Commit | Line | Data |
---|---|---|
ed9eccbe DS |
1 | /* |
2 | module/drivers.c | |
3 | functions for manipulating drivers | |
4 | ||
5 | COMEDI - Linux Control and Measurement Device Interface | |
6 | Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org> | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
21 | ||
22 | */ | |
23 | ||
ed9eccbe DS |
24 | #include <linux/device.h> |
25 | #include <linux/module.h> | |
ed9eccbe | 26 | #include <linux/errno.h> |
78b10615 | 27 | #include <linux/kconfig.h> |
ed9eccbe DS |
28 | #include <linux/kernel.h> |
29 | #include <linux/sched.h> | |
30 | #include <linux/fcntl.h> | |
31 | #include <linux/delay.h> | |
32 | #include <linux/ioport.h> | |
33 | #include <linux/mm.h> | |
34 | #include <linux/slab.h> | |
ed9eccbe DS |
35 | #include <linux/highmem.h> /* for SuSE brokenness */ |
36 | #include <linux/vmalloc.h> | |
37 | #include <linux/cdev.h> | |
38 | #include <linux/dma-mapping.h> | |
5617f9da | 39 | #include <linux/io.h> |
ed9eccbe | 40 | |
242e7ad9 | 41 | #include "comedidev.h" |
3a5fa275 | 42 | #include "comedi_internal.h" |
242e7ad9 | 43 | |
139dfbdf | 44 | struct comedi_driver *comedi_drivers; |
ed9eccbe | 45 | |
da717511 IA |
46 | int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev) |
47 | { | |
de06d7c6 IA |
48 | if (hw_dev == dev->hw_dev) |
49 | return 0; | |
50 | if (dev->hw_dev != NULL) | |
51 | return -EEXIST; | |
da717511 | 52 | dev->hw_dev = get_device(hw_dev); |
da717511 IA |
53 | return 0; |
54 | } | |
55 | EXPORT_SYMBOL_GPL(comedi_set_hw_dev); | |
56 | ||
de06d7c6 IA |
57 | static void comedi_clear_hw_dev(struct comedi_device *dev) |
58 | { | |
59 | put_device(dev->hw_dev); | |
60 | dev->hw_dev = NULL; | |
61 | } | |
62 | ||
8b9ba6e5 | 63 | int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices) |
2f0b9d08 | 64 | { |
03afcf47 | 65 | struct comedi_subdevice *s; |
8b9ba6e5 | 66 | int i; |
2f0b9d08 | 67 | |
7f801c41 HS |
68 | if (num_subdevices < 1) |
69 | return -EINVAL; | |
03afcf47 HS |
70 | |
71 | s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL); | |
72 | if (!s) | |
2f0b9d08 | 73 | return -ENOMEM; |
03afcf47 | 74 | dev->subdevices = s; |
fba1d0fa | 75 | dev->n_subdevices = num_subdevices; |
03afcf47 | 76 | |
2f0b9d08 | 77 | for (i = 0; i < num_subdevices; ++i) { |
5e4c58ce | 78 | s = &dev->subdevices[i]; |
03afcf47 | 79 | s->device = dev; |
90a35c15 | 80 | s->index = i; |
03afcf47 HS |
81 | s->async_dma_dir = DMA_NONE; |
82 | spin_lock_init(&s->spin_lock); | |
83 | s->minor = -1; | |
2f0b9d08 HS |
84 | } |
85 | return 0; | |
86 | } | |
87 | EXPORT_SYMBOL_GPL(comedi_alloc_subdevices); | |
88 | ||
2f69915c HS |
89 | void comedi_spriv_free(struct comedi_device *dev, int subdev_num) |
90 | { | |
91 | struct comedi_subdevice *s; | |
92 | ||
93 | if (dev->subdevices && subdev_num < dev->n_subdevices) { | |
94 | s = &dev->subdevices[subdev_num]; | |
95 | kfree(s->private); | |
96 | s->private = NULL; | |
97 | } | |
98 | } | |
99 | EXPORT_SYMBOL_GPL(comedi_spriv_free); | |
100 | ||
71b5f4f1 | 101 | static void cleanup_device(struct comedi_device *dev) |
ed9eccbe DS |
102 | { |
103 | int i; | |
34c43922 | 104 | struct comedi_subdevice *s; |
ed9eccbe DS |
105 | |
106 | if (dev->subdevices) { | |
107 | for (i = 0; i < dev->n_subdevices; i++) { | |
5e4c58ce | 108 | s = &dev->subdevices[i]; |
ed9eccbe DS |
109 | comedi_free_subdevice_minor(s); |
110 | if (s->async) { | |
111 | comedi_buf_alloc(dev, s, 0); | |
112 | kfree(s->async); | |
113 | } | |
114 | } | |
115 | kfree(dev->subdevices); | |
116 | dev->subdevices = NULL; | |
117 | dev->n_subdevices = 0; | |
118 | } | |
dedd1325 BP |
119 | kfree(dev->private); |
120 | dev->private = NULL; | |
7029a874 | 121 | dev->driver = NULL; |
ed9eccbe DS |
122 | dev->board_name = NULL; |
123 | dev->board_ptr = NULL; | |
124 | dev->iobase = 0; | |
316f97f1 | 125 | dev->iolen = 0; |
00ca6884 | 126 | dev->ioenabled = false; |
ed9eccbe DS |
127 | dev->irq = 0; |
128 | dev->read_subdev = NULL; | |
129 | dev->write_subdev = NULL; | |
130 | dev->open = NULL; | |
131 | dev->close = NULL; | |
de06d7c6 | 132 | comedi_clear_hw_dev(dev); |
ed9eccbe DS |
133 | } |
134 | ||
016599f5 | 135 | void comedi_device_detach(struct comedi_device *dev) |
ed9eccbe | 136 | { |
a7401cdd | 137 | dev->attached = false; |
5617f9da | 138 | if (dev->driver) |
ed9eccbe | 139 | dev->driver->detach(dev); |
ed9eccbe DS |
140 | cleanup_device(dev); |
141 | } | |
142 | ||
01fca378 | 143 | static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s) |
ed9eccbe | 144 | { |
01fca378 | 145 | return -EINVAL; |
ed9eccbe DS |
146 | } |
147 | ||
01fca378 HS |
148 | int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, |
149 | struct comedi_insn *insn, unsigned int *data) | |
ed9eccbe | 150 | { |
01fca378 | 151 | return -EINVAL; |
ed9eccbe DS |
152 | } |
153 | ||
01fca378 HS |
154 | static int insn_rw_emulate_bits(struct comedi_device *dev, |
155 | struct comedi_subdevice *s, | |
156 | struct comedi_insn *insn, unsigned int *data) | |
ed9eccbe | 157 | { |
01fca378 HS |
158 | struct comedi_insn new_insn; |
159 | int ret; | |
160 | static const unsigned channels_per_bitfield = 32; | |
ed9eccbe | 161 | |
01fca378 HS |
162 | unsigned chan = CR_CHAN(insn->chanspec); |
163 | const unsigned base_bitfield_channel = | |
164 | (chan < channels_per_bitfield) ? 0 : chan; | |
165 | unsigned int new_data[2]; | |
166 | memset(new_data, 0, sizeof(new_data)); | |
167 | memset(&new_insn, 0, sizeof(new_insn)); | |
168 | new_insn.insn = INSN_BITS; | |
169 | new_insn.chanspec = base_bitfield_channel; | |
170 | new_insn.n = 2; | |
171 | new_insn.subdev = insn->subdev; | |
ed9eccbe | 172 | |
01fca378 HS |
173 | if (insn->insn == INSN_WRITE) { |
174 | if (!(s->subdev_flags & SDF_WRITABLE)) | |
175 | return -EINVAL; | |
176 | new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */ | |
177 | new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel)) | |
178 | : 0; /* bits */ | |
ed9eccbe DS |
179 | } |
180 | ||
01fca378 HS |
181 | ret = s->insn_bits(dev, s, &new_insn, new_data); |
182 | if (ret < 0) | |
183 | return ret; | |
ed9eccbe | 184 | |
01fca378 HS |
185 | if (insn->insn == INSN_READ) |
186 | data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1; | |
187 | ||
188 | return 1; | |
ed9eccbe DS |
189 | } |
190 | ||
40f58a65 HS |
191 | static int __comedi_device_postconfig_async(struct comedi_device *dev, |
192 | struct comedi_subdevice *s) | |
193 | { | |
194 | struct comedi_async *async; | |
195 | unsigned int buf_size; | |
196 | int ret; | |
197 | ||
57b71c3e HS |
198 | if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) { |
199 | dev_warn(dev->class_dev, | |
200 | "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n"); | |
201 | return -EINVAL; | |
202 | } | |
203 | if (!s->do_cmdtest) { | |
204 | dev_warn(dev->class_dev, | |
205 | "async subdevices must have a do_cmdtest() function\n"); | |
206 | return -EINVAL; | |
207 | } | |
40f58a65 HS |
208 | |
209 | async = kzalloc(sizeof(*async), GFP_KERNEL); | |
78110bb8 | 210 | if (!async) |
40f58a65 | 211 | return -ENOMEM; |
78110bb8 | 212 | |
40f58a65 HS |
213 | init_waitqueue_head(&async->wait_head); |
214 | async->subdevice = s; | |
215 | s->async = async; | |
216 | ||
217 | async->max_bufsize = comedi_default_buf_maxsize_kb * 1024; | |
218 | buf_size = comedi_default_buf_size_kb * 1024; | |
219 | if (buf_size > async->max_bufsize) | |
220 | buf_size = async->max_bufsize; | |
221 | ||
222 | if (comedi_buf_alloc(dev, s, buf_size) < 0) { | |
223 | dev_warn(dev->class_dev, "Buffer allocation failed\n"); | |
224 | return -ENOMEM; | |
225 | } | |
226 | if (s->buf_change) { | |
227 | ret = s->buf_change(dev, s, buf_size); | |
228 | if (ret < 0) | |
229 | return ret; | |
230 | } | |
231 | ||
f65cc544 | 232 | comedi_alloc_subdevice_minor(s); |
40f58a65 HS |
233 | |
234 | return 0; | |
235 | } | |
236 | ||
237 | static int __comedi_device_postconfig(struct comedi_device *dev) | |
ed9eccbe | 238 | { |
34c43922 | 239 | struct comedi_subdevice *s; |
ed9eccbe | 240 | int ret; |
40f58a65 | 241 | int i; |
ed9eccbe DS |
242 | |
243 | for (i = 0; i < dev->n_subdevices; i++) { | |
5e4c58ce | 244 | s = &dev->subdevices[i]; |
ed9eccbe DS |
245 | |
246 | if (s->type == COMEDI_SUBD_UNUSED) | |
247 | continue; | |
248 | ||
249 | if (s->len_chanlist == 0) | |
250 | s->len_chanlist = 1; | |
251 | ||
252 | if (s->do_cmd) { | |
40f58a65 HS |
253 | ret = __comedi_device_postconfig_async(dev, s); |
254 | if (ret) | |
255 | return ret; | |
ed9eccbe DS |
256 | } |
257 | ||
258 | if (!s->range_table && !s->range_table_list) | |
259 | s->range_table = &range_unknown; | |
260 | ||
261 | if (!s->insn_read && s->insn_bits) | |
262 | s->insn_read = insn_rw_emulate_bits; | |
263 | if (!s->insn_write && s->insn_bits) | |
264 | s->insn_write = insn_rw_emulate_bits; | |
265 | ||
266 | if (!s->insn_read) | |
267 | s->insn_read = insn_inval; | |
268 | if (!s->insn_write) | |
269 | s->insn_write = insn_inval; | |
270 | if (!s->insn_bits) | |
271 | s->insn_bits = insn_inval; | |
272 | if (!s->insn_config) | |
273 | s->insn_config = insn_inval; | |
274 | ||
275 | if (!s->poll) | |
276 | s->poll = poll_invalid; | |
277 | } | |
278 | ||
279 | return 0; | |
280 | } | |
281 | ||
01fca378 | 282 | /* do a little post-config cleanup */ |
01fca378 HS |
283 | static int comedi_device_postconfig(struct comedi_device *dev) |
284 | { | |
b2a644b4 IA |
285 | int ret; |
286 | ||
287 | ret = __comedi_device_postconfig(dev); | |
ae5dd5fc | 288 | if (ret < 0) |
01fca378 | 289 | return ret; |
01fca378 | 290 | smp_wmb(); |
a7401cdd | 291 | dev->attached = true; |
01fca378 HS |
292 | return 0; |
293 | } | |
294 | ||
4e2f002f IA |
295 | /* |
296 | * Generic recognize function for drivers that register their supported | |
297 | * board names. | |
298 | * | |
299 | * 'driv->board_name' points to a 'const char *' member within the | |
300 | * zeroth element of an array of some private board information | |
301 | * structure, say 'struct foo_board' containing a member 'const char | |
302 | * *board_name' that is initialized to point to a board name string that | |
303 | * is one of the candidates matched against this function's 'name' | |
304 | * parameter. | |
305 | * | |
306 | * 'driv->offset' is the size of the private board information | |
307 | * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is | |
308 | * the length of the array of private board information structures. | |
309 | * | |
310 | * If one of the board names in the array of private board information | |
311 | * structures matches the name supplied to this function, the function | |
312 | * returns a pointer to the pointer to the board name, otherwise it | |
313 | * returns NULL. The return value ends up in the 'board_ptr' member of | |
314 | * a 'struct comedi_device' that the low-level comedi driver's | |
315 | * 'attach()' hook can convert to a point to a particular element of its | |
316 | * array of private board information structures by subtracting the | |
317 | * offset of the member that points to the board name. (No subtraction | |
318 | * is required if the board name pointer is the first member of the | |
319 | * private board information structure, which is generally the case.) | |
320 | */ | |
7029a874 | 321 | static void *comedi_recognize(struct comedi_driver *driv, const char *name) |
ed9eccbe | 322 | { |
1c9de58a DC |
323 | char **name_ptr = (char **)driv->board_name; |
324 | int i; | |
325 | ||
ed9eccbe DS |
326 | for (i = 0; i < driv->num_names; i++) { |
327 | if (strcmp(*name_ptr, name) == 0) | |
1c9de58a DC |
328 | return name_ptr; |
329 | name_ptr = (void *)name_ptr + driv->offset; | |
ed9eccbe DS |
330 | } |
331 | ||
332 | return NULL; | |
333 | } | |
334 | ||
7029a874 | 335 | static void comedi_report_boards(struct comedi_driver *driv) |
ed9eccbe DS |
336 | { |
337 | unsigned int i; | |
338 | const char *const *name_ptr; | |
339 | ||
4f870fe6 IA |
340 | pr_info("comedi: valid board names for %s driver are:\n", |
341 | driv->driver_name); | |
ed9eccbe DS |
342 | |
343 | name_ptr = driv->board_name; | |
344 | for (i = 0; i < driv->num_names; i++) { | |
4f870fe6 | 345 | pr_info(" %s\n", *name_ptr); |
ed9eccbe DS |
346 | name_ptr = (const char **)((char *)name_ptr + driv->offset); |
347 | } | |
348 | ||
349 | if (driv->num_names == 0) | |
4f870fe6 | 350 | pr_info(" %s\n", driv->driver_name); |
ed9eccbe DS |
351 | } |
352 | ||
f375ac5f | 353 | /** |
ca8b2964 | 354 | * __comedi_request_region() - Request an I/O reqion for a legacy driver. |
f375ac5f HS |
355 | * @dev: comedi_device struct |
356 | * @start: base address of the I/O reqion | |
357 | * @len: length of the I/O region | |
358 | */ | |
ca8b2964 HS |
359 | int __comedi_request_region(struct comedi_device *dev, |
360 | unsigned long start, unsigned long len) | |
f375ac5f HS |
361 | { |
362 | if (!start) { | |
363 | dev_warn(dev->class_dev, | |
364 | "%s: a I/O base address must be specified\n", | |
365 | dev->board_name); | |
366 | return -EINVAL; | |
367 | } | |
368 | ||
369 | if (!request_region(start, len, dev->board_name)) { | |
370 | dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n", | |
371 | dev->board_name, start, len); | |
372 | return -EIO; | |
373 | } | |
f375ac5f HS |
374 | |
375 | return 0; | |
376 | } | |
ca8b2964 HS |
377 | EXPORT_SYMBOL_GPL(__comedi_request_region); |
378 | ||
379 | /** | |
380 | * comedi_request_region() - Request an I/O reqion for a legacy driver. | |
381 | * @dev: comedi_device struct | |
382 | * @start: base address of the I/O reqion | |
383 | * @len: length of the I/O region | |
384 | */ | |
385 | int comedi_request_region(struct comedi_device *dev, | |
386 | unsigned long start, unsigned long len) | |
387 | { | |
388 | int ret; | |
389 | ||
390 | ret = __comedi_request_region(dev, start, len); | |
316f97f1 | 391 | if (ret == 0) { |
ca8b2964 | 392 | dev->iobase = start; |
316f97f1 HS |
393 | dev->iolen = len; |
394 | } | |
ca8b2964 HS |
395 | |
396 | return ret; | |
397 | } | |
f375ac5f HS |
398 | EXPORT_SYMBOL_GPL(comedi_request_region); |
399 | ||
316f97f1 HS |
400 | /** |
401 | * comedi_legacy_detach() - A generic (*detach) function for legacy drivers. | |
402 | * @dev: comedi_device struct | |
403 | */ | |
404 | void comedi_legacy_detach(struct comedi_device *dev) | |
405 | { | |
406 | if (dev->iobase && dev->iolen) { | |
407 | release_region(dev->iobase, dev->iolen); | |
408 | dev->iobase = 0; | |
409 | dev->iolen = 0; | |
410 | } | |
411 | } | |
412 | EXPORT_SYMBOL_GPL(comedi_legacy_detach); | |
413 | ||
01fca378 | 414 | int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it) |
ed9eccbe | 415 | { |
01fca378 HS |
416 | struct comedi_driver *driv; |
417 | int ret; | |
418 | ||
419 | if (dev->attached) | |
420 | return -EBUSY; | |
421 | ||
422 | for (driv = comedi_drivers; driv; driv = driv->next) { | |
423 | if (!try_module_get(driv->module)) | |
424 | continue; | |
425 | if (driv->num_names) { | |
426 | dev->board_ptr = comedi_recognize(driv, it->board_name); | |
427 | if (dev->board_ptr) | |
428 | break; | |
429 | } else if (strcmp(driv->driver_name, it->board_name) == 0) | |
430 | break; | |
431 | module_put(driv->module); | |
432 | } | |
433 | if (driv == NULL) { | |
434 | /* recognize has failed if we get here */ | |
435 | /* report valid board names before returning error */ | |
436 | for (driv = comedi_drivers; driv; driv = driv->next) { | |
437 | if (!try_module_get(driv->module)) | |
438 | continue; | |
439 | comedi_report_boards(driv); | |
440 | module_put(driv->module); | |
441 | } | |
442 | return -EIO; | |
443 | } | |
444 | if (driv->attach == NULL) { | |
445 | /* driver does not support manual configuration */ | |
446 | dev_warn(dev->class_dev, | |
447 | "driver '%s' does not support attach using comedi_config\n", | |
448 | driv->driver_name); | |
449 | module_put(driv->module); | |
450 | return -ENOSYS; | |
451 | } | |
452 | /* initialize dev->driver here so | |
453 | * comedi_error() can be called from attach */ | |
454 | dev->driver = driv; | |
34b68400 HS |
455 | dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr |
456 | : dev->driver->driver_name; | |
01fca378 | 457 | ret = driv->attach(dev, it); |
74ece108 IA |
458 | if (ret >= 0) |
459 | ret = comedi_device_postconfig(dev); | |
01fca378 | 460 | if (ret < 0) { |
016599f5 | 461 | comedi_device_detach(dev); |
dcd7b8bd | 462 | module_put(dev->driver->module); |
01fca378 | 463 | } |
b2a644b4 IA |
464 | /* On success, the driver module count has been incremented. */ |
465 | return ret; | |
ed9eccbe DS |
466 | } |
467 | ||
a588da1d IA |
468 | int comedi_auto_config(struct device *hardware_device, |
469 | struct comedi_driver *driver, unsigned long context) | |
f4011670 | 470 | { |
6013a9a5 | 471 | struct comedi_device *dev; |
f4011670 IA |
472 | int ret; |
473 | ||
f08e0ac5 IA |
474 | if (!hardware_device) { |
475 | pr_warn("BUG! comedi_auto_config called with NULL hardware_device\n"); | |
476 | return -EINVAL; | |
477 | } | |
478 | if (!driver) { | |
479 | dev_warn(hardware_device, | |
480 | "BUG! comedi_auto_config called with NULL comedi driver\n"); | |
481 | return -EINVAL; | |
482 | } | |
483 | ||
a588da1d IA |
484 | if (!driver->auto_attach) { |
485 | dev_warn(hardware_device, | |
486 | "BUG! comedi driver '%s' has no auto_attach handler\n", | |
487 | driver->driver_name); | |
488 | return -EINVAL; | |
489 | } | |
490 | ||
6013a9a5 HS |
491 | dev = comedi_alloc_board_minor(hardware_device); |
492 | if (IS_ERR(dev)) | |
493 | return PTR_ERR(dev); | |
494 | /* Note: comedi_alloc_board_minor() locked dev->mutex. */ | |
f4011670 | 495 | |
6013a9a5 | 496 | dev->driver = driver; |
34b68400 | 497 | dev->board_name = dev->driver->driver_name; |
6013a9a5 | 498 | ret = driver->auto_attach(dev, context); |
74ece108 | 499 | if (ret >= 0) |
6013a9a5 | 500 | ret = comedi_device_postconfig(dev); |
b2a644b4 | 501 | if (ret < 0) |
6013a9a5 HS |
502 | comedi_device_detach(dev); |
503 | mutex_unlock(&dev->mutex); | |
f4011670 IA |
504 | |
505 | if (ret < 0) | |
f5b31e15 | 506 | comedi_release_hardware_device(hardware_device); |
f4011670 IA |
507 | return ret; |
508 | } | |
8ed705af IA |
509 | EXPORT_SYMBOL_GPL(comedi_auto_config); |
510 | ||
511 | void comedi_auto_unconfig(struct device *hardware_device) | |
ed9eccbe | 512 | { |
c43435d7 IA |
513 | if (hardware_device == NULL) |
514 | return; | |
3346b798 | 515 | comedi_release_hardware_device(hardware_device); |
ed9eccbe | 516 | } |
8ed705af | 517 | EXPORT_SYMBOL_GPL(comedi_auto_unconfig); |
1ae6b20b HS |
518 | |
519 | int comedi_driver_register(struct comedi_driver *driver) | |
520 | { | |
521 | driver->next = comedi_drivers; | |
522 | comedi_drivers = driver; | |
523 | ||
524 | return 0; | |
525 | } | |
5660e742 | 526 | EXPORT_SYMBOL_GPL(comedi_driver_register); |
1ae6b20b HS |
527 | |
528 | int comedi_driver_unregister(struct comedi_driver *driver) | |
529 | { | |
530 | struct comedi_driver *prev; | |
531 | int i; | |
532 | ||
533 | /* check for devices using this driver */ | |
534 | for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) { | |
535 | struct comedi_device *dev = comedi_dev_from_minor(i); | |
536 | ||
537 | if (!dev) | |
538 | continue; | |
539 | ||
540 | mutex_lock(&dev->mutex); | |
541 | if (dev->attached && dev->driver == driver) { | |
542 | if (dev->use_count) | |
543 | dev_warn(dev->class_dev, | |
544 | "BUG! detaching device with use_count=%d\n", | |
545 | dev->use_count); | |
546 | comedi_device_detach(dev); | |
547 | } | |
548 | mutex_unlock(&dev->mutex); | |
549 | } | |
550 | ||
551 | if (comedi_drivers == driver) { | |
552 | comedi_drivers = driver->next; | |
553 | return 0; | |
554 | } | |
555 | ||
556 | for (prev = comedi_drivers; prev->next; prev = prev->next) { | |
557 | if (prev->next == driver) { | |
558 | prev->next = driver->next; | |
559 | return 0; | |
560 | } | |
561 | } | |
562 | return -EINVAL; | |
563 | } | |
5660e742 | 564 | EXPORT_SYMBOL_GPL(comedi_driver_unregister); |