linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * transport_class.c - implementation of generic transport classes

 *                     using attribute_containers

 *

 * Copyright (c) 2005 - James Bottomley <James.Bottomley@steeleye.com>

 *

 * The basic idea here is to allow any "device controller" (which

 * would most often be a Host Bus Adapter to use the services of one

 * or more tranport classes for performing transport specific

 * services.  Transport specific services are things that the generic

 * command layer doesn't want to know about (speed settings, line

 * condidtioning, etc), but which the user might be interested in.

 * Thus, the HBA's use the routines exported by the transport classes

 * to perform these functions.  The transport classes export certain

 * values to the user via sysfs using attribute containers.

 *

 * Note: because not every HBA will care about every transport

 * attribute, there's a many to one relationship that goes like this:

 *

 * transport class<-----attribute container<----class device

 *

 * Usually the attribute container is per-HBA, but the design doesn't

 * mandate that.  Although most of the services will be specific to

 * the actual external storage connection used by the HBA, the generic

 * transport class is framed entirely in terms of generic devices to

 * allow it to be used by any physical HBA in the system.

 */

#include <linux/export.h>

#include <linux/attribute_container.h>

#include <linux/transport_class.h>

​

/**

 * transport_class_register - register an initial transport class

 *

 * @tclass: a pointer to the transport class structure to be initialised

 *

 * The transport class contains an embedded class which is used to

 * identify it.  The caller should initialise this structure with

 * zeros and then generic class must have been initialised with the

 * actual transport class unique name.  There's a macro

 * DECLARE_TRANSPORT_CLASS() to do this (declared classes still must

 * be registered).

 *

 * Returns 0 on success or error on failure.

 */

int transport_class_register(struct transport_class *tclass)

{

    return class_register(&tclass->class);

}

EXPORT_SYMBOL_GPL(transport_class_register);

​

/**

 * transport_class_unregister - unregister a previously registered class

 *

 * @tclass: The transport class to unregister

 *

 * Must be called prior to deallocating the memory for the transport

 * class.

 */

void transport_class_unregister(struct transport_class *tclass)

{

    class_unregister(&tclass->class);