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Commit 0edb5860 authored by Cornelia Huck's avatar Cornelia Huck Committed by Greg Kroah-Hartman
Browse files

[PATCH] driver core: add bus_find_device & driver_find_device functions 



Add bus_find_device() and driver_find_device() which allow searching for a
device in the bus's resp. the driver's klist and obtain a reference on it.

Signed-off-by: default avatarCornelia Huck <cohuck@de.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent fd782a4a

drivers/base/bus.c

+34 −0
Original line number Diff line number Diff line
@@ -177,6 +177,39 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start, 
	return error;

}



/**

 * bus_find_device - device iterator for locating a particular device.

 * @bus: bus type

 * @start: Device to begin with

 * @data: Data to pass to match function

 * @match: Callback function to check device

 *

 * This is similar to the bus_for_each_dev() 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, this function will

 * return to the caller and not iterate over any more devices.

 */

struct device * bus_find_device(struct bus_type *bus,

				struct device *start, void *data,

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

{

	struct klist_iter i;

	struct device *dev;



	if (!bus)

		return NULL;



	klist_iter_init_node(&bus->klist_devices, &i,

			     (start ? &start->knode_bus : NULL));

	while ((dev = next_device(&i)))

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

			break;

	klist_iter_exit(&i);

	return dev;

}





static struct device_driver * next_driver(struct klist_iter * i)
@@ -557,6 +590,7 @@ int __init buses_init(void) 




EXPORT_SYMBOL_GPL(bus_for_each_dev);

EXPORT_SYMBOL_GPL(bus_find_device);

EXPORT_SYMBOL_GPL(bus_for_each_drv);



EXPORT_SYMBOL_GPL(bus_add_device);

drivers/base/driver.c

+35 −0
Original line number Diff line number Diff line
@@ -55,6 +55,41 @@ int driver_for_each_device(struct device_driver * drv, struct device * start, 
EXPORT_SYMBOL_GPL(driver_for_each_device);





/**

 * driver_find_device - device iterator for locating a particular device.

 * @driver: The device's driver

 * @start: Device to begin with

 * @data: Data to pass to match function

 * @match: Callback function to check device

 *

 * This is similar to the driver_for_each_device() 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, this function will

 * return to the caller and not iterate over any more devices.

 */

struct device * driver_find_device(struct device_driver *drv,

				   struct device * start, void * data,

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

{

	struct klist_iter i;

	struct device *dev;



	if (!drv)

		return NULL;



	klist_iter_init_node(&drv->klist_devices, &i,

			     (start ? &start->knode_driver : NULL));

	while ((dev = next_device(&i)))

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

			break;

	klist_iter_exit(&i);

	return dev;

}

EXPORT_SYMBOL_GPL(driver_find_device);



/**

 *	driver_create_file - create sysfs file for driver.

 *	@drv:	driver.

include/linux/device.h

+5 −0
Original line number Diff line number Diff line
@@ -80,6 +80,8 @@ extern struct bus_type * find_bus(char * name); 


int bus_for_each_dev(struct bus_type * bus, struct device * start, void * data,

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

struct device * bus_find_device(struct bus_type *bus, struct device *start,

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



int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, 

		     void * data, int (*fn)(struct device_driver *, void *));
@@ -142,6 +144,9 @@ extern void driver_remove_file(struct device_driver *, struct driver_attribute * 


extern int driver_for_each_device(struct device_driver * drv, struct device * start,

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

struct device * driver_find_device(struct device_driver *drv,

				   struct device *start, void *data,

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





/*