/* * 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 * * This file is released under the GPLv2 * */ #include <linux/config.h>#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 <asm/semaphore.h> #include "base.h"#include "power/power.h" int (*platform_notify)(struct device * dev) = NULL;int (*platform_notify_remove)(struct device * dev) = NULL; /* * sysfs bindings for devices. */ /** * 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(struct device *dev){ return dev->driver ? dev->driver->name : (dev->bus ? dev->bus->name : "");}EXPORT_SYMBOL_GPL(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_tdev_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); return ret;} static ssize_tdev_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 { printk(KERN_ERR "Device '%s' does not have a release() function, " "it is broken and must be fixed.\n", dev->bus_id); WARN_ON(1); }} static struct kobj_type ktype_device = { .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 == &ktype_device) { struct device *dev = to_dev(kobj); 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, char **envp, int num_envp, char *buffer, int buffer_size){ struct device *dev = to_dev(kobj); int i = 0; int length = 0; int retval = 0; /* add the major/minor if present */ if (MAJOR(dev->devt)) { add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "MAJOR=%u", MAJOR(dev->devt)); add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "MINOR=%u", MINOR(dev->devt)); } /* add bus name of physical device */ if (dev->bus) add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "PHYSDEVBUS=%s", dev->bus->name); /* add driver name of physical device */ if (dev->driver) add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "PHYSDEVDRIVER=%s", dev->driver->name); /* terminate, set to next free slot, shrink available space */ envp[i] = NULL; envp = &envp[i]; num_envp -= i; buffer = &buffer[length]; buffer_size -= length; if (dev->bus && dev->bus->uevent) { /* have the bus specific function add its stuff */ retval = dev->bus->uevent(dev, envp, num_envp, buffer, buffer_size); if (retval) { pr_debug ("%s - uevent() returned %d\n", __FUNCTION__, 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 store_uevent(struct device *dev, struct device_attribute *attr, const char *buf, size_t count){ kobject_uevent(&dev->kobj, KOBJ_ADD); return count;} static ssize_t show_dev(struct device *dev, struct device_attribute *attr, char *buf){ return print_dev_t(buf, dev->devt);} /* * devices_subsys - structure to be registered with kobject core. */ decl_subsys(devices, &ktype_device, &device_uevent_ops); /** * 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 (get_device(dev)) { error = sysfs_create_file(&dev->kobj, &attr->attr); put_device(dev); } 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 (get_device(dev)) { sysfs_remove_file(&dev->kobj, &attr->attr); put_device(dev); }} 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, * including adding it to the device hierarchy. * It is the first half of device_register(), if called by * that, though it can also be called separately, so one * may use @dev's fields (e.g. the refcount). */ void device_initialize(struct device *dev){ kobj_set_kset_s(dev, devices_subsys); kobject_init(&dev->kobj); klist_init(&dev->klist_children, klist_children_get, klist_children_put); INIT_LIST_HEAD(&dev->dma_pools); INIT_LIST_HEAD(&dev->node); init_MUTEX(&dev->sem); device_init_wakeup(dev, 0);} /** * 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 it 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. */int device_add(struct device *dev){ struct device *parent = NULL; char *class_name = NULL; int error = -EINVAL; dev = get_device(dev); if (!dev || !strlen(dev->bus_id)) goto Error; parent = get_device(dev->parent); pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id); /* first, register with generic layer. */ kobject_set_name(&dev->kobj, "%s", dev->bus_id); if (parent) dev->kobj.parent = &parent->kobj; if ((error = kobject_add(&dev->kobj))) goto Error; dev->uevent_attr.attr.name = "uevent"; dev->uevent_attr.attr.mode = S_IWUSR; if (dev->driver) dev->uevent_attr.attr.owner = dev->driver->owner; dev->uevent_attr.store = store_uevent; device_create_file(dev, &dev->uevent_attr); if (MAJOR(dev->devt)) { struct device_attribute *attr; attr = kzalloc(sizeof(*attr), GFP_KERNEL); if (!attr) { error = -ENOMEM; goto PMError; } attr->attr.name = "dev"; attr->attr.mode = S_IRUGO; if (dev->driver) attr->attr.owner = dev->driver->owner; attr->show = show_dev; error = device_create_file(dev, attr); if (error) { kfree(attr); goto attrError; } dev->devt_attr = attr; } if (dev->class) { sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj, "subsystem"); sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj, dev->bus_id); sysfs_create_link(&dev->kobj, &dev->parent->kobj, "device"); class_name = make_class_name(dev->class->name, &dev->kobj); sysfs_create_link(&dev->parent->kobj, &dev->kobj, class_name); } if ((error = device_pm_add(dev))) goto PMError; if ((error = bus_add_device(dev))) goto BusError; kobject_uevent(&dev->kobj, KOBJ_ADD); bus_attach_device(dev); if (parent) klist_add_tail(&dev->knode_parent, &parent->klist_children); /* notify platform of device entry */ if (platform_notify) platform_notify(dev); Done: kfree(class_name); put_device(dev); return error; BusError: device_pm_remove(dev); PMError: if (dev->devt_attr) { device_remove_file(dev, dev->devt_attr); kfree(dev->devt_attr); } attrError: kobject_uevent(&dev->kobj, KOBJ_REMOVE); kobject_del(&dev->kobj); Error: 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. */ 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){ 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; char *class_name = NULL; if (parent) klist_del(&dev->knode_parent); if (dev->devt_attr) device_remove_file(dev, dev->devt_attr); if (dev->class) { sysfs_remove_link(&dev->kobj, "subsystem"); sysfs_remove_link(&dev->class->subsys.kset.kobj, dev->bus_id); class_name = make_class_name(dev->class->name, &dev->kobj); sysfs_remove_link(&dev->kobj, "device"); sysfs_remove_link(&dev->parent->kobj, class_name); kfree(class_name); } device_remove_file(dev, &dev->uevent_attr); /* Notify the platform of the removal, in case they * need to do anything... */ if (platform_notify_remove) platform_notify_remove(dev); bus_remove_device(dev); device_pm_remove(dev); kobject_uevent(&dev->kobj, KOBJ_REMOVE); kobject_del(&dev->kobj); if (parent) 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("DEV: Unregistering device. ID = '%s'\n", dev->bus_id); 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.Lines 1–500 of 644. Load more
/* * 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 * * This file is released under the GPLv2 * */ #include <linux/config.h> #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 <asm/semaphore.h> #include "base.h" #include "power/power.h" int (*platform_notify)(struct device * dev) = NULL; int (*platform_notify_remove)(struct device * dev) = NULL; /* * sysfs bindings for devices. */ /** * 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(struct device *dev) { return dev->driver ? dev->driver->name : (dev->bus ? dev->bus->name : ""); } EXPORT_SYMBOL_GPL(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); 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 { printk(KERN_ERR "Device '%s' does not have a release() function, " "it is broken and must be fixed.\n", dev->bus_id); WARN_ON(1); } } static struct kobj_type ktype_device = { .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 == &ktype_device) { struct device *dev = to_dev(kobj); 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, char **envp, int num_envp, char *buffer, int buffer_size) { struct device *dev = to_dev(kobj); int i = 0; int length = 0; int retval = 0; /* add the major/minor if present */ if (MAJOR(dev->devt)) { add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "MAJOR=%u", MAJOR(dev->devt)); add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "MINOR=%u", MINOR(dev->devt)); } /* add bus name of physical device */ if (dev->bus) add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "PHYSDEVBUS=%s", dev->bus->name); /* add driver name of physical device */ if (dev->driver) add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "PHYSDEVDRIVER=%s", dev->driver->name); /* terminate, set to next free slot, shrink available space */ envp[i] = NULL; envp = &envp[i]; num_envp -= i; buffer = &buffer[length]; buffer_size -= length; if (dev->bus && dev->bus->uevent) { /* have the bus specific function add its stuff */ retval = dev->bus->uevent(dev, envp, num_envp, buffer, buffer_size); if (retval) { pr_debug ("%s - uevent() returned %d\n", __FUNCTION__, 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 store_uevent(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { kobject_uevent(&dev->kobj, KOBJ_ADD); return count; } static ssize_t show_dev(struct device *dev, struct device_attribute *attr, char *buf) { return print_dev_t(buf, dev->devt); } /* * devices_subsys - structure to be registered with kobject core. */ decl_subsys(devices, &ktype_device, &device_uevent_ops); /** * 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 (get_device(dev)) { error = sysfs_create_file(&dev->kobj, &attr->attr); put_device(dev); } 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 (get_device(dev)) { sysfs_remove_file(&dev->kobj, &attr->attr); put_device(dev); } } 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, * including adding it to the device hierarchy. * It is the first half of device_register(), if called by * that, though it can also be called separately, so one * may use @dev's fields (e.g. the refcount). */ void device_initialize(struct device *dev) { kobj_set_kset_s(dev, devices_subsys); kobject_init(&dev->kobj); klist_init(&dev->klist_children, klist_children_get, klist_children_put); INIT_LIST_HEAD(&dev->dma_pools); INIT_LIST_HEAD(&dev->node); init_MUTEX(&dev->sem); device_init_wakeup(dev, 0); } /** * 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 it 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. */ int device_add(struct device *dev) { struct device *parent = NULL; char *class_name = NULL; int error = -EINVAL; dev = get_device(dev); if (!dev || !strlen(dev->bus_id)) goto Error; parent = get_device(dev->parent); pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id); /* first, register with generic layer. */ kobject_set_name(&dev->kobj, "%s", dev->bus_id); if (parent) dev->kobj.parent = &parent->kobj; if ((error = kobject_add(&dev->kobj))) goto Error; dev->uevent_attr.attr.name = "uevent"; dev->uevent_attr.attr.mode = S_IWUSR; if (dev->driver) dev->uevent_attr.attr.owner = dev->driver->owner; dev->uevent_attr.store = store_uevent; device_create_file(dev, &dev->uevent_attr); if (MAJOR(dev->devt)) { struct device_attribute *attr; attr = kzalloc(sizeof(*attr), GFP_KERNEL); if (!attr) { error = -ENOMEM; goto PMError; } attr->attr.name = "dev"; attr->attr.mode = S_IRUGO; if (dev->driver) attr->attr.owner = dev->driver->owner; attr->show = show_dev; error = device_create_file(dev, attr); if (error) { kfree(attr); goto attrError; } dev->devt_attr = attr; } if (dev->class) { sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj, "subsystem"); sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj, dev->bus_id); sysfs_create_link(&dev->kobj, &dev->parent->kobj, "device"); class_name = make_class_name(dev->class->name, &dev->kobj); sysfs_create_link(&dev->parent->kobj, &dev->kobj, class_name); } if ((error = device_pm_add(dev))) goto PMError; if ((error = bus_add_device(dev))) goto BusError; kobject_uevent(&dev->kobj, KOBJ_ADD); bus_attach_device(dev); if (parent) klist_add_tail(&dev->knode_parent, &parent->klist_children); /* notify platform of device entry */ if (platform_notify) platform_notify(dev); Done: kfree(class_name); put_device(dev); return error; BusError: device_pm_remove(dev); PMError: if (dev->devt_attr) { device_remove_file(dev, dev->devt_attr); kfree(dev->devt_attr); } attrError: kobject_uevent(&dev->kobj, KOBJ_REMOVE); kobject_del(&dev->kobj); Error: 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. */ 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) { 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; char *class_name = NULL; if (parent) klist_del(&dev->knode_parent); if (dev->devt_attr) device_remove_file(dev, dev->devt_attr); if (dev->class) { sysfs_remove_link(&dev->kobj, "subsystem"); sysfs_remove_link(&dev->class->subsys.kset.kobj, dev->bus_id); class_name = make_class_name(dev->class->name, &dev->kobj); sysfs_remove_link(&dev->kobj, "device"); sysfs_remove_link(&dev->parent->kobj, class_name); kfree(class_name); } device_remove_file(dev, &dev->uevent_attr); /* Notify the platform of the removal, in case they * need to do anything... */ if (platform_notify_remove) platform_notify_remove(dev); bus_remove_device(dev); device_pm_remove(dev); kobject_uevent(&dev->kobj, KOBJ_REMOVE); kobject_del(&dev->kobj); if (parent) 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("DEV: Unregistering device. ID = '%s'\n", dev->bus_id); 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.