参照元

説明

引数

返り値

参考

実装

/**
 * device_add - add device to device hierarchy.
 * @dev: device.
 *
 * This is part 2 of device_register(), though may be called
 * separately _iff_ device_initialize() has been called separately.
 *
 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
 * to the global and sibling lists for the device, then
 * adds it to the other relevant subsystems of the driver model.
 *
 * Do not call this routine or device_register() more than once for
 * any device structure.  The driver model core is not designed to work
 * with devices that get unregistered and then spring back to life.
 * (Among other things, it's very hard to guarantee that all references
 * to the previous incarnation of @dev have been dropped.)  Allocate
 * and register a fresh new struct device instead.
 *
 * NOTE: _Never_ directly free @dev after calling this function, even
 * if it returned an error! Always use put_device() to give up your
 * reference instead.
 */
int device_add(struct device *dev)
{
        struct device *parent = NULL;
        struct kobject *kobj;
        struct class_interface *class_intf;
        int error = -EINVAL;
        dev = get_device(dev);
        if (!dev)
                goto done;
        if (!dev->p) {
                error = device_private_init(dev);
                if (error)
                        goto done;
        }
        /*
         * for statically allocated devices, which should all be converted
         * some day, we need to initialize the name. We prevent reading back
         * the name, and force the use of dev_name()
         */
        if (dev->init_name) {
                dev_set_name(dev, "%s", dev->init_name);
                dev->init_name = NULL;
        }
        /* subsystems can specify simple device enumeration */
        if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
                dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
        if (!dev_name(dev)) {
                error = -EINVAL;
                goto name_error;
        }

        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
        parent = get_device(dev->parent);
        kobj = get_device_parent(dev, parent);
        if (kobj)
                dev->kobj.parent = kobj;
        /* use parent numa_node */
        if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
                set_dev_node(dev, dev_to_node(parent));
        /* first, register with generic layer. */
        /* we require the name to be set before, and pass NULL */
        error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
        if (error)
                goto Error;
        /* notify platform of device entry */
        if (platform_notify)
                platform_notify(dev);
        error = device_create_file(dev, &dev_attr_uevent);
        if (error)
                goto attrError;
        error = device_add_class_symlinks(dev);
        if (error)
                goto SymlinkError;
        error = device_add_attrs(dev);
        if (error)
                goto AttrsError;
        error = bus_add_device(dev);
        if (error)
                goto BusError;
        error = dpm_sysfs_add(dev);
        if (error)
                goto DPMError;
        device_pm_add(dev);
        if (MAJOR(dev->devt)) {
                error = device_create_file(dev, &dev_attr_dev);
                if (error)
                        goto DevAttrError;

                error = device_create_sys_dev_entry(dev);
                if (error)
                        goto SysEntryError;

                devtmpfs_create_node(dev);
        }
        /* Notify clients of device addition.  This call must come
         * after dpm_sysfs_add() and before kobject_uevent().
         */
        if (dev->bus)
                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
                                             BUS_NOTIFY_ADD_DEVICE, dev);
        kobject_uevent(&dev->kobj, KOBJ_ADD);
        bus_probe_device(dev);
        if (parent)
                klist_add_tail(&dev->p->knode_parent,
                               &parent->p->klist_children);
        if (dev->class) {
                mutex_lock(&dev->class->p->mutex);
                /* tie the class to the device */
                klist_add_tail(&dev->knode_class,
                               &dev->class->p->klist_devices);

                /* notify any interfaces that the device is here */
                list_for_each_entry(class_intf,
                                    &dev->class->p->interfaces, node)
                        if (class_intf->add_dev)
                                class_intf->add_dev(dev, class_intf);
                mutex_unlock(&dev->class->p->mutex);
        }
done:
        put_device(dev);
        return error;
 SysEntryError:
        if (MAJOR(dev->devt))
                device_remove_file(dev, &dev_attr_dev);
 DevAttrError:
        device_pm_remove(dev);
        dpm_sysfs_remove(dev);
 DPMError:
        bus_remove_device(dev);
 BusError:
        device_remove_attrs(dev);
 AttrsError:
        device_remove_class_symlinks(dev);
 SymlinkError:
        device_remove_file(dev, &dev_attr_uevent);
 attrError:
        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
        kobject_del(&dev->kobj);
 Error:
        cleanup_device_parent(dev);
        put_device(parent);
name_error:
        kfree(dev->p);
        dev->p = NULL;
        goto done;
}
EXPORT_SYMBOL_GPL(device_add);

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Last-modified: 2016-04-22 (金) 01:28:32