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