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

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
......@@ -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);
......
......@@ -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);
/*
......
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