11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * drivers/base/core.c - core driver model code (device registration, etc) 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Copyright (c) 2002-3 Patrick Mochel 51da177e4SLinus Torvalds * Copyright (c) 2002-3 Open Source Development Labs 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * This file is released under the GPLv2 81da177e4SLinus Torvalds * 91da177e4SLinus Torvalds */ 101da177e4SLinus Torvalds 111da177e4SLinus Torvalds #include <linux/config.h> 121da177e4SLinus Torvalds #include <linux/device.h> 131da177e4SLinus Torvalds #include <linux/err.h> 141da177e4SLinus Torvalds #include <linux/init.h> 151da177e4SLinus Torvalds #include <linux/module.h> 161da177e4SLinus Torvalds #include <linux/slab.h> 171da177e4SLinus Torvalds #include <linux/string.h> 181da177e4SLinus Torvalds 191da177e4SLinus Torvalds #include <asm/semaphore.h> 201da177e4SLinus Torvalds 211da177e4SLinus Torvalds #include "base.h" 221da177e4SLinus Torvalds #include "power/power.h" 231da177e4SLinus Torvalds 241da177e4SLinus Torvalds int (*platform_notify)(struct device * dev) = NULL; 251da177e4SLinus Torvalds int (*platform_notify_remove)(struct device * dev) = NULL; 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds /* 281da177e4SLinus Torvalds * sysfs bindings for devices. 291da177e4SLinus Torvalds */ 301da177e4SLinus Torvalds 311da177e4SLinus Torvalds #define to_dev(obj) container_of(obj, struct device, kobj) 321da177e4SLinus Torvalds #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) 331da177e4SLinus Torvalds 341da177e4SLinus Torvalds static ssize_t 351da177e4SLinus Torvalds dev_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) 361da177e4SLinus Torvalds { 371da177e4SLinus Torvalds struct device_attribute * dev_attr = to_dev_attr(attr); 381da177e4SLinus Torvalds struct device * dev = to_dev(kobj); 394a0c20bfSDmitry Torokhov ssize_t ret = -EIO; 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds if (dev_attr->show) 4254b6f35cSYani Ioannou ret = dev_attr->show(dev, dev_attr, buf); 431da177e4SLinus Torvalds return ret; 441da177e4SLinus Torvalds } 451da177e4SLinus Torvalds 461da177e4SLinus Torvalds static ssize_t 471da177e4SLinus Torvalds dev_attr_store(struct kobject * kobj, struct attribute * attr, 481da177e4SLinus Torvalds const char * buf, size_t count) 491da177e4SLinus Torvalds { 501da177e4SLinus Torvalds struct device_attribute * dev_attr = to_dev_attr(attr); 511da177e4SLinus Torvalds struct device * dev = to_dev(kobj); 524a0c20bfSDmitry Torokhov ssize_t ret = -EIO; 531da177e4SLinus Torvalds 541da177e4SLinus Torvalds if (dev_attr->store) 5554b6f35cSYani Ioannou ret = dev_attr->store(dev, dev_attr, buf, count); 561da177e4SLinus Torvalds return ret; 571da177e4SLinus Torvalds } 581da177e4SLinus Torvalds 591da177e4SLinus Torvalds static struct sysfs_ops dev_sysfs_ops = { 601da177e4SLinus Torvalds .show = dev_attr_show, 611da177e4SLinus Torvalds .store = dev_attr_store, 621da177e4SLinus Torvalds }; 631da177e4SLinus Torvalds 641da177e4SLinus Torvalds 651da177e4SLinus Torvalds /** 661da177e4SLinus Torvalds * device_release - free device structure. 671da177e4SLinus Torvalds * @kobj: device's kobject. 681da177e4SLinus Torvalds * 691da177e4SLinus Torvalds * This is called once the reference count for the object 701da177e4SLinus Torvalds * reaches 0. We forward the call to the device's release 711da177e4SLinus Torvalds * method, which should handle actually freeing the structure. 721da177e4SLinus Torvalds */ 731da177e4SLinus Torvalds static void device_release(struct kobject * kobj) 741da177e4SLinus Torvalds { 751da177e4SLinus Torvalds struct device * dev = to_dev(kobj); 761da177e4SLinus Torvalds 771da177e4SLinus Torvalds if (dev->release) 781da177e4SLinus Torvalds dev->release(dev); 791da177e4SLinus Torvalds else { 801da177e4SLinus Torvalds printk(KERN_ERR "Device '%s' does not have a release() function, " 811da177e4SLinus Torvalds "it is broken and must be fixed.\n", 821da177e4SLinus Torvalds dev->bus_id); 831da177e4SLinus Torvalds WARN_ON(1); 841da177e4SLinus Torvalds } 851da177e4SLinus Torvalds } 861da177e4SLinus Torvalds 871da177e4SLinus Torvalds static struct kobj_type ktype_device = { 881da177e4SLinus Torvalds .release = device_release, 891da177e4SLinus Torvalds .sysfs_ops = &dev_sysfs_ops, 901da177e4SLinus Torvalds }; 911da177e4SLinus Torvalds 921da177e4SLinus Torvalds 93312c004dSKay Sievers static int dev_uevent_filter(struct kset *kset, struct kobject *kobj) 941da177e4SLinus Torvalds { 951da177e4SLinus Torvalds struct kobj_type *ktype = get_ktype(kobj); 961da177e4SLinus Torvalds 971da177e4SLinus Torvalds if (ktype == &ktype_device) { 981da177e4SLinus Torvalds struct device *dev = to_dev(kobj); 991da177e4SLinus Torvalds if (dev->bus) 1001da177e4SLinus Torvalds return 1; 1011da177e4SLinus Torvalds } 1021da177e4SLinus Torvalds return 0; 1031da177e4SLinus Torvalds } 1041da177e4SLinus Torvalds 105312c004dSKay Sievers static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj) 1061da177e4SLinus Torvalds { 1071da177e4SLinus Torvalds struct device *dev = to_dev(kobj); 1081da177e4SLinus Torvalds 1091da177e4SLinus Torvalds return dev->bus->name; 1101da177e4SLinus Torvalds } 1111da177e4SLinus Torvalds 112312c004dSKay Sievers static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp, 1131da177e4SLinus Torvalds int num_envp, char *buffer, int buffer_size) 1141da177e4SLinus Torvalds { 1151da177e4SLinus Torvalds struct device *dev = to_dev(kobj); 1161da177e4SLinus Torvalds int i = 0; 1171da177e4SLinus Torvalds int length = 0; 1181da177e4SLinus Torvalds int retval = 0; 1191da177e4SLinus Torvalds 1201da177e4SLinus Torvalds /* add bus name of physical device */ 1211da177e4SLinus Torvalds if (dev->bus) 122312c004dSKay Sievers add_uevent_var(envp, num_envp, &i, 1231da177e4SLinus Torvalds buffer, buffer_size, &length, 1241da177e4SLinus Torvalds "PHYSDEVBUS=%s", dev->bus->name); 1251da177e4SLinus Torvalds 1261da177e4SLinus Torvalds /* add driver name of physical device */ 1271da177e4SLinus Torvalds if (dev->driver) 128312c004dSKay Sievers add_uevent_var(envp, num_envp, &i, 1291da177e4SLinus Torvalds buffer, buffer_size, &length, 1301da177e4SLinus Torvalds "PHYSDEVDRIVER=%s", dev->driver->name); 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds /* terminate, set to next free slot, shrink available space */ 1331da177e4SLinus Torvalds envp[i] = NULL; 1341da177e4SLinus Torvalds envp = &envp[i]; 1351da177e4SLinus Torvalds num_envp -= i; 1361da177e4SLinus Torvalds buffer = &buffer[length]; 1371da177e4SLinus Torvalds buffer_size -= length; 1381da177e4SLinus Torvalds 139312c004dSKay Sievers if (dev->bus && dev->bus->uevent) { 1401da177e4SLinus Torvalds /* have the bus specific function add its stuff */ 141312c004dSKay Sievers retval = dev->bus->uevent(dev, envp, num_envp, buffer, buffer_size); 1421da177e4SLinus Torvalds if (retval) { 143312c004dSKay Sievers pr_debug ("%s - uevent() returned %d\n", 1441da177e4SLinus Torvalds __FUNCTION__, retval); 1451da177e4SLinus Torvalds } 1461da177e4SLinus Torvalds } 1471da177e4SLinus Torvalds 1481da177e4SLinus Torvalds return retval; 1491da177e4SLinus Torvalds } 1501da177e4SLinus Torvalds 151312c004dSKay Sievers static struct kset_uevent_ops device_uevent_ops = { 152312c004dSKay Sievers .filter = dev_uevent_filter, 153312c004dSKay Sievers .name = dev_uevent_name, 154312c004dSKay Sievers .uevent = dev_uevent, 1551da177e4SLinus Torvalds }; 1561da177e4SLinus Torvalds 157a7fd6706SKay Sievers static ssize_t store_uevent(struct device *dev, struct device_attribute *attr, 158a7fd6706SKay Sievers const char *buf, size_t count) 159a7fd6706SKay Sievers { 160312c004dSKay Sievers kobject_uevent(&dev->kobj, KOBJ_ADD); 161a7fd6706SKay Sievers return count; 162a7fd6706SKay Sievers } 163a7fd6706SKay Sievers 164*0863afb3SMartin Waitz /* 165*0863afb3SMartin Waitz * devices_subsys - structure to be registered with kobject core. 1661da177e4SLinus Torvalds */ 1671da177e4SLinus Torvalds 168312c004dSKay Sievers decl_subsys(devices, &ktype_device, &device_uevent_ops); 1691da177e4SLinus Torvalds 1701da177e4SLinus Torvalds 1711da177e4SLinus Torvalds /** 1721da177e4SLinus Torvalds * device_create_file - create sysfs attribute file for device. 1731da177e4SLinus Torvalds * @dev: device. 1741da177e4SLinus Torvalds * @attr: device attribute descriptor. 1751da177e4SLinus Torvalds */ 1761da177e4SLinus Torvalds 1771da177e4SLinus Torvalds int device_create_file(struct device * dev, struct device_attribute * attr) 1781da177e4SLinus Torvalds { 1791da177e4SLinus Torvalds int error = 0; 1801da177e4SLinus Torvalds if (get_device(dev)) { 1811da177e4SLinus Torvalds error = sysfs_create_file(&dev->kobj, &attr->attr); 1821da177e4SLinus Torvalds put_device(dev); 1831da177e4SLinus Torvalds } 1841da177e4SLinus Torvalds return error; 1851da177e4SLinus Torvalds } 1861da177e4SLinus Torvalds 1871da177e4SLinus Torvalds /** 1881da177e4SLinus Torvalds * device_remove_file - remove sysfs attribute file. 1891da177e4SLinus Torvalds * @dev: device. 1901da177e4SLinus Torvalds * @attr: device attribute descriptor. 1911da177e4SLinus Torvalds */ 1921da177e4SLinus Torvalds 1931da177e4SLinus Torvalds void device_remove_file(struct device * dev, struct device_attribute * attr) 1941da177e4SLinus Torvalds { 1951da177e4SLinus Torvalds if (get_device(dev)) { 1961da177e4SLinus Torvalds sysfs_remove_file(&dev->kobj, &attr->attr); 1971da177e4SLinus Torvalds put_device(dev); 1981da177e4SLinus Torvalds } 1991da177e4SLinus Torvalds } 2001da177e4SLinus Torvalds 20134bb61f9SJames Bottomley static void klist_children_get(struct klist_node *n) 20234bb61f9SJames Bottomley { 20334bb61f9SJames Bottomley struct device *dev = container_of(n, struct device, knode_parent); 20434bb61f9SJames Bottomley 20534bb61f9SJames Bottomley get_device(dev); 20634bb61f9SJames Bottomley } 20734bb61f9SJames Bottomley 20834bb61f9SJames Bottomley static void klist_children_put(struct klist_node *n) 20934bb61f9SJames Bottomley { 21034bb61f9SJames Bottomley struct device *dev = container_of(n, struct device, knode_parent); 21134bb61f9SJames Bottomley 21234bb61f9SJames Bottomley put_device(dev); 21334bb61f9SJames Bottomley } 21434bb61f9SJames Bottomley 2151da177e4SLinus Torvalds 2161da177e4SLinus Torvalds /** 2171da177e4SLinus Torvalds * device_initialize - init device structure. 2181da177e4SLinus Torvalds * @dev: device. 2191da177e4SLinus Torvalds * 2201da177e4SLinus Torvalds * This prepares the device for use by other layers, 2211da177e4SLinus Torvalds * including adding it to the device hierarchy. 2221da177e4SLinus Torvalds * It is the first half of device_register(), if called by 2231da177e4SLinus Torvalds * that, though it can also be called separately, so one 2241da177e4SLinus Torvalds * may use @dev's fields (e.g. the refcount). 2251da177e4SLinus Torvalds */ 2261da177e4SLinus Torvalds 2271da177e4SLinus Torvalds void device_initialize(struct device *dev) 2281da177e4SLinus Torvalds { 2291da177e4SLinus Torvalds kobj_set_kset_s(dev, devices_subsys); 2301da177e4SLinus Torvalds kobject_init(&dev->kobj); 23134bb61f9SJames Bottomley klist_init(&dev->klist_children, klist_children_get, 23234bb61f9SJames Bottomley klist_children_put); 2331da177e4SLinus Torvalds INIT_LIST_HEAD(&dev->dma_pools); 234af70316aSmochel@digitalimplant.org init_MUTEX(&dev->sem); 2350ac85241SDavid Brownell device_init_wakeup(dev, 0); 2361da177e4SLinus Torvalds } 2371da177e4SLinus Torvalds 2381da177e4SLinus Torvalds /** 2391da177e4SLinus Torvalds * device_add - add device to device hierarchy. 2401da177e4SLinus Torvalds * @dev: device. 2411da177e4SLinus Torvalds * 2421da177e4SLinus Torvalds * This is part 2 of device_register(), though may be called 2431da177e4SLinus Torvalds * separately _iff_ device_initialize() has been called separately. 2441da177e4SLinus Torvalds * 2451da177e4SLinus Torvalds * This adds it to the kobject hierarchy via kobject_add(), adds it 2461da177e4SLinus Torvalds * to the global and sibling lists for the device, then 2471da177e4SLinus Torvalds * adds it to the other relevant subsystems of the driver model. 2481da177e4SLinus Torvalds */ 2491da177e4SLinus Torvalds int device_add(struct device *dev) 2501da177e4SLinus Torvalds { 2511da177e4SLinus Torvalds struct device *parent = NULL; 2521da177e4SLinus Torvalds int error = -EINVAL; 2531da177e4SLinus Torvalds 2541da177e4SLinus Torvalds dev = get_device(dev); 2551da177e4SLinus Torvalds if (!dev || !strlen(dev->bus_id)) 2561da177e4SLinus Torvalds goto Error; 2571da177e4SLinus Torvalds 2581da177e4SLinus Torvalds parent = get_device(dev->parent); 2591da177e4SLinus Torvalds 2601da177e4SLinus Torvalds pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id); 2611da177e4SLinus Torvalds 2621da177e4SLinus Torvalds /* first, register with generic layer. */ 2631da177e4SLinus Torvalds kobject_set_name(&dev->kobj, "%s", dev->bus_id); 2641da177e4SLinus Torvalds if (parent) 2651da177e4SLinus Torvalds dev->kobj.parent = &parent->kobj; 2661da177e4SLinus Torvalds 2671da177e4SLinus Torvalds if ((error = kobject_add(&dev->kobj))) 2681da177e4SLinus Torvalds goto Error; 269a7fd6706SKay Sievers 270a7fd6706SKay Sievers dev->uevent_attr.attr.name = "uevent"; 271a7fd6706SKay Sievers dev->uevent_attr.attr.mode = S_IWUSR; 272a7fd6706SKay Sievers if (dev->driver) 273a7fd6706SKay Sievers dev->uevent_attr.attr.owner = dev->driver->owner; 274a7fd6706SKay Sievers dev->uevent_attr.store = store_uevent; 275a7fd6706SKay Sievers device_create_file(dev, &dev->uevent_attr); 276a7fd6706SKay Sievers 277312c004dSKay Sievers kobject_uevent(&dev->kobj, KOBJ_ADD); 2781da177e4SLinus Torvalds if ((error = device_pm_add(dev))) 2791da177e4SLinus Torvalds goto PMError; 2801da177e4SLinus Torvalds if ((error = bus_add_device(dev))) 2811da177e4SLinus Torvalds goto BusError; 2821da177e4SLinus Torvalds if (parent) 283d856f1e3SJames Bottomley klist_add_tail(&dev->knode_parent, &parent->klist_children); 2841da177e4SLinus Torvalds 2851da177e4SLinus Torvalds /* notify platform of device entry */ 2861da177e4SLinus Torvalds if (platform_notify) 2871da177e4SLinus Torvalds platform_notify(dev); 2881da177e4SLinus Torvalds Done: 2891da177e4SLinus Torvalds put_device(dev); 2901da177e4SLinus Torvalds return error; 2911da177e4SLinus Torvalds BusError: 2921da177e4SLinus Torvalds device_pm_remove(dev); 2931da177e4SLinus Torvalds PMError: 294312c004dSKay Sievers kobject_uevent(&dev->kobj, KOBJ_REMOVE); 2951da177e4SLinus Torvalds kobject_del(&dev->kobj); 2961da177e4SLinus Torvalds Error: 2971da177e4SLinus Torvalds if (parent) 2981da177e4SLinus Torvalds put_device(parent); 2991da177e4SLinus Torvalds goto Done; 3001da177e4SLinus Torvalds } 3011da177e4SLinus Torvalds 3021da177e4SLinus Torvalds 3031da177e4SLinus Torvalds /** 3041da177e4SLinus Torvalds * device_register - register a device with the system. 3051da177e4SLinus Torvalds * @dev: pointer to the device structure 3061da177e4SLinus Torvalds * 3071da177e4SLinus Torvalds * This happens in two clean steps - initialize the device 3081da177e4SLinus Torvalds * and add it to the system. The two steps can be called 3091da177e4SLinus Torvalds * separately, but this is the easiest and most common. 3101da177e4SLinus Torvalds * I.e. you should only call the two helpers separately if 3111da177e4SLinus Torvalds * have a clearly defined need to use and refcount the device 3121da177e4SLinus Torvalds * before it is added to the hierarchy. 3131da177e4SLinus Torvalds */ 3141da177e4SLinus Torvalds 3151da177e4SLinus Torvalds int device_register(struct device *dev) 3161da177e4SLinus Torvalds { 3171da177e4SLinus Torvalds device_initialize(dev); 3181da177e4SLinus Torvalds return device_add(dev); 3191da177e4SLinus Torvalds } 3201da177e4SLinus Torvalds 3211da177e4SLinus Torvalds 3221da177e4SLinus Torvalds /** 3231da177e4SLinus Torvalds * get_device - increment reference count for device. 3241da177e4SLinus Torvalds * @dev: device. 3251da177e4SLinus Torvalds * 3261da177e4SLinus Torvalds * This simply forwards the call to kobject_get(), though 3271da177e4SLinus Torvalds * we do take care to provide for the case that we get a NULL 3281da177e4SLinus Torvalds * pointer passed in. 3291da177e4SLinus Torvalds */ 3301da177e4SLinus Torvalds 3311da177e4SLinus Torvalds struct device * get_device(struct device * dev) 3321da177e4SLinus Torvalds { 3331da177e4SLinus Torvalds return dev ? to_dev(kobject_get(&dev->kobj)) : NULL; 3341da177e4SLinus Torvalds } 3351da177e4SLinus Torvalds 3361da177e4SLinus Torvalds 3371da177e4SLinus Torvalds /** 3381da177e4SLinus Torvalds * put_device - decrement reference count. 3391da177e4SLinus Torvalds * @dev: device in question. 3401da177e4SLinus Torvalds */ 3411da177e4SLinus Torvalds void put_device(struct device * dev) 3421da177e4SLinus Torvalds { 3431da177e4SLinus Torvalds if (dev) 3441da177e4SLinus Torvalds kobject_put(&dev->kobj); 3451da177e4SLinus Torvalds } 3461da177e4SLinus Torvalds 3471da177e4SLinus Torvalds 3481da177e4SLinus Torvalds /** 3491da177e4SLinus Torvalds * device_del - delete device from system. 3501da177e4SLinus Torvalds * @dev: device. 3511da177e4SLinus Torvalds * 3521da177e4SLinus Torvalds * This is the first part of the device unregistration 3531da177e4SLinus Torvalds * sequence. This removes the device from the lists we control 3541da177e4SLinus Torvalds * from here, has it removed from the other driver model 3551da177e4SLinus Torvalds * subsystems it was added to in device_add(), and removes it 3561da177e4SLinus Torvalds * from the kobject hierarchy. 3571da177e4SLinus Torvalds * 3581da177e4SLinus Torvalds * NOTE: this should be called manually _iff_ device_add() was 3591da177e4SLinus Torvalds * also called manually. 3601da177e4SLinus Torvalds */ 3611da177e4SLinus Torvalds 3621da177e4SLinus Torvalds void device_del(struct device * dev) 3631da177e4SLinus Torvalds { 3641da177e4SLinus Torvalds struct device * parent = dev->parent; 3651da177e4SLinus Torvalds 3661da177e4SLinus Torvalds if (parent) 367d62c0f9fSPatrick Mochel klist_del(&dev->knode_parent); 368a7fd6706SKay Sievers device_remove_file(dev, &dev->uevent_attr); 3691da177e4SLinus Torvalds 3701da177e4SLinus Torvalds /* Notify the platform of the removal, in case they 3711da177e4SLinus Torvalds * need to do anything... 3721da177e4SLinus Torvalds */ 3731da177e4SLinus Torvalds if (platform_notify_remove) 3741da177e4SLinus Torvalds platform_notify_remove(dev); 3751da177e4SLinus Torvalds bus_remove_device(dev); 3761da177e4SLinus Torvalds device_pm_remove(dev); 377312c004dSKay Sievers kobject_uevent(&dev->kobj, KOBJ_REMOVE); 3781da177e4SLinus Torvalds kobject_del(&dev->kobj); 3791da177e4SLinus Torvalds if (parent) 3801da177e4SLinus Torvalds put_device(parent); 3811da177e4SLinus Torvalds } 3821da177e4SLinus Torvalds 3831da177e4SLinus Torvalds /** 3841da177e4SLinus Torvalds * device_unregister - unregister device from system. 3851da177e4SLinus Torvalds * @dev: device going away. 3861da177e4SLinus Torvalds * 3871da177e4SLinus Torvalds * We do this in two parts, like we do device_register(). First, 3881da177e4SLinus Torvalds * we remove it from all the subsystems with device_del(), then 3891da177e4SLinus Torvalds * we decrement the reference count via put_device(). If that 3901da177e4SLinus Torvalds * is the final reference count, the device will be cleaned up 3911da177e4SLinus Torvalds * via device_release() above. Otherwise, the structure will 3921da177e4SLinus Torvalds * stick around until the final reference to the device is dropped. 3931da177e4SLinus Torvalds */ 3941da177e4SLinus Torvalds void device_unregister(struct device * dev) 3951da177e4SLinus Torvalds { 3961da177e4SLinus Torvalds pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id); 3971da177e4SLinus Torvalds device_del(dev); 3981da177e4SLinus Torvalds put_device(dev); 3991da177e4SLinus Torvalds } 4001da177e4SLinus Torvalds 4011da177e4SLinus Torvalds 40236239577Smochel@digitalimplant.org static struct device * next_device(struct klist_iter * i) 40336239577Smochel@digitalimplant.org { 40436239577Smochel@digitalimplant.org struct klist_node * n = klist_next(i); 40536239577Smochel@digitalimplant.org return n ? container_of(n, struct device, knode_parent) : NULL; 40636239577Smochel@digitalimplant.org } 40736239577Smochel@digitalimplant.org 4081da177e4SLinus Torvalds /** 4091da177e4SLinus Torvalds * device_for_each_child - device child iterator. 410c41455fbSRandy Dunlap * @parent: parent struct device. 4111da177e4SLinus Torvalds * @data: data for the callback. 4121da177e4SLinus Torvalds * @fn: function to be called for each device. 4131da177e4SLinus Torvalds * 414c41455fbSRandy Dunlap * Iterate over @parent's child devices, and call @fn for each, 4151da177e4SLinus Torvalds * passing it @data. 4161da177e4SLinus Torvalds * 4171da177e4SLinus Torvalds * We check the return of @fn each time. If it returns anything 4181da177e4SLinus Torvalds * other than 0, we break out and return that value. 4191da177e4SLinus Torvalds */ 42036239577Smochel@digitalimplant.org int device_for_each_child(struct device * parent, void * data, 4211da177e4SLinus Torvalds int (*fn)(struct device *, void *)) 4221da177e4SLinus Torvalds { 42336239577Smochel@digitalimplant.org struct klist_iter i; 4241da177e4SLinus Torvalds struct device * child; 4251da177e4SLinus Torvalds int error = 0; 4261da177e4SLinus Torvalds 42736239577Smochel@digitalimplant.org klist_iter_init(&parent->klist_children, &i); 42836239577Smochel@digitalimplant.org while ((child = next_device(&i)) && !error) 42936239577Smochel@digitalimplant.org error = fn(child, data); 43036239577Smochel@digitalimplant.org klist_iter_exit(&i); 4311da177e4SLinus Torvalds return error; 4321da177e4SLinus Torvalds } 4331da177e4SLinus Torvalds 4341da177e4SLinus Torvalds int __init devices_init(void) 4351da177e4SLinus Torvalds { 4361da177e4SLinus Torvalds return subsystem_register(&devices_subsys); 4371da177e4SLinus Torvalds } 4381da177e4SLinus Torvalds 4391da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_for_each_child); 4401da177e4SLinus Torvalds 4411da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_initialize); 4421da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_add); 4431da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_register); 4441da177e4SLinus Torvalds 4451da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_del); 4461da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_unregister); 4471da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(get_device); 4481da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(put_device); 4491da177e4SLinus Torvalds 4501da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_create_file); 4511da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_remove_file); 452