| /* |
| * attribute_container.c - implementation of a simple container for classes |
| * |
| * Copyright (c) 2005 - James Bottomley <James.Bottomley@steeleye.com> |
| * |
| * This file is licensed under GPLv2 |
| * |
| * The basic idea here is to enable a device to be attached to an |
| * aritrary numer of classes without having to allocate storage for them. |
| * Instead, the contained classes select the devices they need to attach |
| * to via a matching function. |
| */ |
| |
| #include <linux/attribute_container.h> |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/list.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| |
| #include "base.h" |
| |
| /* This is a private structure used to tie the classdev and the |
| * container .. it should never be visible outside this file */ |
| struct internal_container { |
| struct klist_node node; |
| struct attribute_container *cont; |
| struct device classdev; |
| }; |
| |
| static void internal_container_klist_get(struct klist_node *n) |
| { |
| struct internal_container *ic = |
| container_of(n, struct internal_container, node); |
| get_device(&ic->classdev); |
| } |
| |
| static void internal_container_klist_put(struct klist_node *n) |
| { |
| struct internal_container *ic = |
| container_of(n, struct internal_container, node); |
| put_device(&ic->classdev); |
| } |
| |
| |
| /** |
| * attribute_container_classdev_to_container - given a classdev, return the container |
| * |
| * @classdev: the class device created by attribute_container_add_device. |
| * |
| * Returns the container associated with this classdev. |
| */ |
| struct attribute_container * |
| attribute_container_classdev_to_container(struct device *classdev) |
| { |
| struct internal_container *ic = |
| container_of(classdev, struct internal_container, classdev); |
| return ic->cont; |
| } |
| EXPORT_SYMBOL_GPL(attribute_container_classdev_to_container); |
| |
| static LIST_HEAD(attribute_container_list); |
| |
| static DEFINE_MUTEX(attribute_container_mutex); |
| |
| /** |
| * attribute_container_register - register an attribute container |
| * |
| * @cont: The container to register. This must be allocated by the |
| * callee and should also be zeroed by it. |
| */ |
| int |
| attribute_container_register(struct attribute_container *cont) |
| { |
| INIT_LIST_HEAD(&cont->node); |
| klist_init(&cont->containers,internal_container_klist_get, |
| internal_container_klist_put); |
| |
| mutex_lock(&attribute_container_mutex); |
| list_add_tail(&cont->node, &attribute_container_list); |
| mutex_unlock(&attribute_container_mutex); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(attribute_container_register); |
| |
| /** |
| * attribute_container_unregister - remove a container registration |
| * |
| * @cont: previously registered container to remove |
| */ |
| int |
| attribute_container_unregister(struct attribute_container *cont) |
| { |
| int retval = -EBUSY; |
| mutex_lock(&attribute_container_mutex); |
| spin_lock(&cont->containers.k_lock); |
| if (!list_empty(&cont->containers.k_list)) |
| goto out; |
| retval = 0; |
| list_del(&cont->node); |
| out: |
| spin_unlock(&cont->containers.k_lock); |
| mutex_unlock(&attribute_container_mutex); |
| return retval; |
| |
| } |
| EXPORT_SYMBOL_GPL(attribute_container_unregister); |
| |
| /* private function used as class release */ |
| static void attribute_container_release(struct device *classdev) |
| { |
| struct internal_container *ic |
| = container_of(classdev, struct internal_container, classdev); |
| struct device *dev = classdev->parent; |
| |
| kfree(ic); |
| put_device(dev); |
| } |
| |
| /** |
| * attribute_container_add_device - see if any container is interested in dev |
| * |
| * @dev: device to add attributes to |
| * @fn: function to trigger addition of class device. |
| * |
| * This function allocates storage for the class device(s) to be |
| * attached to dev (one for each matching attribute_container). If no |
| * fn is provided, the code will simply register the class device via |
| * device_add. If a function is provided, it is expected to add |
| * the class device at the appropriate time. One of the things that |
| * might be necessary is to allocate and initialise the classdev and |
| * then add it a later time. To do this, call this routine for |
| * allocation and initialisation and then use |
| * attribute_container_device_trigger() to call device_add() on |
| * it. Note: after this, the class device contains a reference to dev |
| * which is not relinquished until the release of the classdev. |
| */ |
| void |
| attribute_container_add_device(struct device *dev, |
| int (*fn)(struct attribute_container *, |
| struct device *, |
| struct device *)) |
| { |
| struct attribute_container *cont; |
| |
| mutex_lock(&attribute_container_mutex); |
| list_for_each_entry(cont, &attribute_container_list, node) { |
| struct internal_container *ic; |
| |
| if (attribute_container_no_classdevs(cont)) |
| continue; |
| |
| if (!cont->match(cont, dev)) |
| continue; |
| |
| ic = kzalloc(sizeof(*ic), GFP_KERNEL); |
| if (!ic) { |
| dev_err(dev, "failed to allocate class container\n"); |
| continue; |
| } |
| |
| ic->cont = cont; |
| device_initialize(&ic->classdev); |
| ic->classdev.parent = get_device(dev); |
| ic->classdev.class = cont->class; |
| cont->class->dev_release = attribute_container_release; |
| dev_set_name(&ic->classdev, "%s", dev_name(dev)); |
| if (fn) |
| fn(cont, dev, &ic->classdev); |
| else |
| attribute_container_add_class_device(&ic->classdev); |
| klist_add_tail(&ic->node, &cont->containers); |
| } |
| mutex_unlock(&attribute_container_mutex); |
| } |
| |
| /* FIXME: can't break out of this unless klist_iter_exit is also |
| * called before doing the break |
| */ |
| #define klist_for_each_entry(pos, head, member, iter) \ |
| for (klist_iter_init(head, iter); (pos = ({ \ |
| struct klist_node *n = klist_next(iter); \ |
| n ? container_of(n, typeof(*pos), member) : \ |
| ({ klist_iter_exit(iter) ; NULL; }); \ |
| }) ) != NULL; ) |
| |
| |
| /** |
| * attribute_container_remove_device - make device eligible for removal. |
| * |
| * @dev: The generic device |
| * @fn: A function to call to remove the device |
| * |
| * This routine triggers device removal. If fn is NULL, then it is |
| * simply done via device_unregister (note that if something |
| * still has a reference to the classdev, then the memory occupied |
| * will not be freed until the classdev is released). If you want a |
| * two phase release: remove from visibility and then delete the |
| * device, then you should use this routine with a fn that calls |
| * device_del() and then use attribute_container_device_trigger() |
| * to do the final put on the classdev. |
| */ |
| void |
| attribute_container_remove_device(struct device *dev, |
| void (*fn)(struct attribute_container *, |
| struct device *, |
| struct device *)) |
| { |
| struct attribute_container *cont; |
| |
| mutex_lock(&attribute_container_mutex); |
| list_for_each_entry(cont, &attribute_container_list, node) { |
| struct internal_container *ic; |
| struct klist_iter iter; |
| |
| if (attribute_container_no_classdevs(cont)) |
| continue; |
| |
| if (!cont->match(cont, dev)) |
| continue; |
| |
| klist_for_each_entry(ic, &cont->containers, node, &iter) { |
| if (dev != ic->classdev.parent) |
| continue; |
| klist_del(&ic->node); |
| if (fn) |
| fn(cont, dev, &ic->classdev); |
| else { |
| attribute_container_remove_attrs(&ic->classdev); |
| device_unregister(&ic->classdev); |
| } |
| } |
| } |
| mutex_unlock(&attribute_container_mutex); |
| } |
| |
| /** |
| * attribute_container_device_trigger - execute a trigger for each matching classdev |
| * |
| * @dev: The generic device to run the trigger for |
| * @fn the function to execute for each classdev. |
| * |
| * This funcion is for executing a trigger when you need to know both |
| * the container and the classdev. If you only care about the |
| * container, then use attribute_container_trigger() instead. |
| */ |
| void |
| attribute_container_device_trigger(struct device *dev, |
| int (*fn)(struct attribute_container *, |
| struct device *, |
| struct device *)) |
| { |
| struct attribute_container *cont; |
| |
| mutex_lock(&attribute_container_mutex); |
| list_for_each_entry(cont, &attribute_container_list, node) { |
| struct internal_container *ic; |
| struct klist_iter iter; |
| |
| if (!cont->match(cont, dev)) |
| continue; |
| |
| if (attribute_container_no_classdevs(cont)) { |
| fn(cont, dev, NULL); |
| continue; |
| } |
| |
| klist_for_each_entry(ic, &cont->containers, node, &iter) { |
| if (dev == ic->classdev.parent) |
| fn(cont, dev, &ic->classdev); |
| } |
| } |
| mutex_unlock(&attribute_container_mutex); |
| } |
| |
| /** |
| * attribute_container_trigger - trigger a function for each matching container |
| * |
| * @dev: The generic device to activate the trigger for |
| * @fn: the function to trigger |
| * |
| * This routine triggers a function that only needs to know the |
| * matching containers (not the classdev) associated with a device. |
| * It is more lightweight than attribute_container_device_trigger, so |
| * should be used in preference unless the triggering function |
| * actually needs to know the classdev. |
| */ |
| void |
| attribute_container_trigger(struct device *dev, |
| int (*fn)(struct attribute_container *, |
| struct device *)) |
| { |
| struct attribute_container *cont; |
| |
| mutex_lock(&attribute_container_mutex); |
| list_for_each_entry(cont, &attribute_container_list, node) { |
| if (cont->match(cont, dev)) |
| fn(cont, dev); |
| } |
| mutex_unlock(&attribute_container_mutex); |
| } |
| |
| /** |
| * attribute_container_add_attrs - add attributes |
| * |
| * @classdev: The class device |
| * |
| * This simply creates all the class device sysfs files from the |
| * attributes listed in the container |
| */ |
| int |
| attribute_container_add_attrs(struct device *classdev) |
| { |
| struct attribute_container *cont = |
| attribute_container_classdev_to_container(classdev); |
| struct device_attribute **attrs = cont->attrs; |
| int i, error; |
| |
| BUG_ON(attrs && cont->grp); |
| |
| if (!attrs && !cont->grp) |
| return 0; |
| |
| if (cont->grp) |
| return sysfs_create_group(&classdev->kobj, cont->grp); |
| |
| for (i = 0; attrs[i]; i++) { |
| sysfs_attr_init(&attrs[i]->attr); |
| error = device_create_file(classdev, attrs[i]); |
| if (error) |
| return error; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * attribute_container_add_class_device - same function as device_add |
| * |
| * @classdev: the class device to add |
| * |
| * This performs essentially the same function as device_add except for |
| * attribute containers, namely add the classdev to the system and then |
| * create the attribute files |
| */ |
| int |
| attribute_container_add_class_device(struct device *classdev) |
| { |
| int error = device_add(classdev); |
| if (error) |
| return error; |
| return attribute_container_add_attrs(classdev); |
| } |
| |
| /** |
| * attribute_container_add_class_device_adapter - simple adapter for triggers |
| * |
| * This function is identical to attribute_container_add_class_device except |
| * that it is designed to be called from the triggers |
| */ |
| int |
| attribute_container_add_class_device_adapter(struct attribute_container *cont, |
| struct device *dev, |
| struct device *classdev) |
| { |
| return attribute_container_add_class_device(classdev); |
| } |
| |
| /** |
| * attribute_container_remove_attrs - remove any attribute files |
| * |
| * @classdev: The class device to remove the files from |
| * |
| */ |
| void |
| attribute_container_remove_attrs(struct device *classdev) |
| { |
| struct attribute_container *cont = |
| attribute_container_classdev_to_container(classdev); |
| struct device_attribute **attrs = cont->attrs; |
| int i; |
| |
| if (!attrs && !cont->grp) |
| return; |
| |
| if (cont->grp) { |
| sysfs_remove_group(&classdev->kobj, cont->grp); |
| return ; |
| } |
| |
| for (i = 0; attrs[i]; i++) |
| device_remove_file(classdev, attrs[i]); |
| } |
| |
| /** |
| * attribute_container_class_device_del - equivalent of class_device_del |
| * |
| * @classdev: the class device |
| * |
| * This function simply removes all the attribute files and then calls |
| * device_del. |
| */ |
| void |
| attribute_container_class_device_del(struct device *classdev) |
| { |
| attribute_container_remove_attrs(classdev); |
| device_del(classdev); |
| } |
| |
| /** |
| * attribute_container_find_class_device - find the corresponding class_device |
| * |
| * @cont: the container |
| * @dev: the generic device |
| * |
| * Looks up the device in the container's list of class devices and returns |
| * the corresponding class_device. |
| */ |
| struct device * |
| attribute_container_find_class_device(struct attribute_container *cont, |
| struct device *dev) |
| { |
| struct device *cdev = NULL; |
| struct internal_container *ic; |
| struct klist_iter iter; |
| |
| klist_for_each_entry(ic, &cont->containers, node, &iter) { |
| if (ic->classdev.parent == dev) { |
| cdev = &ic->classdev; |
| /* FIXME: must exit iterator then break */ |
| klist_iter_exit(&iter); |
| break; |
| } |
| } |
| |
| return cdev; |
| } |
| EXPORT_SYMBOL_GPL(attribute_container_find_class_device); |