Skip to content
Snippets Groups Projects
Select Git revision
  • de3cf786e39f55e3e508622e35ea69d7fff45b39
  • master default protected
  • android-msm-bullhead-3.10-nougat_kgdb_less_changes
  • android-msm-bullhead-3.10-nougat_kgdb
  • android-msm-bullhead-3.10-nougat_klist
  • android-4.4
  • android-msm-vega-4.4-oreo-daydream
  • android-msm-wahoo-4.4-p-preview-5
  • android-msm-wahoo-4.4-pie
  • android-msm-marlin-3.18-p-preview-5
  • android-msm-marlin-3.18-pie
  • android-msm-wahoo-2018.07-oreo-m2
  • android-msm-wahoo-2018.07-oreo-m4
  • android-msm-wahoo-4.4-p-preview-4
  • android-msm-bullhead-3.10-oreo-m6
  • android-msm-angler-3.10-oreo-m6
  • android-msm-marlin-3.18-p-preview-4
  • android-msm-stargazer-3.18-oreo-wear-dr
  • android-msm-catshark-3.18-oreo-wear-dr
  • android-msm-wahoo-4.4-oreo-m2
  • android-msm-wahoo-4.4-oreo-m4
  • android-daydreamos-8.0.0_r0.5
  • android-8.1.0_r0.92
  • android-8.1.0_r0.91
  • android-daydreamos-8.0.0_r0.4
  • android-p-preview-5_r0.2
  • android-p-preview-5_r0.1
  • android-9.0.0_r0.5
  • android-9.0.0_r0.4
  • android-9.0.0_r0.2
  • android-9.0.0_r0.1
  • android-8.1.0_r0.81
  • android-8.1.0_r0.80
  • android-8.1.0_r0.78
  • android-8.1.0_r0.76
  • android-8.1.0_r0.75
  • android-8.1.0_r0.72
  • android-8.1.0_r0.70
  • android-p-preview-4_r0.2
  • android-p-preview-4_r0.1
  • android-wear-8.0.0_r0.30
41 results

transport_class.c

Blame
  • transport_class.c 9.35 KiB
    /*
     * transport_class.c - implementation of generic transport classes
     *                     using attribute_containers
     *
     * Copyright (c) 2005 - James Bottomley <James.Bottomley@steeleye.com>
     *
     * This file is licensed under GPLv2
     *
     * 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);
    }
    EXPORT_SYMBOL_GPL(transport_class_unregister);
    
    static int anon_transport_dummy_function(struct transport_container *tc,
    					 struct device *dev,
    					 struct device *cdev)
    {
    	/* do nothing */
    	return 0;
    }
    
    /**
     * anon_transport_class_register - register an anonymous class
     *
     * @atc: The anon transport class to register
     *
     * The anonymous transport class contains both a transport class and a
     * container.  The idea of an anonymous class is that it never
     * actually has any device attributes associated with it (and thus
     * saves on container storage).  So it can only be used for triggering
     * events.  Use prezero and then use DECLARE_ANON_TRANSPORT_CLASS() to
     * initialise the anon transport class storage.
     */
    int anon_transport_class_register(struct anon_transport_class *atc)
    {
    	int error;
    	atc->container.class = &atc->tclass.class;
    	attribute_container_set_no_classdevs(&atc->container);
    	error = attribute_container_register(&atc->container);
    	if (error)
    		return error;
    	atc->tclass.setup = anon_transport_dummy_function;
    	atc->tclass.remove = anon_transport_dummy_function;
    	return 0;
    }
    EXPORT_SYMBOL_GPL(anon_transport_class_register);
    
    /**
     * anon_transport_class_unregister - unregister an anon class
     *
     * @atc: Pointer to the anon transport class to unregister
     *
     * Must be called prior to deallocating the memory for the anon
     * transport class.
     */
    void anon_transport_class_unregister(struct anon_transport_class *atc)
    {
    	if (unlikely(attribute_container_unregister(&atc->container)))
    		BUG();
    }
    EXPORT_SYMBOL_GPL(anon_transport_class_unregister);
    
    static int transport_setup_classdev(struct attribute_container *cont,
    				    struct device *dev,
    				    struct device *classdev)
    {
    	struct transport_class *tclass = class_to_transport_class(cont->class);
    	struct transport_container *tcont = attribute_container_to_transport_container(cont);
    
    	if (tclass->setup)
    		tclass->setup(tcont, dev, classdev);
    
    	return 0;
    }
    
    /**
     * transport_setup_device - declare a new dev for transport class association but don't make it visible yet.
     * @dev: the generic device representing the entity being added
     *
     * Usually, dev represents some component in the HBA system (either
     * the HBA itself or a device remote across the HBA bus).  This
     * routine is simply a trigger point to see if any set of transport
     * classes wishes to associate with the added device.  This allocates
     * storage for the class device and initialises it, but does not yet
     * add it to the system or add attributes to it (you do this with
     * transport_add_device).  If you have no need for a separate setup
     * and add operations, use transport_register_device (see
     * transport_class.h).
     */
    
    void transport_setup_device(struct device *dev)
    {
    	attribute_container_add_device(dev, transport_setup_classdev);
    }
    EXPORT_SYMBOL_GPL(transport_setup_device);
    
    static int transport_add_class_device(struct attribute_container *cont,
    				      struct device *dev,
    				      struct device *classdev)
    {
    	int error = attribute_container_add_class_device(classdev);
    	struct transport_container *tcont = 
    		attribute_container_to_transport_container(cont);
    
    	if (!error && tcont->statistics)
    		error = sysfs_create_group(&classdev->kobj, tcont->statistics);
    
    	return error;
    }
    
    
    /**
     * transport_add_device - declare a new dev for transport class association
     *
     * @dev: the generic device representing the entity being added
     *
     * Usually, dev represents some component in the HBA system (either
     * the HBA itself or a device remote across the HBA bus).  This
     * routine is simply a trigger point used to add the device to the
     * system and register attributes for it.
     */
    
    void transport_add_device(struct device *dev)
    {
    	attribute_container_device_trigger(dev, transport_add_class_device);
    }
    EXPORT_SYMBOL_GPL(transport_add_device);
    
    static int transport_configure(struct attribute_container *cont,
    			       struct device *dev,
    			       struct device *cdev)
    {
    	struct transport_class *tclass = class_to_transport_class(cont->class);
    	struct transport_container *tcont = attribute_container_to_transport_container(cont);
    
    	if (tclass->configure)
    		tclass->configure(tcont, dev, cdev);
    
    	return 0;
    }
    
    /**
     * transport_configure_device - configure an already set up device
     *
     * @dev: generic device representing device to be configured
     *
     * The idea of configure is simply to provide a point within the setup
     * process to allow the transport class to extract information from a
     * device after it has been setup.  This is used in SCSI because we
     * have to have a setup device to begin using the HBA, but after we
     * send the initial inquiry, we use configure to extract the device
     * parameters.  The device need not have been added to be configured.
     */
    void transport_configure_device(struct device *dev)
    {
    	attribute_container_device_trigger(dev, transport_configure);
    }
    EXPORT_SYMBOL_GPL(transport_configure_device);
    
    static int transport_remove_classdev(struct attribute_container *cont,
    				     struct device *dev,
    				     struct device *classdev)
    {
    	struct transport_container *tcont = 
    		attribute_container_to_transport_container(cont);
    	struct transport_class *tclass = class_to_transport_class(cont->class);
    
    	if (tclass->remove)
    		tclass->remove(tcont, dev, classdev);
    
    	if (tclass->remove != anon_transport_dummy_function) {
    		if (tcont->statistics)
    			sysfs_remove_group(&classdev->kobj, tcont->statistics);
    		attribute_container_class_device_del(classdev);
    	}
    
    	return 0;
    }
    
    
    /**
     * transport_remove_device - remove the visibility of a device
     *
     * @dev: generic device to remove
     *
     * This call removes the visibility of the device (to the user from
     * sysfs), but does not destroy it.  To eliminate a device entirely
     * you must also call transport_destroy_device.  If you don't need to
     * do remove and destroy as separate operations, use
     * transport_unregister_device() (see transport_class.h) which will
     * perform both calls for you.
     */
    void transport_remove_device(struct device *dev)
    {
    	attribute_container_device_trigger(dev, transport_remove_classdev);
    }
    EXPORT_SYMBOL_GPL(transport_remove_device);
    
    static void transport_destroy_classdev(struct attribute_container *cont,
    				      struct device *dev,
    				      struct device *classdev)
    {
    	struct transport_class *tclass = class_to_transport_class(cont->class);
    
    	if (tclass->remove != anon_transport_dummy_function)
    		put_device(classdev);
    }
    
    
    /**
     * transport_destroy_device - destroy a removed device
     *
     * @dev: device to eliminate from the transport class.
     *
     * This call triggers the elimination of storage associated with the
     * transport classdev.  Note: all it really does is relinquish a
     * reference to the classdev.  The memory will not be freed until the
     * last reference goes to zero.  Note also that the classdev retains a
     * reference count on dev, so dev too will remain for as long as the
     * transport class device remains around.
     */
    void transport_destroy_device(struct device *dev)
    {
    	attribute_container_remove_device(dev, transport_destroy_classdev);
    }
    EXPORT_SYMBOL_GPL(transport_destroy_device);