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Commit 03ca370f authored by MyungJoo Ham's avatar MyungJoo Ham Committed by Rafael J. Wysocki
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PM / OPP: Add OPP availability change notifier. 



The patch enables to register notifier_block for an OPP-device in order
to get notified for any changes in the availability of OPPs of the
device. For example, if a new OPP is inserted or enable/disable status
of an OPP is changed, the notifier is executed.

This enables the usage of opp_add, opp_enable, and opp_disable to
directly take effect with any connected entities such as cpufreq or
devfreq.

Signed-off-by: default avatarMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: default avatarMike Turquette <mturquette@ti.com>
Reviewed-by: default avatarKevin Hilman <khilman@ti.com>
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent a102a9ec

drivers/base/power/opp.c

+30 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ struct opp { 
 *		RCU usage: nodes are not modified in the list of device_opp,

 *		however addition is possible and is secured by dev_opp_list_lock

 * @dev:	device pointer

 * @head:	notifier head to notify the OPP availability changes.

 * @opp_list:	list of opps

 *

 * This is an internal data structure maintaining the link to opps attached to
@@ -83,6 +84,7 @@ struct device_opp { 
	struct list_head node;



	struct device *dev;

	struct srcu_notifier_head head;

	struct list_head opp_list;

};
@@ -404,6 +406,7 @@ int opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) 
		}



		dev_opp->dev = dev;

		srcu_init_notifier_head(&dev_opp->head);

		INIT_LIST_HEAD(&dev_opp->opp_list);



		/* Secure the device list modification */
@@ -428,6 +431,11 @@ int opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) 
	list_add_rcu(&new_opp->node, head);

	mutex_unlock(&dev_opp_list_lock);



	/*

	 * Notify the changes in the availability of the operable

	 * frequency/voltage list.

	 */

	srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ADD, new_opp);

	return 0;

}
@@ -504,6 +512,14 @@ static int opp_set_availability(struct device *dev, unsigned long freq, 
	mutex_unlock(&dev_opp_list_lock);

	synchronize_rcu();



	/* Notify the change of the OPP availability */

	if (availability_req)

		srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ENABLE,

					 new_opp);

	else

		srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_DISABLE,

					 new_opp);



	/* clean up old opp */

	new_opp = opp;

	goto out;
@@ -643,3 +659,17 @@ void opp_free_cpufreq_table(struct device *dev, 
	*table = NULL;

}

#endif		/* CONFIG_CPU_FREQ */



/**

 * opp_get_notifier() - find notifier_head of the device with opp

 * @dev:	device pointer used to lookup device OPPs.

 */

struct srcu_notifier_head *opp_get_notifier(struct device *dev)

{

	struct device_opp *dev_opp = find_device_opp(dev);



	if (IS_ERR(dev_opp))

		return ERR_PTR(PTR_ERR(dev_opp)); /* matching type */



	return &dev_opp->head;

}

include/linux/opp.h

+12 −0
Original line number Diff line number Diff line
@@ -16,9 +16,14 @@ 


#include <linux/err.h>

#include <linux/cpufreq.h>

#include <linux/notifier.h>



struct opp;



enum opp_event {

	OPP_EVENT_ADD, OPP_EVENT_ENABLE, OPP_EVENT_DISABLE,

};



#if defined(CONFIG_PM_OPP)



unsigned long opp_get_voltage(struct opp *opp);
@@ -40,6 +45,8 @@ int opp_enable(struct device *dev, unsigned long freq); 


int opp_disable(struct device *dev, unsigned long freq);



struct srcu_notifier_head *opp_get_notifier(struct device *dev);



#else

static inline unsigned long opp_get_voltage(struct opp *opp)

{
@@ -89,6 +96,11 @@ static inline int opp_disable(struct device *dev, unsigned long freq) 
{

	return 0;

}



struct srcu_notifier_head *opp_get_notifier(struct device *dev)

{

	return ERR_PTR(-EINVAL);

}

#endif		/* CONFIG_PM */



#if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)