comedi_fops.c revision ed9eccbe8970f6eedc1b978c157caf1251a896d4
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
48#include <asm/io.h>
49#include <asm/uaccess.h>
50
51//#include "kvmem.h"
52
53MODULE_AUTHOR("http://www.comedi.org");
54MODULE_DESCRIPTION("Comedi core module");
55MODULE_LICENSE("GPL");
56
57#ifdef CONFIG_COMEDI_DEBUG
58int comedi_debug;
59module_param(comedi_debug, int, 0644);
60#endif
61
62static DEFINE_SPINLOCK(comedi_file_info_table_lock);
63static struct comedi_device_file_info* comedi_file_info_table[COMEDI_NUM_MINORS];
64
65static int do_devconfig_ioctl(comedi_device * dev, comedi_devconfig * arg);
66static int do_bufconfig_ioctl(comedi_device * dev, void *arg);
67static int do_devinfo_ioctl(comedi_device * dev, comedi_devinfo * arg,
68	struct file *file);
69static int do_subdinfo_ioctl(comedi_device * dev, comedi_subdinfo * arg,
70	void *file);
71static int do_chaninfo_ioctl(comedi_device * dev, comedi_chaninfo * arg);
72static int do_bufinfo_ioctl(comedi_device * dev, void *arg);
73static int do_cmd_ioctl(comedi_device * dev, void *arg, void *file);
74static int do_lock_ioctl(comedi_device * dev, unsigned int arg, void *file);
75static int do_unlock_ioctl(comedi_device * dev, unsigned int arg, void *file);
76static int do_cancel_ioctl(comedi_device * dev, unsigned int arg, void *file);
77static int do_cmdtest_ioctl(comedi_device * dev, void *arg, void *file);
78static int do_insnlist_ioctl(comedi_device * dev, void *arg, void *file);
79static int do_insn_ioctl(comedi_device * dev, void *arg, void *file);
80static int do_poll_ioctl(comedi_device * dev, unsigned int subd, void *file);
81
82void do_become_nonbusy(comedi_device * dev, comedi_subdevice * s);
83static int do_cancel(comedi_device * dev, comedi_subdevice * s);
84
85static int comedi_fasync(int fd, struct file *file, int on);
86
87static int is_device_busy(comedi_device * dev);
88
89#ifdef HAVE_UNLOCKED_IOCTL
90static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
91	unsigned long arg)
92#else
93static int comedi_ioctl(struct inode *inode, struct file *file,
94	unsigned int cmd, unsigned long arg)
95#endif
96{
97	const unsigned minor = iminor(file->f_dentry->d_inode);
98	struct comedi_device_file_info *dev_file_info = comedi_get_device_file_info(minor);
99	comedi_device *dev = dev_file_info->device;
100	int rc;
101
102	mutex_lock(&dev->mutex);
103
104	/* Device config is special, because it must work on
105	 * an unconfigured device. */
106	if (cmd == COMEDI_DEVCONFIG) {
107		rc = do_devconfig_ioctl(dev, (void *)arg);
108		goto done;
109	}
110
111	if (!dev->attached) {
112		DPRINTK("no driver configured on /dev/comedi%i\n", dev->minor);
113		rc = -ENODEV;
114		goto done;
115	}
116
117	switch (cmd) {
118	case COMEDI_BUFCONFIG:
119		rc = do_bufconfig_ioctl(dev, (void *)arg);
120		break;
121	case COMEDI_DEVINFO:
122		rc = do_devinfo_ioctl(dev, (void *)arg, file);
123		break;
124	case COMEDI_SUBDINFO:
125		rc = do_subdinfo_ioctl(dev, (void *)arg, file);
126		break;
127	case COMEDI_CHANINFO:
128		rc = do_chaninfo_ioctl(dev, (void *)arg);
129		break;
130	case COMEDI_RANGEINFO:
131		rc = do_rangeinfo_ioctl(dev, (void *)arg);
132		break;
133	case COMEDI_BUFINFO:
134		rc = do_bufinfo_ioctl(dev, (void *)arg);
135		break;
136	case COMEDI_LOCK:
137		rc = do_lock_ioctl(dev, arg, file);
138		break;
139	case COMEDI_UNLOCK:
140		rc = do_unlock_ioctl(dev, arg, file);
141		break;
142	case COMEDI_CANCEL:
143		rc = do_cancel_ioctl(dev, arg, file);
144		break;
145	case COMEDI_CMD:
146		rc = do_cmd_ioctl(dev, (void *)arg, file);
147		break;
148	case COMEDI_CMDTEST:
149		rc = do_cmdtest_ioctl(dev, (void *)arg, file);
150		break;
151	case COMEDI_INSNLIST:
152		rc = do_insnlist_ioctl(dev, (void *)arg, file);
153		break;
154	case COMEDI_INSN:
155		rc = do_insn_ioctl(dev, (void *)arg, file);
156		break;
157	case COMEDI_POLL:
158		rc = do_poll_ioctl(dev, arg, file);
159		break;
160	default:
161		rc = -ENOTTY;
162		break;
163	}
164
165      done:
166	mutex_unlock(&dev->mutex);
167	return rc;
168}
169
170/*
171	COMEDI_DEVCONFIG
172	device config ioctl
173
174	arg:
175		pointer to devconfig structure
176
177	reads:
178		devconfig structure at arg
179
180	writes:
181		none
182*/
183static int do_devconfig_ioctl(comedi_device * dev, comedi_devconfig * arg)
184{
185	comedi_devconfig it;
186	int ret;
187	unsigned char *aux_data = NULL;
188	int aux_len;
189
190	if (!capable(CAP_SYS_ADMIN))
191		return -EPERM;
192
193	if (arg == NULL) {
194		if (is_device_busy(dev))
195			return -EBUSY;
196		if(dev->attached)
197		{
198			struct module *driver_module = dev->driver->module;
199			comedi_device_detach(dev);
200			module_put(driver_module);
201		}
202		return 0;
203	}
204
205	if (copy_from_user(&it, arg, sizeof(comedi_devconfig)))
206		return -EFAULT;
207
208	it.board_name[COMEDI_NAMELEN - 1] = 0;
209
210	if (comedi_aux_data(it.options, 0) &&
211		it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH]) {
212		int bit_shift;
213		aux_len = it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH];
214		if (aux_len < 0)
215			return -EFAULT;
216
217		aux_data = vmalloc(aux_len);
218		if (!aux_data)
219			return -ENOMEM;
220
221		if (copy_from_user(aux_data,
222				comedi_aux_data(it.options, 0), aux_len)) {
223			vfree(aux_data);
224			return -EFAULT;
225		}
226		it.options[COMEDI_DEVCONF_AUX_DATA_LO] =
227			(unsigned long)aux_data;
228		if (sizeof(void *) > sizeof(int)) {
229			bit_shift = sizeof(int) * 8;
230			it.options[COMEDI_DEVCONF_AUX_DATA_HI] =
231				((unsigned long)aux_data) >> bit_shift;
232		} else
233			it.options[COMEDI_DEVCONF_AUX_DATA_HI] = 0;
234	}
235
236	ret = comedi_device_attach(dev, &it);
237	if(ret == 0)
238	{
239		if(!try_module_get(dev->driver->module)) {
240			comedi_device_detach(dev);
241			return -ENOSYS;
242		}
243	}
244
245	if (aux_data)
246		vfree(aux_data);
247
248	return ret;
249}
250
251/*
252	COMEDI_BUFCONFIG
253	buffer configuration ioctl
254
255	arg:
256		pointer to bufconfig structure
257
258	reads:
259		bufconfig at arg
260
261	writes:
262		modified bufconfig at arg
263
264*/
265static int do_bufconfig_ioctl(comedi_device * dev, void *arg)
266{
267	comedi_bufconfig bc;
268	comedi_async *async;
269	comedi_subdevice *s;
270	int ret = 0;
271
272	if (copy_from_user(&bc, arg, sizeof(comedi_bufconfig)))
273		return -EFAULT;
274
275	if (bc.subdevice >= dev->n_subdevices || bc.subdevice < 0)
276		return -EINVAL;
277
278	s = dev->subdevices + bc.subdevice;
279	async = s->async;
280
281	if (!async) {
282		DPRINTK("subdevice does not have async capability\n");
283		bc.size = 0;
284		bc.maximum_size = 0;
285		goto copyback;
286	}
287
288	if (bc.maximum_size) {
289		if (!capable(CAP_SYS_ADMIN))
290			return -EPERM;
291
292		async->max_bufsize = bc.maximum_size;
293	}
294
295	if (bc.size) {
296		if (bc.size > async->max_bufsize)
297			return -EPERM;
298
299		if (s->busy) {
300			DPRINTK("subdevice is busy, cannot resize buffer\n");
301			return -EBUSY;
302		}
303		if (async->mmap_count) {
304			DPRINTK("subdevice is mmapped, cannot resize buffer\n");
305			return -EBUSY;
306		}
307
308		if (!async->prealloc_buf)
309			return -EINVAL;
310
311		/* make sure buffer is an integral number of pages
312		 * (we round up) */
313		bc.size = (bc.size + PAGE_SIZE - 1) & PAGE_MASK;
314
315		ret = comedi_buf_alloc(dev, s, bc.size);
316		if (ret < 0)
317			return ret;
318
319		if (s->buf_change) {
320			ret = s->buf_change(dev, s, bc.size);
321			if (ret < 0)
322				return ret;
323		}
324
325		DPRINTK("comedi%i subd %d buffer resized to %i bytes\n",
326			dev->minor, bc.subdevice, async->prealloc_bufsz);
327	}
328
329	bc.size = async->prealloc_bufsz;
330	bc.maximum_size = async->max_bufsize;
331
332      copyback:
333	if (copy_to_user(arg, &bc, sizeof(comedi_bufconfig)))
334		return -EFAULT;
335
336	return 0;
337}
338
339/*
340	COMEDI_DEVINFO
341	device info ioctl
342
343	arg:
344		pointer to devinfo structure
345
346	reads:
347		none
348
349	writes:
350		devinfo structure
351
352*/
353static int do_devinfo_ioctl(comedi_device * dev, comedi_devinfo * arg,
354	struct file *file)
355{
356	comedi_devinfo devinfo;
357	const unsigned minor = iminor(file->f_dentry->d_inode);
358	struct comedi_device_file_info *dev_file_info = comedi_get_device_file_info(minor);
359	comedi_subdevice *read_subdev = comedi_get_read_subdevice(dev_file_info);
360	comedi_subdevice *write_subdev = comedi_get_write_subdevice(dev_file_info);
361
362	memset(&devinfo, 0, sizeof(devinfo));
363
364	/* fill devinfo structure */
365	devinfo.version_code = COMEDI_VERSION_CODE;
366	devinfo.n_subdevs = dev->n_subdevices;
367	memcpy(devinfo.driver_name, dev->driver->driver_name, COMEDI_NAMELEN);
368	memcpy(devinfo.board_name, dev->board_name, COMEDI_NAMELEN);
369
370	if (read_subdev) {
371		devinfo.read_subdevice = read_subdev - dev->subdevices;
372	} else {
373		devinfo.read_subdevice = -1;
374	}
375	if (write_subdev) {
376		devinfo.write_subdevice = write_subdev - dev->subdevices;
377	} else {
378		devinfo.write_subdevice = -1;
379	}
380
381	if (copy_to_user(arg, &devinfo, sizeof(comedi_devinfo)))
382		return -EFAULT;
383
384	return 0;
385}
386
387/*
388	COMEDI_SUBDINFO
389	subdevice info ioctl
390
391	arg:
392		pointer to array of subdevice info structures
393
394	reads:
395		none
396
397	writes:
398		array of subdevice info structures at arg
399
400*/
401static int do_subdinfo_ioctl(comedi_device * dev, comedi_subdinfo * arg,
402	void *file)
403{
404	int ret, i;
405	comedi_subdinfo *tmp, *us;
406	comedi_subdevice *s;
407
408	tmp = kcalloc(dev->n_subdevices, sizeof(comedi_subdinfo), GFP_KERNEL);
409	if (!tmp)
410		return -ENOMEM;
411
412	/* fill subdinfo structs */
413	for (i = 0; i < dev->n_subdevices; i++) {
414		s = dev->subdevices + i;
415		us = tmp + i;
416
417		us->type = s->type;
418		us->n_chan = s->n_chan;
419		us->subd_flags = s->subdev_flags;
420		if (comedi_get_subdevice_runflags(s) & SRF_RUNNING)
421			us->subd_flags |= SDF_RUNNING;
422#define TIMER_nanosec 5		/* backwards compatibility */
423		us->timer_type = TIMER_nanosec;
424		us->len_chanlist = s->len_chanlist;
425		us->maxdata = s->maxdata;
426		if (s->range_table) {
427			us->range_type =
428				(i << 24) | (0 << 16) | (s->
429				range_table->length);
430		} else {
431			us->range_type = 0;	/* XXX */
432		}
433		us->flags = s->flags;
434
435		if (s->busy)
436			us->subd_flags |= SDF_BUSY;
437		if (s->busy == file)
438			us->subd_flags |= SDF_BUSY_OWNER;
439		if (s->lock)
440			us->subd_flags |= SDF_LOCKED;
441		if (s->lock == file)
442			us->subd_flags |= SDF_LOCK_OWNER;
443		if (!s->maxdata && s->maxdata_list)
444			us->subd_flags |= SDF_MAXDATA;
445		if (s->flaglist)
446			us->subd_flags |= SDF_FLAGS;
447		if (s->range_table_list)
448			us->subd_flags |= SDF_RANGETYPE;
449		if (s->do_cmd)
450			us->subd_flags |= SDF_CMD;
451
452		if (s->insn_bits != &insn_inval)
453			us->insn_bits_support = COMEDI_SUPPORTED;
454		else
455			us->insn_bits_support = COMEDI_UNSUPPORTED;
456
457		us->settling_time_0 = s->settling_time_0;
458	}
459
460	ret = copy_to_user(arg, tmp,
461		dev->n_subdevices * sizeof(comedi_subdinfo));
462
463	kfree(tmp);
464
465	return ret ? -EFAULT : 0;
466}
467
468/*
469	COMEDI_CHANINFO
470	subdevice info ioctl
471
472	arg:
473		pointer to chaninfo structure
474
475	reads:
476		chaninfo structure at arg
477
478	writes:
479		arrays at elements of chaninfo structure
480
481*/
482static int do_chaninfo_ioctl(comedi_device * dev, comedi_chaninfo * arg)
483{
484	comedi_subdevice *s;
485	comedi_chaninfo it;
486
487	if (copy_from_user(&it, arg, sizeof(comedi_chaninfo)))
488		return -EFAULT;
489
490	if (it.subdev >= dev->n_subdevices)
491		return -EINVAL;
492	s = dev->subdevices + it.subdev;
493
494	if (it.maxdata_list) {
495		if (s->maxdata || !s->maxdata_list)
496			return -EINVAL;
497		if (copy_to_user(it.maxdata_list, s->maxdata_list,
498				s->n_chan * sizeof(lsampl_t)))
499			return -EFAULT;
500	}
501
502	if (it.flaglist) {
503		if (!s->flaglist)
504			return -EINVAL;
505		if (copy_to_user(it.flaglist, s->flaglist,
506				s->n_chan * sizeof(unsigned int)))
507			return -EFAULT;
508	}
509
510	if (it.rangelist) {
511		int i;
512
513		if (!s->range_table_list)
514			return -EINVAL;
515		for (i = 0; i < s->n_chan; i++) {
516			int x;
517
518			x = (dev->minor << 28) | (it.subdev << 24) | (i << 16) |
519				(s->range_table_list[i]->length);
520			put_user(x, it.rangelist + i);
521		}
522		//if(copy_to_user(it.rangelist,s->range_type_list,s->n_chan*sizeof(unsigned int)))
523		//      return -EFAULT;
524	}
525
526	return 0;
527}
528
529 /*
530    COMEDI_BUFINFO
531    buffer information ioctl
532
533    arg:
534    pointer to bufinfo structure
535
536    reads:
537    bufinfo at arg
538
539    writes:
540    modified bufinfo at arg
541
542  */
543static int do_bufinfo_ioctl(comedi_device * dev, void *arg)
544{
545	comedi_bufinfo bi;
546	comedi_subdevice *s;
547	comedi_async *async;
548
549	if (copy_from_user(&bi, arg, sizeof(comedi_bufinfo)))
550		return -EFAULT;
551
552	if (bi.subdevice >= dev->n_subdevices || bi.subdevice < 0)
553		return -EINVAL;
554
555	s = dev->subdevices + bi.subdevice;
556	async = s->async;
557
558	if (!async) {
559		DPRINTK("subdevice does not have async capability\n");
560		bi.buf_write_ptr = 0;
561		bi.buf_read_ptr = 0;
562		bi.buf_write_count = 0;
563		bi.buf_read_count = 0;
564		goto copyback;
565	}
566
567	if (bi.bytes_read && (s->subdev_flags & SDF_CMD_READ)) {
568		bi.bytes_read = comedi_buf_read_alloc(async, bi.bytes_read);
569		comedi_buf_read_free(async, bi.bytes_read);
570
571		if (!(comedi_get_subdevice_runflags(s) & (SRF_ERROR |
572					SRF_RUNNING))
573			&& async->buf_write_count == async->buf_read_count) {
574			do_become_nonbusy(dev, s);
575		}
576	}
577
578	if (bi.bytes_written && (s->subdev_flags & SDF_CMD_WRITE)) {
579		bi.bytes_written =
580			comedi_buf_write_alloc(async, bi.bytes_written);
581		comedi_buf_write_free(async, bi.bytes_written);
582	}
583
584	bi.buf_write_count = async->buf_write_count;
585	bi.buf_write_ptr = async->buf_write_ptr;
586	bi.buf_read_count = async->buf_read_count;
587	bi.buf_read_ptr = async->buf_read_ptr;
588
589      copyback:
590	if (copy_to_user(arg, &bi, sizeof(comedi_bufinfo)))
591		return -EFAULT;
592
593	return 0;
594}
595
596static int parse_insn(comedi_device * dev, comedi_insn * insn, lsampl_t * data,
597	void *file);
598/*
599 * 	COMEDI_INSNLIST
600 * 	synchronous instructions
601 *
602 * 	arg:
603 * 		pointer to sync cmd structure
604 *
605 * 	reads:
606 * 		sync cmd struct at arg
607 * 		instruction list
608 * 		data (for writes)
609 *
610 * 	writes:
611 * 		data (for reads)
612 */
613/* arbitrary limits */
614#define MAX_SAMPLES 256
615static int do_insnlist_ioctl(comedi_device * dev, void *arg, void *file)
616{
617	comedi_insnlist insnlist;
618	comedi_insn *insns = NULL;
619	lsampl_t *data = NULL;
620	int i = 0;
621	int ret = 0;
622
623	if (copy_from_user(&insnlist, arg, sizeof(comedi_insnlist)))
624		return -EFAULT;
625
626	data = kmalloc(sizeof(lsampl_t) * MAX_SAMPLES, GFP_KERNEL);
627	if (!data) {
628		DPRINTK("kmalloc failed\n");
629		ret = -ENOMEM;
630		goto error;
631	}
632
633	insns = kmalloc(sizeof(comedi_insn) * insnlist.n_insns, GFP_KERNEL);
634	if (!insns) {
635		DPRINTK("kmalloc failed\n");
636		ret = -ENOMEM;
637		goto error;
638	}
639
640	if (copy_from_user(insns, insnlist.insns,
641			sizeof(comedi_insn) * insnlist.n_insns)) {
642		DPRINTK("copy_from_user failed\n");
643		ret = -EFAULT;
644		goto error;
645	}
646
647	for (i = 0; i < insnlist.n_insns; i++) {
648		if (insns[i].n > MAX_SAMPLES) {
649			DPRINTK("number of samples too large\n");
650			ret = -EINVAL;
651			goto error;
652		}
653		if (insns[i].insn & INSN_MASK_WRITE) {
654			if (copy_from_user(data, insns[i].data,
655					insns[i].n * sizeof(lsampl_t))) {
656				DPRINTK("copy_from_user failed\n");
657				ret = -EFAULT;
658				goto error;
659			}
660		}
661		ret = parse_insn(dev, insns + i, data, file);
662		if (ret < 0)
663			goto error;
664		if (insns[i].insn & INSN_MASK_READ) {
665			if (copy_to_user(insns[i].data, data,
666					insns[i].n * sizeof(lsampl_t))) {
667				DPRINTK("copy_to_user failed\n");
668				ret = -EFAULT;
669				goto error;
670			}
671		}
672		if (need_resched())
673			schedule();
674	}
675
676      error:
677	if (insns)
678		kfree(insns);
679	if (data)
680		kfree(data);
681
682	if (ret < 0)
683		return ret;
684	return i;
685}
686
687static int check_insn_config_length(comedi_insn * insn, lsampl_t * data)
688{
689	if(insn->n < 1) return -EINVAL;
690
691	switch (data[0]) {
692	case INSN_CONFIG_DIO_OUTPUT:
693	case INSN_CONFIG_DIO_INPUT:
694	case INSN_CONFIG_DISARM:
695	case INSN_CONFIG_RESET:
696		if (insn->n == 1)
697			return 0;
698		break;
699	case INSN_CONFIG_ARM:
700	case INSN_CONFIG_DIO_QUERY:
701	case INSN_CONFIG_BLOCK_SIZE:
702	case INSN_CONFIG_FILTER:
703	case INSN_CONFIG_SERIAL_CLOCK:
704	case INSN_CONFIG_BIDIRECTIONAL_DATA:
705	case INSN_CONFIG_ALT_SOURCE:
706	case INSN_CONFIG_SET_COUNTER_MODE:
707	case INSN_CONFIG_8254_READ_STATUS:
708	case INSN_CONFIG_SET_ROUTING:
709	case INSN_CONFIG_GET_ROUTING:
710	case INSN_CONFIG_GET_PWM_STATUS:
711	case INSN_CONFIG_PWM_SET_PERIOD:
712	case INSN_CONFIG_PWM_GET_PERIOD:
713		if (insn->n == 2)
714			return 0;
715		break;
716	case INSN_CONFIG_SET_GATE_SRC:
717	case INSN_CONFIG_GET_GATE_SRC:
718	case INSN_CONFIG_SET_CLOCK_SRC:
719	case INSN_CONFIG_GET_CLOCK_SRC:
720	case INSN_CONFIG_SET_OTHER_SRC:
721	case INSN_CONFIG_GET_COUNTER_STATUS:
722	case INSN_CONFIG_PWM_SET_H_BRIDGE:
723	case INSN_CONFIG_PWM_GET_H_BRIDGE:
724	case INSN_CONFIG_GET_HARDWARE_BUFFER_SIZE:
725		if (insn->n == 3)
726			return 0;
727		break;
728	case INSN_CONFIG_PWM_OUTPUT:
729	case INSN_CONFIG_ANALOG_TRIG:
730		if (insn->n == 5)
731			return 0;
732		break;
733		//by default we allow the insn since we don't have checks for all possible cases yet
734	default:
735		rt_printk
736			("comedi: no check for data length of config insn id %i is implemented.\n"
737			" Add a check to %s in %s.\n"
738			" Assuming n=%i is correct.\n", data[0], __FUNCTION__,
739			__FILE__, insn->n);
740		return 0;
741		break;
742	}
743	return -EINVAL;
744}
745
746static int parse_insn(comedi_device * dev, comedi_insn * insn, lsampl_t * data,
747	void *file)
748{
749	comedi_subdevice *s;
750	int ret = 0;
751	int i;
752
753	if (insn->insn & INSN_MASK_SPECIAL) {
754		/* a non-subdevice instruction */
755
756		switch (insn->insn) {
757		case INSN_GTOD:
758			{
759				struct timeval tv;
760
761				if (insn->n != 2) {
762					ret = -EINVAL;
763					break;
764				}
765
766				do_gettimeofday(&tv);
767				data[0] = tv.tv_sec;
768				data[1] = tv.tv_usec;
769				ret = 2;
770
771				break;
772			}
773		case INSN_WAIT:
774			if (insn->n != 1 || data[0] >= 100000) {
775				ret = -EINVAL;
776				break;
777			}
778			udelay(data[0] / 1000);
779			ret = 1;
780			break;
781		case INSN_INTTRIG:
782			if (insn->n != 1) {
783				ret = -EINVAL;
784				break;
785			}
786			if (insn->subdev >= dev->n_subdevices) {
787				DPRINTK("%d not usable subdevice\n",
788					insn->subdev);
789				ret = -EINVAL;
790				break;
791			}
792			s = dev->subdevices + insn->subdev;
793			if (!s->async) {
794				DPRINTK("no async\n");
795				ret = -EINVAL;
796				break;
797			}
798			if (!s->async->inttrig) {
799				DPRINTK("no inttrig\n");
800				ret = -EAGAIN;
801				break;
802			}
803			ret = s->async->inttrig(dev, s, insn->data[0]);
804			if (ret >= 0)
805				ret = 1;
806			break;
807		default:
808			DPRINTK("invalid insn\n");
809			ret = -EINVAL;
810			break;
811		}
812	} else {
813		/* a subdevice instruction */
814		lsampl_t maxdata;
815
816		if (insn->subdev >= dev->n_subdevices) {
817			DPRINTK("subdevice %d out of range\n", insn->subdev);
818			ret = -EINVAL;
819			goto out;
820		}
821		s = dev->subdevices + insn->subdev;
822
823		if (s->type == COMEDI_SUBD_UNUSED) {
824			DPRINTK("%d not usable subdevice\n", insn->subdev);
825			ret = -EIO;
826			goto out;
827		}
828
829		/* are we locked? (ioctl lock) */
830		if (s->lock && s->lock != file) {
831			DPRINTK("device locked\n");
832			ret = -EACCES;
833			goto out;
834		}
835
836		if ((ret = check_chanlist(s, 1, &insn->chanspec)) < 0) {
837			ret = -EINVAL;
838			DPRINTK("bad chanspec\n");
839			goto out;
840		}
841
842		if (s->busy) {
843			ret = -EBUSY;
844			goto out;
845		}
846		/* This looks arbitrary.  It is. */
847		s->busy = &parse_insn;
848		switch (insn->insn) {
849		case INSN_READ:
850			ret = s->insn_read(dev, s, insn, data);
851			break;
852		case INSN_WRITE:
853			maxdata = s->maxdata_list
854				? s->maxdata_list[CR_CHAN(insn->chanspec)]
855				: s->maxdata;
856			for (i = 0; i < insn->n; ++i) {
857				if (data[i] > maxdata) {
858					ret = -EINVAL;
859					DPRINTK("bad data value(s)\n");
860					break;
861				}
862			}
863			if (ret == 0)
864				ret = s->insn_write(dev, s, insn, data);
865			break;
866		case INSN_BITS:
867			if (insn->n != 2) {
868				ret = -EINVAL;
869				break;
870			}
871			ret = s->insn_bits(dev, s, insn, data);
872			break;
873		case INSN_CONFIG:
874			ret = check_insn_config_length(insn, data);
875			if (ret)
876				break;
877			ret = s->insn_config(dev, s, insn, data);
878			break;
879		default:
880			ret = -EINVAL;
881			break;
882		}
883
884		s->busy = NULL;
885	}
886
887      out:
888	return ret;
889}
890
891/*
892 * 	COMEDI_INSN
893 * 	synchronous instructions
894 *
895 * 	arg:
896 * 		pointer to insn
897 *
898 * 	reads:
899 * 		comedi_insn struct at arg
900 * 		data (for writes)
901 *
902 * 	writes:
903 * 		data (for reads)
904 */
905static int do_insn_ioctl(comedi_device * dev, void *arg, void *file)
906{
907	comedi_insn insn;
908	lsampl_t *data = NULL;
909	int ret = 0;
910
911	data = kmalloc(sizeof(lsampl_t) * MAX_SAMPLES, GFP_KERNEL);
912	if (!data) {
913		ret = -ENOMEM;
914		goto error;
915	}
916
917	if (copy_from_user(&insn, arg, sizeof(comedi_insn))) {
918		ret = -EFAULT;
919		goto error;
920	}
921
922	/* This is where the behavior of insn and insnlist deviate. */
923	if (insn.n > MAX_SAMPLES)
924		insn.n = MAX_SAMPLES;
925	if (insn.insn & INSN_MASK_WRITE) {
926		if (copy_from_user(data, insn.data, insn.n * sizeof(lsampl_t))) {
927			ret = -EFAULT;
928			goto error;
929		}
930	}
931	ret = parse_insn(dev, &insn, data, file);
932	if (ret < 0)
933		goto error;
934	if (insn.insn & INSN_MASK_READ) {
935		if (copy_to_user(insn.data, data, insn.n * sizeof(lsampl_t))) {
936			ret = -EFAULT;
937			goto error;
938		}
939	}
940	ret = insn.n;
941
942      error:
943	if (data)
944		kfree(data);
945
946	return ret;
947}
948
949/*
950	COMEDI_CMD
951	command ioctl
952
953	arg:
954		pointer to cmd structure
955
956	reads:
957		cmd structure at arg
958		channel/range list
959
960	writes:
961		modified cmd structure at arg
962
963*/
964static int do_cmd_ioctl(comedi_device * dev, void *arg, void *file)
965{
966	comedi_cmd user_cmd;
967	comedi_subdevice *s;
968	comedi_async *async;
969	int ret = 0;
970	unsigned int *chanlist_saver = NULL;
971
972	if (copy_from_user(&user_cmd, arg, sizeof(comedi_cmd))) {
973		DPRINTK("bad cmd address\n");
974		return -EFAULT;
975	}
976	// save user's chanlist pointer so it can be restored later
977	chanlist_saver = user_cmd.chanlist;
978
979	if (user_cmd.subdev >= dev->n_subdevices) {
980		DPRINTK("%d no such subdevice\n", user_cmd.subdev);
981		return -ENODEV;
982	}
983
984	s = dev->subdevices + user_cmd.subdev;
985	async = s->async;
986
987	if (s->type == COMEDI_SUBD_UNUSED) {
988		DPRINTK("%d not valid subdevice\n", user_cmd.subdev);
989		return -EIO;
990	}
991
992	if (!s->do_cmd || !s->do_cmdtest || !s->async) {
993		DPRINTK("subdevice %i does not support commands\n",
994			user_cmd.subdev);
995		return -EIO;
996	}
997
998	/* are we locked? (ioctl lock) */
999	if (s->lock && s->lock != file) {
1000		DPRINTK("subdevice locked\n");
1001		return -EACCES;
1002	}
1003
1004	/* are we busy? */
1005	if (s->busy) {
1006		DPRINTK("subdevice busy\n");
1007		return -EBUSY;
1008	}
1009	s->busy = file;
1010
1011	/* make sure channel/gain list isn't too long */
1012	if (user_cmd.chanlist_len > s->len_chanlist) {
1013		DPRINTK("channel/gain list too long %u > %d\n",
1014			user_cmd.chanlist_len, s->len_chanlist);
1015		ret = -EINVAL;
1016		goto cleanup;
1017	}
1018
1019	/* make sure channel/gain list isn't too short */
1020	if (user_cmd.chanlist_len < 1) {
1021		DPRINTK("channel/gain list too short %u < 1\n",
1022			user_cmd.chanlist_len);
1023		ret = -EINVAL;
1024		goto cleanup;
1025	}
1026
1027	if (async->cmd.chanlist)
1028		kfree(async->cmd.chanlist);
1029	async->cmd = user_cmd;
1030	async->cmd.data = NULL;
1031	/* load channel/gain list */
1032	async->cmd.chanlist =
1033		kmalloc(async->cmd.chanlist_len * sizeof(int), GFP_KERNEL);
1034	if (!async->cmd.chanlist) {
1035		DPRINTK("allocation failed\n");
1036		ret = -ENOMEM;
1037		goto cleanup;
1038	}
1039
1040	if (copy_from_user(async->cmd.chanlist, user_cmd.chanlist,
1041			async->cmd.chanlist_len * sizeof(int))) {
1042		DPRINTK("fault reading chanlist\n");
1043		ret = -EFAULT;
1044		goto cleanup;
1045	}
1046
1047	/* make sure each element in channel/gain list is valid */
1048	if ((ret = check_chanlist(s, async->cmd.chanlist_len,
1049				async->cmd.chanlist)) < 0) {
1050		DPRINTK("bad chanlist\n");
1051		goto cleanup;
1052	}
1053
1054	ret = s->do_cmdtest(dev, s, &async->cmd);
1055
1056	if (async->cmd.flags & TRIG_BOGUS || ret) {
1057		DPRINTK("test returned %d\n", ret);
1058		user_cmd = async->cmd;
1059		// restore chanlist pointer before copying back
1060		user_cmd.chanlist = chanlist_saver;
1061		user_cmd.data = NULL;
1062		if (copy_to_user(arg, &user_cmd, sizeof(comedi_cmd))) {
1063			DPRINTK("fault writing cmd\n");
1064			ret = -EFAULT;
1065			goto cleanup;
1066		}
1067		ret = -EAGAIN;
1068		goto cleanup;
1069	}
1070
1071	if (!async->prealloc_bufsz) {
1072		ret = -ENOMEM;
1073		DPRINTK("no buffer (?)\n");
1074		goto cleanup;
1075	}
1076
1077	comedi_reset_async_buf(async);
1078
1079	async->cb_mask =
1080		COMEDI_CB_EOA | COMEDI_CB_BLOCK | COMEDI_CB_ERROR |
1081		COMEDI_CB_OVERFLOW;
1082	if (async->cmd.flags & TRIG_WAKE_EOS) {
1083		async->cb_mask |= COMEDI_CB_EOS;
1084	}
1085
1086	comedi_set_subdevice_runflags(s, ~0, SRF_USER | SRF_RUNNING);
1087
1088#ifdef CONFIG_COMEDI_RT
1089	if (async->cmd.flags & TRIG_RT) {
1090		if (comedi_switch_to_rt(dev) == 0)
1091			comedi_set_subdevice_runflags(s, SRF_RT, SRF_RT);
1092	}
1093#endif
1094
1095	ret = s->do_cmd(dev, s);
1096	if (ret == 0)
1097		return 0;
1098
1099      cleanup:
1100	do_become_nonbusy(dev, s);
1101
1102	return ret;
1103}
1104
1105/*
1106	COMEDI_CMDTEST
1107	command testing ioctl
1108
1109	arg:
1110		pointer to cmd structure
1111
1112	reads:
1113		cmd structure at arg
1114		channel/range list
1115
1116	writes:
1117		modified cmd structure at arg
1118
1119*/
1120static int do_cmdtest_ioctl(comedi_device * dev, void *arg, void *file)
1121{
1122	comedi_cmd user_cmd;
1123	comedi_subdevice *s;
1124	int ret = 0;
1125	unsigned int *chanlist = NULL;
1126	unsigned int *chanlist_saver = NULL;
1127
1128	if (copy_from_user(&user_cmd, arg, sizeof(comedi_cmd))) {
1129		DPRINTK("bad cmd address\n");
1130		return -EFAULT;
1131	}
1132	// save user's chanlist pointer so it can be restored later
1133	chanlist_saver = user_cmd.chanlist;
1134
1135	if (user_cmd.subdev >= dev->n_subdevices) {
1136		DPRINTK("%d no such subdevice\n", user_cmd.subdev);
1137		return -ENODEV;
1138	}
1139
1140	s = dev->subdevices + user_cmd.subdev;
1141	if (s->type == COMEDI_SUBD_UNUSED) {
1142		DPRINTK("%d not valid subdevice\n", user_cmd.subdev);
1143		return -EIO;
1144	}
1145
1146	if (!s->do_cmd || !s->do_cmdtest) {
1147		DPRINTK("subdevice %i does not support commands\n",
1148			user_cmd.subdev);
1149		return -EIO;
1150	}
1151
1152	/* make sure channel/gain list isn't too long */
1153	if (user_cmd.chanlist_len > s->len_chanlist) {
1154		DPRINTK("channel/gain list too long %d > %d\n",
1155			user_cmd.chanlist_len, s->len_chanlist);
1156		ret = -EINVAL;
1157		goto cleanup;
1158	}
1159
1160	/* load channel/gain list */
1161	if (user_cmd.chanlist) {
1162		chanlist =
1163			kmalloc(user_cmd.chanlist_len * sizeof(int),
1164			GFP_KERNEL);
1165		if (!chanlist) {
1166			DPRINTK("allocation failed\n");
1167			ret = -ENOMEM;
1168			goto cleanup;
1169		}
1170
1171		if (copy_from_user(chanlist, user_cmd.chanlist,
1172				user_cmd.chanlist_len * sizeof(int))) {
1173			DPRINTK("fault reading chanlist\n");
1174			ret = -EFAULT;
1175			goto cleanup;
1176		}
1177
1178		/* make sure each element in channel/gain list is valid */
1179		if ((ret = check_chanlist(s, user_cmd.chanlist_len,
1180					chanlist)) < 0) {
1181			DPRINTK("bad chanlist\n");
1182			goto cleanup;
1183		}
1184
1185		user_cmd.chanlist = chanlist;
1186	}
1187
1188	ret = s->do_cmdtest(dev, s, &user_cmd);
1189
1190	// restore chanlist pointer before copying back
1191	user_cmd.chanlist = chanlist_saver;
1192
1193	if (copy_to_user(arg, &user_cmd, sizeof(comedi_cmd))) {
1194		DPRINTK("bad cmd address\n");
1195		ret = -EFAULT;
1196		goto cleanup;
1197	}
1198      cleanup:
1199	if (chanlist)
1200		kfree(chanlist);
1201
1202	return ret;
1203}
1204
1205/*
1206	COMEDI_LOCK
1207	lock subdevice
1208
1209	arg:
1210		subdevice number
1211
1212	reads:
1213		none
1214
1215	writes:
1216		none
1217
1218*/
1219
1220static int do_lock_ioctl(comedi_device * dev, unsigned int arg, void *file)
1221{
1222	int ret = 0;
1223	unsigned long flags;
1224	comedi_subdevice *s;
1225
1226	if (arg >= dev->n_subdevices)
1227		return -EINVAL;
1228	s = dev->subdevices + arg;
1229
1230	comedi_spin_lock_irqsave(&s->spin_lock, flags);
1231	if (s->busy || s->lock) {
1232		ret = -EBUSY;
1233	} else {
1234		s->lock = file;
1235	}
1236	comedi_spin_unlock_irqrestore(&s->spin_lock, flags);
1237
1238	if (ret < 0)
1239		return ret;
1240
1241#if 0
1242	if (s->lock_f)
1243		ret = s->lock_f(dev, s);
1244#endif
1245
1246	return ret;
1247}
1248
1249/*
1250	COMEDI_UNLOCK
1251	unlock subdevice
1252
1253	arg:
1254		subdevice number
1255
1256	reads:
1257		none
1258
1259	writes:
1260		none
1261
1262	This function isn't protected by the semaphore, since
1263	we already own the lock.
1264*/
1265static int do_unlock_ioctl(comedi_device * dev, unsigned int arg, void *file)
1266{
1267	comedi_subdevice *s;
1268
1269	if (arg >= dev->n_subdevices)
1270		return -EINVAL;
1271	s = dev->subdevices + arg;
1272
1273	if (s->busy)
1274		return -EBUSY;
1275
1276	if (s->lock && s->lock != file)
1277		return -EACCES;
1278
1279	if (s->lock == file) {
1280#if 0
1281		if (s->unlock)
1282			s->unlock(dev, s);
1283#endif
1284
1285		s->lock = NULL;
1286	}
1287
1288	return 0;
1289}
1290
1291/*
1292	COMEDI_CANCEL
1293	cancel acquisition ioctl
1294
1295	arg:
1296		subdevice number
1297
1298	reads:
1299		nothing
1300
1301	writes:
1302		nothing
1303
1304*/
1305static int do_cancel_ioctl(comedi_device * dev, unsigned int arg, void *file)
1306{
1307	comedi_subdevice *s;
1308
1309	if (arg >= dev->n_subdevices)
1310		return -EINVAL;
1311	s = dev->subdevices + arg;
1312	if (s->async == NULL)
1313		return -EINVAL;
1314
1315	if (s->lock && s->lock != file)
1316		return -EACCES;
1317
1318	if (!s->busy)
1319		return 0;
1320
1321	if (s->busy != file)
1322		return -EBUSY;
1323
1324	return do_cancel(dev, s);
1325}
1326
1327/*
1328	COMEDI_POLL ioctl
1329	instructs driver to synchronize buffers
1330
1331	arg:
1332		subdevice number
1333
1334	reads:
1335		nothing
1336
1337	writes:
1338		nothing
1339
1340*/
1341static int do_poll_ioctl(comedi_device * dev, unsigned int arg, void *file)
1342{
1343	comedi_subdevice *s;
1344
1345	if (arg >= dev->n_subdevices)
1346		return -EINVAL;
1347	s = dev->subdevices + arg;
1348
1349	if (s->lock && s->lock != file)
1350		return -EACCES;
1351
1352	if (!s->busy)
1353		return 0;
1354
1355	if (s->busy != file)
1356		return -EBUSY;
1357
1358	if (s->poll)
1359		return s->poll(dev, s);
1360
1361	return -EINVAL;
1362}
1363
1364static int do_cancel(comedi_device * dev, comedi_subdevice * s)
1365{
1366	int ret = 0;
1367
1368	if ((comedi_get_subdevice_runflags(s) & SRF_RUNNING) && s->cancel)
1369		ret = s->cancel(dev, s);
1370
1371	do_become_nonbusy(dev, s);
1372
1373	return ret;
1374}
1375
1376void comedi_unmap(struct vm_area_struct *area)
1377{
1378	comedi_async *async;
1379	comedi_device *dev;
1380
1381	async = area->vm_private_data;
1382	dev = async->subdevice->device;
1383
1384	mutex_lock(&dev->mutex);
1385	async->mmap_count--;
1386	mutex_unlock(&dev->mutex);
1387}
1388
1389static struct vm_operations_struct comedi_vm_ops = {
1390      close:comedi_unmap,
1391};
1392
1393static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
1394{
1395	const unsigned minor = iminor(file->f_dentry->d_inode);
1396	struct comedi_device_file_info *dev_file_info = comedi_get_device_file_info(minor);
1397	comedi_device *dev = dev_file_info->device;
1398	comedi_async *async = NULL;
1399	unsigned long start = vma->vm_start;
1400	unsigned long size;
1401	int n_pages;
1402	int i;
1403	int retval;
1404	comedi_subdevice *s;
1405
1406	mutex_lock(&dev->mutex);
1407	if (!dev->attached) {
1408		DPRINTK("no driver configured on comedi%i\n", dev->minor);
1409		retval = -ENODEV;
1410		goto done;
1411	}
1412	if (vma->vm_flags & VM_WRITE) {
1413		s = comedi_get_write_subdevice(dev_file_info);
1414	} else {
1415		s = comedi_get_read_subdevice(dev_file_info);
1416	}
1417	if (s == NULL) {
1418		retval = -EINVAL;
1419		goto done;
1420	}
1421	async = s->async;
1422	if (async == NULL) {
1423		retval = -EINVAL;
1424		goto done;
1425	}
1426
1427	if (vma->vm_pgoff != 0) {
1428		DPRINTK("comedi: mmap() offset must be 0.\n");
1429		retval = -EINVAL;
1430		goto done;
1431	}
1432
1433	size = vma->vm_end - vma->vm_start;
1434	if (size > async->prealloc_bufsz) {
1435		retval = -EFAULT;
1436		goto done;
1437	}
1438	if (size & (~PAGE_MASK)) {
1439		retval = -EFAULT;
1440		goto done;
1441	}
1442
1443	n_pages = size >> PAGE_SHIFT;
1444	for (i = 0; i < n_pages; ++i) {
1445		if (remap_pfn_range(vma, start,
1446				page_to_pfn(virt_to_page(async->
1447						buf_page_list[i].virt_addr)),
1448				PAGE_SIZE, PAGE_SHARED)) {
1449			retval = -EAGAIN;
1450			goto done;
1451		}
1452		start += PAGE_SIZE;
1453	}
1454
1455	vma->vm_ops = &comedi_vm_ops;
1456	vma->vm_private_data = async;
1457
1458	async->mmap_count++;
1459
1460	retval = 0;
1461      done:
1462	mutex_unlock(&dev->mutex);
1463	return retval;
1464}
1465
1466static unsigned int comedi_poll(struct file *file, poll_table * wait)
1467{
1468	unsigned int mask = 0;
1469	const unsigned minor = iminor(file->f_dentry->d_inode);
1470	struct comedi_device_file_info *dev_file_info = comedi_get_device_file_info(minor);
1471	comedi_device *dev = dev_file_info->device;
1472	comedi_subdevice *read_subdev;
1473	comedi_subdevice *write_subdev;
1474
1475	mutex_lock(&dev->mutex);
1476	if (!dev->attached) {
1477		DPRINTK("no driver configured on comedi%i\n", dev->minor);
1478		mutex_unlock(&dev->mutex);
1479		return 0;
1480	}
1481
1482	mask = 0;
1483	read_subdev = comedi_get_read_subdevice(dev_file_info);
1484	if (read_subdev) {
1485		poll_wait(file, &read_subdev->async->wait_head, wait);
1486		if (!read_subdev->busy
1487			|| comedi_buf_read_n_available(read_subdev->async) > 0
1488			|| !(comedi_get_subdevice_runflags(read_subdev) &
1489				SRF_RUNNING)) {
1490			mask |= POLLIN | POLLRDNORM;
1491		}
1492	}
1493	write_subdev = comedi_get_write_subdevice(dev_file_info);
1494	if (write_subdev) {
1495		poll_wait(file, &write_subdev->async->wait_head, wait);
1496		comedi_buf_write_alloc(write_subdev->async, write_subdev->async->prealloc_bufsz);
1497		if (!write_subdev->busy
1498			|| !(comedi_get_subdevice_runflags(write_subdev) &
1499				SRF_RUNNING)
1500			|| comedi_buf_write_n_allocated(write_subdev->async) >=
1501			bytes_per_sample(write_subdev->async->subdevice)) {
1502			mask |= POLLOUT | POLLWRNORM;
1503		}
1504	}
1505
1506	mutex_unlock(&dev->mutex);
1507	return mask;
1508}
1509
1510static ssize_t comedi_write(struct file *file, const char *buf, size_t nbytes,
1511	loff_t * offset)
1512{
1513	comedi_subdevice *s;
1514	comedi_async *async;
1515	int n, m, count = 0, retval = 0;
1516	DECLARE_WAITQUEUE(wait, current);
1517	const unsigned minor = iminor(file->f_dentry->d_inode);
1518	struct comedi_device_file_info *dev_file_info = comedi_get_device_file_info(minor);
1519	comedi_device *dev = dev_file_info->device;
1520
1521	if (!dev->attached) {
1522		DPRINTK("no driver configured on comedi%i\n", dev->minor);
1523		retval = -ENODEV;
1524		goto done;
1525	}
1526
1527	s = comedi_get_write_subdevice(dev_file_info);
1528	if (s == NULL) {
1529		retval = -EIO;
1530		goto done;
1531	}
1532	async = s->async;
1533
1534	if (!nbytes) {
1535		retval = 0;
1536		goto done;
1537	}
1538	if (!s->busy) {
1539		retval = 0;
1540		goto done;
1541	}
1542	if (s->busy != file) {
1543		retval = -EACCES;
1544		goto done;
1545	}
1546	add_wait_queue(&async->wait_head, &wait);
1547	while (nbytes > 0 && !retval) {
1548		set_current_state(TASK_INTERRUPTIBLE);
1549
1550		n = nbytes;
1551
1552		m = n;
1553		if (async->buf_write_ptr + m > async->prealloc_bufsz) {
1554			m = async->prealloc_bufsz - async->buf_write_ptr;
1555		}
1556		comedi_buf_write_alloc(async, async->prealloc_bufsz);
1557		if (m > comedi_buf_write_n_allocated(async)) {
1558			m = comedi_buf_write_n_allocated(async);
1559		}
1560		if (m < n)
1561			n = m;
1562
1563		if (n == 0) {
1564			if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
1565				if (comedi_get_subdevice_runflags(s) &
1566					SRF_ERROR) {
1567					retval = -EPIPE;
1568				} else {
1569					retval = 0;
1570				}
1571				do_become_nonbusy(dev, s);
1572				break;
1573			}
1574			if (file->f_flags & O_NONBLOCK) {
1575				retval = -EAGAIN;
1576				break;
1577			}
1578			if (signal_pending(current)) {
1579				retval = -ERESTARTSYS;
1580				break;
1581			}
1582			schedule();
1583			if (!s->busy) {
1584				break;
1585			}
1586			if (s->busy != file) {
1587				retval = -EACCES;
1588				break;
1589			}
1590			continue;
1591		}
1592
1593		m = copy_from_user(async->prealloc_buf + async->buf_write_ptr,
1594			buf, n);
1595		if (m) {
1596			n -= m;
1597			retval = -EFAULT;
1598		}
1599		comedi_buf_write_free(async, n);
1600
1601		count += n;
1602		nbytes -= n;
1603
1604		buf += n;
1605		break;		/* makes device work like a pipe */
1606	}
1607	set_current_state(TASK_RUNNING);
1608	remove_wait_queue(&async->wait_head, &wait);
1609
1610done:
1611	return (count ? count : retval);
1612}
1613
1614static ssize_t comedi_read(struct file *file, char *buf, size_t nbytes,
1615	loff_t * offset)
1616{
1617	comedi_subdevice *s;
1618	comedi_async *async;
1619	int n, m, count = 0, retval = 0;
1620	DECLARE_WAITQUEUE(wait, current);
1621	const unsigned minor = iminor(file->f_dentry->d_inode);
1622	struct comedi_device_file_info *dev_file_info = comedi_get_device_file_info(minor);
1623	comedi_device *dev = dev_file_info->device;
1624
1625	if (!dev->attached) {
1626		DPRINTK("no driver configured on comedi%i\n", dev->minor);
1627		retval = -ENODEV;
1628		goto done;
1629	}
1630
1631	s = comedi_get_read_subdevice(dev_file_info);
1632	if (s == NULL) {
1633		retval = -EIO;
1634		goto done;
1635	}
1636	async = s->async;
1637	if (!nbytes) {
1638		retval = 0;
1639		goto done;
1640	}
1641	if (!s->busy) {
1642		retval = 0;
1643		goto done;
1644	}
1645	if (s->busy != file) {
1646		retval = -EACCES;
1647		goto done;
1648	}
1649
1650	add_wait_queue(&async->wait_head, &wait);
1651	while (nbytes > 0 && !retval) {
1652		set_current_state(TASK_INTERRUPTIBLE);
1653
1654		n = nbytes;
1655
1656		m = comedi_buf_read_n_available(async);
1657//printk("%d available\n",m);
1658		if (async->buf_read_ptr + m > async->prealloc_bufsz) {
1659			m = async->prealloc_bufsz - async->buf_read_ptr;
1660		}
1661//printk("%d contiguous\n",m);
1662		if (m < n)
1663			n = m;
1664
1665		if (n == 0) {
1666			if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
1667				do_become_nonbusy(dev, s);
1668				if (comedi_get_subdevice_runflags(s) &
1669					SRF_ERROR) {
1670					retval = -EPIPE;
1671				} else {
1672					retval = 0;
1673				}
1674				break;
1675			}
1676			if (file->f_flags & O_NONBLOCK) {
1677				retval = -EAGAIN;
1678				break;
1679			}
1680			if (signal_pending(current)) {
1681				retval = -ERESTARTSYS;
1682				break;
1683			}
1684			schedule();
1685			if (!s->busy) {
1686				retval = 0;
1687				break;
1688			}
1689			if (s->busy != file) {
1690				retval = -EACCES;
1691				break;
1692			}
1693			continue;
1694		}
1695		m = copy_to_user(buf, async->prealloc_buf +
1696			async->buf_read_ptr, n);
1697		if (m) {
1698			n -= m;
1699			retval = -EFAULT;
1700		}
1701
1702		comedi_buf_read_alloc(async, n);
1703		comedi_buf_read_free(async, n);
1704
1705		count += n;
1706		nbytes -= n;
1707
1708		buf += n;
1709		break;		/* makes device work like a pipe */
1710	}
1711	if (!(comedi_get_subdevice_runflags(s) & (SRF_ERROR | SRF_RUNNING)) &&
1712		async->buf_read_count - async->buf_write_count == 0) {
1713		do_become_nonbusy(dev, s);
1714	}
1715	set_current_state(TASK_RUNNING);
1716	remove_wait_queue(&async->wait_head, &wait);
1717
1718done:
1719	return (count ? count : retval);
1720}
1721
1722/*
1723   This function restores a subdevice to an idle state.
1724 */
1725void do_become_nonbusy(comedi_device * dev, comedi_subdevice * s)
1726{
1727	comedi_async *async = s->async;
1728
1729	comedi_set_subdevice_runflags(s, SRF_RUNNING, 0);
1730#ifdef CONFIG_COMEDI_RT
1731	if (comedi_get_subdevice_runflags(s) & SRF_RT) {
1732		comedi_switch_to_non_rt(dev);
1733		comedi_set_subdevice_runflags(s, SRF_RT, 0);
1734	}
1735#endif
1736	if (async) {
1737		comedi_reset_async_buf(async);
1738		async->inttrig = NULL;
1739	} else {
1740		printk("BUG: (?) do_become_nonbusy called with async=0\n");
1741	}
1742
1743	s->busy = NULL;
1744}
1745
1746static int comedi_open(struct inode *inode, struct file *file)
1747{
1748	char mod[32];
1749	const unsigned minor = iminor(inode);
1750	struct comedi_device_file_info *dev_file_info = comedi_get_device_file_info(minor);
1751	comedi_device *dev = dev_file_info->device;
1752	if (dev == NULL) {
1753		DPRINTK("invalid minor number\n");
1754		return -ENODEV;
1755	}
1756
1757	/* This is slightly hacky, but we want module autoloading
1758	 * to work for root.
1759	 * case: user opens device, attached -> ok
1760	 * case: user opens device, unattached, in_request_module=0 -> autoload
1761	 * case: user opens device, unattached, in_request_module=1 -> fail
1762	 * case: root opens device, attached -> ok
1763	 * case: root opens device, unattached, in_request_module=1 -> ok
1764	 *   (typically called from modprobe)
1765	 * case: root opens device, unattached, in_request_module=0 -> autoload
1766	 *
1767	 * The last could be changed to "-> ok", which would deny root
1768	 * autoloading.
1769	 */
1770	mutex_lock(&dev->mutex);
1771	if (dev->attached)
1772		goto ok;
1773	if (!capable(CAP_SYS_MODULE) && dev->in_request_module) {
1774		DPRINTK("in request module\n");
1775		mutex_unlock(&dev->mutex);
1776		return -ENODEV;
1777	}
1778	if (capable(CAP_SYS_MODULE) && dev->in_request_module)
1779		goto ok;
1780
1781	dev->in_request_module = 1;
1782
1783	sprintf(mod, "char-major-%i-%i", COMEDI_MAJOR, dev->minor);
1784#ifdef CONFIG_KMOD
1785	mutex_unlock(&dev->mutex);
1786	request_module(mod);
1787	mutex_lock(&dev->mutex);
1788#endif
1789
1790	dev->in_request_module = 0;
1791
1792	if (!dev->attached && !capable(CAP_SYS_MODULE)) {
1793		DPRINTK("not attached and not CAP_SYS_MODULE\n");
1794		mutex_unlock(&dev->mutex);
1795		return -ENODEV;
1796	}
1797ok:
1798	__module_get(THIS_MODULE);
1799
1800	if (dev->attached) {
1801		if (!try_module_get(dev->driver->module)) {
1802			module_put(THIS_MODULE);
1803			mutex_unlock(&dev->mutex);
1804			return -ENOSYS;
1805		}
1806	}
1807
1808	if (dev->attached && dev->use_count == 0 && dev->open) {
1809		dev->open(dev);
1810	}
1811
1812	dev->use_count++;
1813
1814	mutex_unlock(&dev->mutex);
1815
1816	return 0;
1817}
1818
1819static int comedi_close(struct inode *inode, struct file *file)
1820{
1821	const unsigned minor = iminor(inode);
1822	struct comedi_device_file_info *dev_file_info = comedi_get_device_file_info(minor);
1823	comedi_device *dev = dev_file_info->device;
1824	comedi_subdevice *s = NULL;
1825	int i;
1826
1827	mutex_lock(&dev->mutex);
1828
1829	if (dev->subdevices) {
1830		for (i = 0; i < dev->n_subdevices; i++) {
1831			s = dev->subdevices + i;
1832
1833			if (s->busy == file) {
1834				do_cancel(dev, s);
1835			}
1836			if (s->lock == file) {
1837				s->lock = NULL;
1838			}
1839		}
1840	}
1841	if (dev->attached && dev->use_count == 1 && dev->close) {
1842		dev->close(dev);
1843	}
1844
1845	module_put(THIS_MODULE);
1846	if (dev->attached) {
1847		module_put(dev->driver->module);
1848	}
1849
1850	dev->use_count--;
1851
1852	mutex_unlock(&dev->mutex);
1853
1854	if (file->f_flags & FASYNC) {
1855		comedi_fasync(-1, file, 0);
1856	}
1857
1858	return 0;
1859}
1860
1861static int comedi_fasync(int fd, struct file *file, int on)
1862{
1863	const unsigned minor = iminor(file->f_dentry->d_inode);
1864	struct comedi_device_file_info *dev_file_info = comedi_get_device_file_info(minor);
1865	comedi_device *dev = dev_file_info->device;
1866
1867	return fasync_helper(fd, file, on, &dev->async_queue);
1868}
1869
1870const struct file_operations comedi_fops = {
1871      owner:THIS_MODULE,
1872#ifdef HAVE_UNLOCKED_IOCTL
1873      unlocked_ioctl:comedi_unlocked_ioctl,
1874#else
1875      ioctl:comedi_ioctl,
1876#endif
1877#ifdef HAVE_COMPAT_IOCTL
1878      compat_ioctl:comedi_compat_ioctl,
1879#endif
1880      open:comedi_open,
1881      release:comedi_close,
1882      read:comedi_read,
1883      write:comedi_write,
1884      mmap:comedi_mmap,
1885      poll:comedi_poll,
1886      fasync:comedi_fasync,
1887};
1888
1889struct class *comedi_class = NULL;
1890static struct cdev comedi_cdev;
1891
1892static void comedi_cleanup_legacy_minors(void)
1893{
1894	unsigned i;
1895	for (i = 0; i < COMEDI_NUM_LEGACY_MINORS; i++) {
1896		comedi_free_board_minor(i);
1897	}
1898}
1899
1900static int __init comedi_init(void)
1901{
1902	int i;
1903	int retval;
1904
1905	printk("comedi: version " COMEDI_RELEASE
1906		" - http://www.comedi.org\n");
1907
1908	memset(comedi_file_info_table, 0, sizeof(struct comedi_device_file_info*) * COMEDI_NUM_MINORS);
1909
1910	retval = register_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1911		COMEDI_NUM_MINORS, "comedi");
1912	if (retval)
1913		return -EIO;
1914	cdev_init(&comedi_cdev, &comedi_fops);
1915	comedi_cdev.owner = THIS_MODULE;
1916	kobject_set_name(&comedi_cdev.kobj, "comedi");
1917	if (cdev_add(&comedi_cdev, MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS)) {
1918		unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1919			COMEDI_NUM_MINORS);
1920		return -EIO;
1921	}
1922	comedi_class = class_create(THIS_MODULE, "comedi");
1923	if (IS_ERR(comedi_class)) {
1924		printk("comedi: failed to create class");
1925		cdev_del(&comedi_cdev);
1926		unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1927			COMEDI_NUM_MINORS);
1928		return PTR_ERR(comedi_class);
1929	}
1930
1931	/* XXX requires /proc interface */
1932	comedi_proc_init();
1933
1934	// create devices files for legacy/manual use
1935	for (i = 0; i < COMEDI_NUM_LEGACY_MINORS; i++) {
1936		int minor;
1937		minor = comedi_alloc_board_minor(NULL);
1938		if(minor < 0)
1939		{
1940			comedi_cleanup_legacy_minors();
1941			cdev_del(&comedi_cdev);
1942			unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1943				COMEDI_NUM_MINORS);
1944			return minor;
1945		}
1946	}
1947
1948	comedi_rt_init();
1949
1950	comedi_register_ioctl32();
1951
1952	return 0;
1953}
1954
1955static void __exit comedi_cleanup(void)
1956{
1957	int i;
1958
1959	comedi_cleanup_legacy_minors();
1960	for(i = 0; i < COMEDI_NUM_MINORS; ++i)
1961	{
1962		BUG_ON(comedi_file_info_table[i]);
1963	}
1964
1965	class_destroy(comedi_class);
1966	cdev_del(&comedi_cdev);
1967	unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS);
1968
1969	comedi_proc_cleanup();
1970
1971	comedi_rt_cleanup();
1972
1973	comedi_unregister_ioctl32();
1974}
1975
1976module_init(comedi_init);
1977module_exit(comedi_cleanup);
1978
1979void comedi_error(const comedi_device * dev, const char *s)
1980{
1981	rt_printk("comedi%d: %s: %s\n", dev->minor, dev->driver->driver_name,
1982		s);
1983}
1984
1985void comedi_event(comedi_device * dev, comedi_subdevice * s)
1986{
1987	comedi_async *async = s->async;
1988	unsigned runflags = 0;
1989	unsigned runflags_mask = 0;
1990
1991	//DPRINTK("comedi_event 0x%x\n",mask);
1992
1993	if ((comedi_get_subdevice_runflags(s) & SRF_RUNNING) == 0)
1994		return;
1995
1996	if (s->async->
1997		events & (COMEDI_CB_EOA | COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW))
1998	{
1999		runflags_mask |= SRF_RUNNING;
2000	}
2001	/* remember if an error event has occured, so an error
2002	 * can be returned the next time the user does a read() */
2003	if (s->async->events & (COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW)) {
2004		runflags_mask |= SRF_ERROR;
2005		runflags |= SRF_ERROR;
2006	}
2007	if (runflags_mask) {
2008		/*sets SRF_ERROR and SRF_RUNNING together atomically */
2009		comedi_set_subdevice_runflags(s, runflags_mask, runflags);
2010	}
2011
2012	if (async->cb_mask & s->async->events) {
2013		if (comedi_get_subdevice_runflags(s) & SRF_USER) {
2014
2015			if (dev->rt) {
2016#ifdef CONFIG_COMEDI_RT
2017				// pend wake up
2018				comedi_rt_pend_wakeup(&async->wait_head);
2019#else
2020				printk("BUG: comedi_event() code unreachable\n");
2021#endif
2022			} else {
2023				wake_up_interruptible(&async->wait_head);
2024				if (s->subdev_flags & SDF_CMD_READ) {
2025					kill_fasync(&dev->async_queue, SIGIO,
2026						POLL_IN);
2027				}
2028				if (s->subdev_flags & SDF_CMD_WRITE) {
2029					kill_fasync(&dev->async_queue, SIGIO,
2030						POLL_OUT);
2031				}
2032			}
2033		} else {
2034			if (async->cb_func)
2035				async->cb_func(s->async->events, async->cb_arg);
2036			/* XXX bug here.  If subdevice A is rt, and
2037			 * subdevice B tries to callback to a normal
2038			 * linux kernel function, it will be at the
2039			 * wrong priority.  Since this isn't very
2040			 * common, I'm not going to worry about it. */
2041		}
2042	}
2043	s->async->events = 0;
2044}
2045
2046void comedi_set_subdevice_runflags(comedi_subdevice * s, unsigned mask,
2047	unsigned bits)
2048{
2049	unsigned long flags;
2050
2051	comedi_spin_lock_irqsave(&s->spin_lock, flags);
2052	s->runflags &= ~mask;
2053	s->runflags |= (bits & mask);
2054	comedi_spin_unlock_irqrestore(&s->spin_lock, flags);
2055}
2056
2057unsigned comedi_get_subdevice_runflags(comedi_subdevice * s)
2058{
2059	unsigned long flags;
2060	unsigned runflags;
2061
2062	comedi_spin_lock_irqsave(&s->spin_lock, flags);
2063	runflags = s->runflags;
2064	comedi_spin_unlock_irqrestore(&s->spin_lock, flags);
2065	return runflags;
2066}
2067
2068static int is_device_busy(comedi_device * dev)
2069{
2070	comedi_subdevice *s;
2071	int i;
2072
2073	if (!dev->attached)
2074		return 0;
2075
2076	for (i = 0; i < dev->n_subdevices; i++) {
2077		s = dev->subdevices + i;
2078		if (s->busy)
2079			return 1;
2080		if (s->async && s->async->mmap_count)
2081			return 1;
2082	}
2083
2084	return 0;
2085}
2086
2087void comedi_device_init(comedi_device *dev)
2088{
2089	memset(dev, 0, sizeof(comedi_device));
2090	spin_lock_init(&dev->spinlock);
2091	mutex_init(&dev->mutex);
2092	dev->minor = -1;
2093}
2094
2095void comedi_device_cleanup(comedi_device *dev)
2096{
2097	if(dev == NULL) return;
2098	mutex_lock(&dev->mutex);
2099	comedi_device_detach(dev);
2100	mutex_unlock(&dev->mutex);
2101	mutex_destroy(&dev->mutex);
2102}
2103
2104int comedi_alloc_board_minor(struct device *hardware_device)
2105{
2106	unsigned long flags;
2107	struct comedi_device_file_info *info;
2108	device_create_result_type *csdev;
2109	unsigned i;
2110
2111	info = kzalloc(sizeof(struct comedi_device_file_info), GFP_KERNEL);
2112	if(info == NULL) return -ENOMEM;
2113	info->device = kzalloc(sizeof(comedi_device), GFP_KERNEL);
2114	if(info->device == NULL)
2115	{
2116		kfree(info);
2117		return -ENOMEM;
2118	}
2119	comedi_device_init(info->device);
2120	comedi_spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2121	for(i = 0; i < COMEDI_NUM_BOARD_MINORS; ++i)
2122	{
2123		if(comedi_file_info_table[i] == NULL)
2124		{
2125			comedi_file_info_table[i] = info;
2126			break;
2127		}
2128	}
2129	comedi_spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2130	if(i == COMEDI_NUM_BOARD_MINORS)
2131	{
2132		comedi_device_cleanup(info->device);
2133		kfree(info->device);
2134		kfree(info);
2135		rt_printk("comedi: error: ran out of minor numbers for board device files.\n");
2136		return -EBUSY;
2137	}
2138	info->device->minor = i;
2139	csdev = COMEDI_DEVICE_CREATE(comedi_class, NULL,
2140		MKDEV(COMEDI_MAJOR, i), NULL, hardware_device, "comedi%i", i);
2141	if(!IS_ERR(csdev)) {
2142		info->device->class_dev = csdev;
2143	}
2144	return i;
2145}
2146
2147void comedi_free_board_minor(unsigned minor)
2148{
2149	unsigned long flags;
2150	struct comedi_device_file_info *info;
2151
2152	BUG_ON(minor >= COMEDI_NUM_BOARD_MINORS);
2153	comedi_spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2154	info = comedi_file_info_table[minor];
2155	comedi_file_info_table[minor] = NULL;
2156	comedi_spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2157
2158	if(info)
2159	{
2160		comedi_device *dev = info->device;
2161		if(dev)
2162		{
2163			if(dev->class_dev)
2164			{
2165				device_destroy(comedi_class, MKDEV(COMEDI_MAJOR, dev->minor));
2166			}
2167			comedi_device_cleanup(dev);
2168			kfree(dev);
2169		}
2170		kfree(info);
2171	}
2172}
2173
2174int comedi_alloc_subdevice_minor(comedi_device *dev, comedi_subdevice *s)
2175{
2176	unsigned long flags;
2177	struct comedi_device_file_info *info;
2178	device_create_result_type *csdev;
2179	unsigned i;
2180
2181	info = kmalloc(sizeof(struct comedi_device_file_info), GFP_KERNEL);
2182	if(info == NULL) return -ENOMEM;
2183	info->device = dev;
2184	info->read_subdevice = s;
2185	info->write_subdevice = s;
2186	comedi_spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2187	for(i = COMEDI_FIRST_SUBDEVICE_MINOR; i < COMEDI_NUM_BOARD_MINORS; ++i)
2188	{
2189		if(comedi_file_info_table[i] == NULL)
2190		{
2191			comedi_file_info_table[i] = info;
2192			break;
2193		}
2194	}
2195	comedi_spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2196	if(i == COMEDI_NUM_MINORS)
2197	{
2198		kfree(info);
2199		rt_printk("comedi: error: ran out of minor numbers for board device files.\n");
2200		return -EBUSY;
2201	}
2202	s->minor = i;
2203	csdev = COMEDI_DEVICE_CREATE(comedi_class, dev->class_dev,
2204		MKDEV(COMEDI_MAJOR, i), NULL, NULL, "comedi%i_subd%i", dev->minor, (int)(s - dev->subdevices));
2205	if(!IS_ERR(csdev))
2206	{
2207		s->class_dev = csdev;
2208	}
2209	return i;
2210}
2211
2212void comedi_free_subdevice_minor(comedi_subdevice *s)
2213{
2214	unsigned long flags;
2215	struct comedi_device_file_info *info;
2216
2217	if(s == NULL) return;
2218	if(s->minor < 0) return;
2219
2220	BUG_ON(s->minor >= COMEDI_NUM_MINORS);
2221	BUG_ON(s->minor < COMEDI_FIRST_SUBDEVICE_MINOR);
2222
2223	comedi_spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2224	info = comedi_file_info_table[s->minor];
2225	comedi_file_info_table[s->minor] = NULL;
2226	comedi_spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2227
2228	if(s->class_dev)
2229	{
2230		device_destroy(comedi_class, MKDEV(COMEDI_MAJOR, s->minor));
2231		s->class_dev = NULL;
2232	}
2233	kfree(info);
2234}
2235
2236struct comedi_device_file_info *comedi_get_device_file_info(unsigned minor)
2237{
2238	unsigned long flags;
2239	struct comedi_device_file_info *info;
2240
2241	BUG_ON(minor >= COMEDI_NUM_MINORS);
2242	comedi_spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2243	info = comedi_file_info_table[minor];
2244	comedi_spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2245	return info;
2246}
2247