1 /*
2 * comedi/comedi_fops.c
3 * comedi kernel module
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
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20
21 #include "comedi_compat32.h"
22
23 #include <linux/module.h>
24 #include <linux/errno.h>
25 #include <linux/kernel.h>
26 #include <linux/sched.h>
27 #include <linux/fcntl.h>
28 #include <linux/delay.h>
29 #include <linux/mm.h>
30 #include <linux/slab.h>
31 #include <linux/kmod.h>
32 #include <linux/poll.h>
33 #include <linux/init.h>
34 #include <linux/device.h>
35 #include <linux/vmalloc.h>
36 #include <linux/fs.h>
37 #include "comedidev.h"
38 #include <linux/cdev.h>
39 #include <linux/stat.h>
40
41 #include <linux/io.h>
42 #include <linux/uaccess.h>
43
44 #include "comedi_internal.h"
45
46 /*
47 * comedi_subdevice "runflags"
48 * COMEDI_SRF_RT: DEPRECATED: command is running real-time
49 * COMEDI_SRF_ERROR: indicates an COMEDI_CB_ERROR event has occurred
50 * since the last command was started
51 * COMEDI_SRF_RUNNING: command is running
52 * COMEDI_SRF_FREE_SPRIV: free s->private on detach
53 *
54 * COMEDI_SRF_BUSY_MASK: runflags that indicate the subdevice is "busy"
55 */
56 #define COMEDI_SRF_RT BIT(1)
57 #define COMEDI_SRF_ERROR BIT(2)
58 #define COMEDI_SRF_RUNNING BIT(27)
59 #define COMEDI_SRF_FREE_SPRIV BIT(31)
60
61 #define COMEDI_SRF_BUSY_MASK (COMEDI_SRF_ERROR | COMEDI_SRF_RUNNING)
62
63 /**
64 * struct comedi_file - Per-file private data for COMEDI device
65 * @dev: COMEDI device.
66 * @read_subdev: Current "read" subdevice.
67 * @write_subdev: Current "write" subdevice.
68 * @last_detach_count: Last known detach count.
69 * @last_attached: Last known attached/detached state.
70 */
71 struct comedi_file {
72 struct comedi_device *dev;
73 struct comedi_subdevice *read_subdev;
74 struct comedi_subdevice *write_subdev;
75 unsigned int last_detach_count;
76 bool last_attached:1;
77 };
78
79 #define COMEDI_NUM_MINORS 0x100
80 #define COMEDI_NUM_SUBDEVICE_MINORS \
81 (COMEDI_NUM_MINORS - COMEDI_NUM_BOARD_MINORS)
82
83 static int comedi_num_legacy_minors;
84 module_param(comedi_num_legacy_minors, int, S_IRUGO);
85 MODULE_PARM_DESC(comedi_num_legacy_minors,
86 "number of comedi minor devices to reserve for non-auto-configured devices (default 0)"
87 );
88
89 unsigned int comedi_default_buf_size_kb = CONFIG_COMEDI_DEFAULT_BUF_SIZE_KB;
90 module_param(comedi_default_buf_size_kb, uint, S_IRUGO | S_IWUSR);
91 MODULE_PARM_DESC(comedi_default_buf_size_kb,
92 "default asynchronous buffer size in KiB (default "
93 __MODULE_STRING(CONFIG_COMEDI_DEFAULT_BUF_SIZE_KB) ")");
94
95 unsigned int comedi_default_buf_maxsize_kb
96 = CONFIG_COMEDI_DEFAULT_BUF_MAXSIZE_KB;
97 module_param(comedi_default_buf_maxsize_kb, uint, S_IRUGO | S_IWUSR);
98 MODULE_PARM_DESC(comedi_default_buf_maxsize_kb,
99 "default maximum size of asynchronous buffer in KiB (default "
100 __MODULE_STRING(CONFIG_COMEDI_DEFAULT_BUF_MAXSIZE_KB) ")");
101
102 static DEFINE_MUTEX(comedi_board_minor_table_lock);
103 static struct comedi_device
104 *comedi_board_minor_table[COMEDI_NUM_BOARD_MINORS];
105
106 static DEFINE_MUTEX(comedi_subdevice_minor_table_lock);
107 /* Note: indexed by minor - COMEDI_NUM_BOARD_MINORS. */
108 static struct comedi_subdevice
109 *comedi_subdevice_minor_table[COMEDI_NUM_SUBDEVICE_MINORS];
110
111 static struct class *comedi_class;
112 static struct cdev comedi_cdev;
113
comedi_device_init(struct comedi_device * dev)114 static void comedi_device_init(struct comedi_device *dev)
115 {
116 kref_init(&dev->refcount);
117 spin_lock_init(&dev->spinlock);
118 mutex_init(&dev->mutex);
119 init_rwsem(&dev->attach_lock);
120 dev->minor = -1;
121 }
122
comedi_dev_kref_release(struct kref * kref)123 static void comedi_dev_kref_release(struct kref *kref)
124 {
125 struct comedi_device *dev =
126 container_of(kref, struct comedi_device, refcount);
127
128 mutex_destroy(&dev->mutex);
129 put_device(dev->class_dev);
130 kfree(dev);
131 }
132
133 /**
134 * comedi_dev_put() - Release a use of a COMEDI device
135 * @dev: COMEDI device.
136 *
137 * Must be called when a user of a COMEDI device is finished with it.
138 * When the last user of the COMEDI device calls this function, the
139 * COMEDI device is destroyed.
140 *
141 * Return: 1 if the COMEDI device is destroyed by this call or @dev is
142 * NULL, otherwise return 0. Callers must not assume the COMEDI
143 * device is still valid if this function returns 0.
144 */
comedi_dev_put(struct comedi_device * dev)145 int comedi_dev_put(struct comedi_device *dev)
146 {
147 if (dev)
148 return kref_put(&dev->refcount, comedi_dev_kref_release);
149 return 1;
150 }
151 EXPORT_SYMBOL_GPL(comedi_dev_put);
152
comedi_dev_get(struct comedi_device * dev)153 static struct comedi_device *comedi_dev_get(struct comedi_device *dev)
154 {
155 if (dev)
156 kref_get(&dev->refcount);
157 return dev;
158 }
159
comedi_device_cleanup(struct comedi_device * dev)160 static void comedi_device_cleanup(struct comedi_device *dev)
161 {
162 struct module *driver_module = NULL;
163
164 if (!dev)
165 return;
166 mutex_lock(&dev->mutex);
167 if (dev->attached)
168 driver_module = dev->driver->module;
169 comedi_device_detach(dev);
170 if (driver_module && dev->use_count)
171 module_put(driver_module);
172 mutex_unlock(&dev->mutex);
173 }
174
comedi_clear_board_dev(struct comedi_device * dev)175 static bool comedi_clear_board_dev(struct comedi_device *dev)
176 {
177 unsigned int i = dev->minor;
178 bool cleared = false;
179
180 mutex_lock(&comedi_board_minor_table_lock);
181 if (dev == comedi_board_minor_table[i]) {
182 comedi_board_minor_table[i] = NULL;
183 cleared = true;
184 }
185 mutex_unlock(&comedi_board_minor_table_lock);
186 return cleared;
187 }
188
comedi_clear_board_minor(unsigned minor)189 static struct comedi_device *comedi_clear_board_minor(unsigned minor)
190 {
191 struct comedi_device *dev;
192
193 mutex_lock(&comedi_board_minor_table_lock);
194 dev = comedi_board_minor_table[minor];
195 comedi_board_minor_table[minor] = NULL;
196 mutex_unlock(&comedi_board_minor_table_lock);
197 return dev;
198 }
199
comedi_free_board_dev(struct comedi_device * dev)200 static void comedi_free_board_dev(struct comedi_device *dev)
201 {
202 if (dev) {
203 comedi_device_cleanup(dev);
204 if (dev->class_dev) {
205 device_destroy(comedi_class,
206 MKDEV(COMEDI_MAJOR, dev->minor));
207 }
208 comedi_dev_put(dev);
209 }
210 }
211
212 static struct comedi_subdevice
comedi_subdevice_from_minor(const struct comedi_device * dev,unsigned minor)213 *comedi_subdevice_from_minor(const struct comedi_device *dev, unsigned minor)
214 {
215 struct comedi_subdevice *s;
216 unsigned int i = minor - COMEDI_NUM_BOARD_MINORS;
217
218 mutex_lock(&comedi_subdevice_minor_table_lock);
219 s = comedi_subdevice_minor_table[i];
220 if (s && s->device != dev)
221 s = NULL;
222 mutex_unlock(&comedi_subdevice_minor_table_lock);
223 return s;
224 }
225
comedi_dev_get_from_board_minor(unsigned minor)226 static struct comedi_device *comedi_dev_get_from_board_minor(unsigned minor)
227 {
228 struct comedi_device *dev;
229
230 mutex_lock(&comedi_board_minor_table_lock);
231 dev = comedi_dev_get(comedi_board_minor_table[minor]);
232 mutex_unlock(&comedi_board_minor_table_lock);
233 return dev;
234 }
235
comedi_dev_get_from_subdevice_minor(unsigned minor)236 static struct comedi_device *comedi_dev_get_from_subdevice_minor(unsigned minor)
237 {
238 struct comedi_device *dev;
239 struct comedi_subdevice *s;
240 unsigned int i = minor - COMEDI_NUM_BOARD_MINORS;
241
242 mutex_lock(&comedi_subdevice_minor_table_lock);
243 s = comedi_subdevice_minor_table[i];
244 dev = comedi_dev_get(s ? s->device : NULL);
245 mutex_unlock(&comedi_subdevice_minor_table_lock);
246 return dev;
247 }
248
249 /**
250 * comedi_dev_get_from_minor() - Get COMEDI device by minor device number
251 * @minor: Minor device number.
252 *
253 * Finds the COMEDI device associated with the minor device number, if any,
254 * and increments its reference count. The COMEDI device is prevented from
255 * being freed until a matching call is made to comedi_dev_put().
256 *
257 * Return: A pointer to the COMEDI device if it exists, with its usage
258 * reference incremented. Return NULL if no COMEDI device exists with the
259 * specified minor device number.
260 */
comedi_dev_get_from_minor(unsigned minor)261 struct comedi_device *comedi_dev_get_from_minor(unsigned minor)
262 {
263 if (minor < COMEDI_NUM_BOARD_MINORS)
264 return comedi_dev_get_from_board_minor(minor);
265
266 return comedi_dev_get_from_subdevice_minor(minor);
267 }
268 EXPORT_SYMBOL_GPL(comedi_dev_get_from_minor);
269
270 static struct comedi_subdevice *
comedi_read_subdevice(const struct comedi_device * dev,unsigned int minor)271 comedi_read_subdevice(const struct comedi_device *dev, unsigned int minor)
272 {
273 struct comedi_subdevice *s;
274
275 if (minor >= COMEDI_NUM_BOARD_MINORS) {
276 s = comedi_subdevice_from_minor(dev, minor);
277 if (!s || (s->subdev_flags & SDF_CMD_READ))
278 return s;
279 }
280 return dev->read_subdev;
281 }
282
283 static struct comedi_subdevice *
comedi_write_subdevice(const struct comedi_device * dev,unsigned int minor)284 comedi_write_subdevice(const struct comedi_device *dev, unsigned int minor)
285 {
286 struct comedi_subdevice *s;
287
288 if (minor >= COMEDI_NUM_BOARD_MINORS) {
289 s = comedi_subdevice_from_minor(dev, minor);
290 if (!s || (s->subdev_flags & SDF_CMD_WRITE))
291 return s;
292 }
293 return dev->write_subdev;
294 }
295
comedi_file_reset(struct file * file)296 static void comedi_file_reset(struct file *file)
297 {
298 struct comedi_file *cfp = file->private_data;
299 struct comedi_device *dev = cfp->dev;
300 struct comedi_subdevice *s, *read_s, *write_s;
301 unsigned int minor = iminor(file_inode(file));
302
303 read_s = dev->read_subdev;
304 write_s = dev->write_subdev;
305 if (minor >= COMEDI_NUM_BOARD_MINORS) {
306 s = comedi_subdevice_from_minor(dev, minor);
307 if (!s || s->subdev_flags & SDF_CMD_READ)
308 read_s = s;
309 if (!s || s->subdev_flags & SDF_CMD_WRITE)
310 write_s = s;
311 }
312 cfp->last_attached = dev->attached;
313 cfp->last_detach_count = dev->detach_count;
314 ACCESS_ONCE(cfp->read_subdev) = read_s;
315 ACCESS_ONCE(cfp->write_subdev) = write_s;
316 }
317
comedi_file_check(struct file * file)318 static void comedi_file_check(struct file *file)
319 {
320 struct comedi_file *cfp = file->private_data;
321 struct comedi_device *dev = cfp->dev;
322
323 if (cfp->last_attached != dev->attached ||
324 cfp->last_detach_count != dev->detach_count)
325 comedi_file_reset(file);
326 }
327
comedi_file_read_subdevice(struct file * file)328 static struct comedi_subdevice *comedi_file_read_subdevice(struct file *file)
329 {
330 struct comedi_file *cfp = file->private_data;
331
332 comedi_file_check(file);
333 return ACCESS_ONCE(cfp->read_subdev);
334 }
335
comedi_file_write_subdevice(struct file * file)336 static struct comedi_subdevice *comedi_file_write_subdevice(struct file *file)
337 {
338 struct comedi_file *cfp = file->private_data;
339
340 comedi_file_check(file);
341 return ACCESS_ONCE(cfp->write_subdev);
342 }
343
resize_async_buffer(struct comedi_device * dev,struct comedi_subdevice * s,unsigned new_size)344 static int resize_async_buffer(struct comedi_device *dev,
345 struct comedi_subdevice *s, unsigned new_size)
346 {
347 struct comedi_async *async = s->async;
348 int retval;
349
350 if (new_size > async->max_bufsize)
351 return -EPERM;
352
353 if (s->busy) {
354 dev_dbg(dev->class_dev,
355 "subdevice is busy, cannot resize buffer\n");
356 return -EBUSY;
357 }
358 if (comedi_buf_is_mmapped(s)) {
359 dev_dbg(dev->class_dev,
360 "subdevice is mmapped, cannot resize buffer\n");
361 return -EBUSY;
362 }
363
364 /* make sure buffer is an integral number of pages (we round up) */
365 new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
366
367 retval = comedi_buf_alloc(dev, s, new_size);
368 if (retval < 0)
369 return retval;
370
371 if (s->buf_change) {
372 retval = s->buf_change(dev, s);
373 if (retval < 0)
374 return retval;
375 }
376
377 dev_dbg(dev->class_dev, "subd %d buffer resized to %i bytes\n",
378 s->index, async->prealloc_bufsz);
379 return 0;
380 }
381
382 /* sysfs attribute files */
383
max_read_buffer_kb_show(struct device * csdev,struct device_attribute * attr,char * buf)384 static ssize_t max_read_buffer_kb_show(struct device *csdev,
385 struct device_attribute *attr, char *buf)
386 {
387 unsigned int minor = MINOR(csdev->devt);
388 struct comedi_device *dev;
389 struct comedi_subdevice *s;
390 unsigned int size = 0;
391
392 dev = comedi_dev_get_from_minor(minor);
393 if (!dev)
394 return -ENODEV;
395
396 mutex_lock(&dev->mutex);
397 s = comedi_read_subdevice(dev, minor);
398 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async)
399 size = s->async->max_bufsize / 1024;
400 mutex_unlock(&dev->mutex);
401
402 comedi_dev_put(dev);
403 return snprintf(buf, PAGE_SIZE, "%u\n", size);
404 }
405
max_read_buffer_kb_store(struct device * csdev,struct device_attribute * attr,const char * buf,size_t count)406 static ssize_t max_read_buffer_kb_store(struct device *csdev,
407 struct device_attribute *attr,
408 const char *buf, size_t count)
409 {
410 unsigned int minor = MINOR(csdev->devt);
411 struct comedi_device *dev;
412 struct comedi_subdevice *s;
413 unsigned int size;
414 int err;
415
416 err = kstrtouint(buf, 10, &size);
417 if (err)
418 return err;
419 if (size > (UINT_MAX / 1024))
420 return -EINVAL;
421 size *= 1024;
422
423 dev = comedi_dev_get_from_minor(minor);
424 if (!dev)
425 return -ENODEV;
426
427 mutex_lock(&dev->mutex);
428 s = comedi_read_subdevice(dev, minor);
429 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async)
430 s->async->max_bufsize = size;
431 else
432 err = -EINVAL;
433 mutex_unlock(&dev->mutex);
434
435 comedi_dev_put(dev);
436 return err ? err : count;
437 }
438 static DEVICE_ATTR_RW(max_read_buffer_kb);
439
read_buffer_kb_show(struct device * csdev,struct device_attribute * attr,char * buf)440 static ssize_t read_buffer_kb_show(struct device *csdev,
441 struct device_attribute *attr, char *buf)
442 {
443 unsigned int minor = MINOR(csdev->devt);
444 struct comedi_device *dev;
445 struct comedi_subdevice *s;
446 unsigned int size = 0;
447
448 dev = comedi_dev_get_from_minor(minor);
449 if (!dev)
450 return -ENODEV;
451
452 mutex_lock(&dev->mutex);
453 s = comedi_read_subdevice(dev, minor);
454 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async)
455 size = s->async->prealloc_bufsz / 1024;
456 mutex_unlock(&dev->mutex);
457
458 comedi_dev_put(dev);
459 return snprintf(buf, PAGE_SIZE, "%u\n", size);
460 }
461
read_buffer_kb_store(struct device * csdev,struct device_attribute * attr,const char * buf,size_t count)462 static ssize_t read_buffer_kb_store(struct device *csdev,
463 struct device_attribute *attr,
464 const char *buf, size_t count)
465 {
466 unsigned int minor = MINOR(csdev->devt);
467 struct comedi_device *dev;
468 struct comedi_subdevice *s;
469 unsigned int size;
470 int err;
471
472 err = kstrtouint(buf, 10, &size);
473 if (err)
474 return err;
475 if (size > (UINT_MAX / 1024))
476 return -EINVAL;
477 size *= 1024;
478
479 dev = comedi_dev_get_from_minor(minor);
480 if (!dev)
481 return -ENODEV;
482
483 mutex_lock(&dev->mutex);
484 s = comedi_read_subdevice(dev, minor);
485 if (s && (s->subdev_flags & SDF_CMD_READ) && s->async)
486 err = resize_async_buffer(dev, s, size);
487 else
488 err = -EINVAL;
489 mutex_unlock(&dev->mutex);
490
491 comedi_dev_put(dev);
492 return err ? err : count;
493 }
494 static DEVICE_ATTR_RW(read_buffer_kb);
495
max_write_buffer_kb_show(struct device * csdev,struct device_attribute * attr,char * buf)496 static ssize_t max_write_buffer_kb_show(struct device *csdev,
497 struct device_attribute *attr,
498 char *buf)
499 {
500 unsigned int minor = MINOR(csdev->devt);
501 struct comedi_device *dev;
502 struct comedi_subdevice *s;
503 unsigned int size = 0;
504
505 dev = comedi_dev_get_from_minor(minor);
506 if (!dev)
507 return -ENODEV;
508
509 mutex_lock(&dev->mutex);
510 s = comedi_write_subdevice(dev, minor);
511 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async)
512 size = s->async->max_bufsize / 1024;
513 mutex_unlock(&dev->mutex);
514
515 comedi_dev_put(dev);
516 return snprintf(buf, PAGE_SIZE, "%u\n", size);
517 }
518
max_write_buffer_kb_store(struct device * csdev,struct device_attribute * attr,const char * buf,size_t count)519 static ssize_t max_write_buffer_kb_store(struct device *csdev,
520 struct device_attribute *attr,
521 const char *buf, size_t count)
522 {
523 unsigned int minor = MINOR(csdev->devt);
524 struct comedi_device *dev;
525 struct comedi_subdevice *s;
526 unsigned int size;
527 int err;
528
529 err = kstrtouint(buf, 10, &size);
530 if (err)
531 return err;
532 if (size > (UINT_MAX / 1024))
533 return -EINVAL;
534 size *= 1024;
535
536 dev = comedi_dev_get_from_minor(minor);
537 if (!dev)
538 return -ENODEV;
539
540 mutex_lock(&dev->mutex);
541 s = comedi_write_subdevice(dev, minor);
542 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async)
543 s->async->max_bufsize = size;
544 else
545 err = -EINVAL;
546 mutex_unlock(&dev->mutex);
547
548 comedi_dev_put(dev);
549 return err ? err : count;
550 }
551 static DEVICE_ATTR_RW(max_write_buffer_kb);
552
write_buffer_kb_show(struct device * csdev,struct device_attribute * attr,char * buf)553 static ssize_t write_buffer_kb_show(struct device *csdev,
554 struct device_attribute *attr, char *buf)
555 {
556 unsigned int minor = MINOR(csdev->devt);
557 struct comedi_device *dev;
558 struct comedi_subdevice *s;
559 unsigned int size = 0;
560
561 dev = comedi_dev_get_from_minor(minor);
562 if (!dev)
563 return -ENODEV;
564
565 mutex_lock(&dev->mutex);
566 s = comedi_write_subdevice(dev, minor);
567 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async)
568 size = s->async->prealloc_bufsz / 1024;
569 mutex_unlock(&dev->mutex);
570
571 comedi_dev_put(dev);
572 return snprintf(buf, PAGE_SIZE, "%u\n", size);
573 }
574
write_buffer_kb_store(struct device * csdev,struct device_attribute * attr,const char * buf,size_t count)575 static ssize_t write_buffer_kb_store(struct device *csdev,
576 struct device_attribute *attr,
577 const char *buf, size_t count)
578 {
579 unsigned int minor = MINOR(csdev->devt);
580 struct comedi_device *dev;
581 struct comedi_subdevice *s;
582 unsigned int size;
583 int err;
584
585 err = kstrtouint(buf, 10, &size);
586 if (err)
587 return err;
588 if (size > (UINT_MAX / 1024))
589 return -EINVAL;
590 size *= 1024;
591
592 dev = comedi_dev_get_from_minor(minor);
593 if (!dev)
594 return -ENODEV;
595
596 mutex_lock(&dev->mutex);
597 s = comedi_write_subdevice(dev, minor);
598 if (s && (s->subdev_flags & SDF_CMD_WRITE) && s->async)
599 err = resize_async_buffer(dev, s, size);
600 else
601 err = -EINVAL;
602 mutex_unlock(&dev->mutex);
603
604 comedi_dev_put(dev);
605 return err ? err : count;
606 }
607 static DEVICE_ATTR_RW(write_buffer_kb);
608
609 static struct attribute *comedi_dev_attrs[] = {
610 &dev_attr_max_read_buffer_kb.attr,
611 &dev_attr_read_buffer_kb.attr,
612 &dev_attr_max_write_buffer_kb.attr,
613 &dev_attr_write_buffer_kb.attr,
614 NULL,
615 };
616 ATTRIBUTE_GROUPS(comedi_dev);
617
__comedi_clear_subdevice_runflags(struct comedi_subdevice * s,unsigned bits)618 static void __comedi_clear_subdevice_runflags(struct comedi_subdevice *s,
619 unsigned bits)
620 {
621 s->runflags &= ~bits;
622 }
623
__comedi_set_subdevice_runflags(struct comedi_subdevice * s,unsigned bits)624 static void __comedi_set_subdevice_runflags(struct comedi_subdevice *s,
625 unsigned bits)
626 {
627 s->runflags |= bits;
628 }
629
comedi_update_subdevice_runflags(struct comedi_subdevice * s,unsigned mask,unsigned bits)630 static void comedi_update_subdevice_runflags(struct comedi_subdevice *s,
631 unsigned mask, unsigned bits)
632 {
633 unsigned long flags;
634
635 spin_lock_irqsave(&s->spin_lock, flags);
636 __comedi_clear_subdevice_runflags(s, mask);
637 __comedi_set_subdevice_runflags(s, bits & mask);
638 spin_unlock_irqrestore(&s->spin_lock, flags);
639 }
640
__comedi_get_subdevice_runflags(struct comedi_subdevice * s)641 static unsigned __comedi_get_subdevice_runflags(struct comedi_subdevice *s)
642 {
643 return s->runflags;
644 }
645
comedi_get_subdevice_runflags(struct comedi_subdevice * s)646 static unsigned comedi_get_subdevice_runflags(struct comedi_subdevice *s)
647 {
648 unsigned long flags;
649 unsigned runflags;
650
651 spin_lock_irqsave(&s->spin_lock, flags);
652 runflags = __comedi_get_subdevice_runflags(s);
653 spin_unlock_irqrestore(&s->spin_lock, flags);
654 return runflags;
655 }
656
comedi_is_runflags_running(unsigned runflags)657 static bool comedi_is_runflags_running(unsigned runflags)
658 {
659 return runflags & COMEDI_SRF_RUNNING;
660 }
661
comedi_is_runflags_in_error(unsigned runflags)662 static bool comedi_is_runflags_in_error(unsigned runflags)
663 {
664 return runflags & COMEDI_SRF_ERROR;
665 }
666
667 /**
668 * comedi_is_subdevice_running() - Check if async command running on subdevice
669 * @s: COMEDI subdevice.
670 *
671 * Return: %true if an asynchronous COMEDI command is active on the
672 * subdevice, else %false.
673 */
comedi_is_subdevice_running(struct comedi_subdevice * s)674 bool comedi_is_subdevice_running(struct comedi_subdevice *s)
675 {
676 unsigned runflags = comedi_get_subdevice_runflags(s);
677
678 return comedi_is_runflags_running(runflags);
679 }
680 EXPORT_SYMBOL_GPL(comedi_is_subdevice_running);
681
__comedi_is_subdevice_running(struct comedi_subdevice * s)682 static bool __comedi_is_subdevice_running(struct comedi_subdevice *s)
683 {
684 unsigned runflags = __comedi_get_subdevice_runflags(s);
685
686 return comedi_is_runflags_running(runflags);
687 }
688
comedi_is_subdevice_idle(struct comedi_subdevice * s)689 static bool comedi_is_subdevice_idle(struct comedi_subdevice *s)
690 {
691 unsigned runflags = comedi_get_subdevice_runflags(s);
692
693 return !(runflags & COMEDI_SRF_BUSY_MASK);
694 }
695
comedi_can_auto_free_spriv(struct comedi_subdevice * s)696 bool comedi_can_auto_free_spriv(struct comedi_subdevice *s)
697 {
698 unsigned runflags = __comedi_get_subdevice_runflags(s);
699
700 return runflags & COMEDI_SRF_FREE_SPRIV;
701 }
702
703 /**
704 * comedi_set_spriv_auto_free() - Mark subdevice private data as freeable
705 * @s: COMEDI subdevice.
706 *
707 * Mark the subdevice as having a pointer to private data that can be
708 * automatically freed when the COMEDI device is detached from the low-level
709 * driver.
710 */
comedi_set_spriv_auto_free(struct comedi_subdevice * s)711 void comedi_set_spriv_auto_free(struct comedi_subdevice *s)
712 {
713 __comedi_set_subdevice_runflags(s, COMEDI_SRF_FREE_SPRIV);
714 }
715 EXPORT_SYMBOL_GPL(comedi_set_spriv_auto_free);
716
717 /**
718 * comedi_alloc_spriv - Allocate memory for the subdevice private data
719 * @s: COMEDI subdevice.
720 * @size: Size of the memory to allocate.
721 *
722 * Allocate memory for the subdevice private data and point @s->private
723 * to it. The memory will be freed automatically when the COMEDI device
724 * is detached from the low-level driver.
725 *
726 * Return: A pointer to the allocated memory @s->private on success.
727 * Return NULL on failure.
728 */
comedi_alloc_spriv(struct comedi_subdevice * s,size_t size)729 void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size)
730 {
731 s->private = kzalloc(size, GFP_KERNEL);
732 if (s->private)
733 comedi_set_spriv_auto_free(s);
734 return s->private;
735 }
736 EXPORT_SYMBOL_GPL(comedi_alloc_spriv);
737
738 /*
739 * This function restores a subdevice to an idle state.
740 */
do_become_nonbusy(struct comedi_device * dev,struct comedi_subdevice * s)741 static void do_become_nonbusy(struct comedi_device *dev,
742 struct comedi_subdevice *s)
743 {
744 struct comedi_async *async = s->async;
745
746 comedi_update_subdevice_runflags(s, COMEDI_SRF_RUNNING, 0);
747 if (async) {
748 comedi_buf_reset(s);
749 async->inttrig = NULL;
750 kfree(async->cmd.chanlist);
751 async->cmd.chanlist = NULL;
752 s->busy = NULL;
753 wake_up_interruptible_all(&async->wait_head);
754 } else {
755 dev_err(dev->class_dev,
756 "BUG: (?) do_become_nonbusy called with async=NULL\n");
757 s->busy = NULL;
758 }
759 }
760
do_cancel(struct comedi_device * dev,struct comedi_subdevice * s)761 static int do_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
762 {
763 int ret = 0;
764
765 if (comedi_is_subdevice_running(s) && s->cancel)
766 ret = s->cancel(dev, s);
767
768 do_become_nonbusy(dev, s);
769
770 return ret;
771 }
772
comedi_device_cancel_all(struct comedi_device * dev)773 void comedi_device_cancel_all(struct comedi_device *dev)
774 {
775 struct comedi_subdevice *s;
776 int i;
777
778 if (!dev->attached)
779 return;
780
781 for (i = 0; i < dev->n_subdevices; i++) {
782 s = &dev->subdevices[i];
783 if (s->async)
784 do_cancel(dev, s);
785 }
786 }
787
is_device_busy(struct comedi_device * dev)788 static int is_device_busy(struct comedi_device *dev)
789 {
790 struct comedi_subdevice *s;
791 int i;
792
793 if (!dev->attached)
794 return 0;
795
796 for (i = 0; i < dev->n_subdevices; i++) {
797 s = &dev->subdevices[i];
798 if (s->busy)
799 return 1;
800 if (s->async && comedi_buf_is_mmapped(s))
801 return 1;
802 }
803
804 return 0;
805 }
806
807 /*
808 * COMEDI_DEVCONFIG ioctl
809 * attaches (and configures) or detaches a legacy device
810 *
811 * arg:
812 * pointer to comedi_devconfig structure (NULL if detaching)
813 *
814 * reads:
815 * comedi_devconfig structure (if attaching)
816 *
817 * writes:
818 * nothing
819 */
do_devconfig_ioctl(struct comedi_device * dev,struct comedi_devconfig __user * arg)820 static int do_devconfig_ioctl(struct comedi_device *dev,
821 struct comedi_devconfig __user *arg)
822 {
823 struct comedi_devconfig it;
824
825 if (!capable(CAP_SYS_ADMIN))
826 return -EPERM;
827
828 if (!arg) {
829 if (is_device_busy(dev))
830 return -EBUSY;
831 if (dev->attached) {
832 struct module *driver_module = dev->driver->module;
833
834 comedi_device_detach(dev);
835 module_put(driver_module);
836 }
837 return 0;
838 }
839
840 if (copy_from_user(&it, arg, sizeof(it)))
841 return -EFAULT;
842
843 it.board_name[COMEDI_NAMELEN - 1] = 0;
844
845 if (it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH]) {
846 dev_warn(dev->class_dev,
847 "comedi_config --init_data is deprecated\n");
848 return -EINVAL;
849 }
850
851 if (dev->minor >= comedi_num_legacy_minors)
852 /* don't re-use dynamically allocated comedi devices */
853 return -EBUSY;
854
855 /* This increments the driver module count on success. */
856 return comedi_device_attach(dev, &it);
857 }
858
859 /*
860 * COMEDI_BUFCONFIG ioctl
861 * buffer configuration
862 *
863 * arg:
864 * pointer to comedi_bufconfig structure
865 *
866 * reads:
867 * comedi_bufconfig structure
868 *
869 * writes:
870 * modified comedi_bufconfig structure
871 */
do_bufconfig_ioctl(struct comedi_device * dev,struct comedi_bufconfig __user * arg)872 static int do_bufconfig_ioctl(struct comedi_device *dev,
873 struct comedi_bufconfig __user *arg)
874 {
875 struct comedi_bufconfig bc;
876 struct comedi_async *async;
877 struct comedi_subdevice *s;
878 int retval = 0;
879
880 if (copy_from_user(&bc, arg, sizeof(bc)))
881 return -EFAULT;
882
883 if (bc.subdevice >= dev->n_subdevices)
884 return -EINVAL;
885
886 s = &dev->subdevices[bc.subdevice];
887 async = s->async;
888
889 if (!async) {
890 dev_dbg(dev->class_dev,
891 "subdevice does not have async capability\n");
892 bc.size = 0;
893 bc.maximum_size = 0;
894 goto copyback;
895 }
896
897 if (bc.maximum_size) {
898 if (!capable(CAP_SYS_ADMIN))
899 return -EPERM;
900
901 async->max_bufsize = bc.maximum_size;
902 }
903
904 if (bc.size) {
905 retval = resize_async_buffer(dev, s, bc.size);
906 if (retval < 0)
907 return retval;
908 }
909
910 bc.size = async->prealloc_bufsz;
911 bc.maximum_size = async->max_bufsize;
912
913 copyback:
914 if (copy_to_user(arg, &bc, sizeof(bc)))
915 return -EFAULT;
916
917 return 0;
918 }
919
920 /*
921 * COMEDI_DEVINFO ioctl
922 * device info
923 *
924 * arg:
925 * pointer to comedi_devinfo structure
926 *
927 * reads:
928 * nothing
929 *
930 * writes:
931 * comedi_devinfo structure
932 */
do_devinfo_ioctl(struct comedi_device * dev,struct comedi_devinfo __user * arg,struct file * file)933 static int do_devinfo_ioctl(struct comedi_device *dev,
934 struct comedi_devinfo __user *arg,
935 struct file *file)
936 {
937 struct comedi_subdevice *s;
938 struct comedi_devinfo devinfo;
939
940 memset(&devinfo, 0, sizeof(devinfo));
941
942 /* fill devinfo structure */
943 devinfo.version_code = COMEDI_VERSION_CODE;
944 devinfo.n_subdevs = dev->n_subdevices;
945 strlcpy(devinfo.driver_name, dev->driver->driver_name, COMEDI_NAMELEN);
946 strlcpy(devinfo.board_name, dev->board_name, COMEDI_NAMELEN);
947
948 s = comedi_file_read_subdevice(file);
949 if (s)
950 devinfo.read_subdevice = s->index;
951 else
952 devinfo.read_subdevice = -1;
953
954 s = comedi_file_write_subdevice(file);
955 if (s)
956 devinfo.write_subdevice = s->index;
957 else
958 devinfo.write_subdevice = -1;
959
960 if (copy_to_user(arg, &devinfo, sizeof(devinfo)))
961 return -EFAULT;
962
963 return 0;
964 }
965
966 /*
967 * COMEDI_SUBDINFO ioctl
968 * subdevices info
969 *
970 * arg:
971 * pointer to array of comedi_subdinfo structures
972 *
973 * reads:
974 * nothing
975 *
976 * writes:
977 * array of comedi_subdinfo structures
978 */
do_subdinfo_ioctl(struct comedi_device * dev,struct comedi_subdinfo __user * arg,void * file)979 static int do_subdinfo_ioctl(struct comedi_device *dev,
980 struct comedi_subdinfo __user *arg, void *file)
981 {
982 int ret, i;
983 struct comedi_subdinfo *tmp, *us;
984 struct comedi_subdevice *s;
985
986 tmp = kcalloc(dev->n_subdevices, sizeof(*tmp), GFP_KERNEL);
987 if (!tmp)
988 return -ENOMEM;
989
990 /* fill subdinfo structs */
991 for (i = 0; i < dev->n_subdevices; i++) {
992 s = &dev->subdevices[i];
993 us = tmp + i;
994
995 us->type = s->type;
996 us->n_chan = s->n_chan;
997 us->subd_flags = s->subdev_flags;
998 if (comedi_is_subdevice_running(s))
999 us->subd_flags |= SDF_RUNNING;
1000 #define TIMER_nanosec 5 /* backwards compatibility */
1001 us->timer_type = TIMER_nanosec;
1002 us->len_chanlist = s->len_chanlist;
1003 us->maxdata = s->maxdata;
1004 if (s->range_table) {
1005 us->range_type =
1006 (i << 24) | (0 << 16) | (s->range_table->length);
1007 } else {
1008 us->range_type = 0; /* XXX */
1009 }
1010
1011 if (s->busy)
1012 us->subd_flags |= SDF_BUSY;
1013 if (s->busy == file)
1014 us->subd_flags |= SDF_BUSY_OWNER;
1015 if (s->lock)
1016 us->subd_flags |= SDF_LOCKED;
1017 if (s->lock == file)
1018 us->subd_flags |= SDF_LOCK_OWNER;
1019 if (!s->maxdata && s->maxdata_list)
1020 us->subd_flags |= SDF_MAXDATA;
1021 if (s->range_table_list)
1022 us->subd_flags |= SDF_RANGETYPE;
1023 if (s->do_cmd)
1024 us->subd_flags |= SDF_CMD;
1025
1026 if (s->insn_bits != &insn_inval)
1027 us->insn_bits_support = COMEDI_SUPPORTED;
1028 else
1029 us->insn_bits_support = COMEDI_UNSUPPORTED;
1030 }
1031
1032 ret = copy_to_user(arg, tmp, dev->n_subdevices * sizeof(*tmp));
1033
1034 kfree(tmp);
1035
1036 return ret ? -EFAULT : 0;
1037 }
1038
1039 /*
1040 * COMEDI_CHANINFO ioctl
1041 * subdevice channel info
1042 *
1043 * arg:
1044 * pointer to comedi_chaninfo structure
1045 *
1046 * reads:
1047 * comedi_chaninfo structure
1048 *
1049 * writes:
1050 * array of maxdata values to chaninfo->maxdata_list if requested
1051 * array of range table lengths to chaninfo->range_table_list if requested
1052 */
do_chaninfo_ioctl(struct comedi_device * dev,struct comedi_chaninfo __user * arg)1053 static int do_chaninfo_ioctl(struct comedi_device *dev,
1054 struct comedi_chaninfo __user *arg)
1055 {
1056 struct comedi_subdevice *s;
1057 struct comedi_chaninfo it;
1058
1059 if (copy_from_user(&it, arg, sizeof(it)))
1060 return -EFAULT;
1061
1062 if (it.subdev >= dev->n_subdevices)
1063 return -EINVAL;
1064 s = &dev->subdevices[it.subdev];
1065
1066 if (it.maxdata_list) {
1067 if (s->maxdata || !s->maxdata_list)
1068 return -EINVAL;
1069 if (copy_to_user(it.maxdata_list, s->maxdata_list,
1070 s->n_chan * sizeof(unsigned int)))
1071 return -EFAULT;
1072 }
1073
1074 if (it.flaglist)
1075 return -EINVAL; /* flaglist not supported */
1076
1077 if (it.rangelist) {
1078 int i;
1079
1080 if (!s->range_table_list)
1081 return -EINVAL;
1082 for (i = 0; i < s->n_chan; i++) {
1083 int x;
1084
1085 x = (dev->minor << 28) | (it.subdev << 24) | (i << 16) |
1086 (s->range_table_list[i]->length);
1087 if (put_user(x, it.rangelist + i))
1088 return -EFAULT;
1089 }
1090 }
1091
1092 return 0;
1093 }
1094
1095 /*
1096 * COMEDI_BUFINFO ioctl
1097 * buffer information
1098 *
1099 * arg:
1100 * pointer to comedi_bufinfo structure
1101 *
1102 * reads:
1103 * comedi_bufinfo structure
1104 *
1105 * writes:
1106 * modified comedi_bufinfo structure
1107 */
do_bufinfo_ioctl(struct comedi_device * dev,struct comedi_bufinfo __user * arg,void * file)1108 static int do_bufinfo_ioctl(struct comedi_device *dev,
1109 struct comedi_bufinfo __user *arg, void *file)
1110 {
1111 struct comedi_bufinfo bi;
1112 struct comedi_subdevice *s;
1113 struct comedi_async *async;
1114
1115 if (copy_from_user(&bi, arg, sizeof(bi)))
1116 return -EFAULT;
1117
1118 if (bi.subdevice >= dev->n_subdevices)
1119 return -EINVAL;
1120
1121 s = &dev->subdevices[bi.subdevice];
1122
1123 async = s->async;
1124
1125 if (!async) {
1126 dev_dbg(dev->class_dev,
1127 "subdevice does not have async capability\n");
1128 bi.buf_write_ptr = 0;
1129 bi.buf_read_ptr = 0;
1130 bi.buf_write_count = 0;
1131 bi.buf_read_count = 0;
1132 bi.bytes_read = 0;
1133 bi.bytes_written = 0;
1134 goto copyback;
1135 }
1136 if (!s->busy) {
1137 bi.bytes_read = 0;
1138 bi.bytes_written = 0;
1139 goto copyback_position;
1140 }
1141 if (s->busy != file)
1142 return -EACCES;
1143
1144 if (bi.bytes_read && !(async->cmd.flags & CMDF_WRITE)) {
1145 bi.bytes_read = comedi_buf_read_alloc(s, bi.bytes_read);
1146 comedi_buf_read_free(s, bi.bytes_read);
1147
1148 if (comedi_is_subdevice_idle(s) &&
1149 comedi_buf_read_n_available(s) == 0) {
1150 do_become_nonbusy(dev, s);
1151 }
1152 }
1153
1154 if (bi.bytes_written && (async->cmd.flags & CMDF_WRITE)) {
1155 bi.bytes_written =
1156 comedi_buf_write_alloc(s, bi.bytes_written);
1157 comedi_buf_write_free(s, bi.bytes_written);
1158 }
1159
1160 copyback_position:
1161 bi.buf_write_count = async->buf_write_count;
1162 bi.buf_write_ptr = async->buf_write_ptr;
1163 bi.buf_read_count = async->buf_read_count;
1164 bi.buf_read_ptr = async->buf_read_ptr;
1165
1166 copyback:
1167 if (copy_to_user(arg, &bi, sizeof(bi)))
1168 return -EFAULT;
1169
1170 return 0;
1171 }
1172
check_insn_config_length(struct comedi_insn * insn,unsigned int * data)1173 static int check_insn_config_length(struct comedi_insn *insn,
1174 unsigned int *data)
1175 {
1176 if (insn->n < 1)
1177 return -EINVAL;
1178
1179 switch (data[0]) {
1180 case INSN_CONFIG_DIO_OUTPUT:
1181 case INSN_CONFIG_DIO_INPUT:
1182 case INSN_CONFIG_DISARM:
1183 case INSN_CONFIG_RESET:
1184 if (insn->n == 1)
1185 return 0;
1186 break;
1187 case INSN_CONFIG_ARM:
1188 case INSN_CONFIG_DIO_QUERY:
1189 case INSN_CONFIG_BLOCK_SIZE:
1190 case INSN_CONFIG_FILTER:
1191 case INSN_CONFIG_SERIAL_CLOCK:
1192 case INSN_CONFIG_BIDIRECTIONAL_DATA:
1193 case INSN_CONFIG_ALT_SOURCE:
1194 case INSN_CONFIG_SET_COUNTER_MODE:
1195 case INSN_CONFIG_8254_READ_STATUS:
1196 case INSN_CONFIG_SET_ROUTING:
1197 case INSN_CONFIG_GET_ROUTING:
1198 case INSN_CONFIG_GET_PWM_STATUS:
1199 case INSN_CONFIG_PWM_SET_PERIOD:
1200 case INSN_CONFIG_PWM_GET_PERIOD:
1201 if (insn->n == 2)
1202 return 0;
1203 break;
1204 case INSN_CONFIG_SET_GATE_SRC:
1205 case INSN_CONFIG_GET_GATE_SRC:
1206 case INSN_CONFIG_SET_CLOCK_SRC:
1207 case INSN_CONFIG_GET_CLOCK_SRC:
1208 case INSN_CONFIG_SET_OTHER_SRC:
1209 case INSN_CONFIG_GET_COUNTER_STATUS:
1210 case INSN_CONFIG_PWM_SET_H_BRIDGE:
1211 case INSN_CONFIG_PWM_GET_H_BRIDGE:
1212 case INSN_CONFIG_GET_HARDWARE_BUFFER_SIZE:
1213 if (insn->n == 3)
1214 return 0;
1215 break;
1216 case INSN_CONFIG_PWM_OUTPUT:
1217 case INSN_CONFIG_ANALOG_TRIG:
1218 if (insn->n == 5)
1219 return 0;
1220 break;
1221 case INSN_CONFIG_DIGITAL_TRIG:
1222 if (insn->n == 6)
1223 return 0;
1224 break;
1225 /*
1226 * by default we allow the insn since we don't have checks for
1227 * all possible cases yet
1228 */
1229 default:
1230 pr_warn("No check for data length of config insn id %i is implemented\n",
1231 data[0]);
1232 pr_warn("Add a check to %s in %s\n", __func__, __FILE__);
1233 pr_warn("Assuming n=%i is correct\n", insn->n);
1234 return 0;
1235 }
1236 return -EINVAL;
1237 }
1238
parse_insn(struct comedi_device * dev,struct comedi_insn * insn,unsigned int * data,void * file)1239 static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn,
1240 unsigned int *data, void *file)
1241 {
1242 struct comedi_subdevice *s;
1243 int ret = 0;
1244 int i;
1245
1246 if (insn->insn & INSN_MASK_SPECIAL) {
1247 /* a non-subdevice instruction */
1248
1249 switch (insn->insn) {
1250 case INSN_GTOD:
1251 {
1252 struct timeval tv;
1253
1254 if (insn->n != 2) {
1255 ret = -EINVAL;
1256 break;
1257 }
1258
1259 do_gettimeofday(&tv);
1260 data[0] = tv.tv_sec;
1261 data[1] = tv.tv_usec;
1262 ret = 2;
1263
1264 break;
1265 }
1266 case INSN_WAIT:
1267 if (insn->n != 1 || data[0] >= 100000) {
1268 ret = -EINVAL;
1269 break;
1270 }
1271 udelay(data[0] / 1000);
1272 ret = 1;
1273 break;
1274 case INSN_INTTRIG:
1275 if (insn->n != 1) {
1276 ret = -EINVAL;
1277 break;
1278 }
1279 if (insn->subdev >= dev->n_subdevices) {
1280 dev_dbg(dev->class_dev,
1281 "%d not usable subdevice\n",
1282 insn->subdev);
1283 ret = -EINVAL;
1284 break;
1285 }
1286 s = &dev->subdevices[insn->subdev];
1287 if (!s->async) {
1288 dev_dbg(dev->class_dev, "no async\n");
1289 ret = -EINVAL;
1290 break;
1291 }
1292 if (!s->async->inttrig) {
1293 dev_dbg(dev->class_dev, "no inttrig\n");
1294 ret = -EAGAIN;
1295 break;
1296 }
1297 ret = s->async->inttrig(dev, s, data[0]);
1298 if (ret >= 0)
1299 ret = 1;
1300 break;
1301 default:
1302 dev_dbg(dev->class_dev, "invalid insn\n");
1303 ret = -EINVAL;
1304 break;
1305 }
1306 } else {
1307 /* a subdevice instruction */
1308 unsigned int maxdata;
1309
1310 if (insn->subdev >= dev->n_subdevices) {
1311 dev_dbg(dev->class_dev, "subdevice %d out of range\n",
1312 insn->subdev);
1313 ret = -EINVAL;
1314 goto out;
1315 }
1316 s = &dev->subdevices[insn->subdev];
1317
1318 if (s->type == COMEDI_SUBD_UNUSED) {
1319 dev_dbg(dev->class_dev, "%d not usable subdevice\n",
1320 insn->subdev);
1321 ret = -EIO;
1322 goto out;
1323 }
1324
1325 /* are we locked? (ioctl lock) */
1326 if (s->lock && s->lock != file) {
1327 dev_dbg(dev->class_dev, "device locked\n");
1328 ret = -EACCES;
1329 goto out;
1330 }
1331
1332 ret = comedi_check_chanlist(s, 1, &insn->chanspec);
1333 if (ret < 0) {
1334 ret = -EINVAL;
1335 dev_dbg(dev->class_dev, "bad chanspec\n");
1336 goto out;
1337 }
1338
1339 if (s->busy) {
1340 ret = -EBUSY;
1341 goto out;
1342 }
1343 /* This looks arbitrary. It is. */
1344 s->busy = parse_insn;
1345 switch (insn->insn) {
1346 case INSN_READ:
1347 ret = s->insn_read(dev, s, insn, data);
1348 if (ret == -ETIMEDOUT) {
1349 dev_dbg(dev->class_dev,
1350 "subdevice %d read instruction timed out\n",
1351 s->index);
1352 }
1353 break;
1354 case INSN_WRITE:
1355 maxdata = s->maxdata_list
1356 ? s->maxdata_list[CR_CHAN(insn->chanspec)]
1357 : s->maxdata;
1358 for (i = 0; i < insn->n; ++i) {
1359 if (data[i] > maxdata) {
1360 ret = -EINVAL;
1361 dev_dbg(dev->class_dev,
1362 "bad data value(s)\n");
1363 break;
1364 }
1365 }
1366 if (ret == 0) {
1367 ret = s->insn_write(dev, s, insn, data);
1368 if (ret == -ETIMEDOUT) {
1369 dev_dbg(dev->class_dev,
1370 "subdevice %d write instruction timed out\n",
1371 s->index);
1372 }
1373 }
1374 break;
1375 case INSN_BITS:
1376 if (insn->n != 2) {
1377 ret = -EINVAL;
1378 } else {
1379 /*
1380 * Most drivers ignore the base channel in
1381 * insn->chanspec. Fix this here if
1382 * the subdevice has <= 32 channels.
1383 */
1384 unsigned int orig_mask = data[0];
1385 unsigned int shift = 0;
1386
1387 if (s->n_chan <= 32) {
1388 shift = CR_CHAN(insn->chanspec);
1389 if (shift > 0) {
1390 insn->chanspec = 0;
1391 data[0] <<= shift;
1392 data[1] <<= shift;
1393 }
1394 }
1395 ret = s->insn_bits(dev, s, insn, data);
1396 data[0] = orig_mask;
1397 if (shift > 0)
1398 data[1] >>= shift;
1399 }
1400 break;
1401 case INSN_CONFIG:
1402 ret = check_insn_config_length(insn, data);
1403 if (ret)
1404 break;
1405 ret = s->insn_config(dev, s, insn, data);
1406 break;
1407 default:
1408 ret = -EINVAL;
1409 break;
1410 }
1411
1412 s->busy = NULL;
1413 }
1414
1415 out:
1416 return ret;
1417 }
1418
1419 /*
1420 * COMEDI_INSNLIST ioctl
1421 * synchronous instruction list
1422 *
1423 * arg:
1424 * pointer to comedi_insnlist structure
1425 *
1426 * reads:
1427 * comedi_insnlist structure
1428 * array of comedi_insn structures from insnlist->insns pointer
1429 * data (for writes) from insns[].data pointers
1430 *
1431 * writes:
1432 * data (for reads) to insns[].data pointers
1433 */
1434 /* arbitrary limits */
1435 #define MAX_SAMPLES 256
do_insnlist_ioctl(struct comedi_device * dev,struct comedi_insnlist __user * arg,void * file)1436 static int do_insnlist_ioctl(struct comedi_device *dev,
1437 struct comedi_insnlist __user *arg, void *file)
1438 {
1439 struct comedi_insnlist insnlist;
1440 struct comedi_insn *insns = NULL;
1441 unsigned int *data = NULL;
1442 int i = 0;
1443 int ret = 0;
1444
1445 if (copy_from_user(&insnlist, arg, sizeof(insnlist)))
1446 return -EFAULT;
1447
1448 data = kmalloc_array(MAX_SAMPLES, sizeof(unsigned int), GFP_KERNEL);
1449 if (!data) {
1450 ret = -ENOMEM;
1451 goto error;
1452 }
1453
1454 insns = kcalloc(insnlist.n_insns, sizeof(*insns), GFP_KERNEL);
1455 if (!insns) {
1456 ret = -ENOMEM;
1457 goto error;
1458 }
1459
1460 if (copy_from_user(insns, insnlist.insns,
1461 sizeof(*insns) * insnlist.n_insns)) {
1462 dev_dbg(dev->class_dev, "copy_from_user failed\n");
1463 ret = -EFAULT;
1464 goto error;
1465 }
1466
1467 for (i = 0; i < insnlist.n_insns; i++) {
1468 if (insns[i].n > MAX_SAMPLES) {
1469 dev_dbg(dev->class_dev,
1470 "number of samples too large\n");
1471 ret = -EINVAL;
1472 goto error;
1473 }
1474 if (insns[i].insn & INSN_MASK_WRITE) {
1475 if (copy_from_user(data, insns[i].data,
1476 insns[i].n * sizeof(unsigned int))) {
1477 dev_dbg(dev->class_dev,
1478 "copy_from_user failed\n");
1479 ret = -EFAULT;
1480 goto error;
1481 }
1482 }
1483 ret = parse_insn(dev, insns + i, data, file);
1484 if (ret < 0)
1485 goto error;
1486 if (insns[i].insn & INSN_MASK_READ) {
1487 if (copy_to_user(insns[i].data, data,
1488 insns[i].n * sizeof(unsigned int))) {
1489 dev_dbg(dev->class_dev,
1490 "copy_to_user failed\n");
1491 ret = -EFAULT;
1492 goto error;
1493 }
1494 }
1495 if (need_resched())
1496 schedule();
1497 }
1498
1499 error:
1500 kfree(insns);
1501 kfree(data);
1502
1503 if (ret < 0)
1504 return ret;
1505 return i;
1506 }
1507
1508 /*
1509 * COMEDI_INSN ioctl
1510 * synchronous instruction
1511 *
1512 * arg:
1513 * pointer to comedi_insn structure
1514 *
1515 * reads:
1516 * comedi_insn structure
1517 * data (for writes) from insn->data pointer
1518 *
1519 * writes:
1520 * data (for reads) to insn->data pointer
1521 */
do_insn_ioctl(struct comedi_device * dev,struct comedi_insn __user * arg,void * file)1522 static int do_insn_ioctl(struct comedi_device *dev,
1523 struct comedi_insn __user *arg, void *file)
1524 {
1525 struct comedi_insn insn;
1526 unsigned int *data = NULL;
1527 int ret = 0;
1528
1529 data = kmalloc_array(MAX_SAMPLES, sizeof(unsigned int), GFP_KERNEL);
1530 if (!data) {
1531 ret = -ENOMEM;
1532 goto error;
1533 }
1534
1535 if (copy_from_user(&insn, arg, sizeof(insn))) {
1536 ret = -EFAULT;
1537 goto error;
1538 }
1539
1540 /* This is where the behavior of insn and insnlist deviate. */
1541 if (insn.n > MAX_SAMPLES)
1542 insn.n = MAX_SAMPLES;
1543 if (insn.insn & INSN_MASK_WRITE) {
1544 if (copy_from_user(data,
1545 insn.data,
1546 insn.n * sizeof(unsigned int))) {
1547 ret = -EFAULT;
1548 goto error;
1549 }
1550 }
1551 ret = parse_insn(dev, &insn, data, file);
1552 if (ret < 0)
1553 goto error;
1554 if (insn.insn & INSN_MASK_READ) {
1555 if (copy_to_user(insn.data,
1556 data,
1557 insn.n * sizeof(unsigned int))) {
1558 ret = -EFAULT;
1559 goto error;
1560 }
1561 }
1562 ret = insn.n;
1563
1564 error:
1565 kfree(data);
1566
1567 return ret;
1568 }
1569
__comedi_get_user_cmd(struct comedi_device * dev,struct comedi_cmd __user * arg,struct comedi_cmd * cmd)1570 static int __comedi_get_user_cmd(struct comedi_device *dev,
1571 struct comedi_cmd __user *arg,
1572 struct comedi_cmd *cmd)
1573 {
1574 struct comedi_subdevice *s;
1575
1576 if (copy_from_user(cmd, arg, sizeof(*cmd))) {
1577 dev_dbg(dev->class_dev, "bad cmd address\n");
1578 return -EFAULT;
1579 }
1580
1581 if (cmd->subdev >= dev->n_subdevices) {
1582 dev_dbg(dev->class_dev, "%d no such subdevice\n", cmd->subdev);
1583 return -ENODEV;
1584 }
1585
1586 s = &dev->subdevices[cmd->subdev];
1587
1588 if (s->type == COMEDI_SUBD_UNUSED) {
1589 dev_dbg(dev->class_dev, "%d not valid subdevice\n",
1590 cmd->subdev);
1591 return -EIO;
1592 }
1593
1594 if (!s->do_cmd || !s->do_cmdtest || !s->async) {
1595 dev_dbg(dev->class_dev,
1596 "subdevice %d does not support commands\n",
1597 cmd->subdev);
1598 return -EIO;
1599 }
1600
1601 /* make sure channel/gain list isn't too long */
1602 if (cmd->chanlist_len > s->len_chanlist) {
1603 dev_dbg(dev->class_dev, "channel/gain list too long %d > %d\n",
1604 cmd->chanlist_len, s->len_chanlist);
1605 return -EINVAL;
1606 }
1607
1608 /*
1609 * Set the CMDF_WRITE flag to the correct state if the subdevice
1610 * supports only "read" commands or only "write" commands.
1611 */
1612 switch (s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) {
1613 case SDF_CMD_READ:
1614 cmd->flags &= ~CMDF_WRITE;
1615 break;
1616 case SDF_CMD_WRITE:
1617 cmd->flags |= CMDF_WRITE;
1618 break;
1619 default:
1620 break;
1621 }
1622
1623 return 0;
1624 }
1625
__comedi_get_user_chanlist(struct comedi_device * dev,struct comedi_subdevice * s,unsigned int __user * user_chanlist,struct comedi_cmd * cmd)1626 static int __comedi_get_user_chanlist(struct comedi_device *dev,
1627 struct comedi_subdevice *s,
1628 unsigned int __user *user_chanlist,
1629 struct comedi_cmd *cmd)
1630 {
1631 unsigned int *chanlist;
1632 int ret;
1633
1634 cmd->chanlist = NULL;
1635 chanlist = memdup_user(user_chanlist,
1636 cmd->chanlist_len * sizeof(unsigned int));
1637 if (IS_ERR(chanlist))
1638 return PTR_ERR(chanlist);
1639
1640 /* make sure each element in channel/gain list is valid */
1641 ret = comedi_check_chanlist(s, cmd->chanlist_len, chanlist);
1642 if (ret < 0) {
1643 kfree(chanlist);
1644 return ret;
1645 }
1646
1647 cmd->chanlist = chanlist;
1648
1649 return 0;
1650 }
1651
1652 /*
1653 * COMEDI_CMD ioctl
1654 * asynchronous acquisition command set-up
1655 *
1656 * arg:
1657 * pointer to comedi_cmd structure
1658 *
1659 * reads:
1660 * comedi_cmd structure
1661 * channel/range list from cmd->chanlist pointer
1662 *
1663 * writes:
1664 * possibly modified comedi_cmd structure (when -EAGAIN returned)
1665 */
do_cmd_ioctl(struct comedi_device * dev,struct comedi_cmd __user * arg,void * file)1666 static int do_cmd_ioctl(struct comedi_device *dev,
1667 struct comedi_cmd __user *arg, void *file)
1668 {
1669 struct comedi_cmd cmd;
1670 struct comedi_subdevice *s;
1671 struct comedi_async *async;
1672 unsigned int __user *user_chanlist;
1673 int ret;
1674
1675 /* get the user's cmd and do some simple validation */
1676 ret = __comedi_get_user_cmd(dev, arg, &cmd);
1677 if (ret)
1678 return ret;
1679
1680 /* save user's chanlist pointer so it can be restored later */
1681 user_chanlist = (unsigned int __user *)cmd.chanlist;
1682
1683 s = &dev->subdevices[cmd.subdev];
1684 async = s->async;
1685
1686 /* are we locked? (ioctl lock) */
1687 if (s->lock && s->lock != file) {
1688 dev_dbg(dev->class_dev, "subdevice locked\n");
1689 return -EACCES;
1690 }
1691
1692 /* are we busy? */
1693 if (s->busy) {
1694 dev_dbg(dev->class_dev, "subdevice busy\n");
1695 return -EBUSY;
1696 }
1697
1698 /* make sure channel/gain list isn't too short */
1699 if (cmd.chanlist_len < 1) {
1700 dev_dbg(dev->class_dev, "channel/gain list too short %u < 1\n",
1701 cmd.chanlist_len);
1702 return -EINVAL;
1703 }
1704
1705 async->cmd = cmd;
1706 async->cmd.data = NULL;
1707
1708 /* load channel/gain list */
1709 ret = __comedi_get_user_chanlist(dev, s, user_chanlist, &async->cmd);
1710 if (ret)
1711 goto cleanup;
1712
1713 ret = s->do_cmdtest(dev, s, &async->cmd);
1714
1715 if (async->cmd.flags & CMDF_BOGUS || ret) {
1716 dev_dbg(dev->class_dev, "test returned %d\n", ret);
1717 cmd = async->cmd;
1718 /* restore chanlist pointer before copying back */
1719 cmd.chanlist = (unsigned int __force *)user_chanlist;
1720 cmd.data = NULL;
1721 if (copy_to_user(arg, &cmd, sizeof(cmd))) {
1722 dev_dbg(dev->class_dev, "fault writing cmd\n");
1723 ret = -EFAULT;
1724 goto cleanup;
1725 }
1726 ret = -EAGAIN;
1727 goto cleanup;
1728 }
1729
1730 if (!async->prealloc_bufsz) {
1731 ret = -ENOMEM;
1732 dev_dbg(dev->class_dev, "no buffer (?)\n");
1733 goto cleanup;
1734 }
1735
1736 comedi_buf_reset(s);
1737
1738 async->cb_mask = COMEDI_CB_BLOCK | COMEDI_CB_CANCEL_MASK;
1739 if (async->cmd.flags & CMDF_WAKE_EOS)
1740 async->cb_mask |= COMEDI_CB_EOS;
1741
1742 comedi_update_subdevice_runflags(s, COMEDI_SRF_BUSY_MASK,
1743 COMEDI_SRF_RUNNING);
1744
1745 /*
1746 * Set s->busy _after_ setting COMEDI_SRF_RUNNING flag to avoid
1747 * race with comedi_read() or comedi_write().
1748 */
1749 s->busy = file;
1750 ret = s->do_cmd(dev, s);
1751 if (ret == 0)
1752 return 0;
1753
1754 cleanup:
1755 do_become_nonbusy(dev, s);
1756
1757 return ret;
1758 }
1759
1760 /*
1761 * COMEDI_CMDTEST ioctl
1762 * asynchronous acquisition command testing
1763 *
1764 * arg:
1765 * pointer to comedi_cmd structure
1766 *
1767 * reads:
1768 * comedi_cmd structure
1769 * channel/range list from cmd->chanlist pointer
1770 *
1771 * writes:
1772 * possibly modified comedi_cmd structure
1773 */
do_cmdtest_ioctl(struct comedi_device * dev,struct comedi_cmd __user * arg,void * file)1774 static int do_cmdtest_ioctl(struct comedi_device *dev,
1775 struct comedi_cmd __user *arg, void *file)
1776 {
1777 struct comedi_cmd cmd;
1778 struct comedi_subdevice *s;
1779 unsigned int __user *user_chanlist;
1780 int ret;
1781
1782 /* get the user's cmd and do some simple validation */
1783 ret = __comedi_get_user_cmd(dev, arg, &cmd);
1784 if (ret)
1785 return ret;
1786
1787 /* save user's chanlist pointer so it can be restored later */
1788 user_chanlist = (unsigned int __user *)cmd.chanlist;
1789
1790 s = &dev->subdevices[cmd.subdev];
1791
1792 /* user_chanlist can be NULL for COMEDI_CMDTEST ioctl */
1793 if (user_chanlist) {
1794 /* load channel/gain list */
1795 ret = __comedi_get_user_chanlist(dev, s, user_chanlist, &cmd);
1796 if (ret)
1797 return ret;
1798 }
1799
1800 ret = s->do_cmdtest(dev, s, &cmd);
1801
1802 kfree(cmd.chanlist); /* free kernel copy of user chanlist */
1803
1804 /* restore chanlist pointer before copying back */
1805 cmd.chanlist = (unsigned int __force *)user_chanlist;
1806
1807 if (copy_to_user(arg, &cmd, sizeof(cmd))) {
1808 dev_dbg(dev->class_dev, "bad cmd address\n");
1809 ret = -EFAULT;
1810 }
1811
1812 return ret;
1813 }
1814
1815 /*
1816 * COMEDI_LOCK ioctl
1817 * lock subdevice
1818 *
1819 * arg:
1820 * subdevice number
1821 *
1822 * reads:
1823 * nothing
1824 *
1825 * writes:
1826 * nothing
1827 */
do_lock_ioctl(struct comedi_device * dev,unsigned long arg,void * file)1828 static int do_lock_ioctl(struct comedi_device *dev, unsigned long arg,
1829 void *file)
1830 {
1831 int ret = 0;
1832 unsigned long flags;
1833 struct comedi_subdevice *s;
1834
1835 if (arg >= dev->n_subdevices)
1836 return -EINVAL;
1837 s = &dev->subdevices[arg];
1838
1839 spin_lock_irqsave(&s->spin_lock, flags);
1840 if (s->busy || s->lock)
1841 ret = -EBUSY;
1842 else
1843 s->lock = file;
1844 spin_unlock_irqrestore(&s->spin_lock, flags);
1845
1846 return ret;
1847 }
1848
1849 /*
1850 * COMEDI_UNLOCK ioctl
1851 * unlock subdevice
1852 *
1853 * arg:
1854 * subdevice number
1855 *
1856 * reads:
1857 * nothing
1858 *
1859 * writes:
1860 * nothing
1861 */
do_unlock_ioctl(struct comedi_device * dev,unsigned long arg,void * file)1862 static int do_unlock_ioctl(struct comedi_device *dev, unsigned long arg,
1863 void *file)
1864 {
1865 struct comedi_subdevice *s;
1866
1867 if (arg >= dev->n_subdevices)
1868 return -EINVAL;
1869 s = &dev->subdevices[arg];
1870
1871 if (s->busy)
1872 return -EBUSY;
1873
1874 if (s->lock && s->lock != file)
1875 return -EACCES;
1876
1877 if (s->lock == file)
1878 s->lock = NULL;
1879
1880 return 0;
1881 }
1882
1883 /*
1884 * COMEDI_CANCEL ioctl
1885 * cancel asynchronous acquisition
1886 *
1887 * arg:
1888 * subdevice number
1889 *
1890 * reads:
1891 * nothing
1892 *
1893 * writes:
1894 * nothing
1895 */
do_cancel_ioctl(struct comedi_device * dev,unsigned long arg,void * file)1896 static int do_cancel_ioctl(struct comedi_device *dev, unsigned long arg,
1897 void *file)
1898 {
1899 struct comedi_subdevice *s;
1900
1901 if (arg >= dev->n_subdevices)
1902 return -EINVAL;
1903 s = &dev->subdevices[arg];
1904 if (!s->async)
1905 return -EINVAL;
1906
1907 if (!s->busy)
1908 return 0;
1909
1910 if (s->busy != file)
1911 return -EBUSY;
1912
1913 return do_cancel(dev, s);
1914 }
1915
1916 /*
1917 * COMEDI_POLL ioctl
1918 * instructs driver to synchronize buffers
1919 *
1920 * arg:
1921 * subdevice number
1922 *
1923 * reads:
1924 * nothing
1925 *
1926 * writes:
1927 * nothing
1928 */
do_poll_ioctl(struct comedi_device * dev,unsigned long arg,void * file)1929 static int do_poll_ioctl(struct comedi_device *dev, unsigned long arg,
1930 void *file)
1931 {
1932 struct comedi_subdevice *s;
1933
1934 if (arg >= dev->n_subdevices)
1935 return -EINVAL;
1936 s = &dev->subdevices[arg];
1937
1938 if (!s->busy)
1939 return 0;
1940
1941 if (s->busy != file)
1942 return -EBUSY;
1943
1944 if (s->poll)
1945 return s->poll(dev, s);
1946
1947 return -EINVAL;
1948 }
1949
1950 /*
1951 * COMEDI_SETRSUBD ioctl
1952 * sets the current "read" subdevice on a per-file basis
1953 *
1954 * arg:
1955 * subdevice number
1956 *
1957 * reads:
1958 * nothing
1959 *
1960 * writes:
1961 * nothing
1962 */
do_setrsubd_ioctl(struct comedi_device * dev,unsigned long arg,struct file * file)1963 static int do_setrsubd_ioctl(struct comedi_device *dev, unsigned long arg,
1964 struct file *file)
1965 {
1966 struct comedi_file *cfp = file->private_data;
1967 struct comedi_subdevice *s_old, *s_new;
1968
1969 if (arg >= dev->n_subdevices)
1970 return -EINVAL;
1971
1972 s_new = &dev->subdevices[arg];
1973 s_old = comedi_file_read_subdevice(file);
1974 if (s_old == s_new)
1975 return 0; /* no change */
1976
1977 if (!(s_new->subdev_flags & SDF_CMD_READ))
1978 return -EINVAL;
1979
1980 /*
1981 * Check the file isn't still busy handling a "read" command on the
1982 * old subdevice (if any).
1983 */
1984 if (s_old && s_old->busy == file && s_old->async &&
1985 !(s_old->async->cmd.flags & CMDF_WRITE))
1986 return -EBUSY;
1987
1988 ACCESS_ONCE(cfp->read_subdev) = s_new;
1989 return 0;
1990 }
1991
1992 /*
1993 * COMEDI_SETWSUBD ioctl
1994 * sets the current "write" subdevice on a per-file basis
1995 *
1996 * arg:
1997 * subdevice number
1998 *
1999 * reads:
2000 * nothing
2001 *
2002 * writes:
2003 * nothing
2004 */
do_setwsubd_ioctl(struct comedi_device * dev,unsigned long arg,struct file * file)2005 static int do_setwsubd_ioctl(struct comedi_device *dev, unsigned long arg,
2006 struct file *file)
2007 {
2008 struct comedi_file *cfp = file->private_data;
2009 struct comedi_subdevice *s_old, *s_new;
2010
2011 if (arg >= dev->n_subdevices)
2012 return -EINVAL;
2013
2014 s_new = &dev->subdevices[arg];
2015 s_old = comedi_file_write_subdevice(file);
2016 if (s_old == s_new)
2017 return 0; /* no change */
2018
2019 if (!(s_new->subdev_flags & SDF_CMD_WRITE))
2020 return -EINVAL;
2021
2022 /*
2023 * Check the file isn't still busy handling a "write" command on the
2024 * old subdevice (if any).
2025 */
2026 if (s_old && s_old->busy == file && s_old->async &&
2027 (s_old->async->cmd.flags & CMDF_WRITE))
2028 return -EBUSY;
2029
2030 ACCESS_ONCE(cfp->write_subdev) = s_new;
2031 return 0;
2032 }
2033
comedi_unlocked_ioctl(struct file * file,unsigned int cmd,unsigned long arg)2034 static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
2035 unsigned long arg)
2036 {
2037 unsigned minor = iminor(file_inode(file));
2038 struct comedi_file *cfp = file->private_data;
2039 struct comedi_device *dev = cfp->dev;
2040 int rc;
2041
2042 mutex_lock(&dev->mutex);
2043
2044 /*
2045 * Device config is special, because it must work on
2046 * an unconfigured device.
2047 */
2048 if (cmd == COMEDI_DEVCONFIG) {
2049 if (minor >= COMEDI_NUM_BOARD_MINORS) {
2050 /* Device config not appropriate on non-board minors. */
2051 rc = -ENOTTY;
2052 goto done;
2053 }
2054 rc = do_devconfig_ioctl(dev,
2055 (struct comedi_devconfig __user *)arg);
2056 if (rc == 0) {
2057 if (arg == 0 &&
2058 dev->minor >= comedi_num_legacy_minors) {
2059 /*
2060 * Successfully unconfigured a dynamically
2061 * allocated device. Try and remove it.
2062 */
2063 if (comedi_clear_board_dev(dev)) {
2064 mutex_unlock(&dev->mutex);
2065 comedi_free_board_dev(dev);
2066 return rc;
2067 }
2068 }
2069 }
2070 goto done;
2071 }
2072
2073 if (!dev->attached) {
2074 dev_dbg(dev->class_dev, "no driver attached\n");
2075 rc = -ENODEV;
2076 goto done;
2077 }
2078
2079 switch (cmd) {
2080 case COMEDI_BUFCONFIG:
2081 rc = do_bufconfig_ioctl(dev,
2082 (struct comedi_bufconfig __user *)arg);
2083 break;
2084 case COMEDI_DEVINFO:
2085 rc = do_devinfo_ioctl(dev, (struct comedi_devinfo __user *)arg,
2086 file);
2087 break;
2088 case COMEDI_SUBDINFO:
2089 rc = do_subdinfo_ioctl(dev,
2090 (struct comedi_subdinfo __user *)arg,
2091 file);
2092 break;
2093 case COMEDI_CHANINFO:
2094 rc = do_chaninfo_ioctl(dev, (void __user *)arg);
2095 break;
2096 case COMEDI_RANGEINFO:
2097 rc = do_rangeinfo_ioctl(dev, (void __user *)arg);
2098 break;
2099 case COMEDI_BUFINFO:
2100 rc = do_bufinfo_ioctl(dev,
2101 (struct comedi_bufinfo __user *)arg,
2102 file);
2103 break;
2104 case COMEDI_LOCK:
2105 rc = do_lock_ioctl(dev, arg, file);
2106 break;
2107 case COMEDI_UNLOCK:
2108 rc = do_unlock_ioctl(dev, arg, file);
2109 break;
2110 case COMEDI_CANCEL:
2111 rc = do_cancel_ioctl(dev, arg, file);
2112 break;
2113 case COMEDI_CMD:
2114 rc = do_cmd_ioctl(dev, (struct comedi_cmd __user *)arg, file);
2115 break;
2116 case COMEDI_CMDTEST:
2117 rc = do_cmdtest_ioctl(dev, (struct comedi_cmd __user *)arg,
2118 file);
2119 break;
2120 case COMEDI_INSNLIST:
2121 rc = do_insnlist_ioctl(dev,
2122 (struct comedi_insnlist __user *)arg,
2123 file);
2124 break;
2125 case COMEDI_INSN:
2126 rc = do_insn_ioctl(dev, (struct comedi_insn __user *)arg,
2127 file);
2128 break;
2129 case COMEDI_POLL:
2130 rc = do_poll_ioctl(dev, arg, file);
2131 break;
2132 case COMEDI_SETRSUBD:
2133 rc = do_setrsubd_ioctl(dev, arg, file);
2134 break;
2135 case COMEDI_SETWSUBD:
2136 rc = do_setwsubd_ioctl(dev, arg, file);
2137 break;
2138 default:
2139 rc = -ENOTTY;
2140 break;
2141 }
2142
2143 done:
2144 mutex_unlock(&dev->mutex);
2145 return rc;
2146 }
2147
comedi_vm_open(struct vm_area_struct * area)2148 static void comedi_vm_open(struct vm_area_struct *area)
2149 {
2150 struct comedi_buf_map *bm;
2151
2152 bm = area->vm_private_data;
2153 comedi_buf_map_get(bm);
2154 }
2155
comedi_vm_close(struct vm_area_struct * area)2156 static void comedi_vm_close(struct vm_area_struct *area)
2157 {
2158 struct comedi_buf_map *bm;
2159
2160 bm = area->vm_private_data;
2161 comedi_buf_map_put(bm);
2162 }
2163
2164 static const struct vm_operations_struct comedi_vm_ops = {
2165 .open = comedi_vm_open,
2166 .close = comedi_vm_close,
2167 };
2168
comedi_mmap(struct file * file,struct vm_area_struct * vma)2169 static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
2170 {
2171 struct comedi_file *cfp = file->private_data;
2172 struct comedi_device *dev = cfp->dev;
2173 struct comedi_subdevice *s;
2174 struct comedi_async *async;
2175 struct comedi_buf_map *bm = NULL;
2176 unsigned long start = vma->vm_start;
2177 unsigned long size;
2178 int n_pages;
2179 int i;
2180 int retval;
2181
2182 /*
2183 * 'trylock' avoids circular dependency with current->mm->mmap_sem
2184 * and down-reading &dev->attach_lock should normally succeed without
2185 * contention unless the device is in the process of being attached
2186 * or detached.
2187 */
2188 if (!down_read_trylock(&dev->attach_lock))
2189 return -EAGAIN;
2190
2191 if (!dev->attached) {
2192 dev_dbg(dev->class_dev, "no driver attached\n");
2193 retval = -ENODEV;
2194 goto done;
2195 }
2196
2197 if (vma->vm_flags & VM_WRITE)
2198 s = comedi_file_write_subdevice(file);
2199 else
2200 s = comedi_file_read_subdevice(file);
2201 if (!s) {
2202 retval = -EINVAL;
2203 goto done;
2204 }
2205
2206 async = s->async;
2207 if (!async) {
2208 retval = -EINVAL;
2209 goto done;
2210 }
2211
2212 if (vma->vm_pgoff != 0) {
2213 dev_dbg(dev->class_dev, "mmap() offset must be 0.\n");
2214 retval = -EINVAL;
2215 goto done;
2216 }
2217
2218 size = vma->vm_end - vma->vm_start;
2219 if (size > async->prealloc_bufsz) {
2220 retval = -EFAULT;
2221 goto done;
2222 }
2223 if (size & (~PAGE_MASK)) {
2224 retval = -EFAULT;
2225 goto done;
2226 }
2227
2228 n_pages = size >> PAGE_SHIFT;
2229
2230 /* get reference to current buf map (if any) */
2231 bm = comedi_buf_map_from_subdev_get(s);
2232 if (!bm || n_pages > bm->n_pages) {
2233 retval = -EINVAL;
2234 goto done;
2235 }
2236 for (i = 0; i < n_pages; ++i) {
2237 struct comedi_buf_page *buf = &bm->page_list[i];
2238
2239 if (remap_pfn_range(vma, start,
2240 page_to_pfn(virt_to_page(buf->virt_addr)),
2241 PAGE_SIZE, PAGE_SHARED)) {
2242 retval = -EAGAIN;
2243 goto done;
2244 }
2245 start += PAGE_SIZE;
2246 }
2247
2248 vma->vm_ops = &comedi_vm_ops;
2249 vma->vm_private_data = bm;
2250
2251 vma->vm_ops->open(vma);
2252
2253 retval = 0;
2254 done:
2255 up_read(&dev->attach_lock);
2256 comedi_buf_map_put(bm); /* put reference to buf map - okay if NULL */
2257 return retval;
2258 }
2259
comedi_poll(struct file * file,poll_table * wait)2260 static unsigned int comedi_poll(struct file *file, poll_table *wait)
2261 {
2262 unsigned int mask = 0;
2263 struct comedi_file *cfp = file->private_data;
2264 struct comedi_device *dev = cfp->dev;
2265 struct comedi_subdevice *s, *s_read;
2266
2267 down_read(&dev->attach_lock);
2268
2269 if (!dev->attached) {
2270 dev_dbg(dev->class_dev, "no driver attached\n");
2271 goto done;
2272 }
2273
2274 s = comedi_file_read_subdevice(file);
2275 s_read = s;
2276 if (s && s->async) {
2277 poll_wait(file, &s->async->wait_head, wait);
2278 if (s->busy != file || !comedi_is_subdevice_running(s) ||
2279 (s->async->cmd.flags & CMDF_WRITE) ||
2280 comedi_buf_read_n_available(s) > 0)
2281 mask |= POLLIN | POLLRDNORM;
2282 }
2283
2284 s = comedi_file_write_subdevice(file);
2285 if (s && s->async) {
2286 unsigned int bps = comedi_bytes_per_sample(s);
2287
2288 if (s != s_read)
2289 poll_wait(file, &s->async->wait_head, wait);
2290 if (s->busy != file || !comedi_is_subdevice_running(s) ||
2291 !(s->async->cmd.flags & CMDF_WRITE) ||
2292 comedi_buf_write_n_available(s) >= bps)
2293 mask |= POLLOUT | POLLWRNORM;
2294 }
2295
2296 done:
2297 up_read(&dev->attach_lock);
2298 return mask;
2299 }
2300
comedi_write(struct file * file,const char __user * buf,size_t nbytes,loff_t * offset)2301 static ssize_t comedi_write(struct file *file, const char __user *buf,
2302 size_t nbytes, loff_t *offset)
2303 {
2304 struct comedi_subdevice *s;
2305 struct comedi_async *async;
2306 int n, m, count = 0, retval = 0;
2307 DECLARE_WAITQUEUE(wait, current);
2308 struct comedi_file *cfp = file->private_data;
2309 struct comedi_device *dev = cfp->dev;
2310 bool on_wait_queue = false;
2311 bool attach_locked;
2312 unsigned int old_detach_count;
2313
2314 /* Protect against device detachment during operation. */
2315 down_read(&dev->attach_lock);
2316 attach_locked = true;
2317 old_detach_count = dev->detach_count;
2318
2319 if (!dev->attached) {
2320 dev_dbg(dev->class_dev, "no driver attached\n");
2321 retval = -ENODEV;
2322 goto out;
2323 }
2324
2325 s = comedi_file_write_subdevice(file);
2326 if (!s || !s->async) {
2327 retval = -EIO;
2328 goto out;
2329 }
2330
2331 async = s->async;
2332
2333 if (!s->busy || !nbytes)
2334 goto out;
2335 if (s->busy != file) {
2336 retval = -EACCES;
2337 goto out;
2338 }
2339 if (!(async->cmd.flags & CMDF_WRITE)) {
2340 retval = -EINVAL;
2341 goto out;
2342 }
2343
2344 add_wait_queue(&async->wait_head, &wait);
2345 on_wait_queue = true;
2346 while (nbytes > 0 && !retval) {
2347 unsigned runflags;
2348
2349 set_current_state(TASK_INTERRUPTIBLE);
2350
2351 runflags = comedi_get_subdevice_runflags(s);
2352 if (!comedi_is_runflags_running(runflags)) {
2353 if (count == 0) {
2354 struct comedi_subdevice *new_s;
2355
2356 if (comedi_is_runflags_in_error(runflags))
2357 retval = -EPIPE;
2358 else
2359 retval = 0;
2360 /*
2361 * To avoid deadlock, cannot acquire dev->mutex
2362 * while dev->attach_lock is held. Need to
2363 * remove task from the async wait queue before
2364 * releasing dev->attach_lock, as it might not
2365 * be valid afterwards.
2366 */
2367 remove_wait_queue(&async->wait_head, &wait);
2368 on_wait_queue = false;
2369 up_read(&dev->attach_lock);
2370 attach_locked = false;
2371 mutex_lock(&dev->mutex);
2372 /*
2373 * Become non-busy unless things have changed
2374 * behind our back. Checking dev->detach_count
2375 * is unchanged ought to be sufficient (unless
2376 * there have been 2**32 detaches in the
2377 * meantime!), but check the subdevice pointer
2378 * as well just in case.
2379 */
2380 new_s = comedi_file_write_subdevice(file);
2381 if (dev->attached &&
2382 old_detach_count == dev->detach_count &&
2383 s == new_s && new_s->async == async)
2384 do_become_nonbusy(dev, s);
2385 mutex_unlock(&dev->mutex);
2386 }
2387 break;
2388 }
2389
2390 n = nbytes;
2391
2392 m = n;
2393 if (async->buf_write_ptr + m > async->prealloc_bufsz)
2394 m = async->prealloc_bufsz - async->buf_write_ptr;
2395 comedi_buf_write_alloc(s, async->prealloc_bufsz);
2396 if (m > comedi_buf_write_n_allocated(s))
2397 m = comedi_buf_write_n_allocated(s);
2398 if (m < n)
2399 n = m;
2400
2401 if (n == 0) {
2402 if (file->f_flags & O_NONBLOCK) {
2403 retval = -EAGAIN;
2404 break;
2405 }
2406 schedule();
2407 if (signal_pending(current)) {
2408 retval = -ERESTARTSYS;
2409 break;
2410 }
2411 if (!s->busy)
2412 break;
2413 if (s->busy != file) {
2414 retval = -EACCES;
2415 break;
2416 }
2417 if (!(async->cmd.flags & CMDF_WRITE)) {
2418 retval = -EINVAL;
2419 break;
2420 }
2421 continue;
2422 }
2423
2424 m = copy_from_user(async->prealloc_buf + async->buf_write_ptr,
2425 buf, n);
2426 if (m) {
2427 n -= m;
2428 retval = -EFAULT;
2429 }
2430 comedi_buf_write_free(s, n);
2431
2432 count += n;
2433 nbytes -= n;
2434
2435 buf += n;
2436 break; /* makes device work like a pipe */
2437 }
2438 out:
2439 if (on_wait_queue)
2440 remove_wait_queue(&async->wait_head, &wait);
2441 set_current_state(TASK_RUNNING);
2442 if (attach_locked)
2443 up_read(&dev->attach_lock);
2444
2445 return count ? count : retval;
2446 }
2447
comedi_read(struct file * file,char __user * buf,size_t nbytes,loff_t * offset)2448 static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes,
2449 loff_t *offset)
2450 {
2451 struct comedi_subdevice *s;
2452 struct comedi_async *async;
2453 unsigned int n, m;
2454 ssize_t count = 0;
2455 int retval = 0;
2456 DECLARE_WAITQUEUE(wait, current);
2457 struct comedi_file *cfp = file->private_data;
2458 struct comedi_device *dev = cfp->dev;
2459 unsigned int old_detach_count;
2460 bool become_nonbusy = false;
2461 bool attach_locked;
2462
2463 /* Protect against device detachment during operation. */
2464 down_read(&dev->attach_lock);
2465 attach_locked = true;
2466 old_detach_count = dev->detach_count;
2467
2468 if (!dev->attached) {
2469 dev_dbg(dev->class_dev, "no driver attached\n");
2470 retval = -ENODEV;
2471 goto out;
2472 }
2473
2474 s = comedi_file_read_subdevice(file);
2475 if (!s || !s->async) {
2476 retval = -EIO;
2477 goto out;
2478 }
2479
2480 async = s->async;
2481 if (s->busy != file || (async->cmd.flags & CMDF_WRITE)) {
2482 retval = -EINVAL;
2483 goto out;
2484 }
2485
2486 add_wait_queue(&async->wait_head, &wait);
2487 while (count == 0 && !retval) {
2488 unsigned int rp, n1, n2;
2489
2490 set_current_state(TASK_INTERRUPTIBLE);
2491
2492 m = comedi_buf_read_n_available(s);
2493 n = min_t(size_t, m, nbytes);
2494
2495 if (n == 0) {
2496 unsigned runflags = comedi_get_subdevice_runflags(s);
2497
2498 if (!comedi_is_runflags_running(runflags)) {
2499 if (comedi_is_runflags_in_error(runflags))
2500 retval = -EPIPE;
2501 if (retval || nbytes)
2502 become_nonbusy = true;
2503 break;
2504 }
2505 if (nbytes == 0)
2506 break;
2507 if (file->f_flags & O_NONBLOCK) {
2508 retval = -EAGAIN;
2509 break;
2510 }
2511 schedule();
2512 if (signal_pending(current)) {
2513 retval = -ERESTARTSYS;
2514 break;
2515 }
2516 if (s->busy != file ||
2517 (async->cmd.flags & CMDF_WRITE)) {
2518 retval = -EINVAL;
2519 break;
2520 }
2521 continue;
2522 }
2523 rp = async->buf_read_ptr;
2524 n1 = min(n, async->prealloc_bufsz - rp);
2525 n2 = n - n1;
2526 m = copy_to_user(buf, async->prealloc_buf + rp, n1);
2527 if (m)
2528 m += n2;
2529 else if (n2)
2530 m = copy_to_user(buf + n1, async->prealloc_buf, n2);
2531 if (m) {
2532 n -= m;
2533 retval = -EFAULT;
2534 }
2535
2536 comedi_buf_read_alloc(s, n);
2537 comedi_buf_read_free(s, n);
2538
2539 count += n;
2540 nbytes -= n;
2541
2542 buf += n;
2543 }
2544 remove_wait_queue(&async->wait_head, &wait);
2545 set_current_state(TASK_RUNNING);
2546 if (become_nonbusy && count == 0) {
2547 struct comedi_subdevice *new_s;
2548
2549 /*
2550 * To avoid deadlock, cannot acquire dev->mutex
2551 * while dev->attach_lock is held.
2552 */
2553 up_read(&dev->attach_lock);
2554 attach_locked = false;
2555 mutex_lock(&dev->mutex);
2556 /*
2557 * Check device hasn't become detached behind our back.
2558 * Checking dev->detach_count is unchanged ought to be
2559 * sufficient (unless there have been 2**32 detaches in the
2560 * meantime!), but check the subdevice pointer as well just in
2561 * case.
2562 *
2563 * Also check the subdevice is still in a suitable state to
2564 * become non-busy in case it changed behind our back.
2565 */
2566 new_s = comedi_file_read_subdevice(file);
2567 if (dev->attached && old_detach_count == dev->detach_count &&
2568 s == new_s && new_s->async == async && s->busy == file &&
2569 !(async->cmd.flags & CMDF_WRITE) &&
2570 !comedi_is_subdevice_running(s) &&
2571 comedi_buf_read_n_available(s) == 0)
2572 do_become_nonbusy(dev, s);
2573 mutex_unlock(&dev->mutex);
2574 }
2575 out:
2576 if (attach_locked)
2577 up_read(&dev->attach_lock);
2578
2579 return count ? count : retval;
2580 }
2581
comedi_open(struct inode * inode,struct file * file)2582 static int comedi_open(struct inode *inode, struct file *file)
2583 {
2584 const unsigned minor = iminor(inode);
2585 struct comedi_file *cfp;
2586 struct comedi_device *dev = comedi_dev_get_from_minor(minor);
2587 int rc;
2588
2589 if (!dev) {
2590 pr_debug("invalid minor number\n");
2591 return -ENODEV;
2592 }
2593
2594 cfp = kzalloc(sizeof(*cfp), GFP_KERNEL);
2595 if (!cfp) {
2596 comedi_dev_put(dev);
2597 return -ENOMEM;
2598 }
2599
2600 cfp->dev = dev;
2601
2602 mutex_lock(&dev->mutex);
2603 if (!dev->attached && !capable(CAP_SYS_ADMIN)) {
2604 dev_dbg(dev->class_dev, "not attached and not CAP_SYS_ADMIN\n");
2605 rc = -ENODEV;
2606 goto out;
2607 }
2608 if (dev->attached && dev->use_count == 0) {
2609 if (!try_module_get(dev->driver->module)) {
2610 rc = -ENXIO;
2611 goto out;
2612 }
2613 if (dev->open) {
2614 rc = dev->open(dev);
2615 if (rc < 0) {
2616 module_put(dev->driver->module);
2617 goto out;
2618 }
2619 }
2620 }
2621
2622 dev->use_count++;
2623 file->private_data = cfp;
2624 comedi_file_reset(file);
2625 rc = 0;
2626
2627 out:
2628 mutex_unlock(&dev->mutex);
2629 if (rc) {
2630 comedi_dev_put(dev);
2631 kfree(cfp);
2632 }
2633 return rc;
2634 }
2635
comedi_fasync(int fd,struct file * file,int on)2636 static int comedi_fasync(int fd, struct file *file, int on)
2637 {
2638 struct comedi_file *cfp = file->private_data;
2639 struct comedi_device *dev = cfp->dev;
2640
2641 return fasync_helper(fd, file, on, &dev->async_queue);
2642 }
2643
comedi_close(struct inode * inode,struct file * file)2644 static int comedi_close(struct inode *inode, struct file *file)
2645 {
2646 struct comedi_file *cfp = file->private_data;
2647 struct comedi_device *dev = cfp->dev;
2648 struct comedi_subdevice *s = NULL;
2649 int i;
2650
2651 mutex_lock(&dev->mutex);
2652
2653 if (dev->subdevices) {
2654 for (i = 0; i < dev->n_subdevices; i++) {
2655 s = &dev->subdevices[i];
2656
2657 if (s->busy == file)
2658 do_cancel(dev, s);
2659 if (s->lock == file)
2660 s->lock = NULL;
2661 }
2662 }
2663 if (dev->attached && dev->use_count == 1) {
2664 if (dev->close)
2665 dev->close(dev);
2666 module_put(dev->driver->module);
2667 }
2668
2669 dev->use_count--;
2670
2671 mutex_unlock(&dev->mutex);
2672 comedi_dev_put(dev);
2673 kfree(cfp);
2674
2675 return 0;
2676 }
2677
2678 static const struct file_operations comedi_fops = {
2679 .owner = THIS_MODULE,
2680 .unlocked_ioctl = comedi_unlocked_ioctl,
2681 .compat_ioctl = comedi_compat_ioctl,
2682 .open = comedi_open,
2683 .release = comedi_close,
2684 .read = comedi_read,
2685 .write = comedi_write,
2686 .mmap = comedi_mmap,
2687 .poll = comedi_poll,
2688 .fasync = comedi_fasync,
2689 .llseek = noop_llseek,
2690 };
2691
2692 /**
2693 * comedi_event() - Handle events for asynchronous COMEDI command
2694 * @dev: COMEDI device.
2695 * @s: COMEDI subdevice.
2696 * Context: in_interrupt() (usually), @s->spin_lock spin-lock not held.
2697 *
2698 * If an asynchronous COMEDI command is active on the subdevice, process
2699 * any %COMEDI_CB_... event flags that have been set, usually by an
2700 * interrupt handler. These may change the run state of the asynchronous
2701 * command, wake a task, and/or send a %SIGIO signal.
2702 */
comedi_event(struct comedi_device * dev,struct comedi_subdevice * s)2703 void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s)
2704 {
2705 struct comedi_async *async = s->async;
2706 unsigned int events;
2707 int si_code = 0;
2708 unsigned long flags;
2709
2710 spin_lock_irqsave(&s->spin_lock, flags);
2711
2712 events = async->events;
2713 async->events = 0;
2714 if (!__comedi_is_subdevice_running(s)) {
2715 spin_unlock_irqrestore(&s->spin_lock, flags);
2716 return;
2717 }
2718
2719 if (events & COMEDI_CB_CANCEL_MASK)
2720 __comedi_clear_subdevice_runflags(s, COMEDI_SRF_RUNNING);
2721
2722 /*
2723 * Remember if an error event has occurred, so an error can be
2724 * returned the next time the user does a read() or write().
2725 */
2726 if (events & COMEDI_CB_ERROR_MASK)
2727 __comedi_set_subdevice_runflags(s, COMEDI_SRF_ERROR);
2728
2729 if (async->cb_mask & events) {
2730 wake_up_interruptible(&async->wait_head);
2731 si_code = async->cmd.flags & CMDF_WRITE ? POLL_OUT : POLL_IN;
2732 }
2733
2734 spin_unlock_irqrestore(&s->spin_lock, flags);
2735
2736 if (si_code)
2737 kill_fasync(&dev->async_queue, SIGIO, si_code);
2738 }
2739 EXPORT_SYMBOL_GPL(comedi_event);
2740
2741 /* Note: the ->mutex is pre-locked on successful return */
comedi_alloc_board_minor(struct device * hardware_device)2742 struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device)
2743 {
2744 struct comedi_device *dev;
2745 struct device *csdev;
2746 unsigned i;
2747
2748 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
2749 if (!dev)
2750 return ERR_PTR(-ENOMEM);
2751 comedi_device_init(dev);
2752 comedi_set_hw_dev(dev, hardware_device);
2753 mutex_lock(&dev->mutex);
2754 mutex_lock(&comedi_board_minor_table_lock);
2755 for (i = hardware_device ? comedi_num_legacy_minors : 0;
2756 i < COMEDI_NUM_BOARD_MINORS; ++i) {
2757 if (!comedi_board_minor_table[i]) {
2758 comedi_board_minor_table[i] = dev;
2759 break;
2760 }
2761 }
2762 mutex_unlock(&comedi_board_minor_table_lock);
2763 if (i == COMEDI_NUM_BOARD_MINORS) {
2764 mutex_unlock(&dev->mutex);
2765 comedi_device_cleanup(dev);
2766 comedi_dev_put(dev);
2767 dev_err(hardware_device,
2768 "ran out of minor numbers for board device files\n");
2769 return ERR_PTR(-EBUSY);
2770 }
2771 dev->minor = i;
2772 csdev = device_create(comedi_class, hardware_device,
2773 MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i", i);
2774 if (!IS_ERR(csdev))
2775 dev->class_dev = get_device(csdev);
2776
2777 /* Note: dev->mutex needs to be unlocked by the caller. */
2778 return dev;
2779 }
2780
comedi_release_hardware_device(struct device * hardware_device)2781 void comedi_release_hardware_device(struct device *hardware_device)
2782 {
2783 int minor;
2784 struct comedi_device *dev;
2785
2786 for (minor = comedi_num_legacy_minors; minor < COMEDI_NUM_BOARD_MINORS;
2787 minor++) {
2788 mutex_lock(&comedi_board_minor_table_lock);
2789 dev = comedi_board_minor_table[minor];
2790 if (dev && dev->hw_dev == hardware_device) {
2791 comedi_board_minor_table[minor] = NULL;
2792 mutex_unlock(&comedi_board_minor_table_lock);
2793 comedi_free_board_dev(dev);
2794 break;
2795 }
2796 mutex_unlock(&comedi_board_minor_table_lock);
2797 }
2798 }
2799
comedi_alloc_subdevice_minor(struct comedi_subdevice * s)2800 int comedi_alloc_subdevice_minor(struct comedi_subdevice *s)
2801 {
2802 struct comedi_device *dev = s->device;
2803 struct device *csdev;
2804 unsigned i;
2805
2806 mutex_lock(&comedi_subdevice_minor_table_lock);
2807 for (i = 0; i < COMEDI_NUM_SUBDEVICE_MINORS; ++i) {
2808 if (!comedi_subdevice_minor_table[i]) {
2809 comedi_subdevice_minor_table[i] = s;
2810 break;
2811 }
2812 }
2813 mutex_unlock(&comedi_subdevice_minor_table_lock);
2814 if (i == COMEDI_NUM_SUBDEVICE_MINORS) {
2815 dev_err(dev->class_dev,
2816 "ran out of minor numbers for subdevice files\n");
2817 return -EBUSY;
2818 }
2819 i += COMEDI_NUM_BOARD_MINORS;
2820 s->minor = i;
2821 csdev = device_create(comedi_class, dev->class_dev,
2822 MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i_subd%i",
2823 dev->minor, s->index);
2824 if (!IS_ERR(csdev))
2825 s->class_dev = csdev;
2826
2827 return 0;
2828 }
2829
comedi_free_subdevice_minor(struct comedi_subdevice * s)2830 void comedi_free_subdevice_minor(struct comedi_subdevice *s)
2831 {
2832 unsigned int i;
2833
2834 if (!s)
2835 return;
2836 if (s->minor < COMEDI_NUM_BOARD_MINORS ||
2837 s->minor >= COMEDI_NUM_MINORS)
2838 return;
2839
2840 i = s->minor - COMEDI_NUM_BOARD_MINORS;
2841 mutex_lock(&comedi_subdevice_minor_table_lock);
2842 if (s == comedi_subdevice_minor_table[i])
2843 comedi_subdevice_minor_table[i] = NULL;
2844 mutex_unlock(&comedi_subdevice_minor_table_lock);
2845 if (s->class_dev) {
2846 device_destroy(comedi_class, MKDEV(COMEDI_MAJOR, s->minor));
2847 s->class_dev = NULL;
2848 }
2849 }
2850
comedi_cleanup_board_minors(void)2851 static void comedi_cleanup_board_minors(void)
2852 {
2853 struct comedi_device *dev;
2854 unsigned i;
2855
2856 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
2857 dev = comedi_clear_board_minor(i);
2858 comedi_free_board_dev(dev);
2859 }
2860 }
2861
comedi_init(void)2862 static int __init comedi_init(void)
2863 {
2864 int i;
2865 int retval;
2866
2867 pr_info("version " COMEDI_RELEASE " - http://www.comedi.org\n");
2868
2869 if (comedi_num_legacy_minors < 0 ||
2870 comedi_num_legacy_minors > COMEDI_NUM_BOARD_MINORS) {
2871 pr_err("invalid value for module parameter \"comedi_num_legacy_minors\". Valid values are 0 through %i.\n",
2872 COMEDI_NUM_BOARD_MINORS);
2873 return -EINVAL;
2874 }
2875
2876 retval = register_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
2877 COMEDI_NUM_MINORS, "comedi");
2878 if (retval)
2879 return -EIO;
2880 cdev_init(&comedi_cdev, &comedi_fops);
2881 comedi_cdev.owner = THIS_MODULE;
2882
2883 retval = kobject_set_name(&comedi_cdev.kobj, "comedi");
2884 if (retval) {
2885 unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
2886 COMEDI_NUM_MINORS);
2887 return retval;
2888 }
2889
2890 if (cdev_add(&comedi_cdev, MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS)) {
2891 unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
2892 COMEDI_NUM_MINORS);
2893 return -EIO;
2894 }
2895 comedi_class = class_create(THIS_MODULE, "comedi");
2896 if (IS_ERR(comedi_class)) {
2897 pr_err("failed to create class\n");
2898 cdev_del(&comedi_cdev);
2899 unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
2900 COMEDI_NUM_MINORS);
2901 return PTR_ERR(comedi_class);
2902 }
2903
2904 comedi_class->dev_groups = comedi_dev_groups;
2905
2906 /* create devices files for legacy/manual use */
2907 for (i = 0; i < comedi_num_legacy_minors; i++) {
2908 struct comedi_device *dev;
2909
2910 dev = comedi_alloc_board_minor(NULL);
2911 if (IS_ERR(dev)) {
2912 comedi_cleanup_board_minors();
2913 class_destroy(comedi_class);
2914 cdev_del(&comedi_cdev);
2915 unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
2916 COMEDI_NUM_MINORS);
2917 return PTR_ERR(dev);
2918 }
2919 /* comedi_alloc_board_minor() locked the mutex */
2920 mutex_unlock(&dev->mutex);
2921 }
2922
2923 /* XXX requires /proc interface */
2924 comedi_proc_init();
2925
2926 return 0;
2927 }
2928 module_init(comedi_init);
2929
comedi_cleanup(void)2930 static void __exit comedi_cleanup(void)
2931 {
2932 comedi_cleanup_board_minors();
2933 class_destroy(comedi_class);
2934 cdev_del(&comedi_cdev);
2935 unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS);
2936
2937 comedi_proc_cleanup();
2938 }
2939 module_exit(comedi_cleanup);
2940
2941 MODULE_AUTHOR("http://www.comedi.org");
2942 MODULE_DESCRIPTION("Comedi core module");
2943 MODULE_LICENSE("GPL");
2944