diff options
Diffstat (limited to 'libdde-linux26/lib/src/drivers/base/class.c')
-rw-r--r-- | libdde-linux26/lib/src/drivers/base/class.c | 505 |
1 files changed, 505 insertions, 0 deletions
diff --git a/libdde-linux26/lib/src/drivers/base/class.c b/libdde-linux26/lib/src/drivers/base/class.c new file mode 100644 index 00000000..1417d80b --- /dev/null +++ b/libdde-linux26/lib/src/drivers/base/class.c @@ -0,0 +1,505 @@ +/* + * class.c - basic device class management + * + * Copyright (c) 2002-3 Patrick Mochel + * Copyright (c) 2002-3 Open Source Development Labs + * Copyright (c) 2003-2004 Greg Kroah-Hartman + * Copyright (c) 2003-2004 IBM Corp. + * + * This file is released under the GPLv2 + * + */ + +#include <linux/device.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/kdev_t.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/genhd.h> +#include <linux/mutex.h> +#include "base.h" + +#define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr) + +static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr, + char *buf) +{ + struct class_attribute *class_attr = to_class_attr(attr); + struct class_private *cp = to_class(kobj); + ssize_t ret = -EIO; + + if (class_attr->show) + ret = class_attr->show(cp->class, buf); + return ret; +} + +static ssize_t class_attr_store(struct kobject *kobj, struct attribute *attr, + const char *buf, size_t count) +{ + struct class_attribute *class_attr = to_class_attr(attr); + struct class_private *cp = to_class(kobj); + ssize_t ret = -EIO; + + if (class_attr->store) + ret = class_attr->store(cp->class, buf, count); + return ret; +} + +static void class_release(struct kobject *kobj) +{ + struct class_private *cp = to_class(kobj); + struct class *class = cp->class; + + pr_debug("class '%s': release.\n", class->name); + + if (class->class_release) + class->class_release(class); + else + pr_debug("class '%s' does not have a release() function, " + "be careful\n", class->name); +} + +static struct sysfs_ops class_sysfs_ops = { + .show = class_attr_show, + .store = class_attr_store, +}; + +static struct kobj_type class_ktype = { + .sysfs_ops = &class_sysfs_ops, + .release = class_release, +}; + +/* Hotplug events for classes go to the class class_subsys */ +static struct kset *class_kset; + + +int class_create_file(struct class *cls, const struct class_attribute *attr) +{ + int error; + if (cls) + error = sysfs_create_file(&cls->p->class_subsys.kobj, + &attr->attr); + else + error = -EINVAL; + return error; +} + +void class_remove_file(struct class *cls, const struct class_attribute *attr) +{ + if (cls) + sysfs_remove_file(&cls->p->class_subsys.kobj, &attr->attr); +} + +static struct class *class_get(struct class *cls) +{ + if (cls) + kset_get(&cls->p->class_subsys); + return cls; +} + +static void class_put(struct class *cls) +{ + if (cls) + kset_put(&cls->p->class_subsys); +} + +static int add_class_attrs(struct class *cls) +{ + int i; + int error = 0; + + if (cls->class_attrs) { + for (i = 0; attr_name(cls->class_attrs[i]); i++) { + error = class_create_file(cls, &cls->class_attrs[i]); + if (error) + goto error; + } + } +done: + return error; +error: + while (--i >= 0) + class_remove_file(cls, &cls->class_attrs[i]); + goto done; +} + +static void remove_class_attrs(struct class *cls) +{ + int i; + + if (cls->class_attrs) { + for (i = 0; attr_name(cls->class_attrs[i]); i++) + class_remove_file(cls, &cls->class_attrs[i]); + } +} + +static void klist_class_dev_get(struct klist_node *n) +{ + struct device *dev = container_of(n, struct device, knode_class); + + get_device(dev); +} + +static void klist_class_dev_put(struct klist_node *n) +{ + struct device *dev = container_of(n, struct device, knode_class); + + put_device(dev); +} + +int __class_register(struct class *cls, struct lock_class_key *key) +{ + struct class_private *cp; + int error; + + pr_debug("device class '%s': registering\n", cls->name); + + cp = kzalloc(sizeof(*cp), GFP_KERNEL); + if (!cp) + return -ENOMEM; + klist_init(&cp->class_devices, klist_class_dev_get, klist_class_dev_put); + INIT_LIST_HEAD(&cp->class_interfaces); + kset_init(&cp->class_dirs); + __mutex_init(&cp->class_mutex, "struct class mutex", key); + error = kobject_set_name(&cp->class_subsys.kobj, "%s", cls->name); + if (error) { + kfree(cp); + return error; + } + + /* set the default /sys/dev directory for devices of this class */ + if (!cls->dev_kobj) + cls->dev_kobj = sysfs_dev_char_kobj; + +#if defined(CONFIG_SYSFS_DEPRECATED) && defined(CONFIG_BLOCK) && !defined(DDE_LINUX) + /* let the block class directory show up in the root of sysfs */ + if (cls != &block_class) + cp->class_subsys.kobj.kset = class_kset; +#else + cp->class_subsys.kobj.kset = class_kset; +#endif + cp->class_subsys.kobj.ktype = &class_ktype; + cp->class = cls; + cls->p = cp; + + error = kset_register(&cp->class_subsys); + if (error) { + kfree(cp); + return error; + } + error = add_class_attrs(class_get(cls)); + class_put(cls); + return error; +} +EXPORT_SYMBOL_GPL(__class_register); + +void class_unregister(struct class *cls) +{ + pr_debug("device class '%s': unregistering\n", cls->name); + remove_class_attrs(cls); + kset_unregister(&cls->p->class_subsys); +} + +static void class_create_release(struct class *cls) +{ + pr_debug("%s called for %s\n", __func__, cls->name); + kfree(cls); +} + +/** + * class_create - create a struct class structure + * @owner: pointer to the module that is to "own" this struct class + * @name: pointer to a string for the name of this class. + * @key: the lock_class_key for this class; used by mutex lock debugging + * + * This is used to create a struct class pointer that can then be used + * in calls to device_create(). + * + * Note, the pointer created here is to be destroyed when finished by + * making a call to class_destroy(). + */ +struct class *__class_create(struct module *owner, const char *name, + struct lock_class_key *key) +{ + struct class *cls; + int retval; + + cls = kzalloc(sizeof(*cls), GFP_KERNEL); + if (!cls) { + retval = -ENOMEM; + goto error; + } + + cls->name = name; + cls->owner = owner; + cls->class_release = class_create_release; + + retval = __class_register(cls, key); + if (retval) + goto error; + + return cls; + +error: + kfree(cls); + return ERR_PTR(retval); +} +EXPORT_SYMBOL_GPL(__class_create); + +/** + * class_destroy - destroys a struct class structure + * @cls: pointer to the struct class that is to be destroyed + * + * Note, the pointer to be destroyed must have been created with a call + * to class_create(). + */ +void class_destroy(struct class *cls) +{ + if ((cls == NULL) || (IS_ERR(cls))) + return; + + class_unregister(cls); +} + +#ifdef CONFIG_SYSFS_DEPRECATED +char *make_class_name(const char *name, struct kobject *kobj) +{ + char *class_name; + int size; + + size = strlen(name) + strlen(kobject_name(kobj)) + 2; + + class_name = kmalloc(size, GFP_KERNEL); + if (!class_name) + return NULL; + + strcpy(class_name, name); + strcat(class_name, ":"); + strcat(class_name, kobject_name(kobj)); + return class_name; +} +#endif + +/** + * class_dev_iter_init - initialize class device iterator + * @iter: class iterator to initialize + * @class: the class we wanna iterate over + * @start: the device to start iterating from, if any + * @type: device_type of the devices to iterate over, NULL for all + * + * Initialize class iterator @iter such that it iterates over devices + * of @class. If @start is set, the list iteration will start there, + * otherwise if it is NULL, the iteration starts at the beginning of + * the list. + */ +void class_dev_iter_init(struct class_dev_iter *iter, struct class *class, + struct device *start, const struct device_type *type) +{ + struct klist_node *start_knode = NULL; + + if (start) + start_knode = &start->knode_class; + klist_iter_init_node(&class->p->class_devices, &iter->ki, start_knode); + iter->type = type; +} +EXPORT_SYMBOL_GPL(class_dev_iter_init); + +/** + * class_dev_iter_next - iterate to the next device + * @iter: class iterator to proceed + * + * Proceed @iter to the next device and return it. Returns NULL if + * iteration is complete. + * + * The returned device is referenced and won't be released till + * iterator is proceed to the next device or exited. The caller is + * free to do whatever it wants to do with the device including + * calling back into class code. + */ +struct device *class_dev_iter_next(struct class_dev_iter *iter) +{ + struct klist_node *knode; + struct device *dev; + + while (1) { + knode = klist_next(&iter->ki); + if (!knode) + return NULL; + dev = container_of(knode, struct device, knode_class); + if (!iter->type || iter->type == dev->type) + return dev; + } +} +EXPORT_SYMBOL_GPL(class_dev_iter_next); + +/** + * class_dev_iter_exit - finish iteration + * @iter: class iterator to finish + * + * Finish an iteration. Always call this function after iteration is + * complete whether the iteration ran till the end or not. + */ +void class_dev_iter_exit(struct class_dev_iter *iter) +{ + klist_iter_exit(&iter->ki); +} +EXPORT_SYMBOL_GPL(class_dev_iter_exit); + +/** + * class_for_each_device - device iterator + * @class: the class we're iterating + * @start: the device to start with in the list, if any. + * @data: data for the callback + * @fn: function to be called for each device + * + * Iterate over @class's list of devices, and call @fn for each, + * passing it @data. If @start is set, the list iteration will start + * there, otherwise if it is NULL, the iteration starts at the + * beginning of the list. + * + * We check the return of @fn each time. If it returns anything + * other than 0, we break out and return that value. + * + * @fn is allowed to do anything including calling back into class + * code. There's no locking restriction. + */ +int class_for_each_device(struct class *class, struct device *start, + void *data, int (*fn)(struct device *, void *)) +{ + struct class_dev_iter iter; + struct device *dev; + int error = 0; + + if (!class) + return -EINVAL; + if (!class->p) { + WARN(1, "%s called for class '%s' before it was initialized", + __func__, class->name); + return -EINVAL; + } + + class_dev_iter_init(&iter, class, start, NULL); + while ((dev = class_dev_iter_next(&iter))) { + error = fn(dev, data); + if (error) + break; + } + class_dev_iter_exit(&iter); + + return error; +} +EXPORT_SYMBOL_GPL(class_for_each_device); + +/** + * class_find_device - device iterator for locating a particular device + * @class: the class we're iterating + * @start: Device to begin with + * @data: data for the match function + * @match: function to check device + * + * This is similar to the class_for_each_dev() function above, but it + * returns a reference to a device that is 'found' for later use, as + * determined by the @match callback. + * + * The callback should return 0 if the device doesn't match and non-zero + * if it does. If the callback returns non-zero, this function will + * return to the caller and not iterate over any more devices. + * + * Note, you will need to drop the reference with put_device() after use. + * + * @fn is allowed to do anything including calling back into class + * code. There's no locking restriction. + */ +struct device *class_find_device(struct class *class, struct device *start, + void *data, + int (*match)(struct device *, void *)) +{ + struct class_dev_iter iter; + struct device *dev; + + if (!class) + return NULL; + if (!class->p) { + WARN(1, "%s called for class '%s' before it was initialized", + __func__, class->name); + return NULL; + } + + class_dev_iter_init(&iter, class, start, NULL); + while ((dev = class_dev_iter_next(&iter))) { + if (match(dev, data)) { + get_device(dev); + break; + } + } + class_dev_iter_exit(&iter); + + return dev; +} +EXPORT_SYMBOL_GPL(class_find_device); + +int class_interface_register(struct class_interface *class_intf) +{ + struct class *parent; + struct class_dev_iter iter; + struct device *dev; + + if (!class_intf || !class_intf->class) + return -ENODEV; + + parent = class_get(class_intf->class); + if (!parent) + return -EINVAL; + + mutex_lock(&parent->p->class_mutex); + list_add_tail(&class_intf->node, &parent->p->class_interfaces); + if (class_intf->add_dev) { + class_dev_iter_init(&iter, parent, NULL, NULL); + while ((dev = class_dev_iter_next(&iter))) + class_intf->add_dev(dev, class_intf); + class_dev_iter_exit(&iter); + } + mutex_unlock(&parent->p->class_mutex); + + return 0; +} + +void class_interface_unregister(struct class_interface *class_intf) +{ + struct class *parent = class_intf->class; + struct class_dev_iter iter; + struct device *dev; + + if (!parent) + return; + + mutex_lock(&parent->p->class_mutex); + list_del_init(&class_intf->node); + if (class_intf->remove_dev) { + class_dev_iter_init(&iter, parent, NULL, NULL); + while ((dev = class_dev_iter_next(&iter))) + class_intf->remove_dev(dev, class_intf); + class_dev_iter_exit(&iter); + } + mutex_unlock(&parent->p->class_mutex); + + class_put(parent); +} + +int __init classes_init(void) +{ + class_kset = kset_create_and_add("class", NULL, NULL); + if (!class_kset) + return -ENOMEM; + return 0; +} + +EXPORT_SYMBOL_GPL(class_create_file); +EXPORT_SYMBOL_GPL(class_remove_file); +EXPORT_SYMBOL_GPL(class_unregister); +EXPORT_SYMBOL_GPL(class_destroy); + +EXPORT_SYMBOL_GPL(class_interface_register); +EXPORT_SYMBOL_GPL(class_interface_unregister); |