From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- drivers/base/attribute_container.c | 376 +++++++++++++++++++++++++++++++++++++ 1 file changed, 376 insertions(+) create mode 100644 drivers/base/attribute_container.c (limited to 'drivers/base/attribute_container.c') diff --git a/drivers/base/attribute_container.c b/drivers/base/attribute_container.c new file mode 100644 index 00000000000..ec615d854be --- /dev/null +++ b/drivers/base/attribute_container.c @@ -0,0 +1,376 @@ +/* + * attribute_container.c - implementation of a simple container for classes + * + * Copyright (c) 2005 - James Bottomley + * + * 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 +#include +#include +#include +#include +#include +#include + +/* 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 list_head node; + struct attribute_container *cont; + struct class_device 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 class_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 struct list_head attribute_container_list; + +static DECLARE_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); + INIT_LIST_HEAD(&cont->containers); + + down(&attribute_container_mutex); + list_add_tail(&cont->node, &attribute_container_list); + up(&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; + down(&attribute_container_mutex); + if (!list_empty(&cont->containers)) + goto out; + retval = 0; + list_del(&cont->node); + out: + up(&attribute_container_mutex); + return retval; + +} +EXPORT_SYMBOL_GPL(attribute_container_unregister); + +/* private function used as class release */ +static void attribute_container_release(struct class_device *classdev) +{ + struct internal_container *ic + = container_of(classdev, struct internal_container, classdev); + struct device *dev = classdev->dev; + + 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 + * class_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 class_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 class_device *)) +{ + struct attribute_container *cont; + + down(&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 = kmalloc(sizeof(struct internal_container), GFP_KERNEL); + if (!ic) { + dev_printk(KERN_ERR, dev, "failed to allocate class container\n"); + continue; + } + memset(ic, 0, sizeof(struct internal_container)); + INIT_LIST_HEAD(&ic->node); + ic->cont = cont; + class_device_initialize(&ic->classdev); + ic->classdev.dev = get_device(dev); + ic->classdev.class = cont->class; + cont->class->release = attribute_container_release; + strcpy(ic->classdev.class_id, dev->bus_id); + if (fn) + fn(cont, dev, &ic->classdev); + else + attribute_container_add_class_device(&ic->classdev); + list_add_tail(&ic->node, &cont->containers); + } + up(&attribute_container_mutex); +} + +/** + * 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 class_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 + * class_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 class_device *)) +{ + struct attribute_container *cont; + + down(&attribute_container_mutex); + list_for_each_entry(cont, &attribute_container_list, node) { + struct internal_container *ic, *tmp; + + if (attribute_container_no_classdevs(cont)) + continue; + + if (!cont->match(cont, dev)) + continue; + list_for_each_entry_safe(ic, tmp, &cont->containers, node) { + if (dev != ic->classdev.dev) + continue; + list_del(&ic->node); + if (fn) + fn(cont, dev, &ic->classdev); + else { + attribute_container_remove_attrs(&ic->classdev); + class_device_unregister(&ic->classdev); + } + } + } + up(&attribute_container_mutex); +} +EXPORT_SYMBOL_GPL(attribute_container_remove_device); + +/** + * 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 class_device *)) +{ + struct attribute_container *cont; + + down(&attribute_container_mutex); + list_for_each_entry(cont, &attribute_container_list, node) { + struct internal_container *ic, *tmp; + + if (!cont->match(cont, dev)) + continue; + + list_for_each_entry_safe(ic, tmp, &cont->containers, node) { + if (dev == ic->classdev.dev) + fn(cont, dev, &ic->classdev); + } + } + up(&attribute_container_mutex); +} +EXPORT_SYMBOL_GPL(attribute_container_device_trigger); + +/** + * 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; + + down(&attribute_container_mutex); + list_for_each_entry(cont, &attribute_container_list, node) { + if (cont->match(cont, dev)) + fn(cont, dev); + } + up(&attribute_container_mutex); +} +EXPORT_SYMBOL_GPL(attribute_container_trigger); + +/** + * 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 class_device *classdev) +{ + struct attribute_container *cont = + attribute_container_classdev_to_container(classdev); + struct class_device_attribute **attrs = cont->attrs; + int i, error; + + if (!attrs) + return 0; + + for (i = 0; attrs[i]; i++) { + error = class_device_create_file(classdev, attrs[i]); + if (error) + return error; + } + + return 0; +} +EXPORT_SYMBOL_GPL(attribute_container_add_attrs); + +/** + * attribute_container_add_class_device - same function as class_device_add + * + * @classdev: the class device to add + * + * This performs essentially the same function as class_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 class_device *classdev) +{ + int error = class_device_add(classdev); + if (error) + return error; + return attribute_container_add_attrs(classdev); +} +EXPORT_SYMBOL_GPL(attribute_container_add_class_device); + +/** + * 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 class_device *classdev) +{ + return attribute_container_add_class_device(classdev); +} +EXPORT_SYMBOL_GPL(attribute_container_add_class_device_adapter); + +/** + * attribute_container_remove_attrs - remove any attribute files + * + * @classdev: The class device to remove the files from + * + */ +void +attribute_container_remove_attrs(struct class_device *classdev) +{ + struct attribute_container *cont = + attribute_container_classdev_to_container(classdev); + struct class_device_attribute **attrs = cont->attrs; + int i; + + if (!attrs) + return; + + for (i = 0; attrs[i]; i++) + class_device_remove_file(classdev, attrs[i]); +} +EXPORT_SYMBOL_GPL(attribute_container_remove_attrs); + +/** + * 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 + * class_device_del. + */ +void +attribute_container_class_device_del(struct class_device *classdev) +{ + attribute_container_remove_attrs(classdev); + class_device_del(classdev); +} +EXPORT_SYMBOL_GPL(attribute_container_class_device_del); + +int __init +attribute_container_init(void) +{ + INIT_LIST_HEAD(&attribute_container_list); + return 0; +} -- cgit v1.2.3