	335	static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
	336	unsigned long state)
	337	{
160b7d80	338	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
02361418	339
160b7d80	340	return cpufreq_apply_cooling(cpufreq_device, state);
02361418 ADK	341	}
	342
	343	/* Bind cpufreq callbacks to thermal cooling device ops */
	344	static struct thermal_cooling_device_ops const cpufreq_cooling_ops = {
	345	.get_max_state = cpufreq_get_max_state,
	346	.get_cur_state = cpufreq_get_cur_state,
	347	.set_cur_state = cpufreq_set_cur_state,
	348	};
	349
	350	/* Notifier for cpufreq policy change */
	351	static struct notifier_block thermal_cpufreq_notifier_block = {
	352	.notifier_call = cpufreq_thermal_notifier,
	353	};
	354
	355	/**
	356	* cpufreq_cooling_register - function to create cpufreq cooling device.
	357	* @clip_cpus: cpumask of cpus where the frequency constraints will happen.
	358	*/
	359	struct thermal_cooling_device *cpufreq_cooling_register(
3778ff5c	360	const struct cpumask *clip_cpus)
02361418 ADK	361	{
	362	struct thermal_cooling_device *cool_dev;
	363	struct cpufreq_cooling_device *cpufreq_dev = NULL;
160b7d80	364	unsigned int min = 0, max = 0;
02361418	365	char dev_name[THERMAL_NAME_LENGTH];
a4b6fec9	366	int ret = 0, i;
02361418 ADK	367	struct cpufreq_policy policy;
02361418 ADK	368
02361418 ADK	369	/Verify that all the clip cpus have same freq_min, freq_max limit/
	370	for_each_cpu(i, clip_cpus) {
	371	/continue if cpufreq policy not found and not return error/
	372	if (!cpufreq_get_policy(&policy, i))
	373	continue;
	374	if (min == 0 && max == 0) {
	375	min = policy.cpuinfo.min_freq;
	376	max = policy.cpuinfo.max_freq;
	377	} else {
	378	if (min != policy.cpuinfo.min_freq \|\|
	379	max != policy.cpuinfo.max_freq)
	380	return ERR_PTR(-EINVAL);
6b6519df	381	}
02361418 ADK	382	}
	383	cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device),
	384	GFP_KERNEL);
	385	if (!cpufreq_dev)
	386	return ERR_PTR(-ENOMEM);
	387
	388	cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus);
	389
02361418 ADK	390	ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
	391	if (ret) {
	392	kfree(cpufreq_dev);
	393	return ERR_PTR(-EINVAL);
	394	}
	395
	396	sprintf(dev_name, "thermal-cpufreq-%d", cpufreq_dev->id);
	397
	398	cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev,
	399	&cpufreq_cooling_ops);
	400	if (!cool_dev) {
	401	release_idr(&cpufreq_idr, cpufreq_dev->id);
	402	kfree(cpufreq_dev);
	403	return ERR_PTR(-EINVAL);
	404	}
02361418 ADK	405	cpufreq_dev->cool_dev = cool_dev;
	406	cpufreq_dev->cpufreq_state = 0;
	407	mutex_lock(&cooling_cpufreq_lock);
02361418 ADK	408
	409	/* Register the notifier for first cpufreq cooling device */
	410	if (cpufreq_dev_count == 0)
	411	cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
	412	CPUFREQ_POLICY_NOTIFIER);
160b7d80	413	cpufreq_dev_count++;
02361418 ADK	414
	415	mutex_unlock(&cooling_cpufreq_lock);
	416	return cool_dev;
	417	}
243dbd9c	418	EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
02361418 ADK	419
	420	/**
	421	* cpufreq_cooling_unregister - function to remove cpufreq cooling device.
	422	* @cdev: thermal cooling device pointer.
	423	*/
	424	void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
	425	{
160b7d80	426	struct cpufreq_cooling_device *cpufreq_dev = cdev->devdata;
02361418 ADK	427
02361418 ADK	428	mutex_lock(&cooling_cpufreq_lock);
160b7d80	429	cpufreq_dev_count--;
02361418 ADK	430
02361418 ADK	431	/* Unregister the notifier for the last cpufreq cooling device */
160b7d80	432	if (cpufreq_dev_count == 0) {
02361418 ADK	433	cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
	434	CPUFREQ_POLICY_NOTIFIER);
	435	}
	436	mutex_unlock(&cooling_cpufreq_lock);
160b7d80	437
02361418 ADK	438	thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
02361418 ADK	439	release_idr(&cpufreq_idr, cpufreq_dev->id);
02361418 ADK	440	kfree(cpufreq_dev);
02361418 ADK	441	}
243dbd9c	442	EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);