Commit 01fb4d3c authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

PM / OPP: Parse 'opp-<prop>-<name>' bindings 



OPP bindings (for few properties) allow a platform to choose a
value/range among a set of available options. The options are present as
opp-<prop>-<name>, where the platform needs to supply the <name> string.

The OPP properties which allow such an option are: opp-microvolt and
opp-microamp.

Add support to the OPP-core to parse these bindings, by introducing
dev_pm_opp_{set|put}_prop_name() APIs.

Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Tested-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 7de36b0a

drivers/base/power/opp/core.c

+150 −15
Original line number Diff line number Diff line
@@ -562,6 +562,9 @@ static void _remove_device_opp(struct device_opp *dev_opp) 
	if (dev_opp->supported_hw)

		return;



	if (dev_opp->prop_name)

		return;



	list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,

				    node);
@@ -794,35 +797,48 @@ unlock: 
}



/* TODO: Support multiple regulators */

static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)

static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,

			      struct device_opp *dev_opp)

{

	u32 microvolt[3] = {0};

	u32 val;

	int count, ret;

	struct property *prop = NULL;

	char name[NAME_MAX];



	/* Search for "opp-microvolt-<name>" */

	if (dev_opp->prop_name) {

		sprintf(name, "opp-microvolt-%s", dev_opp->prop_name);

		prop = of_find_property(opp->np, name, NULL);

	}



	if (!prop) {

		/* Search for "opp-microvolt" */

		name[13] = '\0';

		prop = of_find_property(opp->np, name, NULL);



		/* Missing property isn't a problem, but an invalid entry is */

	if (!of_find_property(opp->np, "opp-microvolt", NULL))

		if (!prop)

			return 0;

	}



	count = of_property_count_u32_elems(opp->np, "opp-microvolt");

	count = of_property_count_u32_elems(opp->np, name);

	if (count < 0) {

		dev_err(dev, "%s: Invalid opp-microvolt property (%d)\n",

			__func__, count);

		dev_err(dev, "%s: Invalid %s property (%d)\n",

			__func__, name, count);

		return count;

	}



	/* There can be one or three elements here */

	if (count != 1 && count != 3) {

		dev_err(dev, "%s: Invalid number of elements in opp-microvolt property (%d)\n",

			__func__, count);

		dev_err(dev, "%s: Invalid number of elements in %s property (%d)\n",

			__func__, name, count);

		return -EINVAL;

	}



	ret = of_property_read_u32_array(opp->np, "opp-microvolt", microvolt,

					 count);

	ret = of_property_read_u32_array(opp->np, name, microvolt, count);

	if (ret) {

		dev_err(dev, "%s: error parsing opp-microvolt: %d\n", __func__,

			ret);

		dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);

		return -EINVAL;

	}
@@ -830,7 +846,20 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev) 
	opp->u_volt_min = microvolt[1];

	opp->u_volt_max = microvolt[2];



	if (!of_property_read_u32(opp->np, "opp-microamp", &val))

	/* Search for "opp-microamp-<name>" */

	prop = NULL;

	if (dev_opp->prop_name) {

		sprintf(name, "opp-microamp-%s", dev_opp->prop_name);

		prop = of_find_property(opp->np, name, NULL);

	}



	if (!prop) {

		/* Search for "opp-microamp" */

		name[12] = '\0';

		prop = of_find_property(opp->np, name, NULL);

	}



	if (prop && !of_property_read_u32(opp->np, name, &val))

		opp->u_amp = val;



	return 0;
@@ -948,6 +977,112 @@ unlock: 
}

EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);



/**

 * dev_pm_opp_set_prop_name() - Set prop-extn name

 * @dev: Device for which the regulator has to be set.

 * @name: name to postfix to properties.

 *

 * This is required only for the V2 bindings, and it enables a platform to

 * specify the extn to be used for certain property names. The properties to

 * which the extension will apply are opp-microvolt and opp-microamp. OPP core

 * should postfix the property name with -<name> while looking for them.

 *

 * Locking: The internal device_opp and opp structures are RCU protected.

 * Hence this function internally uses RCU updater strategy with mutex locks

 * to keep the integrity of the internal data structures. Callers should ensure

 * that this function is *NOT* called under RCU protection or in contexts where

 * mutex cannot be locked.

 */

int dev_pm_opp_set_prop_name(struct device *dev, const char *name)

{

	struct device_opp *dev_opp;

	int ret = 0;



	/* Hold our list modification lock here */

	mutex_lock(&dev_opp_list_lock);



	dev_opp = _add_device_opp(dev);

	if (!dev_opp) {

		ret = -ENOMEM;

		goto unlock;

	}



	/* Make sure there are no concurrent readers while updating dev_opp */

	WARN_ON(!list_empty(&dev_opp->opp_list));



	/* Do we already have a prop-name associated with dev_opp? */

	if (dev_opp->prop_name) {

		dev_err(dev, "%s: Already have prop-name %s\n", __func__,

			dev_opp->prop_name);

		ret = -EBUSY;

		goto err;

	}



	dev_opp->prop_name = kstrdup(name, GFP_KERNEL);

	if (!dev_opp->prop_name) {

		ret = -ENOMEM;

		goto err;

	}



	mutex_unlock(&dev_opp_list_lock);

	return 0;



err:

	_remove_device_opp(dev_opp);

unlock:

	mutex_unlock(&dev_opp_list_lock);



	return ret;

}

EXPORT_SYMBOL_GPL(dev_pm_opp_set_prop_name);



/**

 * dev_pm_opp_put_prop_name() - Releases resources blocked for prop-name

 * @dev: Device for which the regulator has to be set.

 *

 * This is required only for the V2 bindings, and is called for a matching

 * dev_pm_opp_set_prop_name(). Until this is called, the device_opp structure

 * will not be freed.

 *

 * Locking: The internal device_opp and opp structures are RCU protected.

 * Hence this function internally uses RCU updater strategy with mutex locks

 * to keep the integrity of the internal data structures. Callers should ensure

 * that this function is *NOT* called under RCU protection or in contexts where

 * mutex cannot be locked.

 */

void dev_pm_opp_put_prop_name(struct device *dev)

{

	struct device_opp *dev_opp;



	/* Hold our list modification lock here */

	mutex_lock(&dev_opp_list_lock);



	/* Check for existing list for 'dev' first */

	dev_opp = _find_device_opp(dev);

	if (IS_ERR(dev_opp)) {

		dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp));

		goto unlock;

	}



	/* Make sure there are no concurrent readers while updating dev_opp */

	WARN_ON(!list_empty(&dev_opp->opp_list));



	if (!dev_opp->prop_name) {

		dev_err(dev, "%s: Doesn't have a prop-name\n", __func__);

		goto unlock;

	}



	kfree(dev_opp->prop_name);

	dev_opp->prop_name = NULL;



	/* Try freeing device_opp if this was the last blocking resource */

	_remove_device_opp(dev_opp);



unlock:

	mutex_unlock(&dev_opp_list_lock);

}

EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);



static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp,

			      struct device_node *np)

{
@@ -1042,7 +1177,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) 
	if (!of_property_read_u32(np, "clock-latency-ns", &val))

		new_opp->clock_latency_ns = val;



	ret = opp_parse_supplies(new_opp, dev);

	ret = opp_parse_supplies(new_opp, dev, dev_opp);

	if (ret)

		goto free_opp;

drivers/base/power/opp/opp.h

+2 −0
Original line number Diff line number Diff line
@@ -131,6 +131,7 @@ struct device_list_opp { 
 * @suspend_opp: Pointer to OPP to be used during device suspend.

 * @supported_hw: Array of version number to support.

 * @supported_hw_count: Number of elements in supported_hw array.

 * @prop_name: A name to postfix to many DT properties, while parsing them.

 * @dentry:	debugfs dentry pointer of the real device directory (not links).

 * @dentry_name: Name of the real dentry.

 *
@@ -157,6 +158,7 @@ struct device_opp { 


	unsigned int *supported_hw;

	unsigned int supported_hw_count;

	const char *prop_name;



#ifdef CONFIG_DEBUG_FS

	struct dentry *dentry;

include/linux/pm_opp.h

+9 −0
Original line number Diff line number Diff line
@@ -58,6 +58,8 @@ struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev); 
int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,

				unsigned int count);

void dev_pm_opp_put_supported_hw(struct device *dev);

int dev_pm_opp_set_prop_name(struct device *dev, const char *name);

void dev_pm_opp_put_prop_name(struct device *dev);

#else

static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)

{
@@ -142,6 +144,13 @@ static inline int dev_pm_opp_set_supported_hw(struct device *dev, 


static inline void dev_pm_opp_put_supported_hw(struct device *dev) {}



static inline int dev_pm_opp_set_prop_name(struct device *dev, const char *name)

{

	return -EINVAL;

}



static inline void dev_pm_opp_put_prop_name(struct device *dev) {}



#endif		/* CONFIG_PM_OPP */



#if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)

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