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20#include <linux/device.h>
21#include <linux/delay.h>
22#include <linux/module.h>
23#include <linux/kthread.h>
24#include <linux/wait.h>
25#include <linux/async.h>
26#include <linux/pm_runtime.h>
27
28#include "base.h"
29#include "power/power.h"
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50static DEFINE_MUTEX(deferred_probe_mutex);
51static LIST_HEAD(deferred_probe_pending_list);
52static LIST_HEAD(deferred_probe_active_list);
53static struct workqueue_struct *deferred_wq;
54
55
56
57
58static void deferred_probe_work_func(struct work_struct *work)
59{
60 struct device *dev;
61 struct device_private *private;
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73
74 mutex_lock(&deferred_probe_mutex);
75 while (!list_empty(&deferred_probe_active_list)) {
76 private = list_first_entry(&deferred_probe_active_list,
77 typeof(*dev->p), deferred_probe);
78 dev = private->device;
79 list_del_init(&private->deferred_probe);
80
81 get_device(dev);
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86
87 mutex_unlock(&deferred_probe_mutex);
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94
95 device_pm_lock();
96 device_pm_move_last(dev);
97 device_pm_unlock();
98
99 dev_dbg(dev, "Retrying from deferred list\n");
100 bus_probe_device(dev);
101
102 mutex_lock(&deferred_probe_mutex);
103
104 put_device(dev);
105 }
106 mutex_unlock(&deferred_probe_mutex);
107}
108static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);
109
110static void driver_deferred_probe_add(struct device *dev)
111{
112 mutex_lock(&deferred_probe_mutex);
113 if (list_empty(&dev->p->deferred_probe)) {
114 dev_dbg(dev, "Added to deferred list\n");
115 list_add_tail(&dev->p->deferred_probe, &deferred_probe_pending_list);
116 }
117 mutex_unlock(&deferred_probe_mutex);
118}
119
120void driver_deferred_probe_del(struct device *dev)
121{
122 mutex_lock(&deferred_probe_mutex);
123 if (!list_empty(&dev->p->deferred_probe)) {
124 dev_dbg(dev, "Removed from deferred list\n");
125 list_del_init(&dev->p->deferred_probe);
126 }
127 mutex_unlock(&deferred_probe_mutex);
128}
129
130static bool driver_deferred_probe_enable = false;
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137
138static void driver_deferred_probe_trigger(void)
139{
140 if (!driver_deferred_probe_enable)
141 return;
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147
148 mutex_lock(&deferred_probe_mutex);
149 list_splice_tail_init(&deferred_probe_pending_list,
150 &deferred_probe_active_list);
151 mutex_unlock(&deferred_probe_mutex);
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157 queue_work(deferred_wq, &deferred_probe_work);
158}
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166
167static int deferred_probe_initcall(void)
168{
169 deferred_wq = create_singlethread_workqueue("deferwq");
170 if (WARN_ON(!deferred_wq))
171 return -ENOMEM;
172
173 driver_deferred_probe_enable = true;
174 driver_deferred_probe_trigger();
175 return 0;
176}
177late_initcall(deferred_probe_initcall);
178
179static void driver_bound(struct device *dev)
180{
181 if (klist_node_attached(&dev->p->knode_driver)) {
182 printk(KERN_WARNING "%s: device %s already bound\n",
183 __func__, kobject_name(&dev->kobj));
184 return;
185 }
186
187 pr_debug("driver: '%s': %s: bound to device '%s'\n", dev_name(dev),
188 __func__, dev->driver->name);
189
190 klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices);
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196 driver_deferred_probe_del(dev);
197 driver_deferred_probe_trigger();
198
199 if (dev->bus)
200 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
201 BUS_NOTIFY_BOUND_DRIVER, dev);
202}
203
204static int driver_sysfs_add(struct device *dev)
205{
206 int ret;
207
208 if (dev->bus)
209 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
210 BUS_NOTIFY_BIND_DRIVER, dev);
211
212 ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj,
213 kobject_name(&dev->kobj));
214 if (ret == 0) {
215 ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj,
216 "driver");
217 if (ret)
218 sysfs_remove_link(&dev->driver->p->kobj,
219 kobject_name(&dev->kobj));
220 }
221 return ret;
222}
223
224static void driver_sysfs_remove(struct device *dev)
225{
226 struct device_driver *drv = dev->driver;
227
228 if (drv) {
229 sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj));
230 sysfs_remove_link(&dev->kobj, "driver");
231 }
232}
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248int device_bind_driver(struct device *dev)
249{
250 int ret;
251
252 ret = driver_sysfs_add(dev);
253 if (!ret)
254 driver_bound(dev);
255 return ret;
256}
257EXPORT_SYMBOL_GPL(device_bind_driver);
258
259static atomic_t probe_count = ATOMIC_INIT(0);
260static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);
261
262static int really_probe(struct device *dev, struct device_driver *drv)
263{
264 int ret = 0;
265
266 atomic_inc(&probe_count);
267 pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
268 drv->bus->name, __func__, drv->name, dev_name(dev));
269 WARN_ON(!list_empty(&dev->devres_head));
270
271 dev->driver = drv;
272 if (driver_sysfs_add(dev)) {
273 printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
274 __func__, dev_name(dev));
275 goto probe_failed;
276 }
277
278 if (dev->bus->probe) {
279 ret = dev->bus->probe(dev);
280 if (ret)
281 goto probe_failed;
282 } else if (drv->probe) {
283 ret = drv->probe(dev);
284 if (ret)
285 goto probe_failed;
286 }
287
288 driver_bound(dev);
289 ret = 1;
290 pr_debug("bus: '%s': %s: bound device %s to driver %s\n",
291 drv->bus->name, __func__, dev_name(dev), drv->name);
292 goto done;
293
294probe_failed:
295 devres_release_all(dev);
296 driver_sysfs_remove(dev);
297 dev->driver = NULL;
298 dev_set_drvdata(dev, NULL);
299
300 if (ret == -EPROBE_DEFER) {
301
302 dev_info(dev, "Driver %s requests probe deferral\n", drv->name);
303 driver_deferred_probe_add(dev);
304 } else if (ret != -ENODEV && ret != -ENXIO) {
305
306 printk(KERN_WARNING
307 "%s: probe of %s failed with error %d\n",
308 drv->name, dev_name(dev), ret);
309 } else {
310 pr_debug("%s: probe of %s rejects match %d\n",
311 drv->name, dev_name(dev), ret);
312 }
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317 ret = 0;
318done:
319 atomic_dec(&probe_count);
320 wake_up(&probe_waitqueue);
321 return ret;
322}
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329
330int driver_probe_done(void)
331{
332 pr_debug("%s: probe_count = %d\n", __func__,
333 atomic_read(&probe_count));
334 if (atomic_read(&probe_count))
335 return -EBUSY;
336 return 0;
337}
338
339
340
341
342
343void wait_for_device_probe(void)
344{
345
346 wait_event(probe_waitqueue, atomic_read(&probe_count) == 0);
347 async_synchronize_full();
348}
349EXPORT_SYMBOL_GPL(wait_for_device_probe);
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362int driver_probe_device(struct device_driver *drv, struct device *dev)
363{
364 int ret = 0;
365
366 if (!device_is_registered(dev))
367 return -ENODEV;
368
369 pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
370 drv->bus->name, __func__, dev_name(dev), drv->name);
371
372 pm_runtime_barrier(dev);
373 ret = really_probe(dev, drv);
374 pm_runtime_idle(dev);
375
376 return ret;
377}
378
379static int __device_attach(struct device_driver *drv, void *data)
380{
381 struct device *dev = data;
382
383 if (!driver_match_device(drv, dev))
384 return 0;
385
386 return driver_probe_device(drv, dev);
387}
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403int device_attach(struct device *dev)
404{
405 int ret = 0;
406
407 device_lock(dev);
408 if (dev->driver) {
409 if (klist_node_attached(&dev->p->knode_driver)) {
410 ret = 1;
411 goto out_unlock;
412 }
413 ret = device_bind_driver(dev);
414 if (ret == 0)
415 ret = 1;
416 else {
417 dev->driver = NULL;
418 ret = 0;
419 }
420 } else {
421 ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
422 pm_runtime_idle(dev);
423 }
424out_unlock:
425 device_unlock(dev);
426 return ret;
427}
428EXPORT_SYMBOL_GPL(device_attach);
429
430static int __driver_attach(struct device *dev, void *data)
431{
432 struct device_driver *drv = data;
433
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444 if (!driver_match_device(drv, dev))
445 return 0;
446
447 if (dev->parent)
448 device_lock(dev->parent);
449 device_lock(dev);
450 if (!dev->driver)
451 driver_probe_device(drv, dev);
452 device_unlock(dev);
453 if (dev->parent)
454 device_unlock(dev->parent);
455
456 return 0;
457}
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467
468int driver_attach(struct device_driver *drv)
469{
470 return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
471}
472EXPORT_SYMBOL_GPL(driver_attach);
473
474
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476
477
478static void __device_release_driver(struct device *dev)
479{
480 struct device_driver *drv;
481
482 drv = dev->driver;
483 if (drv) {
484 pm_runtime_get_sync(dev);
485
486 driver_sysfs_remove(dev);
487
488 if (dev->bus)
489 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
490 BUS_NOTIFY_UNBIND_DRIVER,
491 dev);
492
493 pm_runtime_put_sync(dev);
494
495 if (dev->bus && dev->bus->remove)
496 dev->bus->remove(dev);
497 else if (drv->remove)
498 drv->remove(dev);
499 devres_release_all(dev);
500 dev->driver = NULL;
501 dev_set_drvdata(dev, NULL);
502 klist_remove(&dev->p->knode_driver);
503 if (dev->bus)
504 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
505 BUS_NOTIFY_UNBOUND_DRIVER,
506 dev);
507
508 }
509}
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517
518void device_release_driver(struct device *dev)
519{
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525 device_lock(dev);
526 __device_release_driver(dev);
527 device_unlock(dev);
528}
529EXPORT_SYMBOL_GPL(device_release_driver);
530
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535void driver_detach(struct device_driver *drv)
536{
537 struct device_private *dev_prv;
538 struct device *dev;
539
540 for (;;) {
541 spin_lock(&drv->p->klist_devices.k_lock);
542 if (list_empty(&drv->p->klist_devices.k_list)) {
543 spin_unlock(&drv->p->klist_devices.k_lock);
544 break;
545 }
546 dev_prv = list_entry(drv->p->klist_devices.k_list.prev,
547 struct device_private,
548 knode_driver.n_node);
549 dev = dev_prv->device;
550 get_device(dev);
551 spin_unlock(&drv->p->klist_devices.k_lock);
552
553 if (dev->parent)
554 device_lock(dev->parent);
555 device_lock(dev);
556 if (dev->driver == drv)
557 __device_release_driver(dev);
558 device_unlock(dev);
559 if (dev->parent)
560 device_unlock(dev->parent);
561 put_device(dev);
562 }
563}
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568
569void *dev_get_drvdata(const struct device *dev)
570{
571 if (dev && dev->p)
572 return dev->p->driver_data;
573 return NULL;
574}
575EXPORT_SYMBOL(dev_get_drvdata);
576
577int dev_set_drvdata(struct device *dev, void *data)
578{
579 int error;
580
581 if (!dev->p) {
582 error = device_private_init(dev);
583 if (error)
584 return error;
585 }
586 dev->p->driver_data = data;
587 return 0;
588}
589EXPORT_SYMBOL(dev_set_drvdata);
590