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> 1823681e47SGreg Kroah-Hartman #include <linux/kdev_t.h> 191da177e4SLinus Torvalds 201da177e4SLinus Torvalds #include <asm/semaphore.h> 211da177e4SLinus Torvalds 221da177e4SLinus Torvalds #include "base.h" 231da177e4SLinus Torvalds #include "power/power.h" 241da177e4SLinus Torvalds 251da177e4SLinus Torvalds int (*platform_notify)(struct device * dev) = NULL; 261da177e4SLinus Torvalds int (*platform_notify_remove)(struct device * dev) = NULL; 271da177e4SLinus Torvalds 281da177e4SLinus Torvalds /* 291da177e4SLinus Torvalds * sysfs bindings for devices. 301da177e4SLinus Torvalds */ 311da177e4SLinus Torvalds 321da177e4SLinus Torvalds #define to_dev(obj) container_of(obj, struct device, kobj) 331da177e4SLinus Torvalds #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds static ssize_t 361da177e4SLinus Torvalds dev_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) 371da177e4SLinus Torvalds { 381da177e4SLinus Torvalds struct device_attribute * dev_attr = to_dev_attr(attr); 391da177e4SLinus Torvalds struct device * dev = to_dev(kobj); 404a0c20bfSDmitry Torokhov ssize_t ret = -EIO; 411da177e4SLinus Torvalds 421da177e4SLinus Torvalds if (dev_attr->show) 4354b6f35cSYani Ioannou ret = dev_attr->show(dev, dev_attr, buf); 441da177e4SLinus Torvalds return ret; 451da177e4SLinus Torvalds } 461da177e4SLinus Torvalds 471da177e4SLinus Torvalds static ssize_t 481da177e4SLinus Torvalds dev_attr_store(struct kobject * kobj, struct attribute * attr, 491da177e4SLinus Torvalds const char * buf, size_t count) 501da177e4SLinus Torvalds { 511da177e4SLinus Torvalds struct device_attribute * dev_attr = to_dev_attr(attr); 521da177e4SLinus Torvalds struct device * dev = to_dev(kobj); 534a0c20bfSDmitry Torokhov ssize_t ret = -EIO; 541da177e4SLinus Torvalds 551da177e4SLinus Torvalds if (dev_attr->store) 5654b6f35cSYani Ioannou ret = dev_attr->store(dev, dev_attr, buf, count); 571da177e4SLinus Torvalds return ret; 581da177e4SLinus Torvalds } 591da177e4SLinus Torvalds 601da177e4SLinus Torvalds static struct sysfs_ops dev_sysfs_ops = { 611da177e4SLinus Torvalds .show = dev_attr_show, 621da177e4SLinus Torvalds .store = dev_attr_store, 631da177e4SLinus Torvalds }; 641da177e4SLinus Torvalds 651da177e4SLinus Torvalds 661da177e4SLinus Torvalds /** 671da177e4SLinus Torvalds * device_release - free device structure. 681da177e4SLinus Torvalds * @kobj: device's kobject. 691da177e4SLinus Torvalds * 701da177e4SLinus Torvalds * This is called once the reference count for the object 711da177e4SLinus Torvalds * reaches 0. We forward the call to the device's release 721da177e4SLinus Torvalds * method, which should handle actually freeing the structure. 731da177e4SLinus Torvalds */ 741da177e4SLinus Torvalds static void device_release(struct kobject * kobj) 751da177e4SLinus Torvalds { 761da177e4SLinus Torvalds struct device * dev = to_dev(kobj); 771da177e4SLinus Torvalds 781da177e4SLinus Torvalds if (dev->release) 791da177e4SLinus Torvalds dev->release(dev); 801da177e4SLinus Torvalds else { 811da177e4SLinus Torvalds printk(KERN_ERR "Device '%s' does not have a release() function, " 821da177e4SLinus Torvalds "it is broken and must be fixed.\n", 831da177e4SLinus Torvalds dev->bus_id); 841da177e4SLinus Torvalds WARN_ON(1); 851da177e4SLinus Torvalds } 861da177e4SLinus Torvalds } 871da177e4SLinus Torvalds 881da177e4SLinus Torvalds static struct kobj_type ktype_device = { 891da177e4SLinus Torvalds .release = device_release, 901da177e4SLinus Torvalds .sysfs_ops = &dev_sysfs_ops, 911da177e4SLinus Torvalds }; 921da177e4SLinus Torvalds 931da177e4SLinus Torvalds 94312c004dSKay Sievers static int dev_uevent_filter(struct kset *kset, struct kobject *kobj) 951da177e4SLinus Torvalds { 961da177e4SLinus Torvalds struct kobj_type *ktype = get_ktype(kobj); 971da177e4SLinus Torvalds 981da177e4SLinus Torvalds if (ktype == &ktype_device) { 991da177e4SLinus Torvalds struct device *dev = to_dev(kobj); 1001da177e4SLinus Torvalds if (dev->bus) 1011da177e4SLinus Torvalds return 1; 10223681e47SGreg Kroah-Hartman if (dev->class) 10323681e47SGreg Kroah-Hartman return 1; 1041da177e4SLinus Torvalds } 1051da177e4SLinus Torvalds return 0; 1061da177e4SLinus Torvalds } 1071da177e4SLinus Torvalds 108312c004dSKay Sievers static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj) 1091da177e4SLinus Torvalds { 1101da177e4SLinus Torvalds struct device *dev = to_dev(kobj); 1111da177e4SLinus Torvalds 11223681e47SGreg Kroah-Hartman if (dev->bus) 1131da177e4SLinus Torvalds return dev->bus->name; 11423681e47SGreg Kroah-Hartman if (dev->class) 11523681e47SGreg Kroah-Hartman return dev->class->name; 11623681e47SGreg Kroah-Hartman return NULL; 1171da177e4SLinus Torvalds } 1181da177e4SLinus Torvalds 119312c004dSKay Sievers static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp, 1201da177e4SLinus Torvalds int num_envp, char *buffer, int buffer_size) 1211da177e4SLinus Torvalds { 1221da177e4SLinus Torvalds struct device *dev = to_dev(kobj); 1231da177e4SLinus Torvalds int i = 0; 1241da177e4SLinus Torvalds int length = 0; 1251da177e4SLinus Torvalds int retval = 0; 1261da177e4SLinus Torvalds 12723681e47SGreg Kroah-Hartman /* add the major/minor if present */ 12823681e47SGreg Kroah-Hartman if (MAJOR(dev->devt)) { 12923681e47SGreg Kroah-Hartman add_uevent_var(envp, num_envp, &i, 13023681e47SGreg Kroah-Hartman buffer, buffer_size, &length, 13123681e47SGreg Kroah-Hartman "MAJOR=%u", MAJOR(dev->devt)); 13223681e47SGreg Kroah-Hartman add_uevent_var(envp, num_envp, &i, 13323681e47SGreg Kroah-Hartman buffer, buffer_size, &length, 13423681e47SGreg Kroah-Hartman "MINOR=%u", MINOR(dev->devt)); 13523681e47SGreg Kroah-Hartman } 13623681e47SGreg Kroah-Hartman 1371da177e4SLinus Torvalds /* add bus name of physical device */ 1381da177e4SLinus Torvalds if (dev->bus) 139312c004dSKay Sievers add_uevent_var(envp, num_envp, &i, 1401da177e4SLinus Torvalds buffer, buffer_size, &length, 1411da177e4SLinus Torvalds "PHYSDEVBUS=%s", dev->bus->name); 1421da177e4SLinus Torvalds 1431da177e4SLinus Torvalds /* add driver name of physical device */ 1441da177e4SLinus Torvalds if (dev->driver) 145312c004dSKay Sievers add_uevent_var(envp, num_envp, &i, 1461da177e4SLinus Torvalds buffer, buffer_size, &length, 1471da177e4SLinus Torvalds "PHYSDEVDRIVER=%s", dev->driver->name); 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvalds /* terminate, set to next free slot, shrink available space */ 1501da177e4SLinus Torvalds envp[i] = NULL; 1511da177e4SLinus Torvalds envp = &envp[i]; 1521da177e4SLinus Torvalds num_envp -= i; 1531da177e4SLinus Torvalds buffer = &buffer[length]; 1541da177e4SLinus Torvalds buffer_size -= length; 1551da177e4SLinus Torvalds 156312c004dSKay Sievers if (dev->bus && dev->bus->uevent) { 1571da177e4SLinus Torvalds /* have the bus specific function add its stuff */ 158312c004dSKay Sievers retval = dev->bus->uevent(dev, envp, num_envp, buffer, buffer_size); 1591da177e4SLinus Torvalds if (retval) { 160312c004dSKay Sievers pr_debug ("%s - uevent() returned %d\n", 1611da177e4SLinus Torvalds __FUNCTION__, retval); 1621da177e4SLinus Torvalds } 1631da177e4SLinus Torvalds } 1641da177e4SLinus Torvalds 1651da177e4SLinus Torvalds return retval; 1661da177e4SLinus Torvalds } 1671da177e4SLinus Torvalds 168312c004dSKay Sievers static struct kset_uevent_ops device_uevent_ops = { 169312c004dSKay Sievers .filter = dev_uevent_filter, 170312c004dSKay Sievers .name = dev_uevent_name, 171312c004dSKay Sievers .uevent = dev_uevent, 1721da177e4SLinus Torvalds }; 1731da177e4SLinus Torvalds 174a7fd6706SKay Sievers static ssize_t store_uevent(struct device *dev, struct device_attribute *attr, 175a7fd6706SKay Sievers const char *buf, size_t count) 176a7fd6706SKay Sievers { 177312c004dSKay Sievers kobject_uevent(&dev->kobj, KOBJ_ADD); 178a7fd6706SKay Sievers return count; 179a7fd6706SKay Sievers } 180a7fd6706SKay Sievers 18123681e47SGreg Kroah-Hartman static ssize_t show_dev(struct device *dev, struct device_attribute *attr, 18223681e47SGreg Kroah-Hartman char *buf) 18323681e47SGreg Kroah-Hartman { 18423681e47SGreg Kroah-Hartman return print_dev_t(buf, dev->devt); 18523681e47SGreg Kroah-Hartman } 18623681e47SGreg Kroah-Hartman 1870863afb3SMartin Waitz /* 1880863afb3SMartin Waitz * devices_subsys - structure to be registered with kobject core. 1891da177e4SLinus Torvalds */ 1901da177e4SLinus Torvalds 191312c004dSKay Sievers decl_subsys(devices, &ktype_device, &device_uevent_ops); 1921da177e4SLinus Torvalds 1931da177e4SLinus Torvalds 1941da177e4SLinus Torvalds /** 1951da177e4SLinus Torvalds * device_create_file - create sysfs attribute file for device. 1961da177e4SLinus Torvalds * @dev: device. 1971da177e4SLinus Torvalds * @attr: device attribute descriptor. 1981da177e4SLinus Torvalds */ 1991da177e4SLinus Torvalds 2001da177e4SLinus Torvalds int device_create_file(struct device * dev, struct device_attribute * attr) 2011da177e4SLinus Torvalds { 2021da177e4SLinus Torvalds int error = 0; 2031da177e4SLinus Torvalds if (get_device(dev)) { 2041da177e4SLinus Torvalds error = sysfs_create_file(&dev->kobj, &attr->attr); 2051da177e4SLinus Torvalds put_device(dev); 2061da177e4SLinus Torvalds } 2071da177e4SLinus Torvalds return error; 2081da177e4SLinus Torvalds } 2091da177e4SLinus Torvalds 2101da177e4SLinus Torvalds /** 2111da177e4SLinus Torvalds * device_remove_file - remove sysfs attribute file. 2121da177e4SLinus Torvalds * @dev: device. 2131da177e4SLinus Torvalds * @attr: device attribute descriptor. 2141da177e4SLinus Torvalds */ 2151da177e4SLinus Torvalds 2161da177e4SLinus Torvalds void device_remove_file(struct device * dev, struct device_attribute * attr) 2171da177e4SLinus Torvalds { 2181da177e4SLinus Torvalds if (get_device(dev)) { 2191da177e4SLinus Torvalds sysfs_remove_file(&dev->kobj, &attr->attr); 2201da177e4SLinus Torvalds put_device(dev); 2211da177e4SLinus Torvalds } 2221da177e4SLinus Torvalds } 2231da177e4SLinus Torvalds 22434bb61f9SJames Bottomley static void klist_children_get(struct klist_node *n) 22534bb61f9SJames Bottomley { 22634bb61f9SJames Bottomley struct device *dev = container_of(n, struct device, knode_parent); 22734bb61f9SJames Bottomley 22834bb61f9SJames Bottomley get_device(dev); 22934bb61f9SJames Bottomley } 23034bb61f9SJames Bottomley 23134bb61f9SJames Bottomley static void klist_children_put(struct klist_node *n) 23234bb61f9SJames Bottomley { 23334bb61f9SJames Bottomley struct device *dev = container_of(n, struct device, knode_parent); 23434bb61f9SJames Bottomley 23534bb61f9SJames Bottomley put_device(dev); 23634bb61f9SJames Bottomley } 23734bb61f9SJames Bottomley 2381da177e4SLinus Torvalds 2391da177e4SLinus Torvalds /** 2401da177e4SLinus Torvalds * device_initialize - init device structure. 2411da177e4SLinus Torvalds * @dev: device. 2421da177e4SLinus Torvalds * 2431da177e4SLinus Torvalds * This prepares the device for use by other layers, 2441da177e4SLinus Torvalds * including adding it to the device hierarchy. 2451da177e4SLinus Torvalds * It is the first half of device_register(), if called by 2461da177e4SLinus Torvalds * that, though it can also be called separately, so one 2471da177e4SLinus Torvalds * may use @dev's fields (e.g. the refcount). 2481da177e4SLinus Torvalds */ 2491da177e4SLinus Torvalds 2501da177e4SLinus Torvalds void device_initialize(struct device *dev) 2511da177e4SLinus Torvalds { 2521da177e4SLinus Torvalds kobj_set_kset_s(dev, devices_subsys); 2531da177e4SLinus Torvalds kobject_init(&dev->kobj); 25434bb61f9SJames Bottomley klist_init(&dev->klist_children, klist_children_get, 25534bb61f9SJames Bottomley klist_children_put); 2561da177e4SLinus Torvalds INIT_LIST_HEAD(&dev->dma_pools); 25723681e47SGreg Kroah-Hartman INIT_LIST_HEAD(&dev->node); 258af70316aSmochel@digitalimplant.org init_MUTEX(&dev->sem); 2590ac85241SDavid Brownell device_init_wakeup(dev, 0); 2601da177e4SLinus Torvalds } 2611da177e4SLinus Torvalds 2621da177e4SLinus Torvalds /** 2631da177e4SLinus Torvalds * device_add - add device to device hierarchy. 2641da177e4SLinus Torvalds * @dev: device. 2651da177e4SLinus Torvalds * 2661da177e4SLinus Torvalds * This is part 2 of device_register(), though may be called 2671da177e4SLinus Torvalds * separately _iff_ device_initialize() has been called separately. 2681da177e4SLinus Torvalds * 2691da177e4SLinus Torvalds * This adds it to the kobject hierarchy via kobject_add(), adds it 2701da177e4SLinus Torvalds * to the global and sibling lists for the device, then 2711da177e4SLinus Torvalds * adds it to the other relevant subsystems of the driver model. 2721da177e4SLinus Torvalds */ 2731da177e4SLinus Torvalds int device_add(struct device *dev) 2741da177e4SLinus Torvalds { 2751da177e4SLinus Torvalds struct device *parent = NULL; 2761da177e4SLinus Torvalds int error = -EINVAL; 2771da177e4SLinus Torvalds 2781da177e4SLinus Torvalds dev = get_device(dev); 2791da177e4SLinus Torvalds if (!dev || !strlen(dev->bus_id)) 2801da177e4SLinus Torvalds goto Error; 2811da177e4SLinus Torvalds 2821da177e4SLinus Torvalds parent = get_device(dev->parent); 2831da177e4SLinus Torvalds 2841da177e4SLinus Torvalds pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id); 2851da177e4SLinus Torvalds 2861da177e4SLinus Torvalds /* first, register with generic layer. */ 2871da177e4SLinus Torvalds kobject_set_name(&dev->kobj, "%s", dev->bus_id); 2881da177e4SLinus Torvalds if (parent) 2891da177e4SLinus Torvalds dev->kobj.parent = &parent->kobj; 2901da177e4SLinus Torvalds 2911da177e4SLinus Torvalds if ((error = kobject_add(&dev->kobj))) 2921da177e4SLinus Torvalds goto Error; 293a7fd6706SKay Sievers 294a7fd6706SKay Sievers dev->uevent_attr.attr.name = "uevent"; 295a7fd6706SKay Sievers dev->uevent_attr.attr.mode = S_IWUSR; 296a7fd6706SKay Sievers if (dev->driver) 297a7fd6706SKay Sievers dev->uevent_attr.attr.owner = dev->driver->owner; 298a7fd6706SKay Sievers dev->uevent_attr.store = store_uevent; 299a7fd6706SKay Sievers device_create_file(dev, &dev->uevent_attr); 300a7fd6706SKay Sievers 30123681e47SGreg Kroah-Hartman if (MAJOR(dev->devt)) { 30223681e47SGreg Kroah-Hartman struct device_attribute *attr; 30323681e47SGreg Kroah-Hartman attr = kzalloc(sizeof(*attr), GFP_KERNEL); 30423681e47SGreg Kroah-Hartman if (!attr) { 30523681e47SGreg Kroah-Hartman error = -ENOMEM; 30623681e47SGreg Kroah-Hartman goto PMError; 30723681e47SGreg Kroah-Hartman } 30823681e47SGreg Kroah-Hartman attr->attr.name = "dev"; 30923681e47SGreg Kroah-Hartman attr->attr.mode = S_IRUGO; 31023681e47SGreg Kroah-Hartman if (dev->driver) 31123681e47SGreg Kroah-Hartman attr->attr.owner = dev->driver->owner; 31223681e47SGreg Kroah-Hartman attr->show = show_dev; 31323681e47SGreg Kroah-Hartman error = device_create_file(dev, attr); 31423681e47SGreg Kroah-Hartman if (error) { 31523681e47SGreg Kroah-Hartman kfree(attr); 31623681e47SGreg Kroah-Hartman goto attrError; 31723681e47SGreg Kroah-Hartman } 31823681e47SGreg Kroah-Hartman 31923681e47SGreg Kroah-Hartman dev->devt_attr = attr; 32023681e47SGreg Kroah-Hartman } 32123681e47SGreg Kroah-Hartman 32223681e47SGreg Kroah-Hartman if (dev->class) 32323681e47SGreg Kroah-Hartman sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj, 32423681e47SGreg Kroah-Hartman dev->bus_id); 32523681e47SGreg Kroah-Hartman 3261da177e4SLinus Torvalds if ((error = device_pm_add(dev))) 3271da177e4SLinus Torvalds goto PMError; 3281da177e4SLinus Torvalds if ((error = bus_add_device(dev))) 3291da177e4SLinus Torvalds goto BusError; 33053877d06SKay Sievers kobject_uevent(&dev->kobj, KOBJ_ADD); 33153877d06SKay Sievers bus_attach_device(dev); 3321da177e4SLinus Torvalds if (parent) 333d856f1e3SJames Bottomley klist_add_tail(&dev->knode_parent, &parent->klist_children); 3341da177e4SLinus Torvalds 3351da177e4SLinus Torvalds /* notify platform of device entry */ 3361da177e4SLinus Torvalds if (platform_notify) 3371da177e4SLinus Torvalds platform_notify(dev); 3381da177e4SLinus Torvalds Done: 3391da177e4SLinus Torvalds put_device(dev); 3401da177e4SLinus Torvalds return error; 3411da177e4SLinus Torvalds BusError: 3421da177e4SLinus Torvalds device_pm_remove(dev); 3431da177e4SLinus Torvalds PMError: 34423681e47SGreg Kroah-Hartman if (dev->devt_attr) { 34523681e47SGreg Kroah-Hartman device_remove_file(dev, dev->devt_attr); 34623681e47SGreg Kroah-Hartman kfree(dev->devt_attr); 34723681e47SGreg Kroah-Hartman } 34823681e47SGreg Kroah-Hartman attrError: 349312c004dSKay Sievers kobject_uevent(&dev->kobj, KOBJ_REMOVE); 3501da177e4SLinus Torvalds kobject_del(&dev->kobj); 3511da177e4SLinus Torvalds Error: 3521da177e4SLinus Torvalds if (parent) 3531da177e4SLinus Torvalds put_device(parent); 3541da177e4SLinus Torvalds goto Done; 3551da177e4SLinus Torvalds } 3561da177e4SLinus Torvalds 3571da177e4SLinus Torvalds 3581da177e4SLinus Torvalds /** 3591da177e4SLinus Torvalds * device_register - register a device with the system. 3601da177e4SLinus Torvalds * @dev: pointer to the device structure 3611da177e4SLinus Torvalds * 3621da177e4SLinus Torvalds * This happens in two clean steps - initialize the device 3631da177e4SLinus Torvalds * and add it to the system. The two steps can be called 3641da177e4SLinus Torvalds * separately, but this is the easiest and most common. 3651da177e4SLinus Torvalds * I.e. you should only call the two helpers separately if 3661da177e4SLinus Torvalds * have a clearly defined need to use and refcount the device 3671da177e4SLinus Torvalds * before it is added to the hierarchy. 3681da177e4SLinus Torvalds */ 3691da177e4SLinus Torvalds 3701da177e4SLinus Torvalds int device_register(struct device *dev) 3711da177e4SLinus Torvalds { 3721da177e4SLinus Torvalds device_initialize(dev); 3731da177e4SLinus Torvalds return device_add(dev); 3741da177e4SLinus Torvalds } 3751da177e4SLinus Torvalds 3761da177e4SLinus Torvalds 3771da177e4SLinus Torvalds /** 3781da177e4SLinus Torvalds * get_device - increment reference count for device. 3791da177e4SLinus Torvalds * @dev: device. 3801da177e4SLinus Torvalds * 3811da177e4SLinus Torvalds * This simply forwards the call to kobject_get(), though 3821da177e4SLinus Torvalds * we do take care to provide for the case that we get a NULL 3831da177e4SLinus Torvalds * pointer passed in. 3841da177e4SLinus Torvalds */ 3851da177e4SLinus Torvalds 3861da177e4SLinus Torvalds struct device * get_device(struct device * dev) 3871da177e4SLinus Torvalds { 3881da177e4SLinus Torvalds return dev ? to_dev(kobject_get(&dev->kobj)) : NULL; 3891da177e4SLinus Torvalds } 3901da177e4SLinus Torvalds 3911da177e4SLinus Torvalds 3921da177e4SLinus Torvalds /** 3931da177e4SLinus Torvalds * put_device - decrement reference count. 3941da177e4SLinus Torvalds * @dev: device in question. 3951da177e4SLinus Torvalds */ 3961da177e4SLinus Torvalds void put_device(struct device * dev) 3971da177e4SLinus Torvalds { 3981da177e4SLinus Torvalds if (dev) 3991da177e4SLinus Torvalds kobject_put(&dev->kobj); 4001da177e4SLinus Torvalds } 4011da177e4SLinus Torvalds 4021da177e4SLinus Torvalds 4031da177e4SLinus Torvalds /** 4041da177e4SLinus Torvalds * device_del - delete device from system. 4051da177e4SLinus Torvalds * @dev: device. 4061da177e4SLinus Torvalds * 4071da177e4SLinus Torvalds * This is the first part of the device unregistration 4081da177e4SLinus Torvalds * sequence. This removes the device from the lists we control 4091da177e4SLinus Torvalds * from here, has it removed from the other driver model 4101da177e4SLinus Torvalds * subsystems it was added to in device_add(), and removes it 4111da177e4SLinus Torvalds * from the kobject hierarchy. 4121da177e4SLinus Torvalds * 4131da177e4SLinus Torvalds * NOTE: this should be called manually _iff_ device_add() was 4141da177e4SLinus Torvalds * also called manually. 4151da177e4SLinus Torvalds */ 4161da177e4SLinus Torvalds 4171da177e4SLinus Torvalds void device_del(struct device * dev) 4181da177e4SLinus Torvalds { 4191da177e4SLinus Torvalds struct device * parent = dev->parent; 4201da177e4SLinus Torvalds 4211da177e4SLinus Torvalds if (parent) 422d62c0f9fSPatrick Mochel klist_del(&dev->knode_parent); 42323681e47SGreg Kroah-Hartman if (dev->devt_attr) 42423681e47SGreg Kroah-Hartman device_remove_file(dev, dev->devt_attr); 42523681e47SGreg Kroah-Hartman if (dev->class) 42623681e47SGreg Kroah-Hartman sysfs_remove_link(&dev->class->subsys.kset.kobj, dev->bus_id); 427a7fd6706SKay Sievers device_remove_file(dev, &dev->uevent_attr); 4281da177e4SLinus Torvalds 4291da177e4SLinus Torvalds /* Notify the platform of the removal, in case they 4301da177e4SLinus Torvalds * need to do anything... 4311da177e4SLinus Torvalds */ 4321da177e4SLinus Torvalds if (platform_notify_remove) 4331da177e4SLinus Torvalds platform_notify_remove(dev); 4341da177e4SLinus Torvalds bus_remove_device(dev); 4351da177e4SLinus Torvalds device_pm_remove(dev); 436312c004dSKay Sievers kobject_uevent(&dev->kobj, KOBJ_REMOVE); 4371da177e4SLinus Torvalds kobject_del(&dev->kobj); 4381da177e4SLinus Torvalds if (parent) 4391da177e4SLinus Torvalds put_device(parent); 4401da177e4SLinus Torvalds } 4411da177e4SLinus Torvalds 4421da177e4SLinus Torvalds /** 4431da177e4SLinus Torvalds * device_unregister - unregister device from system. 4441da177e4SLinus Torvalds * @dev: device going away. 4451da177e4SLinus Torvalds * 4461da177e4SLinus Torvalds * We do this in two parts, like we do device_register(). First, 4471da177e4SLinus Torvalds * we remove it from all the subsystems with device_del(), then 4481da177e4SLinus Torvalds * we decrement the reference count via put_device(). If that 4491da177e4SLinus Torvalds * is the final reference count, the device will be cleaned up 4501da177e4SLinus Torvalds * via device_release() above. Otherwise, the structure will 4511da177e4SLinus Torvalds * stick around until the final reference to the device is dropped. 4521da177e4SLinus Torvalds */ 4531da177e4SLinus Torvalds void device_unregister(struct device * dev) 4541da177e4SLinus Torvalds { 4551da177e4SLinus Torvalds pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id); 4561da177e4SLinus Torvalds device_del(dev); 4571da177e4SLinus Torvalds put_device(dev); 4581da177e4SLinus Torvalds } 4591da177e4SLinus Torvalds 4601da177e4SLinus Torvalds 46136239577Smochel@digitalimplant.org static struct device * next_device(struct klist_iter * i) 46236239577Smochel@digitalimplant.org { 46336239577Smochel@digitalimplant.org struct klist_node * n = klist_next(i); 46436239577Smochel@digitalimplant.org return n ? container_of(n, struct device, knode_parent) : NULL; 46536239577Smochel@digitalimplant.org } 46636239577Smochel@digitalimplant.org 4671da177e4SLinus Torvalds /** 4681da177e4SLinus Torvalds * device_for_each_child - device child iterator. 469c41455fbSRandy Dunlap * @parent: parent struct device. 4701da177e4SLinus Torvalds * @data: data for the callback. 4711da177e4SLinus Torvalds * @fn: function to be called for each device. 4721da177e4SLinus Torvalds * 473c41455fbSRandy Dunlap * Iterate over @parent's child devices, and call @fn for each, 4741da177e4SLinus Torvalds * passing it @data. 4751da177e4SLinus Torvalds * 4761da177e4SLinus Torvalds * We check the return of @fn each time. If it returns anything 4771da177e4SLinus Torvalds * other than 0, we break out and return that value. 4781da177e4SLinus Torvalds */ 47936239577Smochel@digitalimplant.org int device_for_each_child(struct device * parent, void * data, 4801da177e4SLinus Torvalds int (*fn)(struct device *, void *)) 4811da177e4SLinus Torvalds { 48236239577Smochel@digitalimplant.org struct klist_iter i; 4831da177e4SLinus Torvalds struct device * child; 4841da177e4SLinus Torvalds int error = 0; 4851da177e4SLinus Torvalds 48636239577Smochel@digitalimplant.org klist_iter_init(&parent->klist_children, &i); 48736239577Smochel@digitalimplant.org while ((child = next_device(&i)) && !error) 48836239577Smochel@digitalimplant.org error = fn(child, data); 48936239577Smochel@digitalimplant.org klist_iter_exit(&i); 4901da177e4SLinus Torvalds return error; 4911da177e4SLinus Torvalds } 4921da177e4SLinus Torvalds 4931da177e4SLinus Torvalds int __init devices_init(void) 4941da177e4SLinus Torvalds { 4951da177e4SLinus Torvalds return subsystem_register(&devices_subsys); 4961da177e4SLinus Torvalds } 4971da177e4SLinus Torvalds 4981da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_for_each_child); 4991da177e4SLinus Torvalds 5001da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_initialize); 5011da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_add); 5021da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_register); 5031da177e4SLinus Torvalds 5041da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_del); 5051da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_unregister); 5061da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(get_device); 5071da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(put_device); 5081da177e4SLinus Torvalds 5091da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_create_file); 5101da177e4SLinus Torvalds EXPORT_SYMBOL_GPL(device_remove_file); 51123681e47SGreg Kroah-Hartman 51223681e47SGreg Kroah-Hartman 51323681e47SGreg Kroah-Hartman static void device_create_release(struct device *dev) 51423681e47SGreg Kroah-Hartman { 51523681e47SGreg Kroah-Hartman pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id); 51623681e47SGreg Kroah-Hartman kfree(dev); 51723681e47SGreg Kroah-Hartman } 51823681e47SGreg Kroah-Hartman 51923681e47SGreg Kroah-Hartman /** 52023681e47SGreg Kroah-Hartman * device_create - creates a device and registers it with sysfs 52123681e47SGreg Kroah-Hartman * @cs: pointer to the struct class that this device should be registered to. 52223681e47SGreg Kroah-Hartman * @parent: pointer to the parent struct device of this new device, if any. 52323681e47SGreg Kroah-Hartman * @dev: the dev_t for the char device to be added. 52423681e47SGreg Kroah-Hartman * @fmt: string for the class device's name 52523681e47SGreg Kroah-Hartman * 52623681e47SGreg Kroah-Hartman * This function can be used by char device classes. A struct 52723681e47SGreg Kroah-Hartman * device will be created in sysfs, registered to the specified 52823681e47SGreg Kroah-Hartman * class. 52923681e47SGreg Kroah-Hartman * A "dev" file will be created, showing the dev_t for the device, if 53023681e47SGreg Kroah-Hartman * the dev_t is not 0,0. 53123681e47SGreg Kroah-Hartman * If a pointer to a parent struct device is passed in, the newly 53223681e47SGreg Kroah-Hartman * created struct device will be a child of that device in sysfs. The 53323681e47SGreg Kroah-Hartman * pointer to the struct device will be returned from the call. Any 53423681e47SGreg Kroah-Hartman * further sysfs files that might be required can be created using this 53523681e47SGreg Kroah-Hartman * pointer. 53623681e47SGreg Kroah-Hartman * 53723681e47SGreg Kroah-Hartman * Note: the struct class passed to this function must have previously 53823681e47SGreg Kroah-Hartman * been created with a call to class_create(). 53923681e47SGreg Kroah-Hartman */ 54023681e47SGreg Kroah-Hartman struct device *device_create(struct class *class, struct device *parent, 54123681e47SGreg Kroah-Hartman dev_t devt, char *fmt, ...) 54223681e47SGreg Kroah-Hartman { 54323681e47SGreg Kroah-Hartman va_list args; 54423681e47SGreg Kroah-Hartman struct device *dev = NULL; 54523681e47SGreg Kroah-Hartman int retval = -ENODEV; 54623681e47SGreg Kroah-Hartman 54723681e47SGreg Kroah-Hartman if (class == NULL || IS_ERR(class)) 54823681e47SGreg Kroah-Hartman goto error; 54923681e47SGreg Kroah-Hartman if (parent == NULL) { 55023681e47SGreg Kroah-Hartman printk(KERN_WARNING "%s does not work yet for NULL parents\n", __FUNCTION__); 55123681e47SGreg Kroah-Hartman goto error; 55223681e47SGreg Kroah-Hartman } 55323681e47SGreg Kroah-Hartman 55423681e47SGreg Kroah-Hartman dev = kzalloc(sizeof(*dev), GFP_KERNEL); 55523681e47SGreg Kroah-Hartman if (!dev) { 55623681e47SGreg Kroah-Hartman retval = -ENOMEM; 55723681e47SGreg Kroah-Hartman goto error; 55823681e47SGreg Kroah-Hartman } 55923681e47SGreg Kroah-Hartman 56023681e47SGreg Kroah-Hartman dev->devt = devt; 56123681e47SGreg Kroah-Hartman dev->class = class; 56223681e47SGreg Kroah-Hartman dev->parent = parent; 56323681e47SGreg Kroah-Hartman dev->release = device_create_release; 56423681e47SGreg Kroah-Hartman 56523681e47SGreg Kroah-Hartman va_start(args, fmt); 56623681e47SGreg Kroah-Hartman vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args); 56723681e47SGreg Kroah-Hartman va_end(args); 56823681e47SGreg Kroah-Hartman retval = device_register(dev); 56923681e47SGreg Kroah-Hartman if (retval) 57023681e47SGreg Kroah-Hartman goto error; 57123681e47SGreg Kroah-Hartman 57223681e47SGreg Kroah-Hartman /* tie the class to the device */ 57323681e47SGreg Kroah-Hartman down(&class->sem); 57423681e47SGreg Kroah-Hartman list_add_tail(&dev->node, &class->devices); 57523681e47SGreg Kroah-Hartman up(&class->sem); 57623681e47SGreg Kroah-Hartman 57723681e47SGreg Kroah-Hartman return dev; 57823681e47SGreg Kroah-Hartman 57923681e47SGreg Kroah-Hartman error: 58023681e47SGreg Kroah-Hartman kfree(dev); 58123681e47SGreg Kroah-Hartman return ERR_PTR(retval); 58223681e47SGreg Kroah-Hartman } 58323681e47SGreg Kroah-Hartman EXPORT_SYMBOL_GPL(device_create); 58423681e47SGreg Kroah-Hartman 58523681e47SGreg Kroah-Hartman /** 58623681e47SGreg Kroah-Hartman * device_destroy - removes a device that was created with device_create() 58723681e47SGreg Kroah-Hartman * @class: the pointer to the struct class that this device was registered * with. 58823681e47SGreg Kroah-Hartman * @dev: the dev_t of the device that was previously registered. 58923681e47SGreg Kroah-Hartman * 59023681e47SGreg Kroah-Hartman * This call unregisters and cleans up a class device that was created with a 59123681e47SGreg Kroah-Hartman * call to class_device_create() 59223681e47SGreg Kroah-Hartman */ 59323681e47SGreg Kroah-Hartman void device_destroy(struct class *class, dev_t devt) 59423681e47SGreg Kroah-Hartman { 59523681e47SGreg Kroah-Hartman struct device *dev = NULL; 59623681e47SGreg Kroah-Hartman struct device *dev_tmp; 59723681e47SGreg Kroah-Hartman 59823681e47SGreg Kroah-Hartman down(&class->sem); 59923681e47SGreg Kroah-Hartman list_for_each_entry(dev_tmp, &class->devices, node) { 60023681e47SGreg Kroah-Hartman if (dev_tmp->devt == devt) { 60123681e47SGreg Kroah-Hartman dev = dev_tmp; 60223681e47SGreg Kroah-Hartman break; 60323681e47SGreg Kroah-Hartman } 60423681e47SGreg Kroah-Hartman } 60523681e47SGreg Kroah-Hartman up(&class->sem); 60623681e47SGreg Kroah-Hartman 60723681e47SGreg Kroah-Hartman if (dev) { 60823681e47SGreg Kroah-Hartman list_del_init(&dev->node); 60923681e47SGreg Kroah-Hartman device_unregister(dev); 61023681e47SGreg Kroah-Hartman } 61123681e47SGreg Kroah-Hartman } 61223681e47SGreg Kroah-Hartman EXPORT_SYMBOL_GPL(device_destroy); 613