Commit | Line | Data |
---|---|---|
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 | 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 | 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 | |
9ba8af66 | 144 | * trigger event has already occurred and will be stuck there. |
58b116bc GL |
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 | 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 | ||
e90d5532 RW |
301 | if (dev->pm_domain && dev->pm_domain->activate) { |
302 | ret = dev->pm_domain->activate(dev); | |
303 | if (ret) | |
304 | goto probe_failed; | |
305 | } | |
306 | ||
52cdbdd4 GS |
307 | /* |
308 | * Ensure devices are listed in devices_kset in correct order | |
309 | * It's important to move Dev to the end of devices_kset before | |
310 | * calling .probe, because it could be recursive and parent Dev | |
311 | * should always go first | |
312 | */ | |
313 | devices_kset_move_last(dev); | |
314 | ||
594c8281 RK |
315 | if (dev->bus->probe) { |
316 | ret = dev->bus->probe(dev); | |
1901fb26 | 317 | if (ret) |
d779249e | 318 | goto probe_failed; |
594c8281 | 319 | } else if (drv->probe) { |
0d3e5a2e | 320 | ret = drv->probe(dev); |
1901fb26 | 321 | if (ret) |
d779249e | 322 | goto probe_failed; |
f86db396 | 323 | } |
1901fb26 | 324 | |
ef0eebc0 DA |
325 | pinctrl_init_done(dev); |
326 | ||
e90d5532 RW |
327 | if (dev->pm_domain && dev->pm_domain->sync) |
328 | dev->pm_domain->sync(dev); | |
329 | ||
1901fb26 | 330 | driver_bound(dev); |
0d3e5a2e | 331 | ret = 1; |
7dc72b28 | 332 | pr_debug("bus: '%s': %s: bound device %s to driver %s\n", |
1e0b2cf9 | 333 | drv->bus->name, __func__, dev_name(dev), drv->name); |
d779249e | 334 | goto done; |
0d3e5a2e | 335 | |
d779249e | 336 | probe_failed: |
9ac7849e | 337 | devres_release_all(dev); |
1901fb26 KS |
338 | driver_sysfs_remove(dev); |
339 | dev->driver = NULL; | |
0998d063 | 340 | dev_set_drvdata(dev, NULL); |
e90d5532 RW |
341 | if (dev->pm_domain && dev->pm_domain->dismiss) |
342 | dev->pm_domain->dismiss(dev); | |
1901fb26 | 343 | |
bb2b4075 SS |
344 | switch (ret) { |
345 | case -EPROBE_DEFER: | |
d1c3414c | 346 | /* Driver requested deferred probing */ |
13fcffbb | 347 | dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name); |
d1c3414c | 348 | driver_deferred_probe_add(dev); |
58b116bc GL |
349 | /* Did a trigger occur while probing? Need to re-trigger if yes */ |
350 | if (local_trigger_count != atomic_read(&deferred_trigger_count)) | |
351 | driver_deferred_probe_trigger(); | |
bb2b4075 SS |
352 | break; |
353 | case -ENODEV: | |
354 | case -ENXIO: | |
355 | pr_debug("%s: probe of %s rejects match %d\n", | |
356 | drv->name, dev_name(dev), ret); | |
357 | break; | |
358 | default: | |
0d3e5a2e PM |
359 | /* driver matched but the probe failed */ |
360 | printk(KERN_WARNING | |
361 | "%s: probe of %s failed with error %d\n", | |
1e0b2cf9 | 362 | drv->name, dev_name(dev), ret); |
0d3e5a2e | 363 | } |
c578abbc CH |
364 | /* |
365 | * Ignore errors returned by ->probe so that the next driver can try | |
366 | * its luck. | |
367 | */ | |
368 | ret = 0; | |
d779249e | 369 | done: |
d779249e | 370 | atomic_dec(&probe_count); |
735a7ffb | 371 | wake_up(&probe_waitqueue); |
d779249e GKH |
372 | return ret; |
373 | } | |
374 | ||
375 | /** | |
376 | * driver_probe_done | |
377 | * Determine if the probe sequence is finished or not. | |
378 | * | |
379 | * Should somehow figure out how to use a semaphore, not an atomic variable... | |
380 | */ | |
381 | int driver_probe_done(void) | |
382 | { | |
2b3a302a | 383 | pr_debug("%s: probe_count = %d\n", __func__, |
d779249e GKH |
384 | atomic_read(&probe_count)); |
385 | if (atomic_read(&probe_count)) | |
386 | return -EBUSY; | |
387 | return 0; | |
388 | } | |
389 | ||
216773a7 AV |
390 | /** |
391 | * wait_for_device_probe | |
392 | * Wait for device probing to be completed. | |
216773a7 | 393 | */ |
b23530eb | 394 | void wait_for_device_probe(void) |
216773a7 AV |
395 | { |
396 | /* wait for the known devices to complete their probing */ | |
b23530eb | 397 | wait_event(probe_waitqueue, atomic_read(&probe_count) == 0); |
216773a7 | 398 | async_synchronize_full(); |
216773a7 | 399 | } |
d4d5291c | 400 | EXPORT_SYMBOL_GPL(wait_for_device_probe); |
216773a7 | 401 | |
d779249e GKH |
402 | /** |
403 | * driver_probe_device - attempt to bind device & driver together | |
404 | * @drv: driver to bind a device to | |
405 | * @dev: device to try to bind to the driver | |
406 | * | |
49b420a1 | 407 | * This function returns -ENODEV if the device is not registered, |
af901ca1 | 408 | * 1 if the device is bound successfully and 0 otherwise. |
d779249e | 409 | * |
8e9394ce GKH |
410 | * This function must be called with @dev lock held. When called for a |
411 | * USB interface, @dev->parent lock must be held as well. | |
ddef08dd RW |
412 | * |
413 | * If the device has a parent, runtime-resume the parent before driver probing. | |
d779249e | 414 | */ |
4a3ad20c | 415 | int driver_probe_device(struct device_driver *drv, struct device *dev) |
d779249e | 416 | { |
d779249e GKH |
417 | int ret = 0; |
418 | ||
f2eaae19 AS |
419 | if (!device_is_registered(dev)) |
420 | return -ENODEV; | |
d779249e | 421 | |
7dc72b28 | 422 | pr_debug("bus: '%s': %s: matched device %s with driver %s\n", |
1e0b2cf9 | 423 | drv->bus->name, __func__, dev_name(dev), drv->name); |
d779249e | 424 | |
ddef08dd RW |
425 | if (dev->parent) |
426 | pm_runtime_get_sync(dev->parent); | |
427 | ||
5e928f77 | 428 | pm_runtime_barrier(dev); |
21c7f30b | 429 | ret = really_probe(dev, drv); |
fa180eb4 | 430 | pm_request_idle(dev); |
d779249e | 431 | |
ddef08dd RW |
432 | if (dev->parent) |
433 | pm_runtime_put(dev->parent); | |
434 | ||
0d3e5a2e | 435 | return ret; |
07e4a3e2 | 436 | } |
437 | ||
765230b5 | 438 | bool driver_allows_async_probing(struct device_driver *drv) |
2287c322 | 439 | { |
d173a137 LR |
440 | switch (drv->probe_type) { |
441 | case PROBE_PREFER_ASYNCHRONOUS: | |
f2411da7 LR |
442 | return true; |
443 | ||
d173a137 LR |
444 | case PROBE_FORCE_SYNCHRONOUS: |
445 | return false; | |
446 | ||
447 | default: | |
80c6e146 | 448 | if (module_requested_async_probing(drv->owner)) |
d173a137 | 449 | return true; |
f2411da7 | 450 | |
d173a137 LR |
451 | return false; |
452 | } | |
765230b5 DT |
453 | } |
454 | ||
455 | struct device_attach_data { | |
456 | struct device *dev; | |
457 | ||
458 | /* | |
459 | * Indicates whether we are are considering asynchronous probing or | |
460 | * not. Only initial binding after device or driver registration | |
461 | * (including deferral processing) may be done asynchronously, the | |
462 | * rest is always synchronous, as we expect it is being done by | |
463 | * request from userspace. | |
464 | */ | |
465 | bool check_async; | |
466 | ||
467 | /* | |
468 | * Indicates if we are binding synchronous or asynchronous drivers. | |
469 | * When asynchronous probing is enabled we'll execute 2 passes | |
470 | * over drivers: first pass doing synchronous probing and second | |
471 | * doing asynchronous probing (if synchronous did not succeed - | |
472 | * most likely because there was no driver requiring synchronous | |
473 | * probing - and we found asynchronous driver during first pass). | |
474 | * The 2 passes are done because we can't shoot asynchronous | |
475 | * probe for given device and driver from bus_for_each_drv() since | |
476 | * driver pointer is not guaranteed to stay valid once | |
477 | * bus_for_each_drv() iterates to the next driver on the bus. | |
478 | */ | |
479 | bool want_async; | |
480 | ||
481 | /* | |
482 | * We'll set have_async to 'true' if, while scanning for matching | |
483 | * driver, we'll encounter one that requests asynchronous probing. | |
484 | */ | |
485 | bool have_async; | |
486 | }; | |
487 | ||
488 | static int __device_attach_driver(struct device_driver *drv, void *_data) | |
489 | { | |
490 | struct device_attach_data *data = _data; | |
491 | struct device *dev = data->dev; | |
492 | bool async_allowed; | |
493 | ||
494 | /* | |
495 | * Check if device has already been claimed. This may | |
496 | * happen with driver loading, device discovery/registration, | |
497 | * and deferred probe processing happens all at once with | |
498 | * multiple threads. | |
499 | */ | |
500 | if (dev->driver) | |
501 | return -EBUSY; | |
49b420a1 ML |
502 | |
503 | if (!driver_match_device(drv, dev)) | |
504 | return 0; | |
505 | ||
765230b5 DT |
506 | async_allowed = driver_allows_async_probing(drv); |
507 | ||
508 | if (async_allowed) | |
509 | data->have_async = true; | |
510 | ||
511 | if (data->check_async && async_allowed != data->want_async) | |
512 | return 0; | |
513 | ||
0d3e5a2e | 514 | return driver_probe_device(drv, dev); |
2287c322 | 515 | } |
516 | ||
765230b5 DT |
517 | static void __device_attach_async_helper(void *_dev, async_cookie_t cookie) |
518 | { | |
519 | struct device *dev = _dev; | |
520 | struct device_attach_data data = { | |
521 | .dev = dev, | |
522 | .check_async = true, | |
523 | .want_async = true, | |
524 | }; | |
525 | ||
526 | device_lock(dev); | |
527 | ||
ddef08dd RW |
528 | if (dev->parent) |
529 | pm_runtime_get_sync(dev->parent); | |
530 | ||
765230b5 DT |
531 | bus_for_each_drv(dev->bus, NULL, &data, __device_attach_driver); |
532 | dev_dbg(dev, "async probe completed\n"); | |
533 | ||
534 | pm_request_idle(dev); | |
535 | ||
ddef08dd RW |
536 | if (dev->parent) |
537 | pm_runtime_put(dev->parent); | |
538 | ||
765230b5 DT |
539 | device_unlock(dev); |
540 | ||
541 | put_device(dev); | |
542 | } | |
543 | ||
802a87fd | 544 | static int __device_attach(struct device *dev, bool allow_async) |
07e4a3e2 | 545 | { |
0d3e5a2e PM |
546 | int ret = 0; |
547 | ||
8e9394ce | 548 | device_lock(dev); |
07e4a3e2 | 549 | if (dev->driver) { |
8497d6a2 SO |
550 | if (klist_node_attached(&dev->p->knode_driver)) { |
551 | ret = 1; | |
552 | goto out_unlock; | |
553 | } | |
f86db396 AM |
554 | ret = device_bind_driver(dev); |
555 | if (ret == 0) | |
556 | ret = 1; | |
c6a46696 CH |
557 | else { |
558 | dev->driver = NULL; | |
559 | ret = 0; | |
560 | } | |
21c7f30b | 561 | } else { |
765230b5 DT |
562 | struct device_attach_data data = { |
563 | .dev = dev, | |
564 | .check_async = allow_async, | |
565 | .want_async = false, | |
566 | }; | |
567 | ||
ddef08dd RW |
568 | if (dev->parent) |
569 | pm_runtime_get_sync(dev->parent); | |
570 | ||
765230b5 DT |
571 | ret = bus_for_each_drv(dev->bus, NULL, &data, |
572 | __device_attach_driver); | |
573 | if (!ret && allow_async && data.have_async) { | |
574 | /* | |
575 | * If we could not find appropriate driver | |
576 | * synchronously and we are allowed to do | |
577 | * async probes and there are drivers that | |
578 | * want to probe asynchronously, we'll | |
579 | * try them. | |
580 | */ | |
581 | dev_dbg(dev, "scheduling asynchronous probe\n"); | |
582 | get_device(dev); | |
583 | async_schedule(__device_attach_async_helper, dev); | |
584 | } else { | |
585 | pm_request_idle(dev); | |
586 | } | |
ddef08dd RW |
587 | |
588 | if (dev->parent) | |
589 | pm_runtime_put(dev->parent); | |
21c7f30b | 590 | } |
8497d6a2 | 591 | out_unlock: |
8e9394ce | 592 | device_unlock(dev); |
0d3e5a2e | 593 | return ret; |
2287c322 | 594 | } |
765230b5 DT |
595 | |
596 | /** | |
597 | * device_attach - try to attach device to a driver. | |
598 | * @dev: device. | |
599 | * | |
600 | * Walk the list of drivers that the bus has and call | |
601 | * driver_probe_device() for each pair. If a compatible | |
602 | * pair is found, break out and return. | |
603 | * | |
604 | * Returns 1 if the device was bound to a driver; | |
605 | * 0 if no matching driver was found; | |
606 | * -ENODEV if the device is not registered. | |
607 | * | |
608 | * When called for a USB interface, @dev->parent lock must be held. | |
609 | */ | |
610 | int device_attach(struct device *dev) | |
611 | { | |
612 | return __device_attach(dev, false); | |
613 | } | |
4a3ad20c | 614 | EXPORT_SYMBOL_GPL(device_attach); |
2287c322 | 615 | |
765230b5 DT |
616 | void device_initial_probe(struct device *dev) |
617 | { | |
618 | __device_attach(dev, true); | |
619 | } | |
620 | ||
4a3ad20c | 621 | static int __driver_attach(struct device *dev, void *data) |
2287c322 | 622 | { |
4a3ad20c | 623 | struct device_driver *drv = data; |
0d3e5a2e PM |
624 | |
625 | /* | |
626 | * Lock device and try to bind to it. We drop the error | |
627 | * here and always return 0, because we need to keep trying | |
628 | * to bind to devices and some drivers will return an error | |
629 | * simply if it didn't support the device. | |
630 | * | |
631 | * driver_probe_device() will spit a warning if there | |
632 | * is an error. | |
633 | */ | |
634 | ||
49b420a1 | 635 | if (!driver_match_device(drv, dev)) |
6cd49586 AV |
636 | return 0; |
637 | ||
bf74ad5b | 638 | if (dev->parent) /* Needed for USB */ |
8e9394ce GKH |
639 | device_lock(dev->parent); |
640 | device_lock(dev); | |
0d3e5a2e PM |
641 | if (!dev->driver) |
642 | driver_probe_device(drv, dev); | |
8e9394ce | 643 | device_unlock(dev); |
bf74ad5b | 644 | if (dev->parent) |
8e9394ce | 645 | device_unlock(dev->parent); |
0d3e5a2e | 646 | |
07e4a3e2 | 647 | return 0; |
648 | } | |
649 | ||
650 | /** | |
4a3ad20c GKH |
651 | * driver_attach - try to bind driver to devices. |
652 | * @drv: driver. | |
07e4a3e2 | 653 | * |
4a3ad20c GKH |
654 | * Walk the list of devices that the bus has on it and try to |
655 | * match the driver with each one. If driver_probe_device() | |
656 | * returns 0 and the @dev->driver is set, we've found a | |
657 | * compatible pair. | |
07e4a3e2 | 658 | */ |
4a3ad20c | 659 | int driver_attach(struct device_driver *drv) |
07e4a3e2 | 660 | { |
f86db396 | 661 | return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach); |
07e4a3e2 | 662 | } |
4a3ad20c | 663 | EXPORT_SYMBOL_GPL(driver_attach); |
07e4a3e2 | 664 | |
ab71c6f0 | 665 | /* |
8e9394ce GKH |
666 | * __device_release_driver() must be called with @dev lock held. |
667 | * When called for a USB interface, @dev->parent lock must be held as well. | |
07e4a3e2 | 668 | */ |
4a3ad20c | 669 | static void __device_release_driver(struct device *dev) |
07e4a3e2 | 670 | { |
4a3ad20c | 671 | struct device_driver *drv; |
07e4a3e2 | 672 | |
ef2c5174 | 673 | drv = dev->driver; |
c95a6b05 | 674 | if (drv) { |
765230b5 DT |
675 | if (driver_allows_async_probing(drv)) |
676 | async_synchronize_full(); | |
677 | ||
e1866b33 | 678 | pm_runtime_get_sync(dev); |
5e928f77 | 679 | |
1901fb26 | 680 | driver_sysfs_remove(dev); |
0d3e5a2e | 681 | |
116af378 | 682 | if (dev->bus) |
c6f7e72a | 683 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
116af378 BH |
684 | BUS_NOTIFY_UNBIND_DRIVER, |
685 | dev); | |
686 | ||
baab52de | 687 | pm_runtime_put_sync(dev); |
e1866b33 | 688 | |
0f836ca4 | 689 | if (dev->bus && dev->bus->remove) |
594c8281 RK |
690 | dev->bus->remove(dev); |
691 | else if (drv->remove) | |
0d3e5a2e | 692 | drv->remove(dev); |
9ac7849e | 693 | devres_release_all(dev); |
0d3e5a2e | 694 | dev->driver = NULL; |
0998d063 | 695 | dev_set_drvdata(dev, NULL); |
e90d5532 RW |
696 | if (dev->pm_domain && dev->pm_domain->dismiss) |
697 | dev->pm_domain->dismiss(dev); | |
698 | ||
8940b4f3 | 699 | klist_remove(&dev->p->knode_driver); |
309b7d60 JR |
700 | if (dev->bus) |
701 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
702 | BUS_NOTIFY_UNBOUND_DRIVER, | |
703 | dev); | |
5e928f77 | 704 | |
0d3e5a2e | 705 | } |
07e4a3e2 | 706 | } |
707 | ||
ab71c6f0 | 708 | /** |
4a3ad20c GKH |
709 | * device_release_driver - manually detach device from driver. |
710 | * @dev: device. | |
ab71c6f0 | 711 | * |
4a3ad20c | 712 | * Manually detach device from driver. |
8e9394ce | 713 | * When called for a USB interface, @dev->parent lock must be held. |
ab71c6f0 | 714 | */ |
4a3ad20c | 715 | void device_release_driver(struct device *dev) |
94e7b1c5 | 716 | { |
c95a6b05 AS |
717 | /* |
718 | * If anyone calls device_release_driver() recursively from | |
719 | * within their ->remove callback for the same device, they | |
720 | * will deadlock right here. | |
721 | */ | |
8e9394ce | 722 | device_lock(dev); |
c95a6b05 | 723 | __device_release_driver(dev); |
8e9394ce | 724 | device_unlock(dev); |
94e7b1c5 | 725 | } |
4a3ad20c | 726 | EXPORT_SYMBOL_GPL(device_release_driver); |
c95a6b05 | 727 | |
07e4a3e2 | 728 | /** |
729 | * driver_detach - detach driver from all devices it controls. | |
730 | * @drv: driver. | |
731 | */ | |
4a3ad20c | 732 | void driver_detach(struct device_driver *drv) |
07e4a3e2 | 733 | { |
8940b4f3 | 734 | struct device_private *dev_prv; |
4a3ad20c | 735 | struct device *dev; |
c95a6b05 AS |
736 | |
737 | for (;;) { | |
e5dd1278 GKH |
738 | spin_lock(&drv->p->klist_devices.k_lock); |
739 | if (list_empty(&drv->p->klist_devices.k_list)) { | |
740 | spin_unlock(&drv->p->klist_devices.k_lock); | |
c95a6b05 AS |
741 | break; |
742 | } | |
8940b4f3 GKH |
743 | dev_prv = list_entry(drv->p->klist_devices.k_list.prev, |
744 | struct device_private, | |
745 | knode_driver.n_node); | |
746 | dev = dev_prv->device; | |
c95a6b05 | 747 | get_device(dev); |
e5dd1278 | 748 | spin_unlock(&drv->p->klist_devices.k_lock); |
c95a6b05 | 749 | |
bf74ad5b | 750 | if (dev->parent) /* Needed for USB */ |
8e9394ce GKH |
751 | device_lock(dev->parent); |
752 | device_lock(dev); | |
c95a6b05 AS |
753 | if (dev->driver == drv) |
754 | __device_release_driver(dev); | |
8e9394ce | 755 | device_unlock(dev); |
bf74ad5b | 756 | if (dev->parent) |
8e9394ce | 757 | device_unlock(dev->parent); |
c95a6b05 AS |
758 | put_device(dev); |
759 | } | |
07e4a3e2 | 760 | } |