device_find_child(9) [minix man page]

DEVICE_FIND_CHILD(9)					   Device drivers infrastructure				      DEVICE_FIND_CHILD(9)

NAME

       device_find_child - device iterator for locating a particular device.

SYNOPSIS

       struct device * device_find_child(struct device * parent, void * data, int (*match) (struct device *dev, void *data));

ARGUMENTS

       parent
	   parent struct device

       data
	   Data to pass to match function

       match
	   Callback function to check device

DESCRIPTION

       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.

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010						      DEVICE_FIND_CHILD(9)

DEVICE_SCHEDULE_CALL(9) 				   Device drivers infrastructure				   DEVICE_SCHEDULE_CALL(9)

NAME

       device_schedule_callback_owner - helper to schedule a callback for a device

SYNOPSIS

       int device_schedule_callback_owner(struct device * dev, void (*func) (struct device *), struct module * owner);

ARGUMENTS

       dev
	   device.

       func
	   callback function to invoke later.

       owner
	   module owning the callback routine

DESCRIPTION

       Attribute methods must not unregister themselves or their parent device (which would amount to the same thing). Attempts to do so will
       deadlock, since unregistration is mutually exclusive with driver callbacks.

       Instead methods can call this routine, which will attempt to allocate and schedule a workqueue request to call back func with dev as its
       argument in the workqueue's process context.  dev will be pinned until func returns.

       This routine is usually called via the inline device_schedule_callback, which automatically sets owner to THIS_MODULE.

       Returns 0 if the request was submitted, -ENOMEM if storage could not be allocated, -ENODEV if a reference to owner isn't available.

NOTE

       This routine won't work if CONFIG_SYSFS isn't set! It uses an underlying sysfs routine (since it is intended for use by attribute methods),
       and if sysfs isn't available you'll get nothing but -ENOSYS.

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010						   DEVICE_SCHEDULE_CALL(9)