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Commit | Line | Data |
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07e4a3e2 | 1 | /* |
4a3ad20c | 2 | * drivers/base/dd.c - The core device/driver interactions. |
07e4a3e2 | 3 | * |
4a3ad20c GKH |
4 | * This file contains the (sometimes tricky) code that controls the |
5 | * interactions between devices and drivers, which primarily includes | |
6 | * driver binding and unbinding. | |
07e4a3e2 | 7 | * |
4a3ad20c GKH |
8 | * 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'. | |
07e4a3e2 | 11 | * |
4a3ad20c GKH |
12 | * Copyright (c) 2002-5 Patrick Mochel |
13 | * Copyright (c) 2002-3 Open Source Development Labs | |
b4028437 GKH |
14 | * Copyright (c) 2007-2009 Greg Kroah-Hartman <gregkh@suse.de> |
15 | * Copyright (c) 2007-2009 Novell Inc. | |
07e4a3e2 | 16 | * |
4a3ad20c | 17 | * This file is released under the GPLv2 |
07e4a3e2 PM |
18 | */ |
19 | ||
20 | #include <linux/device.h> | |
216773a7 | 21 | #include <linux/delay.h> |
07e4a3e2 | 22 | #include <linux/module.h> |
d779249e | 23 | #include <linux/kthread.h> |
735a7ffb | 24 | #include <linux/wait.h> |
216773a7 | 25 | #include <linux/async.h> |
5e928f77 | 26 | #include <linux/pm_runtime.h> |
ab78029e | 27 | #include <linux/pinctrl/devinfo.h> |
07e4a3e2 PM |
28 | |
29 | #include "base.h" | |
30 | #include "power/power.h" | |
31 | ||
d1c3414c GL |
32 | /* |
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 | |
ef8a3fd6 | 49 | * of the (struct device*)->p->deferred_probe pointers are manipulated |
d1c3414c GL |
50 | */ |
51 | static DEFINE_MUTEX(deferred_probe_mutex); | |
52 | static LIST_HEAD(deferred_probe_pending_list); | |
53 | static LIST_HEAD(deferred_probe_active_list); | |
54 | static struct workqueue_struct *deferred_wq; | |
58b116bc | 55 | static atomic_t deferred_trigger_count = ATOMIC_INIT(0); |
d1c3414c | 56 | |
41575335 | 57 | /* |
d1c3414c GL |
58 | * deferred_probe_work_func() - Retry probing devices in the active list. |
59 | */ | |
60 | static void deferred_probe_work_func(struct work_struct *work) | |
61 | { | |
62 | struct device *dev; | |
ef8a3fd6 | 63 | struct device_private *private; |
d1c3414c GL |
64 | /* |
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)) { | |
ef8a3fd6 GKH |
78 | 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); | |
d1c3414c GL |
82 | |
83 | get_device(dev); | |
84 | ||
8b0372a2 GKH |
85 | /* |
86 | * Drop the mutex while probing each device; the probe path may | |
87 | * manipulate the deferred list | |
88 | */ | |
d1c3414c | 89 | mutex_unlock(&deferred_probe_mutex); |
8153584e MB |
90 | |
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 | ||
d1c3414c GL |
101 | dev_dbg(dev, "Retrying from deferred list\n"); |
102 | bus_probe_device(dev); | |
8153584e | 103 | |
d1c3414c GL |
104 | mutex_lock(&deferred_probe_mutex); |
105 | ||
106 | put_device(dev); | |
107 | } | |
108 | mutex_unlock(&deferred_probe_mutex); | |
109 | } | |
110 | static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func); | |
111 | ||
112 | static void driver_deferred_probe_add(struct device *dev) | |
113 | { | |
114 | mutex_lock(&deferred_probe_mutex); | |
ef8a3fd6 | 115 | if (list_empty(&dev->p->deferred_probe)) { |
d1c3414c | 116 | dev_dbg(dev, "Added to deferred list\n"); |
1d29cfa5 | 117 | list_add_tail(&dev->p->deferred_probe, &deferred_probe_pending_list); |
d1c3414c GL |
118 | } |
119 | mutex_unlock(&deferred_probe_mutex); | |
120 | } | |
121 | ||
122 | void driver_deferred_probe_del(struct device *dev) | |
123 | { | |
124 | mutex_lock(&deferred_probe_mutex); | |
ef8a3fd6 | 125 | if (!list_empty(&dev->p->deferred_probe)) { |
d1c3414c | 126 | dev_dbg(dev, "Removed from deferred list\n"); |
ef8a3fd6 | 127 | list_del_init(&dev->p->deferred_probe); |
d1c3414c GL |
128 | } |
129 | mutex_unlock(&deferred_probe_mutex); | |
130 | } | |
131 | ||
132 | static 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. | |
58b116bc GL |
139 | * |
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. | |
d1c3414c GL |
150 | */ |
151 | static void driver_deferred_probe_trigger(void) | |
152 | { | |
153 | if (!driver_deferred_probe_enable) | |
154 | return; | |
155 | ||
8b0372a2 GKH |
156 | /* |
157 | * A successful probe means that all the devices in the pending list | |
d1c3414c | 158 | * should be triggered to be reprobed. Move all the deferred devices |
8b0372a2 GKH |
159 | * into the active list so they can be retried by the workqueue |
160 | */ | |
d1c3414c | 161 | mutex_lock(&deferred_probe_mutex); |
58b116bc | 162 | atomic_inc(&deferred_trigger_count); |
d1c3414c GL |
163 | list_splice_tail_init(&deferred_probe_pending_list, |
164 | &deferred_probe_active_list); | |
165 | mutex_unlock(&deferred_probe_mutex); | |
166 | ||
8b0372a2 GKH |
167 | /* |
168 | * Kick the re-probe thread. It may already be scheduled, but it is | |
169 | * safe to kick it again. | |
170 | */ | |
d1c3414c GL |
171 | 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 | */ | |
181 | static 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(); | |
d72cca1e GL |
189 | /* Sort as many dependencies as possible before exiting initcalls */ |
190 | flush_workqueue(deferred_wq); | |
d1c3414c GL |
191 | return 0; |
192 | } | |
193 | late_initcall(deferred_probe_initcall); | |
07e4a3e2 | 194 | |
1901fb26 | 195 | static void driver_bound(struct device *dev) |
07e4a3e2 | 196 | { |
8940b4f3 | 197 | if (klist_node_attached(&dev->p->knode_driver)) { |
f86db396 | 198 | printk(KERN_WARNING "%s: device %s already bound\n", |
2b3a302a | 199 | __func__, kobject_name(&dev->kobj)); |
1901fb26 | 200 | return; |
f86db396 | 201 | } |
4c898c7f | 202 | |
94f8cc0e FR |
203 | pr_debug("driver: '%s': %s: bound to device '%s'\n", dev->driver->name, |
204 | __func__, dev_name(dev)); | |
116af378 | 205 | |
fbb88fad SS |
206 | klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices); |
207 | ||
8b0372a2 GKH |
208 | /* |
209 | * Make sure the device is no longer in one of the deferred lists and | |
210 | * kick off retrying all pending devices | |
211 | */ | |
d1c3414c GL |
212 | driver_deferred_probe_del(dev); |
213 | driver_deferred_probe_trigger(); | |
214 | ||
116af378 | 215 | if (dev->bus) |
c6f7e72a | 216 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
116af378 | 217 | BUS_NOTIFY_BOUND_DRIVER, dev); |
1901fb26 KS |
218 | } |
219 | ||
220 | static int driver_sysfs_add(struct device *dev) | |
221 | { | |
222 | int ret; | |
223 | ||
45daef0f MD |
224 | if (dev->bus) |
225 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
226 | BUS_NOTIFY_BIND_DRIVER, dev); | |
227 | ||
e5dd1278 | 228 | ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj, |
07e4a3e2 | 229 | kobject_name(&dev->kobj)); |
f86db396 | 230 | if (ret == 0) { |
e5dd1278 | 231 | ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj, |
f86db396 AM |
232 | "driver"); |
233 | if (ret) | |
e5dd1278 | 234 | sysfs_remove_link(&dev->driver->p->kobj, |
f86db396 AM |
235 | kobject_name(&dev->kobj)); |
236 | } | |
237 | return ret; | |
07e4a3e2 PM |
238 | } |
239 | ||
1901fb26 KS |
240 | static void driver_sysfs_remove(struct device *dev) |
241 | { | |
242 | struct device_driver *drv = dev->driver; | |
243 | ||
244 | if (drv) { | |
e5dd1278 | 245 | sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj)); |
1901fb26 KS |
246 | sysfs_remove_link(&dev->kobj, "driver"); |
247 | } | |
248 | } | |
249 | ||
250 | /** | |
4a3ad20c GKH |
251 | * device_bind_driver - bind a driver to one device. |
252 | * @dev: device. | |
1901fb26 | 253 | * |
4a3ad20c GKH |
254 | * Allow manual attachment of a driver to a device. |
255 | * Caller must have already set @dev->driver. | |
1901fb26 | 256 | * |
4a3ad20c GKH |
257 | * 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.) | |
1901fb26 | 261 | * |
8e9394ce | 262 | * This function must be called with the device lock held. |
1901fb26 KS |
263 | */ |
264 | int device_bind_driver(struct device *dev) | |
265 | { | |
cb986b74 CH |
266 | int ret; |
267 | ||
268 | ret = driver_sysfs_add(dev); | |
269 | if (!ret) | |
270 | driver_bound(dev); | |
271 | return ret; | |
1901fb26 | 272 | } |
4a3ad20c | 273 | EXPORT_SYMBOL_GPL(device_bind_driver); |
1901fb26 | 274 | |
d779249e | 275 | static atomic_t probe_count = ATOMIC_INIT(0); |
735a7ffb AM |
276 | static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue); |
277 | ||
21c7f30b | 278 | static int really_probe(struct device *dev, struct device_driver *drv) |
07e4a3e2 | 279 | { |
0d3e5a2e | 280 | int ret = 0; |
58b116bc | 281 | int local_trigger_count = atomic_read(&deferred_trigger_count); |
07e4a3e2 | 282 | |
d779249e | 283 | atomic_inc(&probe_count); |
7dc72b28 | 284 | pr_debug("bus: '%s': %s: probing driver %s with device %s\n", |
1e0b2cf9 | 285 | drv->bus->name, __func__, drv->name, dev_name(dev)); |
9ac7849e | 286 | WARN_ON(!list_empty(&dev->devres_head)); |
07e4a3e2 | 287 | |
07e4a3e2 | 288 | dev->driver = drv; |
ab78029e LW |
289 | |
290 | /* If using pinctrl, bind pins now before probing */ | |
291 | ret = pinctrl_bind_pins(dev); | |
292 | if (ret) | |
293 | goto probe_failed; | |
294 | ||
1901fb26 KS |
295 | if (driver_sysfs_add(dev)) { |
296 | printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n", | |
1e0b2cf9 | 297 | __func__, dev_name(dev)); |
1901fb26 KS |
298 | goto probe_failed; |
299 | } | |
300 | ||
594c8281 RK |
301 | if (dev->bus->probe) { |
302 | ret = dev->bus->probe(dev); | |
1901fb26 | 303 | if (ret) |
d779249e | 304 | goto probe_failed; |
594c8281 | 305 | } else if (drv->probe) { |
0d3e5a2e | 306 | ret = drv->probe(dev); |
1901fb26 | 307 | if (ret) |
d779249e | 308 | goto probe_failed; |
f86db396 | 309 | } |
1901fb26 KS |
310 | |
311 | driver_bound(dev); | |
0d3e5a2e | 312 | ret = 1; |
7dc72b28 | 313 | pr_debug("bus: '%s': %s: bound device %s to driver %s\n", |
1e0b2cf9 | 314 | drv->bus->name, __func__, dev_name(dev), drv->name); |
d779249e | 315 | goto done; |
0d3e5a2e | 316 | |
d779249e | 317 | probe_failed: |
9ac7849e | 318 | devres_release_all(dev); |
1901fb26 KS |
319 | driver_sysfs_remove(dev); |
320 | dev->driver = NULL; | |
0998d063 | 321 | dev_set_drvdata(dev, NULL); |
1901fb26 | 322 | |
bb2b4075 SS |
323 | switch (ret) { |
324 | case -EPROBE_DEFER: | |
d1c3414c GL |
325 | /* Driver requested deferred probing */ |
326 | dev_info(dev, "Driver %s requests probe deferral\n", drv->name); | |
327 | driver_deferred_probe_add(dev); | |
58b116bc GL |
328 | /* Did a trigger occur while probing? Need to re-trigger if yes */ |
329 | if (local_trigger_count != atomic_read(&deferred_trigger_count)) | |
330 | driver_deferred_probe_trigger(); | |
bb2b4075 SS |
331 | break; |
332 | case -ENODEV: | |
333 | case -ENXIO: | |
334 | pr_debug("%s: probe of %s rejects match %d\n", | |
335 | drv->name, dev_name(dev), ret); | |
336 | break; | |
337 | default: | |
0d3e5a2e PM |
338 | /* driver matched but the probe failed */ |
339 | printk(KERN_WARNING | |
340 | "%s: probe of %s failed with error %d\n", | |
1e0b2cf9 | 341 | drv->name, dev_name(dev), ret); |
0d3e5a2e | 342 | } |
c578abbc CH |
343 | /* |
344 | * Ignore errors returned by ->probe so that the next driver can try | |
345 | * its luck. | |
346 | */ | |
347 | ret = 0; | |
d779249e | 348 | done: |
d779249e | 349 | atomic_dec(&probe_count); |
735a7ffb | 350 | wake_up(&probe_waitqueue); |
d779249e GKH |
351 | return ret; |
352 | } | |
353 | ||
354 | /** | |
355 | * driver_probe_done | |
356 | * Determine if the probe sequence is finished or not. | |
357 | * | |
358 | * Should somehow figure out how to use a semaphore, not an atomic variable... | |
359 | */ | |
360 | int driver_probe_done(void) | |
361 | { | |
2b3a302a | 362 | pr_debug("%s: probe_count = %d\n", __func__, |
d779249e GKH |
363 | atomic_read(&probe_count)); |
364 | if (atomic_read(&probe_count)) | |
365 | return -EBUSY; | |
366 | return 0; | |
367 | } | |
368 | ||
216773a7 AV |
369 | /** |
370 | * wait_for_device_probe | |
371 | * Wait for device probing to be completed. | |
216773a7 | 372 | */ |
b23530eb | 373 | void wait_for_device_probe(void) |
216773a7 AV |
374 | { |
375 | /* wait for the known devices to complete their probing */ | |
b23530eb | 376 | wait_event(probe_waitqueue, atomic_read(&probe_count) == 0); |
216773a7 | 377 | async_synchronize_full(); |
216773a7 | 378 | } |
d4d5291c | 379 | EXPORT_SYMBOL_GPL(wait_for_device_probe); |
216773a7 | 380 | |
d779249e GKH |
381 | /** |
382 | * driver_probe_device - attempt to bind device & driver together | |
383 | * @drv: driver to bind a device to | |
384 | * @dev: device to try to bind to the driver | |
385 | * | |
49b420a1 | 386 | * This function returns -ENODEV if the device is not registered, |
af901ca1 | 387 | * 1 if the device is bound successfully and 0 otherwise. |
d779249e | 388 | * |
8e9394ce GKH |
389 | * This function must be called with @dev lock held. When called for a |
390 | * USB interface, @dev->parent lock must be held as well. | |
d779249e | 391 | */ |
4a3ad20c | 392 | int driver_probe_device(struct device_driver *drv, struct device *dev) |
d779249e | 393 | { |
d779249e GKH |
394 | int ret = 0; |
395 | ||
f2eaae19 AS |
396 | if (!device_is_registered(dev)) |
397 | return -ENODEV; | |
d779249e | 398 | |
7dc72b28 | 399 | pr_debug("bus: '%s': %s: matched device %s with driver %s\n", |
1e0b2cf9 | 400 | drv->bus->name, __func__, dev_name(dev), drv->name); |
d779249e | 401 | |
5e928f77 | 402 | pm_runtime_barrier(dev); |
21c7f30b | 403 | ret = really_probe(dev, drv); |
fa180eb4 | 404 | pm_request_idle(dev); |
d779249e | 405 | |
0d3e5a2e | 406 | return ret; |
07e4a3e2 PM |
407 | } |
408 | ||
4a3ad20c | 409 | static int __device_attach(struct device_driver *drv, void *data) |
2287c322 | 410 | { |
4a3ad20c | 411 | struct device *dev = data; |
49b420a1 ML |
412 | |
413 | if (!driver_match_device(drv, dev)) | |
414 | return 0; | |
415 | ||
0d3e5a2e | 416 | return driver_probe_device(drv, dev); |
2287c322 PM |
417 | } |
418 | ||
07e4a3e2 | 419 | /** |
4a3ad20c GKH |
420 | * device_attach - try to attach device to a driver. |
421 | * @dev: device. | |
07e4a3e2 | 422 | * |
4a3ad20c GKH |
423 | * Walk the list of drivers that the bus has and call |
424 | * driver_probe_device() for each pair. If a compatible | |
425 | * pair is found, break out and return. | |
0d3e5a2e | 426 | * |
4a3ad20c | 427 | * Returns 1 if the device was bound to a driver; |
59a3cd7f | 428 | * 0 if no matching driver was found; |
4a3ad20c | 429 | * -ENODEV if the device is not registered. |
bf74ad5b | 430 | * |
8e9394ce | 431 | * When called for a USB interface, @dev->parent lock must be held. |
07e4a3e2 | 432 | */ |
4a3ad20c | 433 | int device_attach(struct device *dev) |
07e4a3e2 | 434 | { |
0d3e5a2e PM |
435 | int ret = 0; |
436 | ||
8e9394ce | 437 | device_lock(dev); |
07e4a3e2 | 438 | if (dev->driver) { |
8497d6a2 SO |
439 | if (klist_node_attached(&dev->p->knode_driver)) { |
440 | ret = 1; | |
441 | goto out_unlock; | |
442 | } | |
f86db396 AM |
443 | ret = device_bind_driver(dev); |
444 | if (ret == 0) | |
445 | ret = 1; | |
c6a46696 CH |
446 | else { |
447 | dev->driver = NULL; | |
448 | ret = 0; | |
449 | } | |
21c7f30b | 450 | } else { |
5adc55da | 451 | ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach); |
fa180eb4 | 452 | pm_request_idle(dev); |
21c7f30b | 453 | } |
8497d6a2 | 454 | out_unlock: |
8e9394ce | 455 | device_unlock(dev); |
0d3e5a2e | 456 | return ret; |
2287c322 | 457 | } |
4a3ad20c | 458 | EXPORT_SYMBOL_GPL(device_attach); |
2287c322 | 459 | |
4a3ad20c | 460 | static int __driver_attach(struct device *dev, void *data) |
2287c322 | 461 | { |
4a3ad20c | 462 | struct device_driver *drv = data; |
0d3e5a2e PM |
463 | |
464 | /* | |
465 | * Lock device and try to bind to it. We drop the error | |
466 | * here and always return 0, because we need to keep trying | |
467 | * to bind to devices and some drivers will return an error | |
468 | * simply if it didn't support the device. | |
469 | * | |
470 | * driver_probe_device() will spit a warning if there | |
471 | * is an error. | |
472 | */ | |
473 | ||
49b420a1 | 474 | if (!driver_match_device(drv, dev)) |
6cd49586 AV |
475 | return 0; |
476 | ||
bf74ad5b | 477 | if (dev->parent) /* Needed for USB */ |
8e9394ce GKH |
478 | device_lock(dev->parent); |
479 | device_lock(dev); | |
0d3e5a2e PM |
480 | if (!dev->driver) |
481 | driver_probe_device(drv, dev); | |
8e9394ce | 482 | device_unlock(dev); |
bf74ad5b | 483 | if (dev->parent) |
8e9394ce | 484 | device_unlock(dev->parent); |
0d3e5a2e | 485 | |
07e4a3e2 PM |
486 | return 0; |
487 | } | |
488 | ||
489 | /** | |
4a3ad20c GKH |
490 | * driver_attach - try to bind driver to devices. |
491 | * @drv: driver. | |
07e4a3e2 | 492 | * |
4a3ad20c GKH |
493 | * Walk the list of devices that the bus has on it and try to |
494 | * match the driver with each one. If driver_probe_device() | |
495 | * returns 0 and the @dev->driver is set, we've found a | |
496 | * compatible pair. | |
07e4a3e2 | 497 | */ |
4a3ad20c | 498 | int driver_attach(struct device_driver *drv) |
07e4a3e2 | 499 | { |
f86db396 | 500 | return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach); |
07e4a3e2 | 501 | } |
4a3ad20c | 502 | EXPORT_SYMBOL_GPL(driver_attach); |
07e4a3e2 | 503 | |
ab71c6f0 | 504 | /* |
8e9394ce GKH |
505 | * __device_release_driver() must be called with @dev lock held. |
506 | * When called for a USB interface, @dev->parent lock must be held as well. | |
07e4a3e2 | 507 | */ |
4a3ad20c | 508 | static void __device_release_driver(struct device *dev) |
07e4a3e2 | 509 | { |
4a3ad20c | 510 | struct device_driver *drv; |
07e4a3e2 | 511 | |
ef2c5174 | 512 | drv = dev->driver; |
c95a6b05 | 513 | if (drv) { |
e1866b33 | 514 | pm_runtime_get_sync(dev); |
5e928f77 | 515 | |
1901fb26 | 516 | driver_sysfs_remove(dev); |
0d3e5a2e | 517 | |
116af378 | 518 | if (dev->bus) |
c6f7e72a | 519 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
116af378 BH |
520 | BUS_NOTIFY_UNBIND_DRIVER, |
521 | dev); | |
522 | ||
baab52de | 523 | pm_runtime_put_sync(dev); |
e1866b33 | 524 | |
0f836ca4 | 525 | if (dev->bus && dev->bus->remove) |
594c8281 RK |
526 | dev->bus->remove(dev); |
527 | else if (drv->remove) | |
0d3e5a2e | 528 | drv->remove(dev); |
9ac7849e | 529 | devres_release_all(dev); |
0d3e5a2e | 530 | dev->driver = NULL; |
0998d063 | 531 | dev_set_drvdata(dev, NULL); |
8940b4f3 | 532 | klist_remove(&dev->p->knode_driver); |
309b7d60 JR |
533 | if (dev->bus) |
534 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
535 | BUS_NOTIFY_UNBOUND_DRIVER, | |
536 | dev); | |
5e928f77 | 537 | |
0d3e5a2e | 538 | } |
07e4a3e2 PM |
539 | } |
540 | ||
ab71c6f0 | 541 | /** |
4a3ad20c GKH |
542 | * device_release_driver - manually detach device from driver. |
543 | * @dev: device. | |
ab71c6f0 | 544 | * |
4a3ad20c | 545 | * Manually detach device from driver. |
8e9394ce | 546 | * When called for a USB interface, @dev->parent lock must be held. |
ab71c6f0 | 547 | */ |
4a3ad20c | 548 | void device_release_driver(struct device *dev) |
94e7b1c5 | 549 | { |
c95a6b05 AS |
550 | /* |
551 | * If anyone calls device_release_driver() recursively from | |
552 | * within their ->remove callback for the same device, they | |
553 | * will deadlock right here. | |
554 | */ | |
8e9394ce | 555 | device_lock(dev); |
c95a6b05 | 556 | __device_release_driver(dev); |
8e9394ce | 557 | device_unlock(dev); |
94e7b1c5 | 558 | } |
4a3ad20c | 559 | EXPORT_SYMBOL_GPL(device_release_driver); |
c95a6b05 | 560 | |
07e4a3e2 PM |
561 | /** |
562 | * driver_detach - detach driver from all devices it controls. | |
563 | * @drv: driver. | |
564 | */ | |
4a3ad20c | 565 | void driver_detach(struct device_driver *drv) |
07e4a3e2 | 566 | { |
8940b4f3 | 567 | struct device_private *dev_prv; |
4a3ad20c | 568 | struct device *dev; |
c95a6b05 AS |
569 | |
570 | for (;;) { | |
e5dd1278 GKH |
571 | spin_lock(&drv->p->klist_devices.k_lock); |
572 | if (list_empty(&drv->p->klist_devices.k_list)) { | |
573 | spin_unlock(&drv->p->klist_devices.k_lock); | |
c95a6b05 AS |
574 | break; |
575 | } | |
8940b4f3 GKH |
576 | dev_prv = list_entry(drv->p->klist_devices.k_list.prev, |
577 | struct device_private, | |
578 | knode_driver.n_node); | |
579 | dev = dev_prv->device; | |
c95a6b05 | 580 | get_device(dev); |
e5dd1278 | 581 | spin_unlock(&drv->p->klist_devices.k_lock); |
c95a6b05 | 582 | |
bf74ad5b | 583 | if (dev->parent) /* Needed for USB */ |
8e9394ce GKH |
584 | device_lock(dev->parent); |
585 | device_lock(dev); | |
c95a6b05 AS |
586 | if (dev->driver == drv) |
587 | __device_release_driver(dev); | |
8e9394ce | 588 | device_unlock(dev); |
bf74ad5b | 589 | if (dev->parent) |
8e9394ce | 590 | device_unlock(dev->parent); |
c95a6b05 AS |
591 | put_device(dev); |
592 | } | |
07e4a3e2 | 593 | } |