Commit 3ca9bb33 authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

PM / OPP: Add clock-latency-ns support 



With "operating-points-v2" bindings, clock-latency is defined per OPP.
Users of this value expect a single value which defines the latency to
switch to any clock rate. Find maximum clock-latency-ns from the OPP
table to service requests from such users.

Reviewed-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Reviewed-by: default avatarBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 27465902

drivers/base/power/opp.c

+39 −2
Original line number Diff line number Diff line
@@ -57,6 +57,8 @@ 
 * @u_volt_min:	Minimum voltage in microvolts corresponding to this OPP

 * @u_volt_max:	Maximum voltage in microvolts corresponding to this OPP

 * @u_amp:	Maximum current drawn by the device in microamperes

 * @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's

 *		frequency from any other OPP's frequency.

 * @dev_opp:	points back to the device_opp struct this opp belongs to

 * @rcu_head:	RCU callback head used for deferred freeing

 * @np:		OPP's device node.
@@ -75,6 +77,7 @@ struct dev_pm_opp { 
	unsigned long u_volt_min;

	unsigned long u_volt_max;

	unsigned long u_amp;

	unsigned long clock_latency_ns;



	struct device_opp *dev_opp;

	struct rcu_head rcu_head;
@@ -109,6 +112,8 @@ struct device_opp { 
	struct srcu_notifier_head srcu_head;

	struct rcu_head rcu_head;

	struct list_head opp_list;



	unsigned long clock_latency_ns_max;

};



/*
@@ -225,6 +230,32 @@ unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp) 
}

EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);



/**

 * dev_pm_opp_get_max_clock_latency() - Get max clock latency in nanoseconds

 * @dev:	device for which we do this operation

 *

 * Return: This function returns the max clock latency in nanoseconds.

 *

 * Locking: This function takes rcu_read_lock().

 */

unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)

{

	struct device_opp *dev_opp;

	unsigned long clock_latency_ns;



	rcu_read_lock();



	dev_opp = _find_device_opp(dev);

	if (IS_ERR(dev_opp))

		clock_latency_ns = 0;

	else

		clock_latency_ns = dev_opp->clock_latency_ns_max;



	rcu_read_unlock();

	return clock_latency_ns;

}

EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);



/**

 * dev_pm_opp_get_opp_count() - Get number of opps available in the opp list

 * @dev:	device for which we do this operation
@@ -779,6 +810,8 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) 
	new_opp->np = np;

	new_opp->dynamic = false;

	new_opp->available = true;

	of_property_read_u32(np, "clock-latency-ns",

			     (u32 *)&new_opp->clock_latency_ns);



	ret = opp_get_microvolt(new_opp, dev);

	if (ret)
@@ -790,11 +823,15 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) 
	if (ret)

		goto free_opp;



	if (new_opp->clock_latency_ns > dev_opp->clock_latency_ns_max)

		dev_opp->clock_latency_ns_max = new_opp->clock_latency_ns;



	mutex_unlock(&dev_opp_list_lock);



	pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu\n",

	pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n",

		 __func__, new_opp->turbo, new_opp->rate, new_opp->u_volt,

		 new_opp->u_volt_min, new_opp->u_volt_max);

		 new_opp->u_volt_min, new_opp->u_volt_max,

		 new_opp->clock_latency_ns);



	/*

	 * Notify the changes in the availability of the operable

include/linux/pm_opp.h

+6 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp); 
unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp);



int dev_pm_opp_get_opp_count(struct device *dev);

unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev);



struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,

					      unsigned long freq,
@@ -67,6 +68,11 @@ static inline int dev_pm_opp_get_opp_count(struct device *dev) 
	return 0;

}



static inline unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)

{

	return 0;

}



static inline struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,

					unsigned long freq, bool available)

{

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