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mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -08001/*
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08002 * drivers/base/dd.c - The core device/driver interactions.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -08003 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08004 * This file contains the (sometimes tricky) code that controls the
5 * interactions between devices and drivers, which primarily includes
6 * driver binding and unbinding.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -08007 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08008 * All of this code used to exist in drivers/base/bus.c, but was
9 * relocated to here in the name of compartmentalization (since it wasn't
10 * strictly code just for the 'struct bus_type'.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080011 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080012 * Copyright (c) 2002-5 Patrick Mochel
13 * Copyright (c) 2002-3 Open Source Development Labs
Greg Kroah-Hartmanb4028432009-05-11 14:16:57 -070014 * Copyright (c) 2007-2009 Greg Kroah-Hartman <gregkh@suse.de>
15 * Copyright (c) 2007-2009 Novell Inc.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080016 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080017 * This file is released under the GPLv2
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080018 */
19
20#include <linux/device.h>
Arjan van de Ven216773a2009-02-14 01:59:06 +010021#include <linux/delay.h>
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080022#include <linux/module.h>
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -070023#include <linux/kthread.h>
Andrew Morton735a7ff2006-10-27 11:42:37 -070024#include <linux/wait.h>
Arjan van de Ven216773a2009-02-14 01:59:06 +010025#include <linux/async.h>
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +020026#include <linux/pm_runtime.h>
Linus Walleijab780292013-01-22 10:56:14 -070027#include <linux/pinctrl/devinfo.h>
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080028
29#include "base.h"
30#include "power/power.h"
31
Grant Likelyd1c34142012-03-05 08:47:41 -070032/*
33 * Deferred Probe infrastructure.
34 *
35 * Sometimes driver probe order matters, but the kernel doesn't always have
36 * dependency information which means some drivers will get probed before a
37 * resource it depends on is available. For example, an SDHCI driver may
38 * first need a GPIO line from an i2c GPIO controller before it can be
39 * initialized. If a required resource is not available yet, a driver can
40 * request probing to be deferred by returning -EPROBE_DEFER from its probe hook
41 *
42 * Deferred probe maintains two lists of devices, a pending list and an active
43 * list. A driver returning -EPROBE_DEFER causes the device to be added to the
44 * pending list. A successful driver probe will trigger moving all devices
45 * from the pending to the active list so that the workqueue will eventually
46 * retry them.
47 *
48 * The deferred_probe_mutex must be held any time the deferred_probe_*_list
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -080049 * of the (struct device*)->p->deferred_probe pointers are manipulated
Grant Likelyd1c34142012-03-05 08:47:41 -070050 */
51static DEFINE_MUTEX(deferred_probe_mutex);
52static LIST_HEAD(deferred_probe_pending_list);
53static LIST_HEAD(deferred_probe_active_list);
54static struct workqueue_struct *deferred_wq;
Grant Likely58b116b2014-04-29 12:05:22 +010055static atomic_t deferred_trigger_count = ATOMIC_INIT(0);
Grant Likelyd1c34142012-03-05 08:47:41 -070056
Thierry Reding41575332014-08-08 15:56:36 +020057/*
Grant Likelyd1c34142012-03-05 08:47:41 -070058 * deferred_probe_work_func() - Retry probing devices in the active list.
59 */
60static void deferred_probe_work_func(struct work_struct *work)
61{
62 struct device *dev;
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -080063 struct device_private *private;
Grant Likelyd1c34142012-03-05 08:47:41 -070064 /*
65 * This block processes every device in the deferred 'active' list.
66 * Each device is removed from the active list and passed to
67 * bus_probe_device() to re-attempt the probe. The loop continues
68 * until every device in the active list is removed and retried.
69 *
70 * Note: Once the device is removed from the list and the mutex is
71 * released, it is possible for the device get freed by another thread
72 * and cause a illegal pointer dereference. This code uses
73 * get/put_device() to ensure the device structure cannot disappear
74 * from under our feet.
75 */
76 mutex_lock(&deferred_probe_mutex);
77 while (!list_empty(&deferred_probe_active_list)) {
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -080078 private = list_first_entry(&deferred_probe_active_list,
79 typeof(*dev->p), deferred_probe);
80 dev = private->device;
81 list_del_init(&private->deferred_probe);
Grant Likelyd1c34142012-03-05 08:47:41 -070082
83 get_device(dev);
84
Greg Kroah-Hartman8b0372a2012-03-08 12:20:37 -080085 /*
86 * Drop the mutex while probing each device; the probe path may
87 * manipulate the deferred list
88 */
Grant Likelyd1c34142012-03-05 08:47:41 -070089 mutex_unlock(&deferred_probe_mutex);
Mark Brown81535842012-07-05 14:04:44 +010090
91 /*
92 * Force the device to the end of the dpm_list since
93 * the PM code assumes that the order we add things to
94 * the list is a good order for suspend but deferred
95 * probe makes that very unsafe.
96 */
97 device_pm_lock();
98 device_pm_move_last(dev);
99 device_pm_unlock();
100
Grant Likelyd1c34142012-03-05 08:47:41 -0700101 dev_dbg(dev, "Retrying from deferred list\n");
102 bus_probe_device(dev);
Mark Brown81535842012-07-05 14:04:44 +0100103
Grant Likelyd1c34142012-03-05 08:47:41 -0700104 mutex_lock(&deferred_probe_mutex);
105
106 put_device(dev);
107 }
108 mutex_unlock(&deferred_probe_mutex);
109}
110static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);
111
112static void driver_deferred_probe_add(struct device *dev)
113{
114 mutex_lock(&deferred_probe_mutex);
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -0800115 if (list_empty(&dev->p->deferred_probe)) {
Grant Likelyd1c34142012-03-05 08:47:41 -0700116 dev_dbg(dev, "Added to deferred list\n");
Kuninori Morimoto1d29cfa52012-05-29 18:46:06 -0700117 list_add_tail(&dev->p->deferred_probe, &deferred_probe_pending_list);
Grant Likelyd1c34142012-03-05 08:47:41 -0700118 }
119 mutex_unlock(&deferred_probe_mutex);
120}
121
122void driver_deferred_probe_del(struct device *dev)
123{
124 mutex_lock(&deferred_probe_mutex);
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -0800125 if (!list_empty(&dev->p->deferred_probe)) {
Grant Likelyd1c34142012-03-05 08:47:41 -0700126 dev_dbg(dev, "Removed from deferred list\n");
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -0800127 list_del_init(&dev->p->deferred_probe);
Grant Likelyd1c34142012-03-05 08:47:41 -0700128 }
129 mutex_unlock(&deferred_probe_mutex);
130}
131
132static bool driver_deferred_probe_enable = false;
133/**
134 * driver_deferred_probe_trigger() - Kick off re-probing deferred devices
135 *
136 * This functions moves all devices from the pending list to the active
137 * list and schedules the deferred probe workqueue to process them. It
138 * should be called anytime a driver is successfully bound to a device.
Grant Likely58b116b2014-04-29 12:05:22 +0100139 *
140 * Note, there is a race condition in multi-threaded probe. In the case where
141 * more than one device is probing at the same time, it is possible for one
142 * probe to complete successfully while another is about to defer. If the second
143 * depends on the first, then it will get put on the pending list after the
144 * trigger event has already occured and will be stuck there.
145 *
146 * The atomic 'deferred_trigger_count' is used to determine if a successful
147 * trigger has occurred in the midst of probing a driver. If the trigger count
148 * changes in the midst of a probe, then deferred processing should be triggered
149 * again.
Grant Likelyd1c34142012-03-05 08:47:41 -0700150 */
151static void driver_deferred_probe_trigger(void)
152{
153 if (!driver_deferred_probe_enable)
154 return;
155
Greg Kroah-Hartman8b0372a2012-03-08 12:20:37 -0800156 /*
157 * A successful probe means that all the devices in the pending list
Grant Likelyd1c34142012-03-05 08:47:41 -0700158 * should be triggered to be reprobed. Move all the deferred devices
Greg Kroah-Hartman8b0372a2012-03-08 12:20:37 -0800159 * into the active list so they can be retried by the workqueue
160 */
Grant Likelyd1c34142012-03-05 08:47:41 -0700161 mutex_lock(&deferred_probe_mutex);
Grant Likely58b116b2014-04-29 12:05:22 +0100162 atomic_inc(&deferred_trigger_count);
Grant Likelyd1c34142012-03-05 08:47:41 -0700163 list_splice_tail_init(&deferred_probe_pending_list,
164 &deferred_probe_active_list);
165 mutex_unlock(&deferred_probe_mutex);
166
Greg Kroah-Hartman8b0372a2012-03-08 12:20:37 -0800167 /*
168 * Kick the re-probe thread. It may already be scheduled, but it is
169 * safe to kick it again.
170 */
Grant Likelyd1c34142012-03-05 08:47:41 -0700171 queue_work(deferred_wq, &deferred_probe_work);
172}
173
174/**
175 * deferred_probe_initcall() - Enable probing of deferred devices
176 *
177 * We don't want to get in the way when the bulk of drivers are getting probed.
178 * Instead, this initcall makes sure that deferred probing is delayed until
179 * late_initcall time.
180 */
181static int deferred_probe_initcall(void)
182{
183 deferred_wq = create_singlethread_workqueue("deferwq");
184 if (WARN_ON(!deferred_wq))
185 return -ENOMEM;
186
187 driver_deferred_probe_enable = true;
188 driver_deferred_probe_trigger();
Grant Likelyd72cca12013-02-14 18:14:27 +0000189 /* Sort as many dependencies as possible before exiting initcalls */
190 flush_workqueue(deferred_wq);
Grant Likelyd1c34142012-03-05 08:47:41 -0700191 return 0;
192}
193late_initcall(deferred_probe_initcall);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800194
Kay Sievers1901fb22006-10-07 21:55:55 +0200195static void driver_bound(struct device *dev)
196{
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -0800197 if (klist_node_attached(&dev->p->knode_driver)) {
Kay Sievers1901fb22006-10-07 21:55:55 +0200198 printk(KERN_WARNING "%s: device %s already bound\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800199 __func__, kobject_name(&dev->kobj));
Kay Sievers1901fb22006-10-07 21:55:55 +0200200 return;
201 }
202
Frank Rowand94f8cc02014-04-16 17:12:30 -0700203 pr_debug("driver: '%s': %s: bound to device '%s'\n", dev->driver->name,
204 __func__, dev_name(dev));
Kay Sievers1901fb22006-10-07 21:55:55 +0200205
Stefani Seiboldfbb88fa2010-03-06 17:50:14 +0100206 klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices);
207
Greg Kroah-Hartman8b0372a2012-03-08 12:20:37 -0800208 /*
209 * Make sure the device is no longer in one of the deferred lists and
210 * kick off retrying all pending devices
211 */
Grant Likelyd1c34142012-03-05 08:47:41 -0700212 driver_deferred_probe_del(dev);
213 driver_deferred_probe_trigger();
214
Kay Sievers1901fb22006-10-07 21:55:55 +0200215 if (dev->bus)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700216 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
Kay Sievers1901fb22006-10-07 21:55:55 +0200217 BUS_NOTIFY_BOUND_DRIVER, dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200218}
219
220static int driver_sysfs_add(struct device *dev)
221{
222 int ret;
223
Magnus Damm45daef02010-07-23 19:56:18 +0900224 if (dev->bus)
225 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
226 BUS_NOTIFY_BIND_DRIVER, dev);
227
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800228 ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj,
Kay Sievers1901fb22006-10-07 21:55:55 +0200229 kobject_name(&dev->kobj));
230 if (ret == 0) {
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800231 ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj,
Kay Sievers1901fb22006-10-07 21:55:55 +0200232 "driver");
233 if (ret)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800234 sysfs_remove_link(&dev->driver->p->kobj,
Kay Sievers1901fb22006-10-07 21:55:55 +0200235 kobject_name(&dev->kobj));
236 }
237 return ret;
238}
239
240static void driver_sysfs_remove(struct device *dev)
241{
242 struct device_driver *drv = dev->driver;
243
244 if (drv) {
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800245 sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj));
Kay Sievers1901fb22006-10-07 21:55:55 +0200246 sysfs_remove_link(&dev->kobj, "driver");
247 }
248}
249
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800250/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800251 * device_bind_driver - bind a driver to one device.
252 * @dev: device.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800253 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800254 * Allow manual attachment of a driver to a device.
255 * Caller must have already set @dev->driver.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800256 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800257 * Note that this does not modify the bus reference count
258 * nor take the bus's rwsem. Please verify those are accounted
259 * for before calling this. (It is ok to call with no other effort
260 * from a driver's probe() method.)
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700261 *
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800262 * This function must be called with the device lock held.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800263 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700264int device_bind_driver(struct device *dev)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800265{
Cornelia Huckcb986b72006-11-27 10:35:12 +0100266 int ret;
267
268 ret = driver_sysfs_add(dev);
269 if (!ret)
270 driver_bound(dev);
271 return ret;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800272}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800273EXPORT_SYMBOL_GPL(device_bind_driver);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800274
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700275static atomic_t probe_count = ATOMIC_INIT(0);
Andrew Morton735a7ff2006-10-27 11:42:37 -0700276static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);
277
Cornelia Huck21c7f302007-02-05 16:15:25 -0800278static int really_probe(struct device *dev, struct device_driver *drv)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800279{
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700280 int ret = 0;
Grant Likely58b116b2014-04-29 12:05:22 +0100281 int local_trigger_count = atomic_read(&deferred_trigger_count);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800282
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700283 atomic_inc(&probe_count);
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800284 pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100285 drv->bus->name, __func__, drv->name, dev_name(dev));
Tejun Heo9ac78492007-01-20 16:00:26 +0900286 WARN_ON(!list_empty(&dev->devres_head));
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800287
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800288 dev->driver = drv;
Linus Walleijab780292013-01-22 10:56:14 -0700289
290 /* If using pinctrl, bind pins now before probing */
291 ret = pinctrl_bind_pins(dev);
292 if (ret)
293 goto probe_failed;
294
Kay Sievers1901fb22006-10-07 21:55:55 +0200295 if (driver_sysfs_add(dev)) {
296 printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100297 __func__, dev_name(dev));
Kay Sievers1901fb22006-10-07 21:55:55 +0200298 goto probe_failed;
299 }
300
Russell King594c8282006-01-05 14:29:51 +0000301 if (dev->bus->probe) {
302 ret = dev->bus->probe(dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200303 if (ret)
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700304 goto probe_failed;
Russell King594c8282006-01-05 14:29:51 +0000305 } else if (drv->probe) {
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700306 ret = drv->probe(dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200307 if (ret)
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700308 goto probe_failed;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800309 }
Kay Sievers1901fb22006-10-07 21:55:55 +0200310
311 driver_bound(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700312 ret = 1;
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800313 pr_debug("bus: '%s': %s: bound device %s to driver %s\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100314 drv->bus->name, __func__, dev_name(dev), drv->name);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700315 goto done;
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700316
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700317probe_failed:
Tejun Heo9ac78492007-01-20 16:00:26 +0900318 devres_release_all(dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200319 driver_sysfs_remove(dev);
320 dev->driver = NULL;
Hans de Goede0998d062012-05-23 00:09:34 +0200321 dev_set_drvdata(dev, NULL);
Kay Sievers1901fb22006-10-07 21:55:55 +0200322
Grant Likelyd1c34142012-03-05 08:47:41 -0700323 if (ret == -EPROBE_DEFER) {
324 /* Driver requested deferred probing */
325 dev_info(dev, "Driver %s requests probe deferral\n", drv->name);
326 driver_deferred_probe_add(dev);
Grant Likely58b116b2014-04-29 12:05:22 +0100327 /* Did a trigger occur while probing? Need to re-trigger if yes */
328 if (local_trigger_count != atomic_read(&deferred_trigger_count))
329 driver_deferred_probe_trigger();
Grant Likelyd1c34142012-03-05 08:47:41 -0700330 } else if (ret != -ENODEV && ret != -ENXIO) {
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700331 /* driver matched but the probe failed */
332 printk(KERN_WARNING
333 "%s: probe of %s failed with error %d\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100334 drv->name, dev_name(dev), ret);
Wolfram Sangbcbe4f92011-09-20 19:41:17 +0200335 } else {
336 pr_debug("%s: probe of %s rejects match %d\n",
337 drv->name, dev_name(dev), ret);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700338 }
Cornelia Huckc578abb2006-11-27 10:35:10 +0100339 /*
340 * Ignore errors returned by ->probe so that the next driver can try
341 * its luck.
342 */
343 ret = 0;
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700344done:
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700345 atomic_dec(&probe_count);
Andrew Morton735a7ff2006-10-27 11:42:37 -0700346 wake_up(&probe_waitqueue);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700347 return ret;
348}
349
350/**
351 * driver_probe_done
352 * Determine if the probe sequence is finished or not.
353 *
354 * Should somehow figure out how to use a semaphore, not an atomic variable...
355 */
356int driver_probe_done(void)
357{
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800358 pr_debug("%s: probe_count = %d\n", __func__,
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700359 atomic_read(&probe_count));
360 if (atomic_read(&probe_count))
361 return -EBUSY;
362 return 0;
363}
364
365/**
Arjan van de Ven216773a2009-02-14 01:59:06 +0100366 * wait_for_device_probe
367 * Wait for device probing to be completed.
Arjan van de Ven216773a2009-02-14 01:59:06 +0100368 */
Ming Leib23530e2009-02-21 16:45:07 +0800369void wait_for_device_probe(void)
Arjan van de Ven216773a2009-02-14 01:59:06 +0100370{
371 /* wait for the known devices to complete their probing */
Ming Leib23530e2009-02-21 16:45:07 +0800372 wait_event(probe_waitqueue, atomic_read(&probe_count) == 0);
Arjan van de Ven216773a2009-02-14 01:59:06 +0100373 async_synchronize_full();
Arjan van de Ven216773a2009-02-14 01:59:06 +0100374}
Arjan van de Vend4d52912009-04-21 13:32:54 -0700375EXPORT_SYMBOL_GPL(wait_for_device_probe);
Arjan van de Ven216773a2009-02-14 01:59:06 +0100376
377/**
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700378 * driver_probe_device - attempt to bind device & driver together
379 * @drv: driver to bind a device to
380 * @dev: device to try to bind to the driver
381 *
Ming Lei49b420a2009-01-21 23:27:47 +0800382 * This function returns -ENODEV if the device is not registered,
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200383 * 1 if the device is bound successfully and 0 otherwise.
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700384 *
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800385 * This function must be called with @dev lock held. When called for a
386 * USB interface, @dev->parent lock must be held as well.
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700387 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800388int driver_probe_device(struct device_driver *drv, struct device *dev)
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700389{
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700390 int ret = 0;
391
Alan Sternf2eaae12006-09-18 16:22:34 -0400392 if (!device_is_registered(dev))
393 return -ENODEV;
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700394
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800395 pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100396 drv->bus->name, __func__, dev_name(dev), drv->name);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700397
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200398 pm_runtime_barrier(dev);
Cornelia Huck21c7f302007-02-05 16:15:25 -0800399 ret = really_probe(dev, drv);
Ulf Hanssonfa180eb2013-04-10 17:00:48 +0200400 pm_request_idle(dev);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700401
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700402 return ret;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800403}
404
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800405static int __device_attach(struct device_driver *drv, void *data)
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800406{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800407 struct device *dev = data;
Ming Lei49b420a2009-01-21 23:27:47 +0800408
409 if (!driver_match_device(drv, dev))
410 return 0;
411
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700412 return driver_probe_device(drv, dev);
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800413}
414
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800415/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800416 * device_attach - try to attach device to a driver.
417 * @dev: device.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800418 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800419 * Walk the list of drivers that the bus has and call
420 * driver_probe_device() for each pair. If a compatible
421 * pair is found, break out and return.
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700422 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800423 * Returns 1 if the device was bound to a driver;
Dmitry Torokhov59a3cd72009-05-05 20:38:28 -0700424 * 0 if no matching driver was found;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800425 * -ENODEV if the device is not registered.
Alan Sternbf74ad52005-11-17 16:54:12 -0500426 *
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800427 * When called for a USB interface, @dev->parent lock must be held.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800428 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800429int device_attach(struct device *dev)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800430{
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700431 int ret = 0;
432
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800433 device_lock(dev);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800434 if (dev->driver) {
Sebastian Ott8497d6a2011-04-12 19:05:37 +0200435 if (klist_node_attached(&dev->p->knode_driver)) {
436 ret = 1;
437 goto out_unlock;
438 }
Andrew Mortonf86db392006-08-14 22:43:20 -0700439 ret = device_bind_driver(dev);
440 if (ret == 0)
441 ret = 1;
Cornelia Huckc6a46692007-02-05 16:15:26 -0800442 else {
443 dev->driver = NULL;
444 ret = 0;
445 }
Cornelia Huck21c7f302007-02-05 16:15:25 -0800446 } else {
Adrian Bunk5adc55d2007-03-27 03:02:51 +0200447 ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
Ulf Hanssonfa180eb2013-04-10 17:00:48 +0200448 pm_request_idle(dev);
Cornelia Huck21c7f302007-02-05 16:15:25 -0800449 }
Sebastian Ott8497d6a2011-04-12 19:05:37 +0200450out_unlock:
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800451 device_unlock(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700452 return ret;
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800453}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800454EXPORT_SYMBOL_GPL(device_attach);
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800455
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800456static int __driver_attach(struct device *dev, void *data)
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800457{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800458 struct device_driver *drv = data;
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800459
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700460 /*
461 * Lock device and try to bind to it. We drop the error
462 * here and always return 0, because we need to keep trying
463 * to bind to devices and some drivers will return an error
464 * simply if it didn't support the device.
465 *
466 * driver_probe_device() will spit a warning if there
467 * is an error.
468 */
469
Ming Lei49b420a2009-01-21 23:27:47 +0800470 if (!driver_match_device(drv, dev))
Arjan van de Ven6cd49582008-09-14 08:32:06 -0700471 return 0;
472
Alan Sternbf74ad52005-11-17 16:54:12 -0500473 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800474 device_lock(dev->parent);
475 device_lock(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700476 if (!dev->driver)
477 driver_probe_device(drv, dev);
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800478 device_unlock(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500479 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800480 device_unlock(dev->parent);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700481
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800482 return 0;
483}
484
485/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800486 * driver_attach - try to bind driver to devices.
487 * @drv: driver.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800488 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800489 * Walk the list of devices that the bus has on it and try to
490 * match the driver with each one. If driver_probe_device()
491 * returns 0 and the @dev->driver is set, we've found a
492 * compatible pair.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800493 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800494int driver_attach(struct device_driver *drv)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800495{
Andrew Mortonf86db392006-08-14 22:43:20 -0700496 return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800497}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800498EXPORT_SYMBOL_GPL(driver_attach);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800499
Stefan Richterab71c6f2007-06-17 11:02:12 +0200500/*
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800501 * __device_release_driver() must be called with @dev lock held.
502 * When called for a USB interface, @dev->parent lock must be held as well.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800503 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800504static void __device_release_driver(struct device *dev)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800505{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800506 struct device_driver *drv;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800507
Alan Sternef2c5172007-11-16 11:57:28 -0500508 drv = dev->driver;
Alan Sternc95a6b02005-05-06 15:38:33 -0400509 if (drv) {
Rafael J. Wysockie1866b32011-04-29 00:33:45 +0200510 pm_runtime_get_sync(dev);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200511
Kay Sievers1901fb22006-10-07 21:55:55 +0200512 driver_sysfs_remove(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700513
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000514 if (dev->bus)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700515 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000516 BUS_NOTIFY_UNBIND_DRIVER,
517 dev);
518
Rafael J. Wysockibaab52d2013-11-07 01:51:15 +0100519 pm_runtime_put_sync(dev);
Rafael J. Wysockie1866b32011-04-29 00:33:45 +0200520
Alan Stern0f836ca2006-03-31 11:52:25 -0500521 if (dev->bus && dev->bus->remove)
Russell King594c8282006-01-05 14:29:51 +0000522 dev->bus->remove(dev);
523 else if (drv->remove)
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700524 drv->remove(dev);
Tejun Heo9ac78492007-01-20 16:00:26 +0900525 devres_release_all(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700526 dev->driver = NULL;
Hans de Goede0998d062012-05-23 00:09:34 +0200527 dev_set_drvdata(dev, NULL);
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -0800528 klist_remove(&dev->p->knode_driver);
Joerg Roedel309b7d62009-04-24 14:57:00 +0200529 if (dev->bus)
530 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
531 BUS_NOTIFY_UNBOUND_DRIVER,
532 dev);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200533
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700534 }
Alan Sternc95a6b02005-05-06 15:38:33 -0400535}
536
Stefan Richterab71c6f2007-06-17 11:02:12 +0200537/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800538 * device_release_driver - manually detach device from driver.
539 * @dev: device.
Stefan Richterab71c6f2007-06-17 11:02:12 +0200540 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800541 * Manually detach device from driver.
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800542 * When called for a USB interface, @dev->parent lock must be held.
Stefan Richterab71c6f2007-06-17 11:02:12 +0200543 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800544void device_release_driver(struct device *dev)
Alan Sternc95a6b02005-05-06 15:38:33 -0400545{
546 /*
547 * If anyone calls device_release_driver() recursively from
548 * within their ->remove callback for the same device, they
549 * will deadlock right here.
550 */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800551 device_lock(dev);
Alan Sternc95a6b02005-05-06 15:38:33 -0400552 __device_release_driver(dev);
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800553 device_unlock(dev);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800554}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800555EXPORT_SYMBOL_GPL(device_release_driver);
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -0800556
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800557/**
558 * driver_detach - detach driver from all devices it controls.
559 * @drv: driver.
560 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800561void driver_detach(struct device_driver *drv)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800562{
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -0800563 struct device_private *dev_prv;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800564 struct device *dev;
Alan Sternc95a6b02005-05-06 15:38:33 -0400565
566 for (;;) {
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800567 spin_lock(&drv->p->klist_devices.k_lock);
568 if (list_empty(&drv->p->klist_devices.k_list)) {
569 spin_unlock(&drv->p->klist_devices.k_lock);
Alan Sternc95a6b02005-05-06 15:38:33 -0400570 break;
571 }
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -0800572 dev_prv = list_entry(drv->p->klist_devices.k_list.prev,
573 struct device_private,
574 knode_driver.n_node);
575 dev = dev_prv->device;
Alan Sternc95a6b02005-05-06 15:38:33 -0400576 get_device(dev);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800577 spin_unlock(&drv->p->klist_devices.k_lock);
Alan Sternc95a6b02005-05-06 15:38:33 -0400578
Alan Sternbf74ad52005-11-17 16:54:12 -0500579 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800580 device_lock(dev->parent);
581 device_lock(dev);
Alan Sternc95a6b02005-05-06 15:38:33 -0400582 if (dev->driver == drv)
583 __device_release_driver(dev);
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800584 device_unlock(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500585 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800586 device_unlock(dev->parent);
Alan Sternc95a6b02005-05-06 15:38:33 -0400587 put_device(dev);
588 }
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800589}