[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 frequency transitioning capability.
 * @cpu: cpu for which check is needed.
 *
 * This function will check the current state of the system if
 * it is capable of changing the frequency for a given @cpu.
 *
 * Return: 0 if the system is not currently capable of changing
 * the frequency of given cpu. !0 in case the frequency is changeable.
 */
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,
};

/**
 * get_property - fetch a property of interest for a give cpu.
 * @cpu: cpu for which the property is required
 * @input: query parameter
 * @output: query return
 * @property: type of query (frequency, level, max level)
 *
 * 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.
 *
 * Return: 0 on success, -EINVAL when invalid parameters are passed.
 */
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;
}

/**
 * cpufreq_cooling_get_level - for a give 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)
{
	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	/**
82b9ee40	100	* is_cpufreq_valid - function to check frequency transitioning capability.
02361418	101	* @cpu: cpu for which check is needed.
82b9ee40 EV	102	*
	103	* This function will check the current state of the system if
	104	* it is capable of changing the frequency for a given @cpu.
	105	*
	106	* Return: 0 if the system is not currently capable of changing
	107	* the frequency of given cpu. !0 in case the frequency is changeable.
02361418 ADK	108	*/
	109	static int is_cpufreq_valid(int cpu)
	110	{
	111	struct cpufreq_policy policy;
	112	return !cpufreq_get_policy(&policy, cpu);
	113	}
	114
fc35b35c ZR	115	enum cpufreq_cooling_property {
	116	GET_LEVEL,
	117	GET_FREQ,
	118	GET_MAXL,
	119	};
	120
2d6f28fe EV	121	/**
	122	* get_property - fetch a property of interest for a give cpu.
	123	* @cpu: cpu for which the property is required
	124	* @input: query parameter
	125	* @output: query return
	126	* @property: type of query (frequency, level, max level)
	127	*
	128	* This is the common function to
fc35b35c ZR	129	* 1. get maximum cpu cooling states
	130	* 2. translate frequency to cooling state
	131	* 3. translate cooling state to frequency
	132	* Note that the code may be not in good shape
	133	* but it is written in this way in order to:
	134	* a) reduce duplicate code as most of the code can be shared.
	135	* b) make sure the logic is consistent when translating between
	136	* cooling states and frequencies.
2d6f28fe EV	137	*
	138	* Return: 0 on success, -EINVAL when invalid parameters are passed.
	139	*/
fc35b35c ZR	140	static int get_property(unsigned int cpu, unsigned long input,
fc35b35c ZR	141	unsigned int* output, enum cpufreq_cooling_property property)
02361418	142	{
fc35b35c	143	int i, j;
4469b997	144	unsigned long max_level = 0, level = 0;
fc35b35c ZR	145	unsigned int freq = CPUFREQ_ENTRY_INVALID;
fc35b35c ZR	146	int descend = -1;
02361418 ADK	147	struct cpufreq_frequency_table *table =
02361418 ADK	148	cpufreq_frequency_get_table(cpu);
fc35b35c ZR	149
	150	if (!output)
	151	return -EINVAL;
	152
02361418	153	if (!table)
fc35b35c	154	return -EINVAL;
02361418	155
fc35b35c ZR	156
	157	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
	158	/* ignore invalid entries */
02361418 ADK	159	if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
	160	continue;
	161
fc35b35c ZR	162	/* ignore duplicate entry */
	163	if (freq == table[i].frequency)
	164	continue;
	165
	166	/* get the frequency order */
	167	if (freq != CPUFREQ_ENTRY_INVALID && descend != -1)
	168	descend = !!(freq > table[i].frequency);
02361418	169
fc35b35c ZR	170	freq = table[i].frequency;
fc35b35c ZR	171	max_level++;
02361418	172	}
02361418	173
fc35b35c ZR	174	/* get max level */
	175	if (property == GET_MAXL) {
	176	*output = (unsigned int)max_level;
	177	return 0;
	178	}
02361418	179
fc35b35c ZR	180	if (property == GET_FREQ)
	181	level = descend ? input : (max_level - input -1);
	182
02361418	183
fc35b35c ZR	184	for (i = 0, j = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
fc35b35c ZR	185	/* ignore invalid entry */
02361418 ADK	186	if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
02361418 ADK	187	continue;
fc35b35c ZR	188
	189	/* ignore duplicate entry */
	190	if (freq == table[i].frequency)
	191	continue;
	192
	193	/* now we have a valid frequency entry */
	194	freq = table[i].frequency;
	195
	196	if (property == GET_LEVEL && (unsigned int)input == freq) {
	197	/* get level by frequency */
	198	*output = descend ? j : (max_level - j - 1);
	199	return 0;
	200	}
	201	if (property == GET_FREQ && level == j) {
	202	/* get frequency by level */
	203	*output = freq;
	204	return 0;
	205	}
	206	j++;
02361418	207	}
fc35b35c ZR	208	return -EINVAL;
	209	}
	210
44952d33 EV	211	/**
	212	* cpufreq_cooling_get_level - for a give cpu, return the cooling level.
	213	* @cpu: cpu for which the level is required
	214	* @freq: the frequency of interest
	215	*
	216	* This function will match the cooling level corresponding to the
	217	* requested @freq and return it.
	218	*
	219	* Return: The matched cooling level on success or THERMAL_CSTATE_INVALID
	220	* otherwise.
	221	*/
57df8106 ZR	222	unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
	223	{
	224	unsigned int val;
	225
	226	if (get_property(cpu, (unsigned long)freq, &val, GET_LEVEL))
	227	return THERMAL_CSTATE_INVALID;
	228	return (unsigned long)val;
	229	}
243dbd9c	230	EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level);
57df8106	231
fc35b35c ZR	232	/**
	233	* get_cpu_frequency - get the absolute value of frequency from level.
	234	* @cpu: cpu for which frequency is fetched.
	235	* @level: level of frequency, equals cooling state of cpu cooling device
	236	* e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc
	237	*/
	238	static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level)
	239	{
	240	int ret = 0;
	241	unsigned int freq;
	242
	243	ret = get_property(cpu, level, &freq, GET_FREQ);
	244	if (ret)
	245	return 0;
	246	return freq;
02361418 ADK	247	}
	248
	249	/**
	250	* cpufreq_apply_cooling - function to apply frequency clipping.
	251	* @cpufreq_device: cpufreq_cooling_device pointer containing frequency
	252	* clipping data.
	253	* @cooling_state: value of the cooling state.
	254	*/
	255	static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device,
	256	unsigned long cooling_state)
	257	{
	258	unsigned int cpuid, clip_freq;
bde00663 LNM	259	struct cpumask *mask = &cpufreq_device->allowed_cpus;
bde00663 LNM	260	unsigned int cpu = cpumask_any(mask);
02361418 ADK	261
	262
	263	/* Check if the old cooling action is same as new cooling action */
	264	if (cpufreq_device->cpufreq_state == cooling_state)
	265	return 0;
	266
	267	clip_freq = get_cpu_frequency(cpu, cooling_state);
	268	if (!clip_freq)
	269	return -EINVAL;
	270
	271	cpufreq_device->cpufreq_state = cooling_state;
	272	cpufreq_device->cpufreq_val = clip_freq;
	273	notify_device = cpufreq_device;
	274
bde00663	275	for_each_cpu(cpuid, mask) {
02361418 ADK	276	if (is_cpufreq_valid(cpuid))
	277	cpufreq_update_policy(cpuid);
	278	}
	279
	280	notify_device = NOTIFY_INVALID;
	281
	282	return 0;
	283	}
	284
	285	/**
	286	* cpufreq_thermal_notifier - notifier callback for cpufreq policy change.
	287	* @nb: struct notifier_block * with callback info.
	288	* @event: value showing cpufreq event for which this function invoked.
	289	* @data: callback-specific data
	290	*/
	291	static int cpufreq_thermal_notifier(struct notifier_block *nb,
	292	unsigned long event, void *data)
	293	{
	294	struct cpufreq_policy *policy = data;
	295	unsigned long max_freq = 0;
	296
	297	if (event != CPUFREQ_ADJUST \|\| notify_device == NOTIFY_INVALID)
	298	return 0;
	299
	300	if (cpumask_test_cpu(policy->cpu, &notify_device->allowed_cpus))
	301	max_freq = notify_device->cpufreq_val;
	302
	303	/* Never exceed user_policy.max*/
	304	if (max_freq > policy->user_policy.max)
	305	max_freq = policy->user_policy.max;
	306
	307	if (policy->max != max_freq)
	308	cpufreq_verify_within_limits(policy, 0, max_freq);
	309
	310	return 0;
	311	}
	312
	313	/*
	314	* cpufreq cooling device callback functions are defined below
	315	*/
	316
	317	/**
	318	* cpufreq_get_max_state - callback function to get the max cooling state.
	319	* @cdev: thermal cooling device pointer.
	320	* @state: fill this variable with the max cooling state.
	321	*/
	322	static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
	323	unsigned long *state)
	324	{
160b7d80	325	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
bde00663	326	struct cpumask *mask = &cpufreq_device->allowed_cpus;
02361418	327	unsigned int cpu;
4f89038f	328	unsigned int count = 0;
fc35b35c	329	int ret;
02361418	330
bde00663	331	cpu = cpumask_any(mask);
02361418	332
4f89038f	333	ret = get_property(cpu, 0, &count, GET_MAXL);
9c51b05a	334
fc35b35c ZR	335	if (count > 0)
fc35b35c ZR	336	*state = count;
02361418	337
fc35b35c	338	return ret;
02361418 ADK	339	}
	340
	341	/**
	342	* cpufreq_get_cur_state - callback function to get the current cooling state.
	343	* @cdev: thermal cooling device pointer.
	344	* @state: fill this variable with the current cooling state.
	345	*/
	346	static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
	347	unsigned long *state)
	348	{
160b7d80	349	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
02361418	350
160b7d80	351	*state = cpufreq_device->cpufreq_state;
160b7d80	352	return 0;
02361418 ADK	353	}
	354
	355	/**
	356	* cpufreq_set_cur_state - callback function to set the current cooling state.
	357	* @cdev: thermal cooling device pointer.
	358	* @state: set this variable to the current cooling state.
	359	*/
	360	static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
	361	unsigned long state)
	362	{
160b7d80	363	struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
02361418	364
160b7d80	365	return cpufreq_apply_cooling(cpufreq_device, state);
02361418 ADK	366	}
	367
	368	/* Bind cpufreq callbacks to thermal cooling device ops */
	369	static struct thermal_cooling_device_ops const cpufreq_cooling_ops = {
	370	.get_max_state = cpufreq_get_max_state,
	371	.get_cur_state = cpufreq_get_cur_state,
	372	.set_cur_state = cpufreq_set_cur_state,
	373	};
	374
	375	/* Notifier for cpufreq policy change */
	376	static struct notifier_block thermal_cpufreq_notifier_block = {
	377	.notifier_call = cpufreq_thermal_notifier,
	378	};
	379
	380	/**
	381	* cpufreq_cooling_register - function to create cpufreq cooling device.
	382	* @clip_cpus: cpumask of cpus where the frequency constraints will happen.
	383	*/
	384	struct thermal_cooling_device *cpufreq_cooling_register(
3778ff5c	385	const struct cpumask *clip_cpus)
02361418 ADK	386	{
	387	struct thermal_cooling_device *cool_dev;
	388	struct cpufreq_cooling_device *cpufreq_dev = NULL;
160b7d80	389	unsigned int min = 0, max = 0;
02361418	390	char dev_name[THERMAL_NAME_LENGTH];
a4b6fec9	391	int ret = 0, i;
02361418 ADK	392	struct cpufreq_policy policy;
02361418 ADK	393
02361418 ADK	394	/Verify that all the clip cpus have same freq_min, freq_max limit/
	395	for_each_cpu(i, clip_cpus) {
	396	/continue if cpufreq policy not found and not return error/
	397	if (!cpufreq_get_policy(&policy, i))
	398	continue;
	399	if (min == 0 && max == 0) {
	400	min = policy.cpuinfo.min_freq;
	401	max = policy.cpuinfo.max_freq;
	402	} else {
	403	if (min != policy.cpuinfo.min_freq \|\|
	404	max != policy.cpuinfo.max_freq)
	405	return ERR_PTR(-EINVAL);
6b6519df	406	}
02361418 ADK	407	}
	408	cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device),
	409	GFP_KERNEL);
	410	if (!cpufreq_dev)
	411	return ERR_PTR(-ENOMEM);
	412
	413	cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus);
	414
02361418 ADK	415	ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
	416	if (ret) {
	417	kfree(cpufreq_dev);
	418	return ERR_PTR(-EINVAL);
	419	}
	420
	421	sprintf(dev_name, "thermal-cpufreq-%d", cpufreq_dev->id);
	422
	423	cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev,
	424	&cpufreq_cooling_ops);
	425	if (!cool_dev) {
	426	release_idr(&cpufreq_idr, cpufreq_dev->id);
	427	kfree(cpufreq_dev);
	428	return ERR_PTR(-EINVAL);
	429	}
02361418 ADK	430	cpufreq_dev->cool_dev = cool_dev;
	431	cpufreq_dev->cpufreq_state = 0;
	432	mutex_lock(&cooling_cpufreq_lock);
02361418 ADK	433
	434	/* Register the notifier for first cpufreq cooling device */
	435	if (cpufreq_dev_count == 0)
	436	cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
	437	CPUFREQ_POLICY_NOTIFIER);
160b7d80	438	cpufreq_dev_count++;
02361418 ADK	439
	440	mutex_unlock(&cooling_cpufreq_lock);
	441	return cool_dev;
	442	}
243dbd9c	443	EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
02361418 ADK	444
	445	/**
	446	* cpufreq_cooling_unregister - function to remove cpufreq cooling device.
	447	* @cdev: thermal cooling device pointer.
	448	*/
	449	void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
	450	{
160b7d80	451	struct cpufreq_cooling_device *cpufreq_dev = cdev->devdata;
02361418 ADK	452
02361418 ADK	453	mutex_lock(&cooling_cpufreq_lock);
160b7d80	454	cpufreq_dev_count--;
02361418 ADK	455
02361418 ADK	456	/* Unregister the notifier for the last cpufreq cooling device */
160b7d80	457	if (cpufreq_dev_count == 0) {
02361418 ADK	458	cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
	459	CPUFREQ_POLICY_NOTIFIER);
	460	}
	461	mutex_unlock(&cooling_cpufreq_lock);
160b7d80	462
02361418 ADK	463	thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
02361418 ADK	464	release_idr(&cpufreq_idr, cpufreq_dev->id);
02361418 ADK	465	kfree(cpufreq_dev);
02361418 ADK	466	}
243dbd9c	467	EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);