Commit 5ab69981 authored by Cornelia Huck's avatar Cornelia Huck Committed by Greg Kroah-Hartman
Browse files

driver core: Introduce device_find_child(). 



Introduce device_find_child() to match device_for_each_child().

Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 035ed7a4

drivers/base/core.c

+33 −0
Original line number Diff line number Diff line
@@ -750,12 +750,45 @@ int device_for_each_child(struct device * parent, void * data, 
	return error;

}



/**

 * device_find_child - device iterator for locating a particular device.

 * @parent: parent struct device

 * @data: Data to pass to match function

 * @match: Callback function to check device

 *

 * This is similar to the device_for_each_child() function above, but it

 * returns a reference to a device that is 'found' for later use, as

 * determined by the @match callback.

 *

 * The callback should return 0 if the device doesn't match and non-zero

 * if it does.  If the callback returns non-zero and a reference to the

 * current device can be obtained, this function will return to the caller

 * and not iterate over any more devices.

 */

struct device * device_find_child(struct device *parent, void *data,

				  int (*match)(struct device *, void *))

{

	struct klist_iter i;

	struct device *child;



	if (!parent)

		return NULL;



	klist_iter_init(&parent->klist_children, &i);

	while ((child = next_device(&i)))

		if (match(child, data) && get_device(child))

			break;

	klist_iter_exit(&i);

	return child;

}



int __init devices_init(void)

{

	return subsystem_register(&devices_subsys);

}



EXPORT_SYMBOL_GPL(device_for_each_child);

EXPORT_SYMBOL_GPL(device_find_child);



EXPORT_SYMBOL_GPL(device_initialize);

EXPORT_SYMBOL_GPL(device_add);

include/linux/device.h

+2 −0
Original line number Diff line number Diff line
@@ -421,6 +421,8 @@ extern int __must_check device_add(struct device * dev); 
extern void device_del(struct device * dev);

extern int device_for_each_child(struct device *, void *,

		     int (*fn)(struct device *, void *));

extern struct device *device_find_child(struct device *, void *data,

					int (*match)(struct device *, void *));

extern int device_rename(struct device *dev, char *new_name);



/*