Commit eaa0d302 authored by Jerome Brunet's avatar Jerome Brunet Committed by Greg Kroah-Hartman
Browse files

driver core: auxiliary bus: add device creation helpers 



Add helper functions to create a device on the auxiliary bus.

This is meant for fairly simple usage of the auxiliary bus, to avoid having
the same code repeated in the different drivers.

Suggested-by: default avatarStephen Boyd <sboyd@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarJerome Brunet <jbrunet@baylibre.com>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarIra Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20250218-aux-device-create-helper-v4-1-c3d7dfdea2e6@baylibre.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d487858e

drivers/base/auxiliary.c

+108 −0
Original line number Diff line number Diff line
@@ -385,6 +385,114 @@ void auxiliary_driver_unregister(struct auxiliary_driver *auxdrv) 
}

EXPORT_SYMBOL_GPL(auxiliary_driver_unregister);



static void auxiliary_device_release(struct device *dev)

{

	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);



	kfree(auxdev);

}



/**

 * auxiliary_device_create - create a device on the auxiliary bus

 * @dev: parent device

 * @modname: module name used to create the auxiliary driver name.

 * @devname: auxiliary bus device name

 * @platform_data: auxiliary bus device platform data

 * @id: auxiliary bus device id

 *

 * Helper to create an auxiliary bus device.

 * The device created matches driver 'modname.devname' on the auxiliary bus.

 */

struct auxiliary_device *auxiliary_device_create(struct device *dev,

						 const char *modname,

						 const char *devname,

						 void *platform_data,

						 int id)

{

	struct auxiliary_device *auxdev;

	int ret;



	auxdev = kzalloc(sizeof(*auxdev), GFP_KERNEL);

	if (!auxdev)

		return NULL;



	auxdev->id = id;

	auxdev->name = devname;

	auxdev->dev.parent = dev;

	auxdev->dev.platform_data = platform_data;

	auxdev->dev.release = auxiliary_device_release;

	device_set_of_node_from_dev(&auxdev->dev, dev);



	ret = auxiliary_device_init(auxdev);

	if (ret) {

		kfree(auxdev);

		return NULL;

	}



	ret = __auxiliary_device_add(auxdev, modname);

	if (ret) {

		/*

		 * It may look odd but auxdev should not be freed here.

		 * auxiliary_device_uninit() calls device_put() which call

		 * the device release function, freeing auxdev.

		 */

		auxiliary_device_uninit(auxdev);

		return NULL;

	}



	return auxdev;

}

EXPORT_SYMBOL_GPL(auxiliary_device_create);



/**

 * auxiliary_device_destroy - remove an auxiliary device

 * @auxdev: pointer to the auxdev to be removed

 *

 * Helper to remove an auxiliary device created with

 * auxiliary_device_create()

 */

void auxiliary_device_destroy(void *auxdev)

{

	struct auxiliary_device *_auxdev = auxdev;



	auxiliary_device_delete(_auxdev);

	auxiliary_device_uninit(_auxdev);

}

EXPORT_SYMBOL_GPL(auxiliary_device_destroy);



/**

 * __devm_auxiliary_device_create - create a managed device on the auxiliary bus

 * @dev: parent device

 * @modname: module name used to create the auxiliary driver name.

 * @devname: auxiliary bus device name

 * @platform_data: auxiliary bus device platform data

 * @id: auxiliary bus device id

 *

 * Device managed helper to create an auxiliary bus device.

 * The device created matches driver 'modname.devname' on the auxiliary bus.

 */

struct auxiliary_device *__devm_auxiliary_device_create(struct device *dev,

							const char *modname,

							const char *devname,

							void *platform_data,

							int id)

{

	struct auxiliary_device *auxdev;

	int ret;



	auxdev = auxiliary_device_create(dev, modname, devname, platform_data, id);

	if (IS_ERR(auxdev))

		return auxdev;



	ret = devm_add_action_or_reset(dev, auxiliary_device_destroy,

				       auxdev);

	if (ret)

		return ERR_PTR(ret);



	return auxdev;

}

EXPORT_SYMBOL_GPL(__devm_auxiliary_device_create);



void __init auxiliary_bus_init(void)

{

	WARN_ON(bus_register(&auxiliary_bus_type));

include/linux/auxiliary_bus.h

+17 −0
Original line number Diff line number Diff line
@@ -254,6 +254,23 @@ int __auxiliary_driver_register(struct auxiliary_driver *auxdrv, struct module * 


void auxiliary_driver_unregister(struct auxiliary_driver *auxdrv);



struct auxiliary_device *auxiliary_device_create(struct device *dev,

						 const char *modname,

						 const char *devname,

						 void *platform_data,

						 int id);

void auxiliary_device_destroy(void *auxdev);



struct auxiliary_device *__devm_auxiliary_device_create(struct device *dev,

							const char *modname,

							const char *devname,

							void *platform_data,

							int id);



#define devm_auxiliary_device_create(dev, devname, platform_data)     \

	__devm_auxiliary_device_create(dev, KBUILD_MODNAME, devname,  \

				       platform_data, 0)



/**

 * module_auxiliary_driver() - Helper macro for registering an auxiliary driver

 * @__auxiliary_driver: auxiliary driver struct