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Commit 0fe3a664 authored by Chanwoo Choi's avatar Chanwoo Choi Committed by MyungJoo Ham
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PM / devfreq: Add new DEVFREQ_TRANSITION_NOTIFIER notifier 



This patch adds the new DEVFREQ_TRANSITION_NOTIFIER notifier to send
the notification when the frequency of device is changed.
This notifier has two state as following:
- DEVFREQ_PRECHANGE  : Notify it before chaning the frequency of device
- DEVFREQ_POSTCHANGE : Notify it after changed the frequency of device

And this patch adds the resourced-managed function to release the resource
automatically when error happen.

Signed-off-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
[m.reichl and linux.amoon: Tested it on exynos4412-odroidu3 board]
Tested-by: default avatarMarkus Reichl <m.reichl@fivetechno.de>
Tested-by: default avatarAnand Moon <linux.amoon@gmail.com>
Signed-off-by: default avatarMyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: default avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
parent 8f510aeb

drivers/devfreq/devfreq.c

+162 −1
Original line number Diff line number Diff line
@@ -189,6 +189,29 @@ static struct devfreq_governor *find_devfreq_governor(const char *name) 
	return ERR_PTR(-ENODEV);

}



static int devfreq_notify_transition(struct devfreq *devfreq,

		struct devfreq_freqs *freqs, unsigned int state)

{

	if (!devfreq)

		return -EINVAL;



	switch (state) {

	case DEVFREQ_PRECHANGE:

		srcu_notifier_call_chain(&devfreq->transition_notifier_list,

				DEVFREQ_PRECHANGE, freqs);

		break;



	case DEVFREQ_POSTCHANGE:

		srcu_notifier_call_chain(&devfreq->transition_notifier_list,

				DEVFREQ_POSTCHANGE, freqs);

		break;

	default:

		return -EINVAL;

	}



	return 0;

}



/* Load monitoring helper functions for governors use */



/**
@@ -200,7 +223,8 @@ static struct devfreq_governor *find_devfreq_governor(const char *name) 
 */

int update_devfreq(struct devfreq *devfreq)

{

	unsigned long freq;

	struct devfreq_freqs freqs;

	unsigned long freq, cur_freq;

	int err = 0;

	u32 flags = 0;
@@ -234,10 +258,22 @@ int update_devfreq(struct devfreq *devfreq) 
		flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */

	}



	if (devfreq->profile->get_cur_freq)

		devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);

	else

		cur_freq = devfreq->previous_freq;



	freqs.old = cur_freq;

	freqs.new = freq;

	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);



	err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);

	if (err)

		return err;



	freqs.new = freq;

	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);



	if (devfreq->profile->freq_table)

		if (devfreq_update_status(devfreq, freq))

			dev_err(&devfreq->dev,
@@ -542,6 +578,8 @@ struct devfreq *devfreq_add_device(struct device *dev, 
		goto err_out;

	}



	srcu_init_notifier_head(&devfreq->transition_notifier_list);



	mutex_unlock(&devfreq->lock);



	mutex_lock(&devfreq_list_lock);
@@ -1310,6 +1348,129 @@ void devm_devfreq_unregister_opp_notifier(struct device *dev, 
}

EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);



/**

 * devfreq_register_notifier() - Register a driver with devfreq

 * @devfreq:	The devfreq object.

 * @nb:		The notifier block to register.

 * @list:	DEVFREQ_TRANSITION_NOTIFIER.

 */

int devfreq_register_notifier(struct devfreq *devfreq,

				struct notifier_block *nb,

				unsigned int list)

{

	int ret = 0;



	if (!devfreq)

		return -EINVAL;



	switch (list) {

	case DEVFREQ_TRANSITION_NOTIFIER:

		ret = srcu_notifier_chain_register(

				&devfreq->transition_notifier_list, nb);

		break;

	default:

		ret = -EINVAL;

	}



	return ret;

}

EXPORT_SYMBOL(devfreq_register_notifier);



/*

 * devfreq_unregister_notifier() - Unregister a driver with devfreq

 * @devfreq:	The devfreq object.

 * @nb:		The notifier block to be unregistered.

 * @list:	DEVFREQ_TRANSITION_NOTIFIER.

 */

int devfreq_unregister_notifier(struct devfreq *devfreq,

				struct notifier_block *nb,

				unsigned int list)

{

	int ret = 0;



	if (!devfreq)

		return -EINVAL;



	switch (list) {

	case DEVFREQ_TRANSITION_NOTIFIER:

		ret = srcu_notifier_chain_unregister(

				&devfreq->transition_notifier_list, nb);

		break;

	default:

		ret = -EINVAL;

	}



	return ret;

}

EXPORT_SYMBOL(devfreq_unregister_notifier);



struct devfreq_notifier_devres {

	struct devfreq *devfreq;

	struct notifier_block *nb;

	unsigned int list;

};



static void devm_devfreq_notifier_release(struct device *dev, void *res)

{

	struct devfreq_notifier_devres *this = res;



	devfreq_unregister_notifier(this->devfreq, this->nb, this->list);

}



/**

 * devm_devfreq_register_notifier()

	- Resource-managed devfreq_register_notifier()

 * @dev:	The devfreq user device. (parent of devfreq)

 * @devfreq:	The devfreq object.

 * @nb:		The notifier block to be unregistered.

 * @list:	DEVFREQ_TRANSITION_NOTIFIER.

 */

int devm_devfreq_register_notifier(struct device *dev,

				struct devfreq *devfreq,

				struct notifier_block *nb,

				unsigned int list)

{

	struct devfreq_notifier_devres *ptr;

	int ret;



	ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr),

				GFP_KERNEL);

	if (!ptr)

		return -ENOMEM;



	ret = devfreq_register_notifier(devfreq, nb, list);

	if (ret) {

		devres_free(ptr);

		return ret;

	}



	ptr->devfreq = devfreq;

	ptr->nb = nb;

	ptr->list = list;

	devres_add(dev, ptr);



	return 0;

}

EXPORT_SYMBOL(devm_devfreq_register_notifier);



/**

 * devm_devfreq_unregister_notifier()

	- Resource-managed devfreq_unregister_notifier()

 * @dev:	The devfreq user device. (parent of devfreq)

 * @devfreq:	The devfreq object.

 * @nb:		The notifier block to be unregistered.

 * @list:	DEVFREQ_TRANSITION_NOTIFIER.

 */

void devm_devfreq_unregister_notifier(struct device *dev,

				struct devfreq *devfreq,

				struct notifier_block *nb,

				unsigned int list)

{

	WARN_ON(devres_release(dev, devm_devfreq_notifier_release,

			       devm_devfreq_dev_match, devfreq));

}

EXPORT_SYMBOL(devm_devfreq_unregister_notifier);



MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");

MODULE_DESCRIPTION("devfreq class support");

MODULE_LICENSE("GPL");

include/linux/devfreq.h

+58 −1
Original line number Diff line number Diff line
@@ -19,6 +19,13 @@ 


#define DEVFREQ_NAME_LEN 16



/* DEVFREQ notifier interface */

#define DEVFREQ_TRANSITION_NOTIFIER	(0)



/* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */

#define	DEVFREQ_PRECHANGE		(0)

#define DEVFREQ_POSTCHANGE		(1)



struct devfreq;



/**
@@ -143,6 +150,7 @@ struct devfreq_governor { 
 * @trans_table:	Statistics of devfreq transitions

 * @time_in_state:	Statistics of devfreq states

 * @last_stat_updated:	The last time stat updated

 * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier

 *

 * This structure stores the devfreq information for a give device.

 *
@@ -177,6 +185,13 @@ struct devfreq { 
	unsigned int *trans_table;

	unsigned long *time_in_state;

	unsigned long last_stat_updated;



	struct srcu_notifier_head transition_notifier_list;

};



struct devfreq_freqs {

	unsigned long old;

	unsigned long new;

};



#if defined(CONFIG_PM_DEVFREQ)
@@ -207,7 +222,20 @@ extern int devm_devfreq_register_opp_notifier(struct device *dev, 
					      struct devfreq *devfreq);

extern void devm_devfreq_unregister_opp_notifier(struct device *dev,

						struct devfreq *devfreq);



extern int devfreq_register_notifier(struct devfreq *devfreq,

					struct notifier_block *nb,

					unsigned int list);

extern int devfreq_unregister_notifier(struct devfreq *devfreq,

					struct notifier_block *nb,

					unsigned int list);

extern int devm_devfreq_register_notifier(struct device *dev,

				struct devfreq *devfreq,

				struct notifier_block *nb,

				unsigned int list);

extern void devm_devfreq_unregister_notifier(struct device *dev,

				struct devfreq *devfreq,

				struct notifier_block *nb,

				unsigned int list);

extern struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,

						int index);
@@ -310,6 +338,35 @@ static inline void devm_devfreq_unregister_opp_notifier(struct device *dev, 
{

}



static inline int devfreq_register_notifier(struct devfreq *devfreq,

					struct notifier_block *nb,

					unsigned int list)

{

	return 0;

}



static inline int devfreq_unregister_notifier(struct devfreq *devfreq,

					struct notifier_block *nb,

					unsigned int list)

{

	return 0;

}



static inline int devm_devfreq_register_notifier(struct device *dev,

				struct devfreq *devfreq,

				struct notifier_block *nb,

				unsigned int list)

{

	return 0;

}



static inline void devm_devfreq_unregister_notifier(struct device *dev,

				struct devfreq *devfreq,

				struct notifier_block *nb,

				unsigned int list)

{

}



static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,

							int index)

{