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> |
07e4a3e2 | 27 | |
28 | #include "base.h" | |
29 | #include "power/power.h" | |
30 | ||
07e4a3e2 | 31 | |
1901fb26 | 32 | static void driver_bound(struct device *dev) |
07e4a3e2 | 33 | { |
8940b4f3 | 34 | if (klist_node_attached(&dev->p->knode_driver)) { |
f86db396 | 35 | printk(KERN_WARNING "%s: device %s already bound\n", |
2b3a302a | 36 | __func__, kobject_name(&dev->kobj)); |
1901fb26 | 37 | return; |
f86db396 | 38 | } |
4c898c7f | 39 | |
1e0b2cf9 | 40 | pr_debug("driver: '%s': %s: bound to device '%s'\n", dev_name(dev), |
2b3a302a | 41 | __func__, dev->driver->name); |
116af378 | 42 | |
fbb88fad SS |
43 | klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices); |
44 | ||
116af378 | 45 | if (dev->bus) |
c6f7e72a | 46 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
116af378 | 47 | BUS_NOTIFY_BOUND_DRIVER, dev); |
1901fb26 KS |
48 | } |
49 | ||
50 | static int driver_sysfs_add(struct device *dev) | |
51 | { | |
52 | int ret; | |
53 | ||
45daef0f MD |
54 | if (dev->bus) |
55 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
56 | BUS_NOTIFY_BIND_DRIVER, dev); | |
57 | ||
e5dd1278 | 58 | ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj, |
07e4a3e2 | 59 | kobject_name(&dev->kobj)); |
f86db396 | 60 | if (ret == 0) { |
e5dd1278 | 61 | ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj, |
f86db396 AM |
62 | "driver"); |
63 | if (ret) | |
e5dd1278 | 64 | sysfs_remove_link(&dev->driver->p->kobj, |
f86db396 AM |
65 | kobject_name(&dev->kobj)); |
66 | } | |
67 | return ret; | |
07e4a3e2 | 68 | } |
69 | ||
1901fb26 KS |
70 | static void driver_sysfs_remove(struct device *dev) |
71 | { | |
72 | struct device_driver *drv = dev->driver; | |
73 | ||
74 | if (drv) { | |
e5dd1278 | 75 | sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj)); |
1901fb26 KS |
76 | sysfs_remove_link(&dev->kobj, "driver"); |
77 | } | |
78 | } | |
79 | ||
80 | /** | |
4a3ad20c GKH |
81 | * device_bind_driver - bind a driver to one device. |
82 | * @dev: device. | |
1901fb26 | 83 | * |
4a3ad20c GKH |
84 | * Allow manual attachment of a driver to a device. |
85 | * Caller must have already set @dev->driver. | |
1901fb26 | 86 | * |
4a3ad20c GKH |
87 | * Note that this does not modify the bus reference count |
88 | * nor take the bus's rwsem. Please verify those are accounted | |
89 | * for before calling this. (It is ok to call with no other effort | |
90 | * from a driver's probe() method.) | |
1901fb26 | 91 | * |
8e9394ce | 92 | * This function must be called with the device lock held. |
1901fb26 KS |
93 | */ |
94 | int device_bind_driver(struct device *dev) | |
95 | { | |
cb986b74 CH |
96 | int ret; |
97 | ||
98 | ret = driver_sysfs_add(dev); | |
99 | if (!ret) | |
100 | driver_bound(dev); | |
101 | return ret; | |
1901fb26 | 102 | } |
4a3ad20c | 103 | EXPORT_SYMBOL_GPL(device_bind_driver); |
1901fb26 | 104 | |
d779249e | 105 | static atomic_t probe_count = ATOMIC_INIT(0); |
735a7ffb AM |
106 | static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue); |
107 | ||
21c7f30b | 108 | static int really_probe(struct device *dev, struct device_driver *drv) |
07e4a3e2 | 109 | { |
0d3e5a2e | 110 | int ret = 0; |
07e4a3e2 | 111 | |
d779249e | 112 | atomic_inc(&probe_count); |
7dc72b28 | 113 | pr_debug("bus: '%s': %s: probing driver %s with device %s\n", |
1e0b2cf9 | 114 | drv->bus->name, __func__, drv->name, dev_name(dev)); |
9ac7849e | 115 | WARN_ON(!list_empty(&dev->devres_head)); |
07e4a3e2 | 116 | |
07e4a3e2 | 117 | dev->driver = drv; |
1901fb26 KS |
118 | if (driver_sysfs_add(dev)) { |
119 | printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n", | |
1e0b2cf9 | 120 | __func__, dev_name(dev)); |
1901fb26 KS |
121 | goto probe_failed; |
122 | } | |
123 | ||
594c8281 RK |
124 | if (dev->bus->probe) { |
125 | ret = dev->bus->probe(dev); | |
1901fb26 | 126 | if (ret) |
d779249e | 127 | goto probe_failed; |
594c8281 | 128 | } else if (drv->probe) { |
0d3e5a2e | 129 | ret = drv->probe(dev); |
1901fb26 | 130 | if (ret) |
d779249e | 131 | goto probe_failed; |
f86db396 | 132 | } |
1901fb26 KS |
133 | |
134 | driver_bound(dev); | |
0d3e5a2e | 135 | ret = 1; |
7dc72b28 | 136 | pr_debug("bus: '%s': %s: bound device %s to driver %s\n", |
1e0b2cf9 | 137 | drv->bus->name, __func__, dev_name(dev), drv->name); |
d779249e | 138 | goto done; |
0d3e5a2e | 139 | |
d779249e | 140 | probe_failed: |
9ac7849e | 141 | devres_release_all(dev); |
1901fb26 KS |
142 | driver_sysfs_remove(dev); |
143 | dev->driver = NULL; | |
144 | ||
c578abbc | 145 | if (ret != -ENODEV && ret != -ENXIO) { |
0d3e5a2e PM |
146 | /* driver matched but the probe failed */ |
147 | printk(KERN_WARNING | |
148 | "%s: probe of %s failed with error %d\n", | |
1e0b2cf9 | 149 | drv->name, dev_name(dev), ret); |
bcbe4f94 WS |
150 | } else { |
151 | pr_debug("%s: probe of %s rejects match %d\n", | |
152 | drv->name, dev_name(dev), ret); | |
0d3e5a2e | 153 | } |
c578abbc CH |
154 | /* |
155 | * Ignore errors returned by ->probe so that the next driver can try | |
156 | * its luck. | |
157 | */ | |
158 | ret = 0; | |
d779249e | 159 | done: |
d779249e | 160 | atomic_dec(&probe_count); |
735a7ffb | 161 | wake_up(&probe_waitqueue); |
d779249e GKH |
162 | return ret; |
163 | } | |
164 | ||
165 | /** | |
166 | * driver_probe_done | |
167 | * Determine if the probe sequence is finished or not. | |
168 | * | |
169 | * Should somehow figure out how to use a semaphore, not an atomic variable... | |
170 | */ | |
171 | int driver_probe_done(void) | |
172 | { | |
2b3a302a | 173 | pr_debug("%s: probe_count = %d\n", __func__, |
d779249e GKH |
174 | atomic_read(&probe_count)); |
175 | if (atomic_read(&probe_count)) | |
176 | return -EBUSY; | |
177 | return 0; | |
178 | } | |
179 | ||
216773a7 AV |
180 | /** |
181 | * wait_for_device_probe | |
182 | * Wait for device probing to be completed. | |
216773a7 | 183 | */ |
b23530eb | 184 | void wait_for_device_probe(void) |
216773a7 AV |
185 | { |
186 | /* wait for the known devices to complete their probing */ | |
b23530eb | 187 | wait_event(probe_waitqueue, atomic_read(&probe_count) == 0); |
216773a7 | 188 | async_synchronize_full(); |
216773a7 | 189 | } |
d4d5291c | 190 | EXPORT_SYMBOL_GPL(wait_for_device_probe); |
216773a7 | 191 | |
d779249e GKH |
192 | /** |
193 | * driver_probe_device - attempt to bind device & driver together | |
194 | * @drv: driver to bind a device to | |
195 | * @dev: device to try to bind to the driver | |
196 | * | |
49b420a1 | 197 | * This function returns -ENODEV if the device is not registered, |
af901ca1 | 198 | * 1 if the device is bound successfully and 0 otherwise. |
d779249e | 199 | * |
8e9394ce GKH |
200 | * This function must be called with @dev lock held. When called for a |
201 | * USB interface, @dev->parent lock must be held as well. | |
d779249e | 202 | */ |
4a3ad20c | 203 | int driver_probe_device(struct device_driver *drv, struct device *dev) |
d779249e | 204 | { |
d779249e GKH |
205 | int ret = 0; |
206 | ||
f2eaae19 AS |
207 | if (!device_is_registered(dev)) |
208 | return -ENODEV; | |
d779249e | 209 | |
7dc72b28 | 210 | pr_debug("bus: '%s': %s: matched device %s with driver %s\n", |
1e0b2cf9 | 211 | drv->bus->name, __func__, dev_name(dev), drv->name); |
d779249e | 212 | |
5e928f77 RW |
213 | pm_runtime_get_noresume(dev); |
214 | pm_runtime_barrier(dev); | |
21c7f30b | 215 | ret = really_probe(dev, drv); |
5e928f77 | 216 | pm_runtime_put_sync(dev); |
d779249e | 217 | |
0d3e5a2e | 218 | return ret; |
07e4a3e2 | 219 | } |
220 | ||
4a3ad20c | 221 | static int __device_attach(struct device_driver *drv, void *data) |
2287c322 | 222 | { |
4a3ad20c | 223 | struct device *dev = data; |
49b420a1 ML |
224 | |
225 | if (!driver_match_device(drv, dev)) | |
226 | return 0; | |
227 | ||
0d3e5a2e | 228 | return driver_probe_device(drv, dev); |
2287c322 | 229 | } |
230 | ||
07e4a3e2 | 231 | /** |
4a3ad20c GKH |
232 | * device_attach - try to attach device to a driver. |
233 | * @dev: device. | |
07e4a3e2 | 234 | * |
4a3ad20c GKH |
235 | * Walk the list of drivers that the bus has and call |
236 | * driver_probe_device() for each pair. If a compatible | |
237 | * pair is found, break out and return. | |
0d3e5a2e | 238 | * |
4a3ad20c | 239 | * Returns 1 if the device was bound to a driver; |
59a3cd7f | 240 | * 0 if no matching driver was found; |
4a3ad20c | 241 | * -ENODEV if the device is not registered. |
bf74ad5b | 242 | * |
8e9394ce | 243 | * When called for a USB interface, @dev->parent lock must be held. |
07e4a3e2 | 244 | */ |
4a3ad20c | 245 | int device_attach(struct device *dev) |
07e4a3e2 | 246 | { |
0d3e5a2e PM |
247 | int ret = 0; |
248 | ||
8e9394ce | 249 | device_lock(dev); |
07e4a3e2 | 250 | if (dev->driver) { |
8497d6a2 SO |
251 | if (klist_node_attached(&dev->p->knode_driver)) { |
252 | ret = 1; | |
253 | goto out_unlock; | |
254 | } | |
f86db396 AM |
255 | ret = device_bind_driver(dev); |
256 | if (ret == 0) | |
257 | ret = 1; | |
c6a46696 CH |
258 | else { |
259 | dev->driver = NULL; | |
260 | ret = 0; | |
261 | } | |
21c7f30b | 262 | } else { |
5e928f77 | 263 | pm_runtime_get_noresume(dev); |
5adc55da | 264 | ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach); |
5e928f77 | 265 | pm_runtime_put_sync(dev); |
21c7f30b | 266 | } |
8497d6a2 | 267 | out_unlock: |
8e9394ce | 268 | device_unlock(dev); |
0d3e5a2e | 269 | return ret; |
2287c322 | 270 | } |
4a3ad20c | 271 | EXPORT_SYMBOL_GPL(device_attach); |
2287c322 | 272 | |
4a3ad20c | 273 | static int __driver_attach(struct device *dev, void *data) |
2287c322 | 274 | { |
4a3ad20c | 275 | struct device_driver *drv = data; |
0d3e5a2e PM |
276 | |
277 | /* | |
278 | * Lock device and try to bind to it. We drop the error | |
279 | * here and always return 0, because we need to keep trying | |
280 | * to bind to devices and some drivers will return an error | |
281 | * simply if it didn't support the device. | |
282 | * | |
283 | * driver_probe_device() will spit a warning if there | |
284 | * is an error. | |
285 | */ | |
286 | ||
49b420a1 | 287 | if (!driver_match_device(drv, dev)) |
6cd49586 AV |
288 | return 0; |
289 | ||
bf74ad5b | 290 | if (dev->parent) /* Needed for USB */ |
8e9394ce GKH |
291 | device_lock(dev->parent); |
292 | device_lock(dev); | |
0d3e5a2e PM |
293 | if (!dev->driver) |
294 | driver_probe_device(drv, dev); | |
8e9394ce | 295 | device_unlock(dev); |
bf74ad5b | 296 | if (dev->parent) |
8e9394ce | 297 | device_unlock(dev->parent); |
0d3e5a2e | 298 | |
07e4a3e2 | 299 | return 0; |
300 | } | |
301 | ||
302 | /** | |
4a3ad20c GKH |
303 | * driver_attach - try to bind driver to devices. |
304 | * @drv: driver. | |
07e4a3e2 | 305 | * |
4a3ad20c GKH |
306 | * Walk the list of devices that the bus has on it and try to |
307 | * match the driver with each one. If driver_probe_device() | |
308 | * returns 0 and the @dev->driver is set, we've found a | |
309 | * compatible pair. | |
07e4a3e2 | 310 | */ |
4a3ad20c | 311 | int driver_attach(struct device_driver *drv) |
07e4a3e2 | 312 | { |
f86db396 | 313 | return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach); |
07e4a3e2 | 314 | } |
4a3ad20c | 315 | EXPORT_SYMBOL_GPL(driver_attach); |
07e4a3e2 | 316 | |
ab71c6f0 | 317 | /* |
8e9394ce GKH |
318 | * __device_release_driver() must be called with @dev lock held. |
319 | * When called for a USB interface, @dev->parent lock must be held as well. | |
07e4a3e2 | 320 | */ |
4a3ad20c | 321 | static void __device_release_driver(struct device *dev) |
07e4a3e2 | 322 | { |
4a3ad20c | 323 | struct device_driver *drv; |
07e4a3e2 | 324 | |
ef2c5174 | 325 | drv = dev->driver; |
c95a6b05 | 326 | if (drv) { |
e1866b33 | 327 | pm_runtime_get_sync(dev); |
5e928f77 | 328 | |
1901fb26 | 329 | driver_sysfs_remove(dev); |
0d3e5a2e | 330 | |
116af378 | 331 | if (dev->bus) |
c6f7e72a | 332 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
116af378 BH |
333 | BUS_NOTIFY_UNBIND_DRIVER, |
334 | dev); | |
335 | ||
e1866b33 RW |
336 | pm_runtime_put_sync(dev); |
337 | ||
0f836ca4 | 338 | if (dev->bus && dev->bus->remove) |
594c8281 RK |
339 | dev->bus->remove(dev); |
340 | else if (drv->remove) | |
0d3e5a2e | 341 | drv->remove(dev); |
9ac7849e | 342 | devres_release_all(dev); |
0d3e5a2e | 343 | dev->driver = NULL; |
8940b4f3 | 344 | klist_remove(&dev->p->knode_driver); |
309b7d60 JR |
345 | if (dev->bus) |
346 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
347 | BUS_NOTIFY_UNBOUND_DRIVER, | |
348 | dev); | |
5e928f77 | 349 | |
0d3e5a2e | 350 | } |
07e4a3e2 | 351 | } |
352 | ||
ab71c6f0 | 353 | /** |
4a3ad20c GKH |
354 | * device_release_driver - manually detach device from driver. |
355 | * @dev: device. | |
ab71c6f0 | 356 | * |
4a3ad20c | 357 | * Manually detach device from driver. |
8e9394ce | 358 | * When called for a USB interface, @dev->parent lock must be held. |
ab71c6f0 | 359 | */ |
4a3ad20c | 360 | void device_release_driver(struct device *dev) |
94e7b1c5 | 361 | { |
c95a6b05 AS |
362 | /* |
363 | * If anyone calls device_release_driver() recursively from | |
364 | * within their ->remove callback for the same device, they | |
365 | * will deadlock right here. | |
366 | */ | |
8e9394ce | 367 | device_lock(dev); |
c95a6b05 | 368 | __device_release_driver(dev); |
8e9394ce | 369 | device_unlock(dev); |
94e7b1c5 | 370 | } |
4a3ad20c | 371 | EXPORT_SYMBOL_GPL(device_release_driver); |
c95a6b05 | 372 | |
07e4a3e2 | 373 | /** |
374 | * driver_detach - detach driver from all devices it controls. | |
375 | * @drv: driver. | |
376 | */ | |
4a3ad20c | 377 | void driver_detach(struct device_driver *drv) |
07e4a3e2 | 378 | { |
8940b4f3 | 379 | struct device_private *dev_prv; |
4a3ad20c | 380 | struct device *dev; |
c95a6b05 AS |
381 | |
382 | for (;;) { | |
e5dd1278 GKH |
383 | spin_lock(&drv->p->klist_devices.k_lock); |
384 | if (list_empty(&drv->p->klist_devices.k_list)) { | |
385 | spin_unlock(&drv->p->klist_devices.k_lock); | |
c95a6b05 AS |
386 | break; |
387 | } | |
8940b4f3 GKH |
388 | dev_prv = list_entry(drv->p->klist_devices.k_list.prev, |
389 | struct device_private, | |
390 | knode_driver.n_node); | |
391 | dev = dev_prv->device; | |
c95a6b05 | 392 | get_device(dev); |
e5dd1278 | 393 | spin_unlock(&drv->p->klist_devices.k_lock); |
c95a6b05 | 394 | |
bf74ad5b | 395 | if (dev->parent) /* Needed for USB */ |
8e9394ce GKH |
396 | device_lock(dev->parent); |
397 | device_lock(dev); | |
c95a6b05 AS |
398 | if (dev->driver == drv) |
399 | __device_release_driver(dev); | |
8e9394ce | 400 | device_unlock(dev); |
bf74ad5b | 401 | if (dev->parent) |
8e9394ce | 402 | device_unlock(dev->parent); |
c95a6b05 AS |
403 | put_device(dev); |
404 | } | |
07e4a3e2 | 405 | } |
b4028437 GKH |
406 | |
407 | /* | |
408 | * These exports can't be _GPL due to .h files using this within them, and it | |
409 | * might break something that was previously working... | |
410 | */ | |
411 | void *dev_get_drvdata(const struct device *dev) | |
412 | { | |
413 | if (dev && dev->p) | |
414 | return dev->p->driver_data; | |
415 | return NULL; | |
416 | } | |
417 | EXPORT_SYMBOL(dev_get_drvdata); | |
418 | ||
c8705082 | 419 | int dev_set_drvdata(struct device *dev, void *data) |
b4028437 GKH |
420 | { |
421 | int error; | |
422 | ||
b4028437 GKH |
423 | if (!dev->p) { |
424 | error = device_private_init(dev); | |
425 | if (error) | |
c8705082 | 426 | return error; |
b4028437 GKH |
427 | } |
428 | dev->p->driver_data = data; | |
c8705082 | 429 | return 0; |
b4028437 GKH |
430 | } |
431 | EXPORT_SYMBOL(dev_set_drvdata); |