Commit eaf91db0 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Philipp Zabel
Browse files

reset: Add reset_control_get_count() 



Currently the reset core has internal support for counting the number of
resets for a device described in DT.  Generalize this to devices using
lookup resets, and export it for public use.

This will be used by generic drivers that need to be sure a device is
controlled by a single, dedicated reset line (e.g. vfio-platform).

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
[p.zabel@pengutronix.de: fixed a typo in reset_control_get_count comment]
Signed-off-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
parent 12c62b9d

drivers/reset/core.c

+41 −0
Original line number Diff line number Diff line
@@ -795,3 +795,44 @@ devm_reset_control_array_get(struct device *dev, bool shared, bool optional) 
	return rstc;

}

EXPORT_SYMBOL_GPL(devm_reset_control_array_get);



static int reset_control_get_count_from_lookup(struct device *dev)

{

	const struct reset_control_lookup *lookup;

	const char *dev_id = dev_name(dev);

	int count = 0;



	if (!dev)

		return -EINVAL;



	mutex_lock(&reset_lookup_mutex);



	list_for_each_entry(lookup, &reset_lookup_list, list) {

		if (!strcmp(lookup->dev_id, dev_id))

			count++;

	}



	mutex_unlock(&reset_lookup_mutex);



	if (count == 0)

		count = -ENOENT;



	return count;

}



/**

 * reset_control_get_count - Count number of resets available with a device

 *

 * @dev: device for which to return the number of resets

 *

 * Returns positive reset count on success, or error number on failure and

 * on count being zero.

 */

int reset_control_get_count(struct device *dev)

{

	if (dev->of_node)

		return of_reset_control_get_count(dev->of_node);



	return reset_control_get_count_from_lookup(dev);

}

EXPORT_SYMBOL_GPL(reset_control_get_count);

include/linux/reset.h

+7 −0
Original line number Diff line number Diff line
@@ -32,6 +32,8 @@ struct reset_control *devm_reset_control_array_get(struct device *dev, 
struct reset_control *of_reset_control_array_get(struct device_node *np,

						 bool shared, bool optional);



int reset_control_get_count(struct device *dev);



#else



static inline int reset_control_reset(struct reset_control *rstc)
@@ -97,6 +99,11 @@ of_reset_control_array_get(struct device_node *np, bool shared, bool optional) 
	return optional ? NULL : ERR_PTR(-ENOTSUPP);

}



static inline int reset_control_get_count(struct device *dev)

{

	return -ENOENT;

}



#endif /* CONFIG_RESET_CONTROLLER */



static inline int __must_check device_reset(struct device *dev)

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