comedi_fops.c revision 81604d43ade6abd316444f99ddb633f2e5a3f3eb
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    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
24#undef DEBUG
25
26#define __NO_VERSION__
27#include "comedi_fops.h"
28#include "comedi_compat32.h"
29
30#include <linux/module.h>
31#include <linux/errno.h>
32#include <linux/kernel.h>
33#include <linux/sched.h>
34#include <linux/fcntl.h>
35#include <linux/delay.h>
36#include <linux/ioport.h>
37#include <linux/mm.h>
38#include <linux/slab.h>
39#include <linux/kmod.h>
40#include <linux/poll.h>
41#include <linux/init.h>
42#include <linux/device.h>
43#include <linux/vmalloc.h>
44#include <linux/fs.h>
45#include "comedidev.h"
46#include <linux/cdev.h>
47#include <linux/stat.h>
48
49#include <linux/io.h>
50#include <linux/uaccess.h>
51
52#include "internal.h"
53
54MODULE_AUTHOR("http://www.comedi.org");
55MODULE_DESCRIPTION("Comedi core module");
56MODULE_LICENSE("GPL");
57
58#ifdef CONFIG_COMEDI_DEBUG
59int comedi_debug;
60EXPORT_SYMBOL(comedi_debug);
61module_param(comedi_debug, int, 0644);
62#endif
63
64int comedi_autoconfig = 1;
65module_param(comedi_autoconfig, bool, 0444);
66
67static int comedi_num_legacy_minors;
68module_param(comedi_num_legacy_minors, int, 0444);
69
70static DEFINE_SPINLOCK(comedi_file_info_table_lock);
71static struct comedi_device_file_info
72*comedi_file_info_table[COMEDI_NUM_MINORS];
73
74static int do_devconfig_ioctl(struct comedi_device *dev,
75			      struct comedi_devconfig __user *arg);
76static int do_bufconfig_ioctl(struct comedi_device *dev,
77			      struct comedi_bufconfig __user *arg);
78static int do_devinfo_ioctl(struct comedi_device *dev,
79			    struct comedi_devinfo __user *arg,
80			    struct file *file);
81static int do_subdinfo_ioctl(struct comedi_device *dev,
82			     struct comedi_subdinfo __user *arg, void *file);
83static int do_chaninfo_ioctl(struct comedi_device *dev,
84			     struct comedi_chaninfo __user *arg);
85static int do_bufinfo_ioctl(struct comedi_device *dev,
86			    struct comedi_bufinfo __user *arg, void *file);
87static int do_cmd_ioctl(struct comedi_device *dev,
88			struct comedi_cmd __user *arg, void *file);
89static int do_lock_ioctl(struct comedi_device *dev, unsigned int arg,
90			 void *file);
91static int do_unlock_ioctl(struct comedi_device *dev, unsigned int arg,
92			   void *file);
93static int do_cancel_ioctl(struct comedi_device *dev, unsigned int arg,
94			   void *file);
95static int do_cmdtest_ioctl(struct comedi_device *dev,
96			    struct comedi_cmd __user *arg, void *file);
97static int do_insnlist_ioctl(struct comedi_device *dev,
98			     struct comedi_insnlist __user *arg, void *file);
99static int do_insn_ioctl(struct comedi_device *dev,
100			 struct comedi_insn __user *arg, void *file);
101static int do_poll_ioctl(struct comedi_device *dev, unsigned int subd,
102			 void *file);
103
104extern void do_become_nonbusy(struct comedi_device *dev,
105			      struct comedi_subdevice *s);
106static int do_cancel(struct comedi_device *dev, struct comedi_subdevice *s);
107
108static int comedi_fasync(int fd, struct file *file, int on);
109
110static int is_device_busy(struct comedi_device *dev);
111static int resize_async_buffer(struct comedi_device *dev,
112			       struct comedi_subdevice *s,
113			       struct comedi_async *async, unsigned new_size);
114
115/* declarations for sysfs attribute files */
116static struct device_attribute dev_attr_max_read_buffer_kb;
117static struct device_attribute dev_attr_read_buffer_kb;
118static struct device_attribute dev_attr_max_write_buffer_kb;
119static struct device_attribute dev_attr_write_buffer_kb;
120
121static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
122				  unsigned long arg)
123{
124	const unsigned minor = iminor(file->f_dentry->d_inode);
125	struct comedi_device_file_info *dev_file_info =
126	    comedi_get_device_file_info(minor);
127	struct comedi_device *dev;
128	int rc;
129
130	if (dev_file_info == NULL || dev_file_info->device == NULL)
131		return -ENODEV;
132	dev = dev_file_info->device;
133
134	mutex_lock(&dev->mutex);
135
136	/* Device config is special, because it must work on
137	 * an unconfigured device. */
138	if (cmd == COMEDI_DEVCONFIG) {
139		rc = do_devconfig_ioctl(dev,
140					(struct comedi_devconfig __user *)arg);
141		goto done;
142	}
143
144	if (!dev->attached) {
145		DPRINTK("no driver configured on /dev/comedi%i\n", dev->minor);
146		rc = -ENODEV;
147		goto done;
148	}
149
150	switch (cmd) {
151	case COMEDI_BUFCONFIG:
152		rc = do_bufconfig_ioctl(dev,
153					(struct comedi_bufconfig __user *)arg);
154		break;
155	case COMEDI_DEVINFO:
156		rc = do_devinfo_ioctl(dev, (struct comedi_devinfo __user *)arg,
157				      file);
158		break;
159	case COMEDI_SUBDINFO:
160		rc = do_subdinfo_ioctl(dev,
161				       (struct comedi_subdinfo __user *)arg,
162				       file);
163		break;
164	case COMEDI_CHANINFO:
165		rc = do_chaninfo_ioctl(dev, (void __user *)arg);
166		break;
167	case COMEDI_RANGEINFO:
168		rc = do_rangeinfo_ioctl(dev, (void __user *)arg);
169		break;
170	case COMEDI_BUFINFO:
171		rc = do_bufinfo_ioctl(dev,
172				      (struct comedi_bufinfo __user *)arg,
173				      file);
174		break;
175	case COMEDI_LOCK:
176		rc = do_lock_ioctl(dev, arg, file);
177		break;
178	case COMEDI_UNLOCK:
179		rc = do_unlock_ioctl(dev, arg, file);
180		break;
181	case COMEDI_CANCEL:
182		rc = do_cancel_ioctl(dev, arg, file);
183		break;
184	case COMEDI_CMD:
185		rc = do_cmd_ioctl(dev, (struct comedi_cmd __user *)arg, file);
186		break;
187	case COMEDI_CMDTEST:
188		rc = do_cmdtest_ioctl(dev, (struct comedi_cmd __user *)arg,
189				      file);
190		break;
191	case COMEDI_INSNLIST:
192		rc = do_insnlist_ioctl(dev,
193				       (struct comedi_insnlist __user *)arg,
194				       file);
195		break;
196	case COMEDI_INSN:
197		rc = do_insn_ioctl(dev, (struct comedi_insn __user *)arg,
198				   file);
199		break;
200	case COMEDI_POLL:
201		rc = do_poll_ioctl(dev, arg, file);
202		break;
203	default:
204		rc = -ENOTTY;
205		break;
206	}
207
208done:
209	mutex_unlock(&dev->mutex);
210	return rc;
211}
212
213/*
214	COMEDI_DEVCONFIG
215	device config ioctl
216
217	arg:
218		pointer to devconfig structure
219
220	reads:
221		devconfig structure at arg
222
223	writes:
224		none
225*/
226static int do_devconfig_ioctl(struct comedi_device *dev,
227			      struct comedi_devconfig __user *arg)
228{
229	struct comedi_devconfig it;
230	int ret;
231	unsigned char *aux_data = NULL;
232	int aux_len;
233
234	if (!capable(CAP_SYS_ADMIN))
235		return -EPERM;
236
237	if (arg == NULL) {
238		if (is_device_busy(dev))
239			return -EBUSY;
240		if (dev->attached) {
241			struct module *driver_module = dev->driver->module;
242			comedi_device_detach(dev);
243			module_put(driver_module);
244		}
245		return 0;
246	}
247
248	if (copy_from_user(&it, arg, sizeof(struct comedi_devconfig)))
249		return -EFAULT;
250
251	it.board_name[COMEDI_NAMELEN - 1] = 0;
252
253	if (comedi_aux_data(it.options, 0) &&
254	    it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH]) {
255		int bit_shift;
256		aux_len = it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH];
257		if (aux_len < 0)
258			return -EFAULT;
259
260		aux_data = vmalloc(aux_len);
261		if (!aux_data)
262			return -ENOMEM;
263
264		if (copy_from_user(aux_data,
265				   comedi_aux_data(it.options, 0), aux_len)) {
266			vfree(aux_data);
267			return -EFAULT;
268		}
269		it.options[COMEDI_DEVCONF_AUX_DATA_LO] =
270		    (unsigned long)aux_data;
271		if (sizeof(void *) > sizeof(int)) {
272			bit_shift = sizeof(int) * 8;
273			it.options[COMEDI_DEVCONF_AUX_DATA_HI] =
274			    ((unsigned long)aux_data) >> bit_shift;
275		} else
276			it.options[COMEDI_DEVCONF_AUX_DATA_HI] = 0;
277	}
278
279	ret = comedi_device_attach(dev, &it);
280	if (ret == 0) {
281		if (!try_module_get(dev->driver->module)) {
282			comedi_device_detach(dev);
283			return -ENOSYS;
284		}
285	}
286
287	if (aux_data)
288		vfree(aux_data);
289
290	return ret;
291}
292
293/*
294	COMEDI_BUFCONFIG
295	buffer configuration ioctl
296
297	arg:
298		pointer to bufconfig structure
299
300	reads:
301		bufconfig at arg
302
303	writes:
304		modified bufconfig at arg
305
306*/
307static int do_bufconfig_ioctl(struct comedi_device *dev,
308			      struct comedi_bufconfig __user *arg)
309{
310	struct comedi_bufconfig bc;
311	struct comedi_async *async;
312	struct comedi_subdevice *s;
313	int retval = 0;
314
315	if (copy_from_user(&bc, arg, sizeof(struct comedi_bufconfig)))
316		return -EFAULT;
317
318	if (bc.subdevice >= dev->n_subdevices || bc.subdevice < 0)
319		return -EINVAL;
320
321	s = dev->subdevices + bc.subdevice;
322	async = s->async;
323
324	if (!async) {
325		DPRINTK("subdevice does not have async capability\n");
326		bc.size = 0;
327		bc.maximum_size = 0;
328		goto copyback;
329	}
330
331	if (bc.maximum_size) {
332		if (!capable(CAP_SYS_ADMIN))
333			return -EPERM;
334
335		async->max_bufsize = bc.maximum_size;
336	}
337
338	if (bc.size) {
339		retval = resize_async_buffer(dev, s, async, bc.size);
340		if (retval < 0)
341			return retval;
342	}
343
344	bc.size = async->prealloc_bufsz;
345	bc.maximum_size = async->max_bufsize;
346
347copyback:
348	if (copy_to_user(arg, &bc, sizeof(struct comedi_bufconfig)))
349		return -EFAULT;
350
351	return 0;
352}
353
354/*
355	COMEDI_DEVINFO
356	device info ioctl
357
358	arg:
359		pointer to devinfo structure
360
361	reads:
362		none
363
364	writes:
365		devinfo structure
366
367*/
368static int do_devinfo_ioctl(struct comedi_device *dev,
369			    struct comedi_devinfo __user *arg,
370			    struct file *file)
371{
372	struct comedi_devinfo devinfo;
373	const unsigned minor = iminor(file->f_dentry->d_inode);
374	struct comedi_device_file_info *dev_file_info =
375	    comedi_get_device_file_info(minor);
376	struct comedi_subdevice *read_subdev =
377	    comedi_get_read_subdevice(dev_file_info);
378	struct comedi_subdevice *write_subdev =
379	    comedi_get_write_subdevice(dev_file_info);
380
381	memset(&devinfo, 0, sizeof(devinfo));
382
383	/* fill devinfo structure */
384	devinfo.version_code = COMEDI_VERSION_CODE;
385	devinfo.n_subdevs = dev->n_subdevices;
386	memcpy(devinfo.driver_name, dev->driver->driver_name, COMEDI_NAMELEN);
387	memcpy(devinfo.board_name, dev->board_name, COMEDI_NAMELEN);
388
389	if (read_subdev)
390		devinfo.read_subdevice = read_subdev - dev->subdevices;
391	else
392		devinfo.read_subdevice = -1;
393
394	if (write_subdev)
395		devinfo.write_subdevice = write_subdev - dev->subdevices;
396	else
397		devinfo.write_subdevice = -1;
398
399	if (copy_to_user(arg, &devinfo, sizeof(struct comedi_devinfo)))
400		return -EFAULT;
401
402	return 0;
403}
404
405/*
406	COMEDI_SUBDINFO
407	subdevice info ioctl
408
409	arg:
410		pointer to array of subdevice info structures
411
412	reads:
413		none
414
415	writes:
416		array of subdevice info structures at arg
417
418*/
419static int do_subdinfo_ioctl(struct comedi_device *dev,
420			     struct comedi_subdinfo __user *arg, void *file)
421{
422	int ret, i;
423	struct comedi_subdinfo *tmp, *us;
424	struct comedi_subdevice *s;
425
426	tmp =
427	    kcalloc(dev->n_subdevices, sizeof(struct comedi_subdinfo),
428		    GFP_KERNEL);
429	if (!tmp)
430		return -ENOMEM;
431
432	/* fill subdinfo structs */
433	for (i = 0; i < dev->n_subdevices; i++) {
434		s = dev->subdevices + i;
435		us = tmp + i;
436
437		us->type = s->type;
438		us->n_chan = s->n_chan;
439		us->subd_flags = s->subdev_flags;
440		if (comedi_get_subdevice_runflags(s) & SRF_RUNNING)
441			us->subd_flags |= SDF_RUNNING;
442#define TIMER_nanosec 5		/* backwards compatibility */
443		us->timer_type = TIMER_nanosec;
444		us->len_chanlist = s->len_chanlist;
445		us->maxdata = s->maxdata;
446		if (s->range_table) {
447			us->range_type =
448			    (i << 24) | (0 << 16) | (s->range_table->length);
449		} else {
450			us->range_type = 0;	/* XXX */
451		}
452		us->flags = s->flags;
453
454		if (s->busy)
455			us->subd_flags |= SDF_BUSY;
456		if (s->busy == file)
457			us->subd_flags |= SDF_BUSY_OWNER;
458		if (s->lock)
459			us->subd_flags |= SDF_LOCKED;
460		if (s->lock == file)
461			us->subd_flags |= SDF_LOCK_OWNER;
462		if (!s->maxdata && s->maxdata_list)
463			us->subd_flags |= SDF_MAXDATA;
464		if (s->flaglist)
465			us->subd_flags |= SDF_FLAGS;
466		if (s->range_table_list)
467			us->subd_flags |= SDF_RANGETYPE;
468		if (s->do_cmd)
469			us->subd_flags |= SDF_CMD;
470
471		if (s->insn_bits != &insn_inval)
472			us->insn_bits_support = COMEDI_SUPPORTED;
473		else
474			us->insn_bits_support = COMEDI_UNSUPPORTED;
475
476		us->settling_time_0 = s->settling_time_0;
477	}
478
479	ret = copy_to_user(arg, tmp,
480			   dev->n_subdevices * sizeof(struct comedi_subdinfo));
481
482	kfree(tmp);
483
484	return ret ? -EFAULT : 0;
485}
486
487/*
488	COMEDI_CHANINFO
489	subdevice info ioctl
490
491	arg:
492		pointer to chaninfo structure
493
494	reads:
495		chaninfo structure at arg
496
497	writes:
498		arrays at elements of chaninfo structure
499
500*/
501static int do_chaninfo_ioctl(struct comedi_device *dev,
502			     struct comedi_chaninfo __user *arg)
503{
504	struct comedi_subdevice *s;
505	struct comedi_chaninfo it;
506
507	if (copy_from_user(&it, arg, sizeof(struct comedi_chaninfo)))
508		return -EFAULT;
509
510	if (it.subdev >= dev->n_subdevices)
511		return -EINVAL;
512	s = dev->subdevices + it.subdev;
513
514	if (it.maxdata_list) {
515		if (s->maxdata || !s->maxdata_list)
516			return -EINVAL;
517		if (copy_to_user(it.maxdata_list, s->maxdata_list,
518				 s->n_chan * sizeof(unsigned int)))
519			return -EFAULT;
520	}
521
522	if (it.flaglist) {
523		if (!s->flaglist)
524			return -EINVAL;
525		if (copy_to_user(it.flaglist, s->flaglist,
526				 s->n_chan * sizeof(unsigned int)))
527			return -EFAULT;
528	}
529
530	if (it.rangelist) {
531		int i;
532
533		if (!s->range_table_list)
534			return -EINVAL;
535		for (i = 0; i < s->n_chan; i++) {
536			int x;
537
538			x = (dev->minor << 28) | (it.subdev << 24) | (i << 16) |
539			    (s->range_table_list[i]->length);
540			if (put_user(x, it.rangelist + i))
541				return -EFAULT;
542		}
543#if 0
544		if (copy_to_user(it.rangelist, s->range_type_list,
545				 s->n_chan * sizeof(unsigned int)))
546			return -EFAULT;
547#endif
548	}
549
550	return 0;
551}
552
553 /*
554    COMEDI_BUFINFO
555    buffer information ioctl
556
557    arg:
558    pointer to bufinfo structure
559
560    reads:
561    bufinfo at arg
562
563    writes:
564    modified bufinfo at arg
565
566  */
567static int do_bufinfo_ioctl(struct comedi_device *dev,
568			    struct comedi_bufinfo __user *arg, void *file)
569{
570	struct comedi_bufinfo bi;
571	struct comedi_subdevice *s;
572	struct comedi_async *async;
573
574	if (copy_from_user(&bi, arg, sizeof(struct comedi_bufinfo)))
575		return -EFAULT;
576
577	if (bi.subdevice >= dev->n_subdevices || bi.subdevice < 0)
578		return -EINVAL;
579
580	s = dev->subdevices + bi.subdevice;
581
582	if (s->lock && s->lock != file)
583		return -EACCES;
584
585	async = s->async;
586
587	if (!async) {
588		DPRINTK("subdevice does not have async capability\n");
589		bi.buf_write_ptr = 0;
590		bi.buf_read_ptr = 0;
591		bi.buf_write_count = 0;
592		bi.buf_read_count = 0;
593		bi.bytes_read = 0;
594		bi.bytes_written = 0;
595		goto copyback;
596	}
597	if (!s->busy) {
598		bi.bytes_read = 0;
599		bi.bytes_written = 0;
600		goto copyback_position;
601	}
602	if (s->busy != file)
603		return -EACCES;
604
605	if (bi.bytes_read && (s->subdev_flags & SDF_CMD_READ)) {
606		bi.bytes_read = comedi_buf_read_alloc(async, bi.bytes_read);
607		comedi_buf_read_free(async, bi.bytes_read);
608
609		if (!(comedi_get_subdevice_runflags(s) & (SRF_ERROR |
610							  SRF_RUNNING))
611		    && async->buf_write_count == async->buf_read_count) {
612			do_become_nonbusy(dev, s);
613		}
614	}
615
616	if (bi.bytes_written && (s->subdev_flags & SDF_CMD_WRITE)) {
617		bi.bytes_written =
618		    comedi_buf_write_alloc(async, bi.bytes_written);
619		comedi_buf_write_free(async, bi.bytes_written);
620	}
621
622copyback_position:
623	bi.buf_write_count = async->buf_write_count;
624	bi.buf_write_ptr = async->buf_write_ptr;
625	bi.buf_read_count = async->buf_read_count;
626	bi.buf_read_ptr = async->buf_read_ptr;
627
628copyback:
629	if (copy_to_user(arg, &bi, sizeof(struct comedi_bufinfo)))
630		return -EFAULT;
631
632	return 0;
633}
634
635static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn,
636		      unsigned int *data, void *file);
637/*
638 *	COMEDI_INSNLIST
639 *	synchronous instructions
640 *
641 *	arg:
642 *		pointer to sync cmd structure
643 *
644 *	reads:
645 *		sync cmd struct at arg
646 *		instruction list
647 *		data (for writes)
648 *
649 *	writes:
650 *		data (for reads)
651 */
652/* arbitrary limits */
653#define MAX_SAMPLES 256
654static int do_insnlist_ioctl(struct comedi_device *dev,
655			     struct comedi_insnlist __user *arg, void *file)
656{
657	struct comedi_insnlist insnlist;
658	struct comedi_insn *insns = NULL;
659	unsigned int *data = NULL;
660	int i = 0;
661	int ret = 0;
662
663	if (copy_from_user(&insnlist, arg, sizeof(struct comedi_insnlist)))
664		return -EFAULT;
665
666	data = kmalloc(sizeof(unsigned int) * MAX_SAMPLES, GFP_KERNEL);
667	if (!data) {
668		DPRINTK("kmalloc failed\n");
669		ret = -ENOMEM;
670		goto error;
671	}
672
673	insns =
674	    kmalloc(sizeof(struct comedi_insn) * insnlist.n_insns, GFP_KERNEL);
675	if (!insns) {
676		DPRINTK("kmalloc failed\n");
677		ret = -ENOMEM;
678		goto error;
679	}
680
681	if (copy_from_user(insns, insnlist.insns,
682			   sizeof(struct comedi_insn) * insnlist.n_insns)) {
683		DPRINTK("copy_from_user failed\n");
684		ret = -EFAULT;
685		goto error;
686	}
687
688	for (i = 0; i < insnlist.n_insns; i++) {
689		if (insns[i].n > MAX_SAMPLES) {
690			DPRINTK("number of samples too large\n");
691			ret = -EINVAL;
692			goto error;
693		}
694		if (insns[i].insn & INSN_MASK_WRITE) {
695			if (copy_from_user(data, insns[i].data,
696					   insns[i].n * sizeof(unsigned int))) {
697				DPRINTK("copy_from_user failed\n");
698				ret = -EFAULT;
699				goto error;
700			}
701		}
702		ret = parse_insn(dev, insns + i, data, file);
703		if (ret < 0)
704			goto error;
705		if (insns[i].insn & INSN_MASK_READ) {
706			if (copy_to_user(insns[i].data, data,
707					 insns[i].n * sizeof(unsigned int))) {
708				DPRINTK("copy_to_user failed\n");
709				ret = -EFAULT;
710				goto error;
711			}
712		}
713		if (need_resched())
714			schedule();
715	}
716
717error:
718	kfree(insns);
719	kfree(data);
720
721	if (ret < 0)
722		return ret;
723	return i;
724}
725
726static int check_insn_config_length(struct comedi_insn *insn,
727				    unsigned int *data)
728{
729	if (insn->n < 1)
730		return -EINVAL;
731
732	switch (data[0]) {
733	case INSN_CONFIG_DIO_OUTPUT:
734	case INSN_CONFIG_DIO_INPUT:
735	case INSN_CONFIG_DISARM:
736	case INSN_CONFIG_RESET:
737		if (insn->n == 1)
738			return 0;
739		break;
740	case INSN_CONFIG_ARM:
741	case INSN_CONFIG_DIO_QUERY:
742	case INSN_CONFIG_BLOCK_SIZE:
743	case INSN_CONFIG_FILTER:
744	case INSN_CONFIG_SERIAL_CLOCK:
745	case INSN_CONFIG_BIDIRECTIONAL_DATA:
746	case INSN_CONFIG_ALT_SOURCE:
747	case INSN_CONFIG_SET_COUNTER_MODE:
748	case INSN_CONFIG_8254_READ_STATUS:
749	case INSN_CONFIG_SET_ROUTING:
750	case INSN_CONFIG_GET_ROUTING:
751	case INSN_CONFIG_GET_PWM_STATUS:
752	case INSN_CONFIG_PWM_SET_PERIOD:
753	case INSN_CONFIG_PWM_GET_PERIOD:
754		if (insn->n == 2)
755			return 0;
756		break;
757	case INSN_CONFIG_SET_GATE_SRC:
758	case INSN_CONFIG_GET_GATE_SRC:
759	case INSN_CONFIG_SET_CLOCK_SRC:
760	case INSN_CONFIG_GET_CLOCK_SRC:
761	case INSN_CONFIG_SET_OTHER_SRC:
762	case INSN_CONFIG_GET_COUNTER_STATUS:
763	case INSN_CONFIG_PWM_SET_H_BRIDGE:
764	case INSN_CONFIG_PWM_GET_H_BRIDGE:
765	case INSN_CONFIG_GET_HARDWARE_BUFFER_SIZE:
766		if (insn->n == 3)
767			return 0;
768		break;
769	case INSN_CONFIG_PWM_OUTPUT:
770	case INSN_CONFIG_ANALOG_TRIG:
771		if (insn->n == 5)
772			return 0;
773		break;
774		/* by default we allow the insn since we don't have checks for
775		 * all possible cases yet */
776	default:
777		printk(KERN_WARNING
778		       "comedi: no check for data length of config insn id "
779		       "%i is implemented.\n"
780		       " Add a check to %s in %s.\n"
781		       " Assuming n=%i is correct.\n", data[0], __func__,
782		       __FILE__, insn->n);
783		return 0;
784		break;
785	}
786	return -EINVAL;
787}
788
789static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn,
790		      unsigned int *data, void *file)
791{
792	struct comedi_subdevice *s;
793	int ret = 0;
794	int i;
795
796	if (insn->insn & INSN_MASK_SPECIAL) {
797		/* a non-subdevice instruction */
798
799		switch (insn->insn) {
800		case INSN_GTOD:
801			{
802				struct timeval tv;
803
804				if (insn->n != 2) {
805					ret = -EINVAL;
806					break;
807				}
808
809				do_gettimeofday(&tv);
810				data[0] = tv.tv_sec;
811				data[1] = tv.tv_usec;
812				ret = 2;
813
814				break;
815			}
816		case INSN_WAIT:
817			if (insn->n != 1 || data[0] >= 100000) {
818				ret = -EINVAL;
819				break;
820			}
821			udelay(data[0] / 1000);
822			ret = 1;
823			break;
824		case INSN_INTTRIG:
825			if (insn->n != 1) {
826				ret = -EINVAL;
827				break;
828			}
829			if (insn->subdev >= dev->n_subdevices) {
830				DPRINTK("%d not usable subdevice\n",
831					insn->subdev);
832				ret = -EINVAL;
833				break;
834			}
835			s = dev->subdevices + insn->subdev;
836			if (!s->async) {
837				DPRINTK("no async\n");
838				ret = -EINVAL;
839				break;
840			}
841			if (!s->async->inttrig) {
842				DPRINTK("no inttrig\n");
843				ret = -EAGAIN;
844				break;
845			}
846			ret = s->async->inttrig(dev, s, insn->data[0]);
847			if (ret >= 0)
848				ret = 1;
849			break;
850		default:
851			DPRINTK("invalid insn\n");
852			ret = -EINVAL;
853			break;
854		}
855	} else {
856		/* a subdevice instruction */
857		unsigned int maxdata;
858
859		if (insn->subdev >= dev->n_subdevices) {
860			DPRINTK("subdevice %d out of range\n", insn->subdev);
861			ret = -EINVAL;
862			goto out;
863		}
864		s = dev->subdevices + insn->subdev;
865
866		if (s->type == COMEDI_SUBD_UNUSED) {
867			DPRINTK("%d not usable subdevice\n", insn->subdev);
868			ret = -EIO;
869			goto out;
870		}
871
872		/* are we locked? (ioctl lock) */
873		if (s->lock && s->lock != file) {
874			DPRINTK("device locked\n");
875			ret = -EACCES;
876			goto out;
877		}
878
879		ret = comedi_check_chanlist(s, 1, &insn->chanspec);
880		if (ret < 0) {
881			ret = -EINVAL;
882			DPRINTK("bad chanspec\n");
883			goto out;
884		}
885
886		if (s->busy) {
887			ret = -EBUSY;
888			goto out;
889		}
890		/* This looks arbitrary.  It is. */
891		s->busy = &parse_insn;
892		switch (insn->insn) {
893		case INSN_READ:
894			ret = s->insn_read(dev, s, insn, data);
895			break;
896		case INSN_WRITE:
897			maxdata = s->maxdata_list
898			    ? s->maxdata_list[CR_CHAN(insn->chanspec)]
899			    : s->maxdata;
900			for (i = 0; i < insn->n; ++i) {
901				if (data[i] > maxdata) {
902					ret = -EINVAL;
903					DPRINTK("bad data value(s)\n");
904					break;
905				}
906			}
907			if (ret == 0)
908				ret = s->insn_write(dev, s, insn, data);
909			break;
910		case INSN_BITS:
911			if (insn->n != 2) {
912				ret = -EINVAL;
913				break;
914			}
915			ret = s->insn_bits(dev, s, insn, data);
916			break;
917		case INSN_CONFIG:
918			ret = check_insn_config_length(insn, data);
919			if (ret)
920				break;
921			ret = s->insn_config(dev, s, insn, data);
922			break;
923		default:
924			ret = -EINVAL;
925			break;
926		}
927
928		s->busy = NULL;
929	}
930
931out:
932	return ret;
933}
934
935/*
936 *	COMEDI_INSN
937 *	synchronous instructions
938 *
939 *	arg:
940 *		pointer to insn
941 *
942 *	reads:
943 *		struct comedi_insn struct at arg
944 *		data (for writes)
945 *
946 *	writes:
947 *		data (for reads)
948 */
949static int do_insn_ioctl(struct comedi_device *dev,
950			 struct comedi_insn __user *arg, void *file)
951{
952	struct comedi_insn insn;
953	unsigned int *data = NULL;
954	int ret = 0;
955
956	data = kmalloc(sizeof(unsigned int) * MAX_SAMPLES, GFP_KERNEL);
957	if (!data) {
958		ret = -ENOMEM;
959		goto error;
960	}
961
962	if (copy_from_user(&insn, arg, sizeof(struct comedi_insn))) {
963		ret = -EFAULT;
964		goto error;
965	}
966
967	/* This is where the behavior of insn and insnlist deviate. */
968	if (insn.n > MAX_SAMPLES)
969		insn.n = MAX_SAMPLES;
970	if (insn.insn & INSN_MASK_WRITE) {
971		if (copy_from_user(data,
972				   insn.data,
973				   insn.n * sizeof(unsigned int))) {
974			ret = -EFAULT;
975			goto error;
976		}
977	}
978	ret = parse_insn(dev, &insn, data, file);
979	if (ret < 0)
980		goto error;
981	if (insn.insn & INSN_MASK_READ) {
982		if (copy_to_user(insn.data,
983				 data,
984				 insn.n * sizeof(unsigned int))) {
985			ret = -EFAULT;
986			goto error;
987		}
988	}
989	ret = insn.n;
990
991error:
992	kfree(data);
993
994	return ret;
995}
996
997static void comedi_set_subdevice_runflags(struct comedi_subdevice *s,
998					  unsigned mask, unsigned bits)
999{
1000	unsigned long flags;
1001
1002	spin_lock_irqsave(&s->spin_lock, flags);
1003	s->runflags &= ~mask;
1004	s->runflags |= (bits & mask);
1005	spin_unlock_irqrestore(&s->spin_lock, flags);
1006}
1007
1008static int do_cmd_ioctl(struct comedi_device *dev,
1009			struct comedi_cmd __user *cmd, void *file)
1010{
1011	struct comedi_cmd user_cmd;
1012	struct comedi_subdevice *s;
1013	struct comedi_async *async;
1014	int ret = 0;
1015	unsigned int __user *chanlist_saver = NULL;
1016
1017	if (copy_from_user(&user_cmd, cmd, sizeof(struct comedi_cmd))) {
1018		DPRINTK("bad cmd address\n");
1019		return -EFAULT;
1020	}
1021	/* save user's chanlist pointer so it can be restored later */
1022	chanlist_saver = user_cmd.chanlist;
1023
1024	if (user_cmd.subdev >= dev->n_subdevices) {
1025		DPRINTK("%d no such subdevice\n", user_cmd.subdev);
1026		return -ENODEV;
1027	}
1028
1029	s = dev->subdevices + user_cmd.subdev;
1030	async = s->async;
1031
1032	if (s->type == COMEDI_SUBD_UNUSED) {
1033		DPRINTK("%d not valid subdevice\n", user_cmd.subdev);
1034		return -EIO;
1035	}
1036
1037	if (!s->do_cmd || !s->do_cmdtest || !s->async) {
1038		DPRINTK("subdevice %i does not support commands\n",
1039			user_cmd.subdev);
1040		return -EIO;
1041	}
1042
1043	/* are we locked? (ioctl lock) */
1044	if (s->lock && s->lock != file) {
1045		DPRINTK("subdevice locked\n");
1046		return -EACCES;
1047	}
1048
1049	/* are we busy? */
1050	if (s->busy) {
1051		DPRINTK("subdevice busy\n");
1052		return -EBUSY;
1053	}
1054	s->busy = file;
1055
1056	/* make sure channel/gain list isn't too long */
1057	if (user_cmd.chanlist_len > s->len_chanlist) {
1058		DPRINTK("channel/gain list too long %u > %d\n",
1059			user_cmd.chanlist_len, s->len_chanlist);
1060		ret = -EINVAL;
1061		goto cleanup;
1062	}
1063
1064	/* make sure channel/gain list isn't too short */
1065	if (user_cmd.chanlist_len < 1) {
1066		DPRINTK("channel/gain list too short %u < 1\n",
1067			user_cmd.chanlist_len);
1068		ret = -EINVAL;
1069		goto cleanup;
1070	}
1071
1072	kfree(async->cmd.chanlist);
1073	async->cmd = user_cmd;
1074	async->cmd.data = NULL;
1075	/* load channel/gain list */
1076	async->cmd.chanlist =
1077	    kmalloc(async->cmd.chanlist_len * sizeof(int), GFP_KERNEL);
1078	if (!async->cmd.chanlist) {
1079		DPRINTK("allocation failed\n");
1080		ret = -ENOMEM;
1081		goto cleanup;
1082	}
1083
1084	if (copy_from_user(async->cmd.chanlist, user_cmd.chanlist,
1085			   async->cmd.chanlist_len * sizeof(int))) {
1086		DPRINTK("fault reading chanlist\n");
1087		ret = -EFAULT;
1088		goto cleanup;
1089	}
1090
1091	/* make sure each element in channel/gain list is valid */
1092	ret = comedi_check_chanlist(s,
1093				    async->cmd.chanlist_len,
1094				    async->cmd.chanlist);
1095	if (ret < 0) {
1096		DPRINTK("bad chanlist\n");
1097		goto cleanup;
1098	}
1099
1100	ret = s->do_cmdtest(dev, s, &async->cmd);
1101
1102	if (async->cmd.flags & TRIG_BOGUS || ret) {
1103		DPRINTK("test returned %d\n", ret);
1104		user_cmd = async->cmd;
1105		/* restore chanlist pointer before copying back */
1106		user_cmd.chanlist = chanlist_saver;
1107		user_cmd.data = NULL;
1108		if (copy_to_user(cmd, &user_cmd, sizeof(struct comedi_cmd))) {
1109			DPRINTK("fault writing cmd\n");
1110			ret = -EFAULT;
1111			goto cleanup;
1112		}
1113		ret = -EAGAIN;
1114		goto cleanup;
1115	}
1116
1117	if (!async->prealloc_bufsz) {
1118		ret = -ENOMEM;
1119		DPRINTK("no buffer (?)\n");
1120		goto cleanup;
1121	}
1122
1123	comedi_reset_async_buf(async);
1124
1125	async->cb_mask =
1126	    COMEDI_CB_EOA | COMEDI_CB_BLOCK | COMEDI_CB_ERROR |
1127	    COMEDI_CB_OVERFLOW;
1128	if (async->cmd.flags & TRIG_WAKE_EOS)
1129		async->cb_mask |= COMEDI_CB_EOS;
1130
1131	comedi_set_subdevice_runflags(s, ~0, SRF_USER | SRF_RUNNING);
1132
1133	ret = s->do_cmd(dev, s);
1134	if (ret == 0)
1135		return 0;
1136
1137cleanup:
1138	do_become_nonbusy(dev, s);
1139
1140	return ret;
1141}
1142
1143/*
1144	COMEDI_CMDTEST
1145	command testing ioctl
1146
1147	arg:
1148		pointer to cmd structure
1149
1150	reads:
1151		cmd structure at arg
1152		channel/range list
1153
1154	writes:
1155		modified cmd structure at arg
1156
1157*/
1158static int do_cmdtest_ioctl(struct comedi_device *dev,
1159			    struct comedi_cmd __user *arg, void *file)
1160{
1161	struct comedi_cmd user_cmd;
1162	struct comedi_subdevice *s;
1163	int ret = 0;
1164	unsigned int *chanlist = NULL;
1165	unsigned int __user *chanlist_saver = NULL;
1166
1167	if (copy_from_user(&user_cmd, arg, sizeof(struct comedi_cmd))) {
1168		DPRINTK("bad cmd address\n");
1169		return -EFAULT;
1170	}
1171	/* save user's chanlist pointer so it can be restored later */
1172	chanlist_saver = user_cmd.chanlist;
1173
1174	if (user_cmd.subdev >= dev->n_subdevices) {
1175		DPRINTK("%d no such subdevice\n", user_cmd.subdev);
1176		return -ENODEV;
1177	}
1178
1179	s = dev->subdevices + user_cmd.subdev;
1180	if (s->type == COMEDI_SUBD_UNUSED) {
1181		DPRINTK("%d not valid subdevice\n", user_cmd.subdev);
1182		return -EIO;
1183	}
1184
1185	if (!s->do_cmd || !s->do_cmdtest) {
1186		DPRINTK("subdevice %i does not support commands\n",
1187			user_cmd.subdev);
1188		return -EIO;
1189	}
1190
1191	/* make sure channel/gain list isn't too long */
1192	if (user_cmd.chanlist_len > s->len_chanlist) {
1193		DPRINTK("channel/gain list too long %d > %d\n",
1194			user_cmd.chanlist_len, s->len_chanlist);
1195		ret = -EINVAL;
1196		goto cleanup;
1197	}
1198
1199	/* load channel/gain list */
1200	if (user_cmd.chanlist) {
1201		chanlist =
1202		    kmalloc(user_cmd.chanlist_len * sizeof(int), GFP_KERNEL);
1203		if (!chanlist) {
1204			DPRINTK("allocation failed\n");
1205			ret = -ENOMEM;
1206			goto cleanup;
1207		}
1208
1209		if (copy_from_user(chanlist, user_cmd.chanlist,
1210				   user_cmd.chanlist_len * sizeof(int))) {
1211			DPRINTK("fault reading chanlist\n");
1212			ret = -EFAULT;
1213			goto cleanup;
1214		}
1215
1216		/* make sure each element in channel/gain list is valid */
1217		ret = comedi_check_chanlist(s, user_cmd.chanlist_len, chanlist);
1218		if (ret < 0) {
1219			DPRINTK("bad chanlist\n");
1220			goto cleanup;
1221		}
1222
1223		user_cmd.chanlist = chanlist;
1224	}
1225
1226	ret = s->do_cmdtest(dev, s, &user_cmd);
1227
1228	/* restore chanlist pointer before copying back */
1229	user_cmd.chanlist = chanlist_saver;
1230
1231	if (copy_to_user(arg, &user_cmd, sizeof(struct comedi_cmd))) {
1232		DPRINTK("bad cmd address\n");
1233		ret = -EFAULT;
1234		goto cleanup;
1235	}
1236cleanup:
1237	kfree(chanlist);
1238
1239	return ret;
1240}
1241
1242/*
1243	COMEDI_LOCK
1244	lock subdevice
1245
1246	arg:
1247		subdevice number
1248
1249	reads:
1250		none
1251
1252	writes:
1253		none
1254
1255*/
1256
1257static int do_lock_ioctl(struct comedi_device *dev, unsigned int arg,
1258			 void *file)
1259{
1260	int ret = 0;
1261	unsigned long flags;
1262	struct comedi_subdevice *s;
1263
1264	if (arg >= dev->n_subdevices)
1265		return -EINVAL;
1266	s = dev->subdevices + arg;
1267
1268	spin_lock_irqsave(&s->spin_lock, flags);
1269	if (s->busy || s->lock)
1270		ret = -EBUSY;
1271	else
1272		s->lock = file;
1273	spin_unlock_irqrestore(&s->spin_lock, flags);
1274
1275	if (ret < 0)
1276		return ret;
1277
1278#if 0
1279	if (s->lock_f)
1280		ret = s->lock_f(dev, s);
1281#endif
1282
1283	return ret;
1284}
1285
1286/*
1287	COMEDI_UNLOCK
1288	unlock subdevice
1289
1290	arg:
1291		subdevice number
1292
1293	reads:
1294		none
1295
1296	writes:
1297		none
1298
1299	This function isn't protected by the semaphore, since
1300	we already own the lock.
1301*/
1302static int do_unlock_ioctl(struct comedi_device *dev, unsigned int arg,
1303			   void *file)
1304{
1305	struct comedi_subdevice *s;
1306
1307	if (arg >= dev->n_subdevices)
1308		return -EINVAL;
1309	s = dev->subdevices + arg;
1310
1311	if (s->busy)
1312		return -EBUSY;
1313
1314	if (s->lock && s->lock != file)
1315		return -EACCES;
1316
1317	if (s->lock == file) {
1318#if 0
1319		if (s->unlock)
1320			s->unlock(dev, s);
1321#endif
1322
1323		s->lock = NULL;
1324	}
1325
1326	return 0;
1327}
1328
1329/*
1330	COMEDI_CANCEL
1331	cancel acquisition ioctl
1332
1333	arg:
1334		subdevice number
1335
1336	reads:
1337		nothing
1338
1339	writes:
1340		nothing
1341
1342*/
1343static int do_cancel_ioctl(struct comedi_device *dev, unsigned int arg,
1344			   void *file)
1345{
1346	struct comedi_subdevice *s;
1347
1348	if (arg >= dev->n_subdevices)
1349		return -EINVAL;
1350	s = dev->subdevices + arg;
1351	if (s->async == NULL)
1352		return -EINVAL;
1353
1354	if (s->lock && s->lock != file)
1355		return -EACCES;
1356
1357	if (!s->busy)
1358		return 0;
1359
1360	if (s->busy != file)
1361		return -EBUSY;
1362
1363	return do_cancel(dev, s);
1364}
1365
1366/*
1367	COMEDI_POLL ioctl
1368	instructs driver to synchronize buffers
1369
1370	arg:
1371		subdevice number
1372
1373	reads:
1374		nothing
1375
1376	writes:
1377		nothing
1378
1379*/
1380static int do_poll_ioctl(struct comedi_device *dev, unsigned int arg,
1381			 void *file)
1382{
1383	struct comedi_subdevice *s;
1384
1385	if (arg >= dev->n_subdevices)
1386		return -EINVAL;
1387	s = dev->subdevices + arg;
1388
1389	if (s->lock && s->lock != file)
1390		return -EACCES;
1391
1392	if (!s->busy)
1393		return 0;
1394
1395	if (s->busy != file)
1396		return -EBUSY;
1397
1398	if (s->poll)
1399		return s->poll(dev, s);
1400
1401	return -EINVAL;
1402}
1403
1404static int do_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
1405{
1406	int ret = 0;
1407
1408	if ((comedi_get_subdevice_runflags(s) & SRF_RUNNING) && s->cancel)
1409		ret = s->cancel(dev, s);
1410
1411	do_become_nonbusy(dev, s);
1412
1413	return ret;
1414}
1415
1416static void comedi_unmap(struct vm_area_struct *area)
1417{
1418	struct comedi_async *async;
1419	struct comedi_device *dev;
1420
1421	async = area->vm_private_data;
1422	dev = async->subdevice->device;
1423
1424	mutex_lock(&dev->mutex);
1425	async->mmap_count--;
1426	mutex_unlock(&dev->mutex);
1427}
1428
1429static struct vm_operations_struct comedi_vm_ops = {
1430	.close = comedi_unmap,
1431};
1432
1433static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
1434{
1435	const unsigned minor = iminor(file->f_dentry->d_inode);
1436	struct comedi_device_file_info *dev_file_info =
1437	    comedi_get_device_file_info(minor);
1438	struct comedi_device *dev = dev_file_info->device;
1439	struct comedi_async *async = NULL;
1440	unsigned long start = vma->vm_start;
1441	unsigned long size;
1442	int n_pages;
1443	int i;
1444	int retval;
1445	struct comedi_subdevice *s;
1446
1447	mutex_lock(&dev->mutex);
1448	if (!dev->attached) {
1449		DPRINTK("no driver configured on comedi%i\n", dev->minor);
1450		retval = -ENODEV;
1451		goto done;
1452	}
1453	if (vma->vm_flags & VM_WRITE)
1454		s = comedi_get_write_subdevice(dev_file_info);
1455	else
1456		s = comedi_get_read_subdevice(dev_file_info);
1457
1458	if (s == NULL) {
1459		retval = -EINVAL;
1460		goto done;
1461	}
1462	async = s->async;
1463	if (async == NULL) {
1464		retval = -EINVAL;
1465		goto done;
1466	}
1467
1468	if (vma->vm_pgoff != 0) {
1469		DPRINTK("comedi: mmap() offset must be 0.\n");
1470		retval = -EINVAL;
1471		goto done;
1472	}
1473
1474	size = vma->vm_end - vma->vm_start;
1475	if (size > async->prealloc_bufsz) {
1476		retval = -EFAULT;
1477		goto done;
1478	}
1479	if (size & (~PAGE_MASK)) {
1480		retval = -EFAULT;
1481		goto done;
1482	}
1483
1484	n_pages = size >> PAGE_SHIFT;
1485	for (i = 0; i < n_pages; ++i) {
1486		if (remap_pfn_range(vma, start,
1487				    page_to_pfn(virt_to_page
1488						(async->buf_page_list
1489						 [i].virt_addr)), PAGE_SIZE,
1490				    PAGE_SHARED)) {
1491			retval = -EAGAIN;
1492			goto done;
1493		}
1494		start += PAGE_SIZE;
1495	}
1496
1497	vma->vm_ops = &comedi_vm_ops;
1498	vma->vm_private_data = async;
1499
1500	async->mmap_count++;
1501
1502	retval = 0;
1503done:
1504	mutex_unlock(&dev->mutex);
1505	return retval;
1506}
1507
1508static unsigned int comedi_poll(struct file *file, poll_table * wait)
1509{
1510	unsigned int mask = 0;
1511	const unsigned minor = iminor(file->f_dentry->d_inode);
1512	struct comedi_device_file_info *dev_file_info =
1513	    comedi_get_device_file_info(minor);
1514	struct comedi_device *dev = dev_file_info->device;
1515	struct comedi_subdevice *read_subdev;
1516	struct comedi_subdevice *write_subdev;
1517
1518	mutex_lock(&dev->mutex);
1519	if (!dev->attached) {
1520		DPRINTK("no driver configured on comedi%i\n", dev->minor);
1521		mutex_unlock(&dev->mutex);
1522		return 0;
1523	}
1524
1525	mask = 0;
1526	read_subdev = comedi_get_read_subdevice(dev_file_info);
1527	if (read_subdev) {
1528		poll_wait(file, &read_subdev->async->wait_head, wait);
1529		if (!read_subdev->busy
1530		    || comedi_buf_read_n_available(read_subdev->async) > 0
1531		    || !(comedi_get_subdevice_runflags(read_subdev) &
1532			 SRF_RUNNING)) {
1533			mask |= POLLIN | POLLRDNORM;
1534		}
1535	}
1536	write_subdev = comedi_get_write_subdevice(dev_file_info);
1537	if (write_subdev) {
1538		poll_wait(file, &write_subdev->async->wait_head, wait);
1539		comedi_buf_write_alloc(write_subdev->async,
1540				       write_subdev->async->prealloc_bufsz);
1541		if (!write_subdev->busy
1542		    || !(comedi_get_subdevice_runflags(write_subdev) &
1543			 SRF_RUNNING)
1544		    || comedi_buf_write_n_allocated(write_subdev->async) >=
1545		    bytes_per_sample(write_subdev->async->subdevice)) {
1546			mask |= POLLOUT | POLLWRNORM;
1547		}
1548	}
1549
1550	mutex_unlock(&dev->mutex);
1551	return mask;
1552}
1553
1554static ssize_t comedi_write(struct file *file, const char __user *buf,
1555			    size_t nbytes, loff_t *offset)
1556{
1557	struct comedi_subdevice *s;
1558	struct comedi_async *async;
1559	int n, m, count = 0, retval = 0;
1560	DECLARE_WAITQUEUE(wait, current);
1561	const unsigned minor = iminor(file->f_dentry->d_inode);
1562	struct comedi_device_file_info *dev_file_info =
1563	    comedi_get_device_file_info(minor);
1564	struct comedi_device *dev = dev_file_info->device;
1565
1566	if (!dev->attached) {
1567		DPRINTK("no driver configured on comedi%i\n", dev->minor);
1568		retval = -ENODEV;
1569		goto done;
1570	}
1571
1572	s = comedi_get_write_subdevice(dev_file_info);
1573	if (s == NULL) {
1574		retval = -EIO;
1575		goto done;
1576	}
1577	async = s->async;
1578
1579	if (!nbytes) {
1580		retval = 0;
1581		goto done;
1582	}
1583	if (!s->busy) {
1584		retval = 0;
1585		goto done;
1586	}
1587	if (s->busy != file) {
1588		retval = -EACCES;
1589		goto done;
1590	}
1591	add_wait_queue(&async->wait_head, &wait);
1592	while (nbytes > 0 && !retval) {
1593		set_current_state(TASK_INTERRUPTIBLE);
1594
1595		if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
1596			if (count == 0) {
1597				if (comedi_get_subdevice_runflags(s) &
1598					SRF_ERROR) {
1599					retval = -EPIPE;
1600				} else {
1601					retval = 0;
1602				}
1603				do_become_nonbusy(dev, s);
1604			}
1605			break;
1606		}
1607
1608		n = nbytes;
1609
1610		m = n;
1611		if (async->buf_write_ptr + m > async->prealloc_bufsz)
1612			m = async->prealloc_bufsz - async->buf_write_ptr;
1613		comedi_buf_write_alloc(async, async->prealloc_bufsz);
1614		if (m > comedi_buf_write_n_allocated(async))
1615			m = comedi_buf_write_n_allocated(async);
1616		if (m < n)
1617			n = m;
1618
1619		if (n == 0) {
1620			if (file->f_flags & O_NONBLOCK) {
1621				retval = -EAGAIN;
1622				break;
1623			}
1624			if (signal_pending(current)) {
1625				retval = -ERESTARTSYS;
1626				break;
1627			}
1628			schedule();
1629			if (!s->busy)
1630				break;
1631			if (s->busy != file) {
1632				retval = -EACCES;
1633				break;
1634			}
1635			continue;
1636		}
1637
1638		m = copy_from_user(async->prealloc_buf + async->buf_write_ptr,
1639				   buf, n);
1640		if (m) {
1641			n -= m;
1642			retval = -EFAULT;
1643		}
1644		comedi_buf_write_free(async, n);
1645
1646		count += n;
1647		nbytes -= n;
1648
1649		buf += n;
1650		break;		/* makes device work like a pipe */
1651	}
1652	set_current_state(TASK_RUNNING);
1653	remove_wait_queue(&async->wait_head, &wait);
1654
1655done:
1656	return count ? count : retval;
1657}
1658
1659static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes,
1660				loff_t *offset)
1661{
1662	struct comedi_subdevice *s;
1663	struct comedi_async *async;
1664	int n, m, count = 0, retval = 0;
1665	DECLARE_WAITQUEUE(wait, current);
1666	const unsigned minor = iminor(file->f_dentry->d_inode);
1667	struct comedi_device_file_info *dev_file_info =
1668	    comedi_get_device_file_info(minor);
1669	struct comedi_device *dev = dev_file_info->device;
1670
1671	if (!dev->attached) {
1672		DPRINTK("no driver configured on comedi%i\n", dev->minor);
1673		retval = -ENODEV;
1674		goto done;
1675	}
1676
1677	s = comedi_get_read_subdevice(dev_file_info);
1678	if (s == NULL) {
1679		retval = -EIO;
1680		goto done;
1681	}
1682	async = s->async;
1683	if (!nbytes) {
1684		retval = 0;
1685		goto done;
1686	}
1687	if (!s->busy) {
1688		retval = 0;
1689		goto done;
1690	}
1691	if (s->busy != file) {
1692		retval = -EACCES;
1693		goto done;
1694	}
1695
1696	add_wait_queue(&async->wait_head, &wait);
1697	while (nbytes > 0 && !retval) {
1698		set_current_state(TASK_INTERRUPTIBLE);
1699
1700		n = nbytes;
1701
1702		m = comedi_buf_read_n_available(async);
1703		/* printk("%d available\n",m); */
1704		if (async->buf_read_ptr + m > async->prealloc_bufsz)
1705			m = async->prealloc_bufsz - async->buf_read_ptr;
1706		/* printk("%d contiguous\n",m); */
1707		if (m < n)
1708			n = m;
1709
1710		if (n == 0) {
1711			if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
1712				do_become_nonbusy(dev, s);
1713				if (comedi_get_subdevice_runflags(s) &
1714				    SRF_ERROR) {
1715					retval = -EPIPE;
1716				} else {
1717					retval = 0;
1718				}
1719				break;
1720			}
1721			if (file->f_flags & O_NONBLOCK) {
1722				retval = -EAGAIN;
1723				break;
1724			}
1725			if (signal_pending(current)) {
1726				retval = -ERESTARTSYS;
1727				break;
1728			}
1729			schedule();
1730			if (!s->busy) {
1731				retval = 0;
1732				break;
1733			}
1734			if (s->busy != file) {
1735				retval = -EACCES;
1736				break;
1737			}
1738			continue;
1739		}
1740		m = copy_to_user(buf, async->prealloc_buf +
1741				 async->buf_read_ptr, n);
1742		if (m) {
1743			n -= m;
1744			retval = -EFAULT;
1745		}
1746
1747		comedi_buf_read_alloc(async, n);
1748		comedi_buf_read_free(async, n);
1749
1750		count += n;
1751		nbytes -= n;
1752
1753		buf += n;
1754		break;		/* makes device work like a pipe */
1755	}
1756	if (!(comedi_get_subdevice_runflags(s) & (SRF_ERROR | SRF_RUNNING)) &&
1757	    async->buf_read_count - async->buf_write_count == 0) {
1758		do_become_nonbusy(dev, s);
1759	}
1760	set_current_state(TASK_RUNNING);
1761	remove_wait_queue(&async->wait_head, &wait);
1762
1763done:
1764	return count ? count : retval;
1765}
1766
1767/*
1768   This function restores a subdevice to an idle state.
1769 */
1770void do_become_nonbusy(struct comedi_device *dev, struct comedi_subdevice *s)
1771{
1772	struct comedi_async *async = s->async;
1773
1774	comedi_set_subdevice_runflags(s, SRF_RUNNING, 0);
1775	if (async) {
1776		comedi_reset_async_buf(async);
1777		async->inttrig = NULL;
1778	} else {
1779		printk(KERN_ERR
1780		       "BUG: (?) do_become_nonbusy called with async=0\n");
1781	}
1782
1783	s->busy = NULL;
1784}
1785
1786static int comedi_open(struct inode *inode, struct file *file)
1787{
1788	const unsigned minor = iminor(inode);
1789	struct comedi_device_file_info *dev_file_info =
1790	    comedi_get_device_file_info(minor);
1791	struct comedi_device *dev =
1792	    dev_file_info ? dev_file_info->device : NULL;
1793
1794	if (dev == NULL) {
1795		DPRINTK("invalid minor number\n");
1796		return -ENODEV;
1797	}
1798
1799	/* This is slightly hacky, but we want module autoloading
1800	 * to work for root.
1801	 * case: user opens device, attached -> ok
1802	 * case: user opens device, unattached, in_request_module=0 -> autoload
1803	 * case: user opens device, unattached, in_request_module=1 -> fail
1804	 * case: root opens device, attached -> ok
1805	 * case: root opens device, unattached, in_request_module=1 -> ok
1806	 *   (typically called from modprobe)
1807	 * case: root opens device, unattached, in_request_module=0 -> autoload
1808	 *
1809	 * The last could be changed to "-> ok", which would deny root
1810	 * autoloading.
1811	 */
1812	mutex_lock(&dev->mutex);
1813	if (dev->attached)
1814		goto ok;
1815	if (!capable(CAP_NET_ADMIN) && dev->in_request_module) {
1816		DPRINTK("in request module\n");
1817		mutex_unlock(&dev->mutex);
1818		return -ENODEV;
1819	}
1820	if (capable(CAP_NET_ADMIN) && dev->in_request_module)
1821		goto ok;
1822
1823	dev->in_request_module = 1;
1824
1825#ifdef CONFIG_KMOD
1826	mutex_unlock(&dev->mutex);
1827	request_module("char-major-%i-%i", COMEDI_MAJOR, dev->minor);
1828	mutex_lock(&dev->mutex);
1829#endif
1830
1831	dev->in_request_module = 0;
1832
1833	if (!dev->attached && !capable(CAP_NET_ADMIN)) {
1834		DPRINTK("not attached and not CAP_NET_ADMIN\n");
1835		mutex_unlock(&dev->mutex);
1836		return -ENODEV;
1837	}
1838ok:
1839	__module_get(THIS_MODULE);
1840
1841	if (dev->attached) {
1842		if (!try_module_get(dev->driver->module)) {
1843			module_put(THIS_MODULE);
1844			mutex_unlock(&dev->mutex);
1845			return -ENOSYS;
1846		}
1847	}
1848
1849	if (dev->attached && dev->use_count == 0 && dev->open) {
1850		int rc = dev->open(dev);
1851		if (rc < 0) {
1852			module_put(dev->driver->module);
1853			module_put(THIS_MODULE);
1854			mutex_unlock(&dev->mutex);
1855			return rc;
1856		}
1857	}
1858
1859	dev->use_count++;
1860
1861	mutex_unlock(&dev->mutex);
1862
1863	return 0;
1864}
1865
1866static int comedi_close(struct inode *inode, struct file *file)
1867{
1868	const unsigned minor = iminor(inode);
1869	struct comedi_device_file_info *dev_file_info =
1870	    comedi_get_device_file_info(minor);
1871	struct comedi_device *dev = dev_file_info->device;
1872	struct comedi_subdevice *s = NULL;
1873	int i;
1874
1875	mutex_lock(&dev->mutex);
1876
1877	if (dev->subdevices) {
1878		for (i = 0; i < dev->n_subdevices; i++) {
1879			s = dev->subdevices + i;
1880
1881			if (s->busy == file)
1882				do_cancel(dev, s);
1883			if (s->lock == file)
1884				s->lock = NULL;
1885		}
1886	}
1887	if (dev->attached && dev->use_count == 1 && dev->close)
1888		dev->close(dev);
1889
1890	module_put(THIS_MODULE);
1891	if (dev->attached)
1892		module_put(dev->driver->module);
1893
1894	dev->use_count--;
1895
1896	mutex_unlock(&dev->mutex);
1897
1898	if (file->f_flags & FASYNC)
1899		comedi_fasync(-1, file, 0);
1900
1901	return 0;
1902}
1903
1904static int comedi_fasync(int fd, struct file *file, int on)
1905{
1906	const unsigned minor = iminor(file->f_dentry->d_inode);
1907	struct comedi_device_file_info *dev_file_info =
1908	    comedi_get_device_file_info(minor);
1909
1910	struct comedi_device *dev = dev_file_info->device;
1911
1912	return fasync_helper(fd, file, on, &dev->async_queue);
1913}
1914
1915const struct file_operations comedi_fops = {
1916	.owner = THIS_MODULE,
1917	.unlocked_ioctl = comedi_unlocked_ioctl,
1918	.compat_ioctl = comedi_compat_ioctl,
1919	.open = comedi_open,
1920	.release = comedi_close,
1921	.read = comedi_read,
1922	.write = comedi_write,
1923	.mmap = comedi_mmap,
1924	.poll = comedi_poll,
1925	.fasync = comedi_fasync,
1926};
1927
1928struct class *comedi_class;
1929static struct cdev comedi_cdev;
1930
1931static void comedi_cleanup_legacy_minors(void)
1932{
1933	unsigned i;
1934
1935	for (i = 0; i < comedi_num_legacy_minors; i++)
1936		comedi_free_board_minor(i);
1937}
1938
1939static int __init comedi_init(void)
1940{
1941	int i;
1942	int retval;
1943
1944	printk(KERN_INFO "comedi: version " COMEDI_RELEASE
1945	       " - http://www.comedi.org\n");
1946
1947	if (comedi_num_legacy_minors < 0 ||
1948	    comedi_num_legacy_minors > COMEDI_NUM_BOARD_MINORS) {
1949		printk(KERN_ERR "comedi: error: invalid value for module "
1950		       "parameter \"comedi_num_legacy_minors\".  Valid values "
1951		       "are 0 through %i.\n", COMEDI_NUM_BOARD_MINORS);
1952		return -EINVAL;
1953	}
1954
1955	/*
1956	 * comedi is unusable if both comedi_autoconfig and
1957	 * comedi_num_legacy_minors are zero, so we might as well adjust the
1958	 * defaults in that case
1959	 */
1960	if (comedi_autoconfig == 0 && comedi_num_legacy_minors == 0)
1961		comedi_num_legacy_minors = 16;
1962
1963	memset(comedi_file_info_table, 0,
1964	       sizeof(struct comedi_device_file_info *) * COMEDI_NUM_MINORS);
1965
1966	retval = register_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1967					COMEDI_NUM_MINORS, "comedi");
1968	if (retval)
1969		return -EIO;
1970	cdev_init(&comedi_cdev, &comedi_fops);
1971	comedi_cdev.owner = THIS_MODULE;
1972	kobject_set_name(&comedi_cdev.kobj, "comedi");
1973	if (cdev_add(&comedi_cdev, MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS)) {
1974		unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1975					 COMEDI_NUM_MINORS);
1976		return -EIO;
1977	}
1978	comedi_class = class_create(THIS_MODULE, "comedi");
1979	if (IS_ERR(comedi_class)) {
1980		printk(KERN_ERR "comedi: failed to create class");
1981		cdev_del(&comedi_cdev);
1982		unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1983					 COMEDI_NUM_MINORS);
1984		return PTR_ERR(comedi_class);
1985	}
1986
1987	/* XXX requires /proc interface */
1988	comedi_proc_init();
1989
1990	/* create devices files for legacy/manual use */
1991	for (i = 0; i < comedi_num_legacy_minors; i++) {
1992		int minor;
1993		minor = comedi_alloc_board_minor(NULL);
1994		if (minor < 0) {
1995			comedi_cleanup_legacy_minors();
1996			cdev_del(&comedi_cdev);
1997			unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1998						 COMEDI_NUM_MINORS);
1999			return minor;
2000		}
2001	}
2002
2003	return 0;
2004}
2005
2006static void __exit comedi_cleanup(void)
2007{
2008	int i;
2009
2010	comedi_cleanup_legacy_minors();
2011	for (i = 0; i < COMEDI_NUM_MINORS; ++i)
2012		BUG_ON(comedi_file_info_table[i]);
2013
2014	class_destroy(comedi_class);
2015	cdev_del(&comedi_cdev);
2016	unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS);
2017
2018	comedi_proc_cleanup();
2019}
2020
2021module_init(comedi_init);
2022module_exit(comedi_cleanup);
2023
2024void comedi_error(const struct comedi_device *dev, const char *s)
2025{
2026	printk(KERN_ERR "comedi%d: %s: %s\n", dev->minor,
2027	       dev->driver->driver_name, s);
2028}
2029EXPORT_SYMBOL(comedi_error);
2030
2031void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s)
2032{
2033	struct comedi_async *async = s->async;
2034	unsigned runflags = 0;
2035	unsigned runflags_mask = 0;
2036
2037	/* DPRINTK("comedi_event 0x%x\n",mask); */
2038
2039	if ((comedi_get_subdevice_runflags(s) & SRF_RUNNING) == 0)
2040		return;
2041
2042	if (s->
2043	    async->events & (COMEDI_CB_EOA | COMEDI_CB_ERROR |
2044			     COMEDI_CB_OVERFLOW)) {
2045		runflags_mask |= SRF_RUNNING;
2046	}
2047	/* remember if an error event has occured, so an error
2048	 * can be returned the next time the user does a read() */
2049	if (s->async->events & (COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW)) {
2050		runflags_mask |= SRF_ERROR;
2051		runflags |= SRF_ERROR;
2052	}
2053	if (runflags_mask) {
2054		/*sets SRF_ERROR and SRF_RUNNING together atomically */
2055		comedi_set_subdevice_runflags(s, runflags_mask, runflags);
2056	}
2057
2058	if (async->cb_mask & s->async->events) {
2059		if (comedi_get_subdevice_runflags(s) & SRF_USER) {
2060			wake_up_interruptible(&async->wait_head);
2061			if (s->subdev_flags & SDF_CMD_READ)
2062				kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
2063			if (s->subdev_flags & SDF_CMD_WRITE)
2064				kill_fasync(&dev->async_queue, SIGIO, POLL_OUT);
2065		} else {
2066			if (async->cb_func)
2067				async->cb_func(s->async->events, async->cb_arg);
2068		}
2069	}
2070	s->async->events = 0;
2071}
2072EXPORT_SYMBOL(comedi_event);
2073
2074unsigned comedi_get_subdevice_runflags(struct comedi_subdevice *s)
2075{
2076	unsigned long flags;
2077	unsigned runflags;
2078
2079	spin_lock_irqsave(&s->spin_lock, flags);
2080	runflags = s->runflags;
2081	spin_unlock_irqrestore(&s->spin_lock, flags);
2082	return runflags;
2083}
2084EXPORT_SYMBOL(comedi_get_subdevice_runflags);
2085
2086static int is_device_busy(struct comedi_device *dev)
2087{
2088	struct comedi_subdevice *s;
2089	int i;
2090
2091	if (!dev->attached)
2092		return 0;
2093
2094	for (i = 0; i < dev->n_subdevices; i++) {
2095		s = dev->subdevices + i;
2096		if (s->busy)
2097			return 1;
2098		if (s->async && s->async->mmap_count)
2099			return 1;
2100	}
2101
2102	return 0;
2103}
2104
2105static void comedi_device_init(struct comedi_device *dev)
2106{
2107	memset(dev, 0, sizeof(struct comedi_device));
2108	spin_lock_init(&dev->spinlock);
2109	mutex_init(&dev->mutex);
2110	dev->minor = -1;
2111}
2112
2113static void comedi_device_cleanup(struct comedi_device *dev)
2114{
2115	if (dev == NULL)
2116		return;
2117	mutex_lock(&dev->mutex);
2118	comedi_device_detach(dev);
2119	mutex_unlock(&dev->mutex);
2120	mutex_destroy(&dev->mutex);
2121}
2122
2123int comedi_alloc_board_minor(struct device *hardware_device)
2124{
2125	unsigned long flags;
2126	struct comedi_device_file_info *info;
2127	struct device *csdev;
2128	unsigned i;
2129	int retval;
2130
2131	info = kzalloc(sizeof(struct comedi_device_file_info), GFP_KERNEL);
2132	if (info == NULL)
2133		return -ENOMEM;
2134	info->device = kzalloc(sizeof(struct comedi_device), GFP_KERNEL);
2135	if (info->device == NULL) {
2136		kfree(info);
2137		return -ENOMEM;
2138	}
2139	comedi_device_init(info->device);
2140	spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2141	for (i = 0; i < COMEDI_NUM_BOARD_MINORS; ++i) {
2142		if (comedi_file_info_table[i] == NULL) {
2143			comedi_file_info_table[i] = info;
2144			break;
2145		}
2146	}
2147	spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2148	if (i == COMEDI_NUM_BOARD_MINORS) {
2149		comedi_device_cleanup(info->device);
2150		kfree(info->device);
2151		kfree(info);
2152		printk(KERN_ERR
2153		       "comedi: error: "
2154		       "ran out of minor numbers for board device files.\n");
2155		return -EBUSY;
2156	}
2157	info->device->minor = i;
2158	csdev = COMEDI_DEVICE_CREATE(comedi_class, NULL,
2159				     MKDEV(COMEDI_MAJOR, i), NULL,
2160				     hardware_device, "comedi%i", i);
2161	if (!IS_ERR(csdev))
2162		info->device->class_dev = csdev;
2163	dev_set_drvdata(csdev, info);
2164	retval = device_create_file(csdev, &dev_attr_max_read_buffer_kb);
2165	if (retval) {
2166		printk(KERN_ERR
2167		       "comedi: "
2168		       "failed to create sysfs attribute file \"%s\".\n",
2169		       dev_attr_max_read_buffer_kb.attr.name);
2170		comedi_free_board_minor(i);
2171		return retval;
2172	}
2173	retval = device_create_file(csdev, &dev_attr_read_buffer_kb);
2174	if (retval) {
2175		printk(KERN_ERR
2176		       "comedi: "
2177		       "failed to create sysfs attribute file \"%s\".\n",
2178		       dev_attr_read_buffer_kb.attr.name);
2179		comedi_free_board_minor(i);
2180		return retval;
2181	}
2182	retval = device_create_file(csdev, &dev_attr_max_write_buffer_kb);
2183	if (retval) {
2184		printk(KERN_ERR
2185		       "comedi: "
2186		       "failed to create sysfs attribute file \"%s\".\n",
2187		       dev_attr_max_write_buffer_kb.attr.name);
2188		comedi_free_board_minor(i);
2189		return retval;
2190	}
2191	retval = device_create_file(csdev, &dev_attr_write_buffer_kb);
2192	if (retval) {
2193		printk(KERN_ERR
2194		       "comedi: "
2195		       "failed to create sysfs attribute file \"%s\".\n",
2196		       dev_attr_write_buffer_kb.attr.name);
2197		comedi_free_board_minor(i);
2198		return retval;
2199	}
2200	return i;
2201}
2202
2203void comedi_free_board_minor(unsigned minor)
2204{
2205	unsigned long flags;
2206	struct comedi_device_file_info *info;
2207
2208	BUG_ON(minor >= COMEDI_NUM_BOARD_MINORS);
2209	spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2210	info = comedi_file_info_table[minor];
2211	comedi_file_info_table[minor] = NULL;
2212	spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2213
2214	if (info) {
2215		struct comedi_device *dev = info->device;
2216		if (dev) {
2217			if (dev->class_dev) {
2218				device_destroy(comedi_class,
2219					       MKDEV(COMEDI_MAJOR, dev->minor));
2220			}
2221			comedi_device_cleanup(dev);
2222			kfree(dev);
2223		}
2224		kfree(info);
2225	}
2226}
2227
2228int comedi_alloc_subdevice_minor(struct comedi_device *dev,
2229				 struct comedi_subdevice *s)
2230{
2231	unsigned long flags;
2232	struct comedi_device_file_info *info;
2233	struct device *csdev;
2234	unsigned i;
2235	int retval;
2236
2237	info = kmalloc(sizeof(struct comedi_device_file_info), GFP_KERNEL);
2238	if (info == NULL)
2239		return -ENOMEM;
2240	info->device = dev;
2241	info->read_subdevice = s;
2242	info->write_subdevice = s;
2243	spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2244	for (i = COMEDI_FIRST_SUBDEVICE_MINOR; i < COMEDI_NUM_MINORS; ++i) {
2245		if (comedi_file_info_table[i] == NULL) {
2246			comedi_file_info_table[i] = info;
2247			break;
2248		}
2249	}
2250	spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2251	if (i == COMEDI_NUM_MINORS) {
2252		kfree(info);
2253		printk(KERN_ERR
2254		       "comedi: error: "
2255		       "ran out of minor numbers for board device files.\n");
2256		return -EBUSY;
2257	}
2258	s->minor = i;
2259	csdev = COMEDI_DEVICE_CREATE(comedi_class, dev->class_dev,
2260				     MKDEV(COMEDI_MAJOR, i), NULL, NULL,
2261				     "comedi%i_subd%i", dev->minor,
2262				     (int)(s - dev->subdevices));
2263	if (!IS_ERR(csdev))
2264		s->class_dev = csdev;
2265	dev_set_drvdata(csdev, info);
2266	retval = device_create_file(csdev, &dev_attr_max_read_buffer_kb);
2267	if (retval) {
2268		printk(KERN_ERR
2269		       "comedi: "
2270		       "failed to create sysfs attribute file \"%s\".\n",
2271		       dev_attr_max_read_buffer_kb.attr.name);
2272		comedi_free_subdevice_minor(s);
2273		return retval;
2274	}
2275	retval = device_create_file(csdev, &dev_attr_read_buffer_kb);
2276	if (retval) {
2277		printk(KERN_ERR
2278		       "comedi: "
2279		       "failed to create sysfs attribute file \"%s\".\n",
2280		       dev_attr_read_buffer_kb.attr.name);
2281		comedi_free_subdevice_minor(s);
2282		return retval;
2283	}
2284	retval = device_create_file(csdev, &dev_attr_max_write_buffer_kb);
2285	if (retval) {
2286		printk(KERN_ERR
2287		       "comedi: "
2288		       "failed to create sysfs attribute file \"%s\".\n",
2289		       dev_attr_max_write_buffer_kb.attr.name);
2290		comedi_free_subdevice_minor(s);
2291		return retval;
2292	}
2293	retval = device_create_file(csdev, &dev_attr_write_buffer_kb);
2294	if (retval) {
2295		printk(KERN_ERR
2296		       "comedi: "
2297		       "failed to create sysfs attribute file \"%s\".\n",
2298		       dev_attr_write_buffer_kb.attr.name);
2299		comedi_free_subdevice_minor(s);
2300		return retval;
2301	}
2302	return i;
2303}
2304
2305void comedi_free_subdevice_minor(struct comedi_subdevice *s)
2306{
2307	unsigned long flags;
2308	struct comedi_device_file_info *info;
2309
2310	if (s == NULL)
2311		return;
2312	if (s->minor < 0)
2313		return;
2314
2315	BUG_ON(s->minor >= COMEDI_NUM_MINORS);
2316	BUG_ON(s->minor < COMEDI_FIRST_SUBDEVICE_MINOR);
2317
2318	spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2319	info = comedi_file_info_table[s->minor];
2320	comedi_file_info_table[s->minor] = NULL;
2321	spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2322
2323	if (s->class_dev) {
2324		device_destroy(comedi_class, MKDEV(COMEDI_MAJOR, s->minor));
2325		s->class_dev = NULL;
2326	}
2327	kfree(info);
2328}
2329
2330struct comedi_device_file_info *comedi_get_device_file_info(unsigned minor)
2331{
2332	unsigned long flags;
2333	struct comedi_device_file_info *info;
2334
2335	BUG_ON(minor >= COMEDI_NUM_MINORS);
2336	spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2337	info = comedi_file_info_table[minor];
2338	spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2339	return info;
2340}
2341EXPORT_SYMBOL_GPL(comedi_get_device_file_info);
2342
2343static int resize_async_buffer(struct comedi_device *dev,
2344			       struct comedi_subdevice *s,
2345			       struct comedi_async *async, unsigned new_size)
2346{
2347	int retval;
2348
2349	if (new_size > async->max_bufsize)
2350		return -EPERM;
2351
2352	if (s->busy) {
2353		DPRINTK("subdevice is busy, cannot resize buffer\n");
2354		return -EBUSY;
2355	}
2356	if (async->mmap_count) {
2357		DPRINTK("subdevice is mmapped, cannot resize buffer\n");
2358		return -EBUSY;
2359	}
2360
2361	if (!async->prealloc_buf)
2362		return -EINVAL;
2363
2364	/* make sure buffer is an integral number of pages
2365	 * (we round up) */
2366	new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
2367
2368	retval = comedi_buf_alloc(dev, s, new_size);
2369	if (retval < 0)
2370		return retval;
2371
2372	if (s->buf_change) {
2373		retval = s->buf_change(dev, s, new_size);
2374		if (retval < 0)
2375			return retval;
2376	}
2377
2378	DPRINTK("comedi%i subd %d buffer resized to %i bytes\n",
2379		dev->minor, (int)(s - dev->subdevices), async->prealloc_bufsz);
2380	return 0;
2381}
2382
2383/* sysfs attribute files */
2384
2385static const unsigned bytes_per_kibi = 1024;
2386
2387static ssize_t show_max_read_buffer_kb(struct device *dev,
2388				       struct device_attribute *attr, char *buf)
2389{
2390	ssize_t retval;
2391	struct comedi_device_file_info *info = dev_get_drvdata(dev);
2392	unsigned max_buffer_size_kb = 0;
2393	struct comedi_subdevice *const read_subdevice =
2394	    comedi_get_read_subdevice(info);
2395
2396	mutex_lock(&info->device->mutex);
2397	if (read_subdevice &&
2398	    (read_subdevice->subdev_flags & SDF_CMD_READ) &&
2399	    read_subdevice->async) {
2400		max_buffer_size_kb = read_subdevice->async->max_bufsize /
2401		    bytes_per_kibi;
2402	}
2403	retval = snprintf(buf, PAGE_SIZE, "%i\n", max_buffer_size_kb);
2404	mutex_unlock(&info->device->mutex);
2405
2406	return retval;
2407}
2408
2409static ssize_t store_max_read_buffer_kb(struct device *dev,
2410					struct device_attribute *attr,
2411					const char *buf, size_t count)
2412{
2413	struct comedi_device_file_info *info = dev_get_drvdata(dev);
2414	unsigned long new_max_size_kb;
2415	uint64_t new_max_size;
2416	struct comedi_subdevice *const read_subdevice =
2417	    comedi_get_read_subdevice(info);
2418
2419	if (strict_strtoul(buf, 10, &new_max_size_kb))
2420		return -EINVAL;
2421	if (new_max_size_kb != (uint32_t) new_max_size_kb)
2422		return -EINVAL;
2423	new_max_size = ((uint64_t) new_max_size_kb) * bytes_per_kibi;
2424	if (new_max_size != (uint32_t) new_max_size)
2425		return -EINVAL;
2426
2427	mutex_lock(&info->device->mutex);
2428	if (read_subdevice == NULL ||
2429	    (read_subdevice->subdev_flags & SDF_CMD_READ) == 0 ||
2430	    read_subdevice->async == NULL) {
2431		mutex_unlock(&info->device->mutex);
2432		return -EINVAL;
2433	}
2434	read_subdevice->async->max_bufsize = new_max_size;
2435	mutex_unlock(&info->device->mutex);
2436
2437	return count;
2438}
2439
2440static struct device_attribute dev_attr_max_read_buffer_kb = {
2441	.attr = {
2442		 .name = "max_read_buffer_kb",
2443		 .mode = S_IRUGO | S_IWUSR},
2444	.show = &show_max_read_buffer_kb,
2445	.store = &store_max_read_buffer_kb
2446};
2447
2448static ssize_t show_read_buffer_kb(struct device *dev,
2449				   struct device_attribute *attr, char *buf)
2450{
2451	ssize_t retval;
2452	struct comedi_device_file_info *info = dev_get_drvdata(dev);
2453	unsigned buffer_size_kb = 0;
2454	struct comedi_subdevice *const read_subdevice =
2455	    comedi_get_read_subdevice(info);
2456
2457	mutex_lock(&info->device->mutex);
2458	if (read_subdevice &&
2459	    (read_subdevice->subdev_flags & SDF_CMD_READ) &&
2460	    read_subdevice->async) {
2461		buffer_size_kb = read_subdevice->async->prealloc_bufsz /
2462		    bytes_per_kibi;
2463	}
2464	retval = snprintf(buf, PAGE_SIZE, "%i\n", buffer_size_kb);
2465	mutex_unlock(&info->device->mutex);
2466
2467	return retval;
2468}
2469
2470static ssize_t store_read_buffer_kb(struct device *dev,
2471				    struct device_attribute *attr,
2472				    const char *buf, size_t count)
2473{
2474	struct comedi_device_file_info *info = dev_get_drvdata(dev);
2475	unsigned long new_size_kb;
2476	uint64_t new_size;
2477	int retval;
2478	struct comedi_subdevice *const read_subdevice =
2479	    comedi_get_read_subdevice(info);
2480
2481	if (strict_strtoul(buf, 10, &new_size_kb))
2482		return -EINVAL;
2483	if (new_size_kb != (uint32_t) new_size_kb)
2484		return -EINVAL;
2485	new_size = ((uint64_t) new_size_kb) * bytes_per_kibi;
2486	if (new_size != (uint32_t) new_size)
2487		return -EINVAL;
2488
2489	mutex_lock(&info->device->mutex);
2490	if (read_subdevice == NULL ||
2491	    (read_subdevice->subdev_flags & SDF_CMD_READ) == 0 ||
2492	    read_subdevice->async == NULL) {
2493		mutex_unlock(&info->device->mutex);
2494		return -EINVAL;
2495	}
2496	retval = resize_async_buffer(info->device, read_subdevice,
2497				     read_subdevice->async, new_size);
2498	mutex_unlock(&info->device->mutex);
2499
2500	if (retval < 0)
2501		return retval;
2502	return count;
2503}
2504
2505static struct device_attribute dev_attr_read_buffer_kb = {
2506	.attr = {
2507		 .name = "read_buffer_kb",
2508		 .mode = S_IRUGO | S_IWUSR | S_IWGRP},
2509	.show = &show_read_buffer_kb,
2510	.store = &store_read_buffer_kb
2511};
2512
2513static ssize_t show_max_write_buffer_kb(struct device *dev,
2514					struct device_attribute *attr,
2515					char *buf)
2516{
2517	ssize_t retval;
2518	struct comedi_device_file_info *info = dev_get_drvdata(dev);
2519	unsigned max_buffer_size_kb = 0;
2520	struct comedi_subdevice *const write_subdevice =
2521	    comedi_get_write_subdevice(info);
2522
2523	mutex_lock(&info->device->mutex);
2524	if (write_subdevice &&
2525	    (write_subdevice->subdev_flags & SDF_CMD_WRITE) &&
2526	    write_subdevice->async) {
2527		max_buffer_size_kb = write_subdevice->async->max_bufsize /
2528		    bytes_per_kibi;
2529	}
2530	retval = snprintf(buf, PAGE_SIZE, "%i\n", max_buffer_size_kb);
2531	mutex_unlock(&info->device->mutex);
2532
2533	return retval;
2534}
2535
2536static ssize_t store_max_write_buffer_kb(struct device *dev,
2537					 struct device_attribute *attr,
2538					 const char *buf, size_t count)
2539{
2540	struct comedi_device_file_info *info = dev_get_drvdata(dev);
2541	unsigned long new_max_size_kb;
2542	uint64_t new_max_size;
2543	struct comedi_subdevice *const write_subdevice =
2544	    comedi_get_write_subdevice(info);
2545
2546	if (strict_strtoul(buf, 10, &new_max_size_kb))
2547		return -EINVAL;
2548	if (new_max_size_kb != (uint32_t) new_max_size_kb)
2549		return -EINVAL;
2550	new_max_size = ((uint64_t) new_max_size_kb) * bytes_per_kibi;
2551	if (new_max_size != (uint32_t) new_max_size)
2552		return -EINVAL;
2553
2554	mutex_lock(&info->device->mutex);
2555	if (write_subdevice == NULL ||
2556	    (write_subdevice->subdev_flags & SDF_CMD_WRITE) == 0 ||
2557	    write_subdevice->async == NULL) {
2558		mutex_unlock(&info->device->mutex);
2559		return -EINVAL;
2560	}
2561	write_subdevice->async->max_bufsize = new_max_size;
2562	mutex_unlock(&info->device->mutex);
2563
2564	return count;
2565}
2566
2567static struct device_attribute dev_attr_max_write_buffer_kb = {
2568	.attr = {
2569		 .name = "max_write_buffer_kb",
2570		 .mode = S_IRUGO | S_IWUSR},
2571	.show = &show_max_write_buffer_kb,
2572	.store = &store_max_write_buffer_kb
2573};
2574
2575static ssize_t show_write_buffer_kb(struct device *dev,
2576				    struct device_attribute *attr, char *buf)
2577{
2578	ssize_t retval;
2579	struct comedi_device_file_info *info = dev_get_drvdata(dev);
2580	unsigned buffer_size_kb = 0;
2581	struct comedi_subdevice *const write_subdevice =
2582	    comedi_get_write_subdevice(info);
2583
2584	mutex_lock(&info->device->mutex);
2585	if (write_subdevice &&
2586	    (write_subdevice->subdev_flags & SDF_CMD_WRITE) &&
2587	    write_subdevice->async) {
2588		buffer_size_kb = write_subdevice->async->prealloc_bufsz /
2589		    bytes_per_kibi;
2590	}
2591	retval = snprintf(buf, PAGE_SIZE, "%i\n", buffer_size_kb);
2592	mutex_unlock(&info->device->mutex);
2593
2594	return retval;
2595}
2596
2597static ssize_t store_write_buffer_kb(struct device *dev,
2598				     struct device_attribute *attr,
2599				     const char *buf, size_t count)
2600{
2601	struct comedi_device_file_info *info = dev_get_drvdata(dev);
2602	unsigned long new_size_kb;
2603	uint64_t new_size;
2604	int retval;
2605	struct comedi_subdevice *const write_subdevice =
2606	    comedi_get_write_subdevice(info);
2607
2608	if (strict_strtoul(buf, 10, &new_size_kb))
2609		return -EINVAL;
2610	if (new_size_kb != (uint32_t) new_size_kb)
2611		return -EINVAL;
2612	new_size = ((uint64_t) new_size_kb) * bytes_per_kibi;
2613	if (new_size != (uint32_t) new_size)
2614		return -EINVAL;
2615
2616	mutex_lock(&info->device->mutex);
2617	if (write_subdevice == NULL ||
2618	    (write_subdevice->subdev_flags & SDF_CMD_WRITE) == 0 ||
2619	    write_subdevice->async == NULL) {
2620		mutex_unlock(&info->device->mutex);
2621		return -EINVAL;
2622	}
2623	retval = resize_async_buffer(info->device, write_subdevice,
2624				     write_subdevice->async, new_size);
2625	mutex_unlock(&info->device->mutex);
2626
2627	if (retval < 0)
2628		return retval;
2629	return count;
2630}
2631
2632static struct device_attribute dev_attr_write_buffer_kb = {
2633	.attr = {
2634		 .name = "write_buffer_kb",
2635		 .mode = S_IRUGO | S_IWUSR | S_IWGRP},
2636	.show = &show_write_buffer_kb,
2637	.store = &store_write_buffer_kb
2638};
2639