diff options
Diffstat (limited to 'drivers/base/core.c')
| -rw-r--r-- | drivers/base/core.c | 1527 |
1 files changed, 1527 insertions, 0 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c new file mode 100644 index 0000000..8c2cc26 --- /dev/null +++ b/drivers/base/core.c @@ -0,0 +1,1527 @@ +/* + * drivers/base/core.c - core driver model code (device registration, etc) + * + * Copyright (c) 2002-3 Patrick Mochel + * Copyright (c) 2002-3 Open Source Development Labs + * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de> + * Copyright (c) 2006 Novell, Inc. + * + * This file is released under the GPLv2 + * + */ + +#include <linux/device.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/kdev_t.h> +#include <linux/notifier.h> +#include <linux/genhd.h> +#include <linux/kallsyms.h> +#include <linux/semaphore.h> +#include <linux/mutex.h> + +#include "base.h" +#include "power/power.h" + +int (*platform_notify)(struct device *dev) = NULL; +int (*platform_notify_remove)(struct device *dev) = NULL; +static struct kobject *dev_kobj; +struct kobject *sysfs_dev_char_kobj; +struct kobject *sysfs_dev_block_kobj; + +#ifdef CONFIG_BLOCK +static inline int device_is_not_partition(struct device *dev) +{ + return !(dev->type == &part_type); +} +#else +static inline int device_is_not_partition(struct device *dev) +{ + return 1; +} +#endif + +/** + * dev_driver_string - Return a device's driver name, if at all possible + * @dev: struct device to get the name of + * + * Will return the device's driver's name if it is bound to a device. If + * the device is not bound to a device, it will return the name of the bus + * it is attached to. If it is not attached to a bus either, an empty + * string will be returned. + */ +const char *dev_driver_string(const struct device *dev) +{ + return dev->driver ? dev->driver->name : + (dev->bus ? dev->bus->name : + (dev->class ? dev->class->name : "")); +} +EXPORT_SYMBOL(dev_driver_string); + +#define to_dev(obj) container_of(obj, struct device, kobj) +#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) + +static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr, + char *buf) +{ + struct device_attribute *dev_attr = to_dev_attr(attr); + struct device *dev = to_dev(kobj); + ssize_t ret = -EIO; + + if (dev_attr->show) + ret = dev_attr->show(dev, dev_attr, buf); + if (ret >= (ssize_t)PAGE_SIZE) { + print_symbol("dev_attr_show: %s returned bad count\n", + (unsigned long)dev_attr->show); + } + return ret; +} + +static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr, + const char *buf, size_t count) +{ + struct device_attribute *dev_attr = to_dev_attr(attr); + struct device *dev = to_dev(kobj); + ssize_t ret = -EIO; + + if (dev_attr->store) + ret = dev_attr->store(dev, dev_attr, buf, count); + return ret; +} + +static struct sysfs_ops dev_sysfs_ops = { + .show = dev_attr_show, + .store = dev_attr_store, +}; + + +/** + * device_release - free device structure. + * @kobj: device's kobject. + * + * This is called once the reference count for the object + * reaches 0. We forward the call to the device's release + * method, which should handle actually freeing the structure. + */ +static void device_release(struct kobject *kobj) +{ + struct device *dev = to_dev(kobj); + + if (dev->release) + dev->release(dev); + else if (dev->type && dev->type->release) + dev->type->release(dev); + else if (dev->class && dev->class->dev_release) + dev->class->dev_release(dev); + else + WARN(1, KERN_ERR "Device '%s' does not have a release() " + "function, it is broken and must be fixed.\n", + dev->bus_id); +} + +static struct kobj_type device_ktype = { + .release = device_release, + .sysfs_ops = &dev_sysfs_ops, +}; + + +static int dev_uevent_filter(struct kset *kset, struct kobject *kobj) +{ + struct kobj_type *ktype = get_ktype(kobj); + + if (ktype == &device_ktype) { + struct device *dev = to_dev(kobj); + if (dev->uevent_suppress) + return 0; + if (dev->bus) + return 1; + if (dev->class) + return 1; + } + return 0; +} + +static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj) +{ + struct device *dev = to_dev(kobj); + + if (dev->bus) + return dev->bus->name; + if (dev->class) + return dev->class->name; + return NULL; +} + +static int dev_uevent(struct kset *kset, struct kobject *kobj, + struct kobj_uevent_env *env) +{ + struct device *dev = to_dev(kobj); + int retval = 0; + + /* add the major/minor if present */ + if (MAJOR(dev->devt)) { + add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt)); + add_uevent_var(env, "MINOR=%u", MINOR(dev->devt)); + } + + if (dev->type && dev->type->name) + add_uevent_var(env, "DEVTYPE=%s", dev->type->name); + + if (dev->driver) + add_uevent_var(env, "DRIVER=%s", dev->driver->name); + +#ifdef CONFIG_SYSFS_DEPRECATED + if (dev->class) { + struct device *parent = dev->parent; + + /* find first bus device in parent chain */ + while (parent && !parent->bus) + parent = parent->parent; + if (parent && parent->bus) { + const char *path; + + path = kobject_get_path(&parent->kobj, GFP_KERNEL); + if (path) { + add_uevent_var(env, "PHYSDEVPATH=%s", path); + kfree(path); + } + + add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name); + + if (parent->driver) + add_uevent_var(env, "PHYSDEVDRIVER=%s", + parent->driver->name); + } + } else if (dev->bus) { + add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name); + + if (dev->driver) + add_uevent_var(env, "PHYSDEVDRIVER=%s", + dev->driver->name); + } +#endif + + /* have the bus specific function add its stuff */ + if (dev->bus && dev->bus->uevent) { + retval = dev->bus->uevent(dev, env); + if (retval) + pr_debug("device: '%s': %s: bus uevent() returned %d\n", + dev->bus_id, __func__, retval); + } + + /* have the class specific function add its stuff */ + if (dev->class && dev->class->dev_uevent) { + retval = dev->class->dev_uevent(dev, env); + if (retval) + pr_debug("device: '%s': %s: class uevent() " + "returned %d\n", dev->bus_id, + __func__, retval); + } + + /* have the device type specific fuction add its stuff */ + if (dev->type && dev->type->uevent) { + retval = dev->type->uevent(dev, env); + if (retval) + pr_debug("device: '%s': %s: dev_type uevent() " + "returned %d\n", dev->bus_id, + __func__, retval); + } + + return retval; +} + +static struct kset_uevent_ops device_uevent_ops = { + .filter = dev_uevent_filter, + .name = dev_uevent_name, + .uevent = dev_uevent, +}; + +static ssize_t show_uevent(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct kobject *top_kobj; + struct kset *kset; + struct kobj_uevent_env *env = NULL; + int i; + size_t count = 0; + int retval; + + /* search the kset, the device belongs to */ + top_kobj = &dev->kobj; + while (!top_kobj->kset && top_kobj->parent) + top_kobj = top_kobj->parent; + if (!top_kobj->kset) + goto out; + + kset = top_kobj->kset; + if (!kset->uevent_ops || !kset->uevent_ops->uevent) + goto out; + + /* respect filter */ + if (kset->uevent_ops && kset->uevent_ops->filter) + if (!kset->uevent_ops->filter(kset, &dev->kobj)) + goto out; + + env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); + if (!env) + return -ENOMEM; + + /* let the kset specific function add its keys */ + retval = kset->uevent_ops->uevent(kset, &dev->kobj, env); + if (retval) + goto out; + + /* copy keys to file */ + for (i = 0; i < env->envp_idx; i++) + count += sprintf(&buf[count], "%s\n", env->envp[i]); +out: + kfree(env); + return count; +} + +static ssize_t store_uevent(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + enum kobject_action action; + + if (kobject_action_type(buf, count, &action) == 0) { + kobject_uevent(&dev->kobj, action); + goto out; + } + + dev_err(dev, "uevent: unsupported action-string; this will " + "be ignored in a future kernel version\n"); + kobject_uevent(&dev->kobj, KOBJ_ADD); +out: + return count; +} + +static struct device_attribute uevent_attr = + __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent); + +static int device_add_attributes(struct device *dev, + struct device_attribute *attrs) +{ + int error = 0; + int i; + + if (attrs) { + for (i = 0; attr_name(attrs[i]); i++) { + error = device_create_file(dev, &attrs[i]); + if (error) + break; + } + if (error) + while (--i >= 0) + device_remove_file(dev, &attrs[i]); + } + return error; +} + +static void device_remove_attributes(struct device *dev, + struct device_attribute *attrs) +{ + int i; + + if (attrs) + for (i = 0; attr_name(attrs[i]); i++) + device_remove_file(dev, &attrs[i]); +} + +static int device_add_groups(struct device *dev, + struct attribute_group **groups) +{ + int error = 0; + int i; + + if (groups) { + for (i = 0; groups[i]; i++) { + error = sysfs_create_group(&dev->kobj, groups[i]); + if (error) { + while (--i >= 0) + sysfs_remove_group(&dev->kobj, + groups[i]); + break; + } + } + } + return error; +} + +static void device_remove_groups(struct device *dev, + struct attribute_group **groups) +{ + int i; + + if (groups) + for (i = 0; groups[i]; i++) + sysfs_remove_group(&dev->kobj, groups[i]); +} + +static int device_add_attrs(struct device *dev) +{ + struct class *class = dev->class; + struct device_type *type = dev->type; + int error; + + if (class) { + error = device_add_attributes(dev, class->dev_attrs); + if (error) + return error; + } + + if (type) { + error = device_add_groups(dev, type->groups); + if (error) + goto err_remove_class_attrs; + } + + error = device_add_groups(dev, dev->groups); + if (error) + goto err_remove_type_groups; + + return 0; + + err_remove_type_groups: + if (type) + device_remove_groups(dev, type->groups); + err_remove_class_attrs: + if (class) + device_remove_attributes(dev, class->dev_attrs); + + return error; +} + +static void device_remove_attrs(struct device *dev) +{ + struct class *class = dev->class; + struct device_type *type = dev->type; + + device_remove_groups(dev, dev->groups); + + if (type) + device_remove_groups(dev, type->groups); + + if (class) + device_remove_attributes(dev, class->dev_attrs); +} + + +static ssize_t show_dev(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return print_dev_t(buf, dev->devt); +} + +static struct device_attribute devt_attr = + __ATTR(dev, S_IRUGO, show_dev, NULL); + +/* kset to create /sys/devices/ */ +struct kset *devices_kset; + +/** + * device_create_file - create sysfs attribute file for device. + * @dev: device. + * @attr: device attribute descriptor. + */ +int device_create_file(struct device *dev, struct device_attribute *attr) +{ + int error = 0; + if (dev) + error = sysfs_create_file(&dev->kobj, &attr->attr); + return error; +} + +/** + * device_remove_file - remove sysfs attribute file. + * @dev: device. + * @attr: device attribute descriptor. + */ +void device_remove_file(struct device *dev, struct device_attribute *attr) +{ + if (dev) + sysfs_remove_file(&dev->kobj, &attr->attr); +} + +/** + * device_create_bin_file - create sysfs binary attribute file for device. + * @dev: device. + * @attr: device binary attribute descriptor. + */ +int device_create_bin_file(struct device *dev, struct bin_attribute *attr) +{ + int error = -EINVAL; + if (dev) + error = sysfs_create_bin_file(&dev->kobj, attr); + return error; +} +EXPORT_SYMBOL_GPL(device_create_bin_file); + +/** + * device_remove_bin_file - remove sysfs binary attribute file + * @dev: device. + * @attr: device binary attribute descriptor. + */ +void device_remove_bin_file(struct device *dev, struct bin_attribute *attr) +{ + if (dev) + sysfs_remove_bin_file(&dev->kobj, attr); +} +EXPORT_SYMBOL_GPL(device_remove_bin_file); + +/** + * device_schedule_callback_owner - helper to schedule a callback for a device + * @dev: device. + * @func: callback function to invoke later. + * @owner: module owning the callback routine + * + * Attribute methods must not unregister themselves or their parent device + * (which would amount to the same thing). Attempts to do so will deadlock, + * since unregistration is mutually exclusive with driver callbacks. + * + * Instead methods can call this routine, which will attempt to allocate + * and schedule a workqueue request to call back @func with @dev as its + * argument in the workqueue's process context. @dev will be pinned until + * @func returns. + * + * This routine is usually called via the inline device_schedule_callback(), + * which automatically sets @owner to THIS_MODULE. + * + * Returns 0 if the request was submitted, -ENOMEM if storage could not + * be allocated, -ENODEV if a reference to @owner isn't available. + * + * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an + * underlying sysfs routine (since it is intended for use by attribute + * methods), and if sysfs isn't available you'll get nothing but -ENOSYS. + */ +int device_schedule_callback_owner(struct device *dev, + void (*func)(struct device *), struct module *owner) +{ + return sysfs_schedule_callback(&dev->kobj, + (void (*)(void *)) func, dev, owner); +} +EXPORT_SYMBOL_GPL(device_schedule_callback_owner); + +static void klist_children_get(struct klist_node *n) +{ + struct device *dev = container_of(n, struct device, knode_parent); + + get_device(dev); +} + +static void klist_children_put(struct klist_node *n) +{ + struct device *dev = container_of(n, struct device, knode_parent); + + put_device(dev); +} + +/** + * device_initialize - init device structure. + * @dev: device. + * + * This prepares the device for use by other layers by initializing + * its fields. + * It is the first half of device_register(), if called by + * that function, though it can also be called separately, so one + * may use @dev's fields. In particular, get_device()/put_device() + * may be used for reference counting of @dev after calling this + * function. + * + * NOTE: Use put_device() to give up your reference instead of freeing + * @dev directly once you have called this function. + */ +void device_initialize(struct device *dev) +{ + dev->kobj.kset = devices_kset; + kobject_init(&dev->kobj, &device_ktype); + klist_init(&dev->klist_children, klist_children_get, + klist_children_put); + INIT_LIST_HEAD(&dev->dma_pools); + init_MUTEX(&dev->sem); + spin_lock_init(&dev->devres_lock); + INIT_LIST_HEAD(&dev->devres_head); + device_init_wakeup(dev, 0); + device_pm_init(dev); + set_dev_node(dev, -1); +} + +#ifdef CONFIG_SYSFS_DEPRECATED +static struct kobject *get_device_parent(struct device *dev, + struct device *parent) +{ + /* class devices without a parent live in /sys/class/<classname>/ */ + if (dev->class && (!parent || parent->class != dev->class)) + return &dev->class->p->class_subsys.kobj; + /* all other devices keep their parent */ + else if (parent) + return &parent->kobj; + + return NULL; +} + +static inline void cleanup_device_parent(struct device *dev) {} +static inline void cleanup_glue_dir(struct device *dev, + struct kobject *glue_dir) {} +#else +static struct kobject *virtual_device_parent(struct device *dev) +{ + static struct kobject *virtual_dir = NULL; + + if (!virtual_dir) + virtual_dir = kobject_create_and_add("virtual", + &devices_kset->kobj); + + return virtual_dir; +} + +static struct kobject *get_device_parent(struct device *dev, + struct device *parent) +{ + int retval; + + if (dev->class) { + struct kobject *kobj = NULL; + struct kobject *parent_kobj; + struct kobject *k; + + /* + * If we have no parent, we live in "virtual". + * Class-devices with a non class-device as parent, live + * in a "glue" directory to prevent namespace collisions. + */ + if (parent == NULL) + parent_kobj = virtual_device_parent(dev); + else if (parent->class) + return &parent->kobj; + else + parent_kobj = &parent->kobj; + + /* find our class-directory at the parent and reference it */ + spin_lock(&dev->class->p->class_dirs.list_lock); + list_for_each_entry(k, &dev->class->p->class_dirs.list, entry) + if (k->parent == parent_kobj) { + kobj = kobject_get(k); + break; + } + spin_unlock(&dev->class->p->class_dirs.list_lock); + if (kobj) + return kobj; + + /* or create a new class-directory at the parent device */ + k = kobject_create(); + if (!k) + return NULL; + k->kset = &dev->class->p->class_dirs; + retval = kobject_add(k, parent_kobj, "%s", dev->class->name); + if (retval < 0) { + kobject_put(k); + return NULL; + } + /* do not emit an uevent for this simple "glue" directory */ + return k; + } + + if (parent) + return &parent->kobj; + return NULL; +} + +static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir) +{ + /* see if we live in a "glue" directory */ + if (!glue_dir || !dev->class || + glue_dir->kset != &dev->class->p->class_dirs) + return; + + kobject_put(glue_dir); +} + +static void cleanup_device_parent(struct device *dev) +{ + cleanup_glue_dir(dev, dev->kobj.parent); +} +#endif + +static void setup_parent(struct device *dev, struct device *parent) +{ + struct kobject *kobj; + kobj = get_device_parent(dev, parent); + if (kobj) + dev->kobj.parent = kobj; +} + +static int device_add_class_symlinks(struct device *dev) +{ + int error; + + if (!dev->class) + return 0; + + error = sysfs_create_link(&dev->kobj, + &dev->class->p->class_subsys.kobj, + "subsystem"); + if (error) + goto out; + +#ifdef CONFIG_SYSFS_DEPRECATED + /* stacked class devices need a symlink in the class directory */ + if (dev->kobj.parent != &dev->class->p->class_subsys.kobj && + device_is_not_partition(dev)) { + error = sysfs_create_link(&dev->class->p->class_subsys.kobj, + &dev->kobj, dev->bus_id); + if (error) + goto out_subsys; + } + + if (dev->parent && device_is_not_partition(dev)) { + struct device *parent = dev->parent; + char *class_name; + + /* + * stacked class devices have the 'device' link + * pointing to the bus device instead of the parent + */ + while (parent->class && !parent->bus && parent->parent) + parent = parent->parent; + + error = sysfs_create_link(&dev->kobj, + &parent->kobj, + "device"); + if (error) + goto out_busid; + + class_name = make_class_name(dev->class->name, + &dev->kobj); + if (class_name) + error = sysfs_create_link(&dev->parent->kobj, + &dev->kobj, class_name); + kfree(class_name); + if (error) + goto out_device; + } + return 0; + +out_device: + if (dev->parent && device_is_not_partition(dev)) + sysfs_remove_link(&dev->kobj, "device"); +out_busid: + if (dev->kobj.parent != &dev->class->p->class_subsys.kobj && + device_is_not_partition(dev)) + sysfs_remove_link(&dev->class->p->class_subsys.kobj, + dev->bus_id); +#else + /* link in the class directory pointing to the device */ + error = sysfs_create_link(&dev->class->p->class_subsys.kobj, + &dev->kobj, dev->bus_id); + if (error) + goto out_subsys; + + if (dev->parent && device_is_not_partition(dev)) { + error = sysfs_create_link(&dev->kobj, &dev->parent->kobj, + "device"); + if (error) + goto out_busid; + } + return 0; + +out_busid: + sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id); +#endif + +out_subsys: + sysfs_remove_link(&dev->kobj, "subsystem"); +out: + return error; +} + +static void device_remove_class_symlinks(struct device *dev) +{ + if (!dev->class) + return; + +#ifdef CONFIG_SYSFS_DEPRECATED + if (dev->parent && device_is_not_partition(dev)) { + char *class_name; + + class_name = make_class_name(dev->class->name, &dev->kobj); + if (class_name) { + sysfs_remove_link(&dev->parent->kobj, class_name); + kfree(class_name); + } + sysfs_remove_link(&dev->kobj, "device"); + } + + if (dev->kobj.parent != &dev->class->p->class_subsys.kobj && + device_is_not_partition(dev)) + sysfs_remove_link(&dev->class->p->class_subsys.kobj, + dev->bus_id); +#else + if (dev->parent && device_is_not_partition(dev)) + sysfs_remove_link(&dev->kobj, "device"); + + sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id); +#endif + + sysfs_remove_link(&dev->kobj, "subsystem"); +} + +/** + * dev_set_name - set a device name + * @dev: device + * @fmt: format string for the device's name + */ +int dev_set_name(struct device *dev, const char *fmt, ...) +{ + va_list vargs; + + va_start(vargs, fmt); + vsnprintf(dev->bus_id, sizeof(dev->bus_id), fmt, vargs); + va_end(vargs); + return 0; +} +EXPORT_SYMBOL_GPL(dev_set_name); + +/** + * device_to_dev_kobj - select a /sys/dev/ directory for the device + * @dev: device + * + * By default we select char/ for new entries. Setting class->dev_obj + * to NULL prevents an entry from being created. class->dev_kobj must + * be set (or cleared) before any devices are registered to the class + * otherwise device_create_sys_dev_entry() and + * device_remove_sys_dev_entry() will disagree about the the presence + * of the link. + */ +static struct kobject *device_to_dev_kobj(struct device *dev) +{ + struct kobject *kobj; + + if (dev->class) + kobj = dev->class->dev_kobj; + else + kobj = sysfs_dev_char_kobj; + + return kobj; +} + +static int device_create_sys_dev_entry(struct device *dev) +{ + struct kobject *kobj = device_to_dev_kobj(dev); + int error = 0; + char devt_str[15]; + + if (kobj) { + format_dev_t(devt_str, dev->devt); + error = sysfs_create_link(kobj, &dev->kobj, devt_str); + } + + return error; +} + +static void device_remove_sys_dev_entry(struct device *dev) +{ + struct kobject *kobj = device_to_dev_kobj(dev); + char devt_str[15]; + + if (kobj) { + format_dev_t(devt_str, dev->devt); + sysfs_remove_link(kobj, devt_str); + } +} + +/** + * 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. + * + * 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 class_interface *class_intf; + int error = -EINVAL; + + dev = get_device(dev); + if (!dev) + goto done; + + /* Temporarily support init_name if it is set. + * It will override bus_id for now */ + if (dev->init_name) + dev_set_name(dev, "%s", dev->init_name); + + if (!strlen(dev->bus_id)) + goto done; + + pr_debug("device: '%s': %s\n", dev->bus_id, __func__); + + parent = get_device(dev->parent); + setup_parent(dev, parent); + + /* use parent numa_node */ + if (parent) + set_dev_node(dev, dev_to_node(parent)); + + /* first, register with generic layer. */ + error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id); + if (error) + goto Error; + + /* notify platform of device entry */ + if (platform_notify) + platform_notify(dev); + + /* notify clients of device entry (new way) */ + if (dev->bus) + blocking_notifier_call_chain(&dev->bus->p->bus_notifier, + BUS_NOTIFY_ADD_DEVICE, dev); + + error = device_create_file(dev, &uevent_attr); + if (error) + goto attrError; + + if (MAJOR(dev->devt)) { + error = device_create_file(dev, &devt_attr); + if (error) + goto ueventattrError; + + error = device_create_sys_dev_entry(dev); + if (error) + goto devtattrError; + } + + 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); + kobject_uevent(&dev->kobj, KOBJ_ADD); + bus_attach_device(dev); + if (parent) + klist_add_tail(&dev->knode_parent, &parent->klist_children); + + if (dev->class) { + mutex_lock(&dev->class->p->class_mutex); + /* tie the class to the device */ + klist_add_tail(&dev->knode_class, + &dev->class->p->class_devices); + + /* notify any interfaces that the device is here */ + list_for_each_entry(class_intf, + &dev->class->p->class_interfaces, node) + if (class_intf->add_dev) + class_intf->add_dev(dev, class_intf); + mutex_unlock(&dev->class->p->class_mutex); + } +done: + put_device(dev); + return error; + DPMError: + bus_remove_device(dev); + BusError: + if (dev->bus) + blocking_notifier_call_chain(&dev->bus->p->bus_notifier, + BUS_NOTIFY_DEL_DEVICE, dev); + device_remove_attrs(dev); + AttrsError: + device_remove_class_symlinks(dev); + SymlinkError: + if (MAJOR(dev->devt)) + device_remove_sys_dev_entry(dev); + devtattrError: + if (MAJOR(dev->devt)) + device_remove_file(dev, &devt_attr); + ueventattrError: + device_remove_file(dev, &uevent_attr); + attrError: + kobject_uevent(&dev->kobj, KOBJ_REMOVE); + kobject_del(&dev->kobj); + Error: + cleanup_device_parent(dev); + if (parent) + put_device(parent); + goto done; +} + +/** + * device_register - register a device with the system. + * @dev: pointer to the device structure + * + * This happens in two clean steps - initialize the device + * and add it to the system. The two steps can be called + * separately, but this is the easiest and most common. + * I.e. you should only call the two helpers separately if + * have a clearly defined need to use and refcount the device + * before it is added to the hierarchy. + * + * NOTE: _Never_ directly free @dev after calling this function, even + * if it returned an error! Always use put_device() to give up the + * reference initialized in this function instead. + */ +int device_register(struct device *dev) +{ + device_initialize(dev); + return device_add(dev); +} + +/** + * get_device - increment reference count for device. + * @dev: device. + * + * This simply forwards the call to kobject_get(), though + * we do take care to provide for the case that we get a NULL + * pointer passed in. + */ +struct device *get_device(struct device *dev) +{ + return dev ? to_dev(kobject_get(&dev->kobj)) : NULL; +} + +/** + * put_device - decrement reference count. + * @dev: device in question. + */ +void put_device(struct device *dev) +{ + /* might_sleep(); */ + if (dev) + kobject_put(&dev->kobj); +} + +/** + * device_del - delete device from system. + * @dev: device. + * + * This is the first part of the device unregistration + * sequence. This removes the device from the lists we control + * from here, has it removed from the other driver model + * subsystems it was added to in device_add(), and removes it + * from the kobject hierarchy. + * + * NOTE: this should be called manually _iff_ device_add() was + * also called manually. + */ +void device_del(struct device *dev) +{ + struct device *parent = dev->parent; + struct class_interface *class_intf; + + device_pm_remove(dev); + dpm_sysfs_remove(dev); + if (parent) + klist_del(&dev->knode_parent); + if (MAJOR(dev->devt)) { + device_remove_sys_dev_entry(dev); + device_remove_file(dev, &devt_attr); + } + if (dev->class) { + device_remove_class_symlinks(dev); + + mutex_lock(&dev->class->p->class_mutex); + /* notify any interfaces that the device is now gone */ + list_for_each_entry(class_intf, + &dev->class->p->class_interfaces, node) + if (class_intf->remove_dev) + class_intf->remove_dev(dev, class_intf); + /* remove the device from the class list */ + klist_del(&dev->knode_class); + mutex_unlock(&dev->class->p->class_mutex); + } + device_remove_file(dev, &uevent_attr); + device_remove_attrs(dev); + bus_remove_device(dev); + + /* + * Some platform devices are driven without driver attached + * and managed resources may have been acquired. Make sure + * all resources are released. + */ + devres_release_all(dev); + + /* Notify the platform of the removal, in case they + * need to do anything... + */ + if (platform_notify_remove) + platform_notify_remove(dev); + if (dev->bus) + blocking_notifier_call_chain(&dev->bus->p->bus_notifier, + BUS_NOTIFY_DEL_DEVICE, dev); + kobject_uevent(&dev->kobj, KOBJ_REMOVE); + cleanup_device_parent(dev); + kobject_del(&dev->kobj); + put_device(parent); +} + +/** + * device_unregister - unregister device from system. + * @dev: device going away. + * + * We do this in two parts, like we do device_register(). First, + * we remove it from all the subsystems with device_del(), then + * we decrement the reference count via put_device(). If that + * is the final reference count, the device will be cleaned up + * via device_release() above. Otherwise, the structure will + * stick around until the final reference to the device is dropped. + */ +void device_unregister(struct device *dev) +{ + pr_debug("device: '%s': %s\n", dev->bus_id, __func__); + device_del(dev); + put_device(dev); +} + +static struct device *next_device(struct klist_iter *i) +{ + struct klist_node *n = klist_next(i); + return n ? container_of(n, struct device, knode_parent) : NULL; +} + +/** + * device_for_each_child - device child iterator. + * @parent: parent struct device. + * @data: data for the callback. + * @fn: function to be called for each device. + * + * Iterate over @parent's child devices, and call @fn for each, + * passing it @data. + * + * We check the return of @fn each time. If it returns anything + * other than 0, we break out and return that value. + */ +int device_for_each_child(struct device *parent, void *data, + int (*fn)(struct device *dev, void *data)) +{ + struct klist_iter i; + struct device *child; + int error = 0; + + klist_iter_init(&parent->klist_children, &i); + while ((child = next_device(&i)) && !error) + error = fn(child, data); + klist_iter_exit(&i); + return error; +} + +/** + * device_find_child - device iterator for locating a particular device. + * @parent: parent struct device + * @data: Data to pass to match function + * @match: Callback function to check device + * + * This is similar to the device_for_each_child() 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 and a reference to the + * current device can be obtained, this function will return to the caller + * and not iterate over any more devices. + */ +struct device *device_find_child(struct device *parent, void *data, + int (*match)(struct device *dev, void *data)) +{ + struct klist_iter i; + struct device *child; + + if (!parent) + return NULL; + + klist_iter_init(&parent->klist_children, &i); + while ((child = next_device(&i))) + if (match(child, data) && get_device(child)) + break; + klist_iter_exit(&i); + return child; +} + +int __init devices_init(void) +{ + devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL); + if (!devices_kset) + return -ENOMEM; + dev_kobj = kobject_create_and_add("dev", NULL); + if (!dev_kobj) + goto dev_kobj_err; + sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj); + if (!sysfs_dev_block_kobj) + goto block_kobj_err; + sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj); + if (!sysfs_dev_char_kobj) + goto char_kobj_err; + + return 0; + + char_kobj_err: + kobject_put(sysfs_dev_block_kobj); + block_kobj_err: + kobject_put(dev_kobj); + dev_kobj_err: + kset_unregister(devices_kset); + return -ENOMEM; +} + +EXPORT_SYMBOL_GPL(device_for_each_child); +EXPORT_SYMBOL_GPL(device_find_child); + +EXPORT_SYMBOL_GPL(device_initialize); +EXPORT_SYMBOL_GPL(device_add); +EXPORT_SYMBOL_GPL(device_register); + +EXPORT_SYMBOL_GPL(device_del); +EXPORT_SYMBOL_GPL(device_unregister); +EXPORT_SYMBOL_GPL(get_device); +EXPORT_SYMBOL_GPL(put_device); + +EXPORT_SYMBOL_GPL(device_create_file); +EXPORT_SYMBOL_GPL(device_remove_file); + + +static void device_create_release(struct device *dev) +{ + pr_debug("device: '%s': %s\n", dev->bus_id, __func__); + kfree(dev); +} + +/** + * device_create_vargs - creates a device and registers it with sysfs + * @class: pointer to the struct class that this device should be registered to + * @parent: pointer to the parent struct device of this new device, if any + * @devt: the dev_t for the char device to be added + * @drvdata: the data to be added to the device for callbacks + * @fmt: string for the device's name + * @args: va_list for the device's name + * + * This function can be used by char device classes. A struct device + * will be created in sysfs, registered to the specified class. + * + * A "dev" file will be created, showing the dev_t for the device, if + * the dev_t is not 0,0. + * If a pointer to a parent struct device is passed in, the newly created + * struct device will be a child of that device in sysfs. + * The pointer to the struct device will be returned from the call. + * Any further sysfs files that might be required can be created using this + * pointer. + * + * Note: the struct class passed to this function must have previously + * been created with a call to class_create(). + */ +struct device *device_create_vargs(struct class *class, struct device *parent, + dev_t devt, void *drvdata, const char *fmt, + va_list args) +{ + struct device *dev = NULL; + int retval = -ENODEV; + + if (class == NULL || IS_ERR(class)) + goto error; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) { + retval = -ENOMEM; + goto error; + } + + dev->devt = devt; + dev->class = class; + dev->parent = parent; + dev->release = device_create_release; + dev_set_drvdata(dev, drvdata); + + vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args); + retval = device_register(dev); + if (retval) + goto error; + + return dev; + +error: + put_device(dev); + return ERR_PTR(retval); +} +EXPORT_SYMBOL_GPL(device_create_vargs); + +/** + * device_create - creates a device and registers it with sysfs + * @class: pointer to the struct class that this device should be registered to + * @parent: pointer to the parent struct device of this new device, if any + * @devt: the dev_t for the char device to be added + * @drvdata: the data to be added to the device for callbacks + * @fmt: string for the device's name + * + * This function can be used by char device classes. A struct device + * will be created in sysfs, registered to the specified class. + * + * A "dev" file will be created, showing the dev_t for the device, if + * the dev_t is not 0,0. + * If a pointer to a parent struct device is passed in, the newly created + * struct device will be a child of that device in sysfs. + * The pointer to the struct device will be returned from the call. + * Any further sysfs files that might be required can be created using this + * pointer. + * + * Note: the struct class passed to this function must have previously + * been created with a call to class_create(). + */ +struct device *device_create(struct class *class, struct device *parent, + dev_t devt, void *drvdata, const char *fmt, ...) +{ + va_list vargs; + struct device *dev; + + va_start(vargs, fmt); + dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs); + va_end(vargs); + return dev; +} +EXPORT_SYMBOL_GPL(device_create); + +static int __match_devt(struct device *dev, void *data) +{ + dev_t *devt = data; + + return dev->devt == *devt; +} + +/** + * device_destroy - removes a device that was created with device_create() + * @class: pointer to the struct class that this device was registered with + * @devt: the dev_t of the device that was previously registered + * + * This call unregisters and cleans up a device that was created with a + * call to device_create(). + */ +void device_destroy(struct class *class, dev_t devt) +{ + struct device *dev; + + dev = class_find_device(class, NULL, &devt, __match_devt); + if (dev) { + put_device(dev); + device_unregister(dev); + } +} +EXPORT_SYMBOL_GPL(device_destroy); + +/** + * device_rename - renames a device + * @dev: the pointer to the struct device to be renamed + * @new_name: the new name of the device + * + * It is the responsibility of the caller to provide mutual + * exclusion between two different calls of device_rename + * on the same device to ensure that new_name is valid and + * won't conflict with other devices. + */ +int device_rename(struct device *dev, char *new_name) +{ + char *old_class_name = NULL; + char *new_class_name = NULL; + char *old_device_name = NULL; + int error; + + dev = get_device(dev); + if (!dev) + return -EINVAL; + + pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id, + __func__, new_name); + +#ifdef CONFIG_SYSFS_DEPRECATED + if ((dev->class) && (dev->parent)) + old_class_name = make_class_name(dev->class->name, &dev->kobj); +#endif + + old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL); + if (!old_device_name) { + error = -ENOMEM; + goto out; + } + strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE); + strlcpy(dev->bus_id, new_name, BUS_ID_SIZE); + + error = kobject_rename(&dev->kobj, new_name); + if (error) { + strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE); + goto out; + } + +#ifdef CONFIG_SYSFS_DEPRECATED + if (old_class_name) { + new_class_name = make_class_name(dev->class->name, &dev->kobj); + if (new_class_name) { + error = sysfs_create_link_nowarn(&dev->parent->kobj, + &dev->kobj, + new_class_name); + if (error) + goto out; + sysfs_remove_link(&dev->parent->kobj, old_class_name); + } + } +#else + if (dev->class) { + error = sysfs_create_link_nowarn(&dev->class->p->class_subsys.kobj, + &dev->kobj, dev->bus_id); + if (error) + goto out; + sysfs_remove_link(&dev->class->p->class_subsys.kobj, + old_device_name); + } +#endif + +out: + put_device(dev); + + kfree(new_class_name); + kfree(old_class_name); + kfree(old_device_name); + + return error; +} +EXPORT_SYMBOL_GPL(device_rename); + +static int device_move_class_links(struct device *dev, + struct device *old_parent, + struct device *new_parent) +{ + int error = 0; +#ifdef CONFIG_SYSFS_DEPRECATED + char *class_name; + + class_name = make_class_name(dev->class->name, &dev->kobj); + if (!class_name) { + error = -ENOMEM; + goto out; + } + if (old_parent) { + sysfs_remove_link(&dev->kobj, "device"); + sysfs_remove_link(&old_parent->kobj, class_name); + } + if (new_parent) { + error = sysfs_create_link(&dev->kobj, &new_parent->kobj, + "device"); + if (error) + goto out; + error = sysfs_create_link(&new_parent->kobj, &dev->kobj, + class_name); + if (error) + sysfs_remove_link(&dev->kobj, "device"); + } else + error = 0; +out: + kfree(class_name); + return error; +#else + if (old_parent) + sysfs_remove_link(&dev->kobj, "device"); + if (new_parent) + error = sysfs_create_link(&dev->kobj, &new_parent->kobj, + "device"); + return error; +#endif +} + +/** + * device_move - moves a device to a new parent + * @dev: the pointer to the struct device to be moved + * @new_parent: the new parent of the device (can by NULL) + */ +int device_move(struct device *dev, struct device *new_parent) +{ + int error; + struct device *old_parent; + struct kobject *new_parent_kobj; + + dev = get_device(dev); + if (!dev) + return -EINVAL; + + new_parent = get_device(new_parent); + new_parent_kobj = get_device_parent(dev, new_parent); + + pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id, + __func__, new_parent ? new_parent->bus_id : "<NULL>"); + error = kobject_move(&dev->kobj, new_parent_kobj); + if (error) { + cleanup_glue_dir(dev, new_parent_kobj); + put_device(new_parent); + goto out; + } + old_parent = dev->parent; + dev->parent = new_parent; + if (old_parent) + klist_remove(&dev->knode_parent); + if (new_parent) { + klist_add_tail(&dev->knode_parent, &new_parent->klist_children); + set_dev_node(dev, dev_to_node(new_parent)); + } + + if (!dev->class) + goto out_put; + error = device_move_class_links(dev, old_parent, new_parent); + if (error) { + /* We ignore errors on cleanup since we're hosed anyway... */ + device_move_class_links(dev, new_parent, old_parent); + if (!kobject_move(&dev->kobj, &old_parent->kobj)) { + if (new_parent) + klist_remove(&dev->knode_parent); + dev->parent = old_parent; + if (old_parent) { + klist_add_tail(&dev->knode_parent, + &old_parent->klist_children); + set_dev_node(dev, dev_to_node(old_parent)); + } + } + cleanup_glue_dir(dev, new_parent_kobj); + put_device(new_parent); + goto out; + } +out_put: + put_device(old_parent); +out: + put_device(dev); + return error; +} +EXPORT_SYMBOL_GPL(device_move); + +/** + * device_shutdown - call ->shutdown() on each device to shutdown. + */ +void device_shutdown(void) +{ + struct device *dev, *devn; + + list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list, + kobj.entry) { + if (dev->bus && dev->bus->shutdown) { + dev_dbg(dev, "shutdown\n"); + dev->bus->shutdown(dev); + } else if (dev->driver && dev->driver->shutdown) { + dev_dbg(dev, "shutdown\n"); + dev->driver->shutdown(dev); + } + } + kobject_put(sysfs_dev_char_kobj); + kobject_put(sysfs_dev_block_kobj); + kobject_put(dev_kobj); +} |
