11da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 21da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * driver.c - centralized device driver management 31da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 41da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Copyright (c) 2002-3 Patrick Mochel 51da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Copyright (c) 2002-3 Open Source Development Labs 6e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de> 7e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman * Copyright (c) 2007 Novell Inc. 81da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 91da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This file is released under the GPLv2 101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/device.h> 141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/module.h> 151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/errno.h> 165a0e3ad6af8660be21ca98a971cd00f331318c05Tejun Heo#include <linux/slab.h> 171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/string.h> 181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include "base.h" 191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 204a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartmanstatic struct device *next_device(struct klist_iter *i) 2194e7b1c5ff2055571703e38b059afffe17658432Patrick Mochel{ 224a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman struct klist_node *n = klist_next(i); 238940b4f312dced51b45004819b776ec3aa7fcd5dGreg Kroah-Hartman struct device *dev = NULL; 248940b4f312dced51b45004819b776ec3aa7fcd5dGreg Kroah-Hartman struct device_private *dev_prv; 258940b4f312dced51b45004819b776ec3aa7fcd5dGreg Kroah-Hartman 268940b4f312dced51b45004819b776ec3aa7fcd5dGreg Kroah-Hartman if (n) { 278940b4f312dced51b45004819b776ec3aa7fcd5dGreg Kroah-Hartman dev_prv = to_device_private_driver(n); 288940b4f312dced51b45004819b776ec3aa7fcd5dGreg Kroah-Hartman dev = dev_prv->device; 298940b4f312dced51b45004819b776ec3aa7fcd5dGreg Kroah-Hartman } 308940b4f312dced51b45004819b776ec3aa7fcd5dGreg Kroah-Hartman return dev; 3194e7b1c5ff2055571703e38b059afffe17658432Patrick Mochel} 3294e7b1c5ff2055571703e38b059afffe17658432Patrick Mochel 33fae3cd00255e3e51ffd59fedb1bdb91ec96be395Patrick Mochel/** 344a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * driver_for_each_device - Iterator for devices bound to a driver. 354a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @drv: Driver we're iterating. 364a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @start: Device to begin with 374a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @data: Data to pass to the callback. 384a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @fn: Function to call for each device. 39fae3cd00255e3e51ffd59fedb1bdb91ec96be395Patrick Mochel * 404a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * Iterate over the @drv's list of devices calling @fn for each one. 41fae3cd00255e3e51ffd59fedb1bdb91ec96be395Patrick Mochel */ 424a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartmanint driver_for_each_device(struct device_driver *drv, struct device *start, 434a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman void *data, int (*fn)(struct device *, void *)) 44fae3cd00255e3e51ffd59fedb1bdb91ec96be395Patrick Mochel{ 4594e7b1c5ff2055571703e38b059afffe17658432Patrick Mochel struct klist_iter i; 464a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman struct device *dev; 47fae3cd00255e3e51ffd59fedb1bdb91ec96be395Patrick Mochel int error = 0; 48fae3cd00255e3e51ffd59fedb1bdb91ec96be395Patrick Mochel 4994e7b1c5ff2055571703e38b059afffe17658432Patrick Mochel if (!drv) 5094e7b1c5ff2055571703e38b059afffe17658432Patrick Mochel return -EINVAL; 5194e7b1c5ff2055571703e38b059afffe17658432Patrick Mochel 52e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman klist_iter_init_node(&drv->p->klist_devices, &i, 538940b4f312dced51b45004819b776ec3aa7fcd5dGreg Kroah-Hartman start ? &start->p->knode_driver : NULL); 5494e7b1c5ff2055571703e38b059afffe17658432Patrick Mochel while ((dev = next_device(&i)) && !error) 55fae3cd00255e3e51ffd59fedb1bdb91ec96be395Patrick Mochel error = fn(dev, data); 5694e7b1c5ff2055571703e38b059afffe17658432Patrick Mochel klist_iter_exit(&i); 57fae3cd00255e3e51ffd59fedb1bdb91ec96be395Patrick Mochel return error; 58fae3cd00255e3e51ffd59fedb1bdb91ec96be395Patrick Mochel} 59126eddfbf8cae8a20c22708192bffcbd77c8a889Greg Kroah-HartmanEXPORT_SYMBOL_GPL(driver_for_each_device); 60fae3cd00255e3e51ffd59fedb1bdb91ec96be395Patrick Mochel 611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 620edb586049e57c56e625536476931117a57671e9Cornelia Huck * driver_find_device - device iterator for locating a particular device. 63c41455fbac06712992da491844449775cf9a8c80Randy Dunlap * @drv: The device's driver 640edb586049e57c56e625536476931117a57671e9Cornelia Huck * @start: Device to begin with 650edb586049e57c56e625536476931117a57671e9Cornelia Huck * @data: Data to pass to match function 660edb586049e57c56e625536476931117a57671e9Cornelia Huck * @match: Callback function to check device 670edb586049e57c56e625536476931117a57671e9Cornelia Huck * 680edb586049e57c56e625536476931117a57671e9Cornelia Huck * This is similar to the driver_for_each_device() function above, but 690edb586049e57c56e625536476931117a57671e9Cornelia Huck * it returns a reference to a device that is 'found' for later use, as 700edb586049e57c56e625536476931117a57671e9Cornelia Huck * determined by the @match callback. 710edb586049e57c56e625536476931117a57671e9Cornelia Huck * 720edb586049e57c56e625536476931117a57671e9Cornelia Huck * The callback should return 0 if the device doesn't match and non-zero 730edb586049e57c56e625536476931117a57671e9Cornelia Huck * if it does. If the callback returns non-zero, this function will 740edb586049e57c56e625536476931117a57671e9Cornelia Huck * return to the caller and not iterate over any more devices. 750edb586049e57c56e625536476931117a57671e9Cornelia Huck */ 764a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartmanstruct device *driver_find_device(struct device_driver *drv, 774a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman struct device *start, void *data, 784a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman int (*match)(struct device *dev, void *data)) 790edb586049e57c56e625536476931117a57671e9Cornelia Huck{ 800edb586049e57c56e625536476931117a57671e9Cornelia Huck struct klist_iter i; 810edb586049e57c56e625536476931117a57671e9Cornelia Huck struct device *dev; 820edb586049e57c56e625536476931117a57671e9Cornelia Huck 830edb586049e57c56e625536476931117a57671e9Cornelia Huck if (!drv) 840edb586049e57c56e625536476931117a57671e9Cornelia Huck return NULL; 850edb586049e57c56e625536476931117a57671e9Cornelia Huck 86e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman klist_iter_init_node(&drv->p->klist_devices, &i, 878940b4f312dced51b45004819b776ec3aa7fcd5dGreg Kroah-Hartman (start ? &start->p->knode_driver : NULL)); 880edb586049e57c56e625536476931117a57671e9Cornelia Huck while ((dev = next_device(&i))) 890edb586049e57c56e625536476931117a57671e9Cornelia Huck if (match(dev, data) && get_device(dev)) 900edb586049e57c56e625536476931117a57671e9Cornelia Huck break; 910edb586049e57c56e625536476931117a57671e9Cornelia Huck klist_iter_exit(&i); 920edb586049e57c56e625536476931117a57671e9Cornelia Huck return dev; 930edb586049e57c56e625536476931117a57671e9Cornelia Huck} 940edb586049e57c56e625536476931117a57671e9Cornelia HuckEXPORT_SYMBOL_GPL(driver_find_device); 950edb586049e57c56e625536476931117a57671e9Cornelia Huck 960edb586049e57c56e625536476931117a57671e9Cornelia Huck/** 974a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * driver_create_file - create sysfs file for driver. 984a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @drv: driver. 994a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @attr: driver attribute descriptor. 1001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1014a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartmanint driver_create_file(struct device_driver *drv, 102099c2f21d8cf0724b85abb2c589d6276953781b7Phil Carmody const struct driver_attribute *attr) 1031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int error; 1050c98b19fe571ede1f14bd95b855bcbe2cca99bcfCornelia Huck if (drv) 106e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman error = sysfs_create_file(&drv->p->kobj, &attr->attr); 1070c98b19fe571ede1f14bd95b855bcbe2cca99bcfCornelia Huck else 1081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds error = -EINVAL; 1091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return error; 1101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1114a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-HartmanEXPORT_SYMBOL_GPL(driver_create_file); 1121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 1144a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * driver_remove_file - remove sysfs file for driver. 1154a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @drv: driver. 1164a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @attr: driver attribute descriptor. 1171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1184a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartmanvoid driver_remove_file(struct device_driver *drv, 119099c2f21d8cf0724b85abb2c589d6276953781b7Phil Carmody const struct driver_attribute *attr) 1201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1210c98b19fe571ede1f14bd95b855bcbe2cca99bcfCornelia Huck if (drv) 122e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman sysfs_remove_file(&drv->p->kobj, &attr->attr); 1231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1244a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-HartmanEXPORT_SYMBOL_GPL(driver_remove_file); 1251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 12657c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huckstatic int driver_add_groups(struct device_driver *drv, 127a4dbd6740df0872cdf0a86841f75beec8381964dDavid Brownell const struct attribute_group **groups) 12857c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck{ 12957c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck int error = 0; 13057c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck int i; 13157c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck 13257c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck if (groups) { 13357c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck for (i = 0; groups[i]; i++) { 134e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman error = sysfs_create_group(&drv->p->kobj, groups[i]); 13557c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck if (error) { 13657c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck while (--i >= 0) 137e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman sysfs_remove_group(&drv->p->kobj, 13857c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck groups[i]); 13957c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck break; 14057c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck } 14157c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck } 14257c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck } 14357c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck return error; 14457c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck} 14557c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck 14657c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huckstatic void driver_remove_groups(struct device_driver *drv, 147a4dbd6740df0872cdf0a86841f75beec8381964dDavid Brownell const struct attribute_group **groups) 14857c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck{ 14957c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck int i; 15057c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck 15157c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck if (groups) 15257c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck for (i = 0; groups[i]; i++) 153e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman sysfs_remove_group(&drv->p->kobj, groups[i]); 15457c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck} 15557c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck 1561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 1574a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * driver_register - register driver with bus 1584a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @drv: driver to register 1591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1604a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * We pass off most of the work to the bus_add_driver() call, 1614a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * since most of the things we have to do deal with the bus 1624a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * structures. 1631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1644a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartmanint driver_register(struct device_driver *drv) 1651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 16657c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck int ret; 16716dc42e018c2868211b4928f20a957c0c216126cStas Sergeev struct device_driver *other; 16857c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck 169f48f3febb2cbfd0f2ecee7690835ba745c1034a4Dave Young BUG_ON(!drv->bus->p); 170f48f3febb2cbfd0f2ecee7690835ba745c1034a4Dave Young 171594c8281f90560faf9632d91bb9d402cbe560e63Russell King if ((drv->bus->probe && drv->probe) || 172594c8281f90560faf9632d91bb9d402cbe560e63Russell King (drv->bus->remove && drv->remove) || 1734a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman (drv->bus->shutdown && drv->shutdown)) 1744a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman printk(KERN_WARNING "Driver '%s' needs updating - please use " 1754a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman "bus_type methods\n", drv->name); 17616dc42e018c2868211b4928f20a957c0c216126cStas Sergeev 17716dc42e018c2868211b4928f20a957c0c216126cStas Sergeev other = driver_find(drv->name, drv->bus); 17816dc42e018c2868211b4928f20a957c0c216126cStas Sergeev if (other) { 17916dc42e018c2868211b4928f20a957c0c216126cStas Sergeev printk(KERN_ERR "Error: Driver '%s' is already registered, " 18016dc42e018c2868211b4928f20a957c0c216126cStas Sergeev "aborting...\n", drv->name); 18139acbc12affcaa23ef1d887ba3d197baca8e6e47Stas Sergeev return -EBUSY; 18216dc42e018c2868211b4928f20a957c0c216126cStas Sergeev } 18316dc42e018c2868211b4928f20a957c0c216126cStas Sergeev 18457c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck ret = bus_add_driver(drv); 18557c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck if (ret) 18657c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck return ret; 18757c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck ret = driver_add_groups(drv, drv->groups); 18857c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck if (ret) 18957c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck bus_remove_driver(drv); 19057c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck return ret; 1911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1924a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-HartmanEXPORT_SYMBOL_GPL(driver_register); 1931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 1954a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * driver_unregister - remove driver from system. 1964a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @drv: driver. 1971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 1984a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * Again, we pass off most of the work to the bus-level call. 1991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 2004a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartmanvoid driver_unregister(struct device_driver *drv) 2011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 2025c8563d773c0e9f0ac2a552e84806decd98ce732Kay Sievers if (!drv || !drv->p) { 2035c8563d773c0e9f0ac2a552e84806decd98ce732Kay Sievers WARN(1, "Unexpected driver unregister!\n"); 2045c8563d773c0e9f0ac2a552e84806decd98ce732Kay Sievers return; 2055c8563d773c0e9f0ac2a552e84806decd98ce732Kay Sievers } 20657c745340a60c51d2b9af3d4dcf7e0ede284855bCornelia Huck driver_remove_groups(drv, drv->groups); 2071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds bus_remove_driver(drv); 2081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2094a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-HartmanEXPORT_SYMBOL_GPL(driver_unregister); 2101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/** 2124a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * driver_find - locate driver on a bus by its name. 2134a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @name: name of the driver. 2144a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * @bus: bus to scan for the driver. 2151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 2164a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * Call kset_find_obj() to iterate over list of drivers on 2174a3ad20ccd8f4d2a0535cf98fa83f7b561ba59a9Greg Kroah-Hartman * a bus to find driver by name. Return driver if found. 2181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 219fde25a9b63b9a3dc91365c394a426ebe64cfc2daAlan Stern * This routine provides no locking to prevent the driver it returns 220fde25a9b63b9a3dc91365c394a426ebe64cfc2daAlan Stern * from being unregistered or unloaded while the caller is using it. 221fde25a9b63b9a3dc91365c394a426ebe64cfc2daAlan Stern * The caller is responsible for preventing this. 2221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 2231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstruct device_driver *driver_find(const char *name, struct bus_type *bus) 2241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 225c6f7e72a3f4641095ade9ded287d910c980c6148Greg Kroah-Hartman struct kobject *k = kset_find_obj(bus->p->drivers_kset, name); 226e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman struct driver_private *priv; 227e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman 228e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman if (k) { 229fde25a9b63b9a3dc91365c394a426ebe64cfc2daAlan Stern /* Drop reference added by kset_find_obj() */ 230fde25a9b63b9a3dc91365c394a426ebe64cfc2daAlan Stern kobject_put(k); 231e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman priv = to_driver(k); 232e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman return priv->driver; 233e5dd12784617f0f1fae5f96a7fac1ec4c49fadbeGreg Kroah-Hartman } 2341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return NULL; 2351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsEXPORT_SYMBOL_GPL(driver_find); 237