1/*
2    include/linux/comedidev.h
3    header file for kernel-only structures, variables, and constants
4
5    COMEDI - Linux Control and Measurement Device Interface
6    Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
7
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 2 of the License, or
11    (at your option) any later version.
12
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17*/
18
19#ifndef _COMEDIDEV_H
20#define _COMEDIDEV_H
21
22#include <linux/dma-mapping.h>
23#include <linux/mutex.h>
24#include <linux/spinlock_types.h>
25#include <linux/rwsem.h>
26#include <linux/kref.h>
27
28#include "comedi.h"
29
30#define COMEDI_VERSION(a, b, c) (((a) << 16) + ((b) << 8) + (c))
31#define COMEDI_VERSION_CODE COMEDI_VERSION(COMEDI_MAJORVERSION, \
32	COMEDI_MINORVERSION, COMEDI_MICROVERSION)
33#define COMEDI_RELEASE VERSION
34
35#define COMEDI_NUM_BOARD_MINORS 0x30
36
37struct comedi_subdevice {
38	struct comedi_device *device;
39	int index;
40	int type;
41	int n_chan;
42	int subdev_flags;
43	int len_chanlist;	/* maximum length of channel/gain list */
44
45	void *private;
46
47	struct comedi_async *async;
48
49	void *lock;
50	void *busy;
51	unsigned runflags;
52	spinlock_t spin_lock;
53
54	unsigned int io_bits;
55
56	unsigned int maxdata;	/* if maxdata==0, use list */
57	const unsigned int *maxdata_list;	/* list is channel specific */
58
59	const struct comedi_lrange *range_table;
60	const struct comedi_lrange *const *range_table_list;
61
62	unsigned int *chanlist;	/* driver-owned chanlist (not used) */
63
64	int (*insn_read)(struct comedi_device *, struct comedi_subdevice *,
65			 struct comedi_insn *, unsigned int *);
66	int (*insn_write)(struct comedi_device *, struct comedi_subdevice *,
67			  struct comedi_insn *, unsigned int *);
68	int (*insn_bits)(struct comedi_device *, struct comedi_subdevice *,
69			 struct comedi_insn *, unsigned int *);
70	int (*insn_config)(struct comedi_device *, struct comedi_subdevice *,
71			   struct comedi_insn *, unsigned int *);
72
73	int (*do_cmd)(struct comedi_device *, struct comedi_subdevice *);
74	int (*do_cmdtest)(struct comedi_device *, struct comedi_subdevice *,
75			  struct comedi_cmd *);
76	int (*poll)(struct comedi_device *, struct comedi_subdevice *);
77	int (*cancel)(struct comedi_device *, struct comedi_subdevice *);
78
79	/* called when the buffer changes */
80	int (*buf_change)(struct comedi_device *, struct comedi_subdevice *);
81
82	void (*munge)(struct comedi_device *dev, struct comedi_subdevice *s,
83		      void *data, unsigned int num_bytes,
84		      unsigned int start_chan_index);
85	enum dma_data_direction async_dma_dir;
86
87	unsigned int state;
88
89	struct device *class_dev;
90	int minor;
91
92	unsigned int *readback;
93};
94
95struct comedi_buf_page {
96	void *virt_addr;
97	dma_addr_t dma_addr;
98};
99
100struct comedi_buf_map {
101	struct device *dma_hw_dev;
102	struct comedi_buf_page *page_list;
103	unsigned int n_pages;
104	enum dma_data_direction dma_dir;
105	struct kref refcount;
106};
107
108/**
109 * struct comedi_async - control data for asynchronous comedi commands
110 * @prealloc_buf:	preallocated buffer
111 * @prealloc_bufsz:	buffer size (in bytes)
112 * @buf_map:		map of buffer pages
113 * @max_bufsize:	maximum buffer size (in bytes)
114 * @buf_write_count:	"write completed" count (in bytes, modulo 2**32)
115 * @buf_write_alloc_count: "allocated for writing" count (in bytes,
116 *			modulo 2**32)
117 * @buf_read_count:	"read completed" count (in bytes, modulo 2**32)
118 * @buf_read_alloc_count: "allocated for reading" count (in bytes,
119 *			modulo 2**32)
120 * @buf_write_ptr:	buffer position for writer
121 * @buf_read_ptr:	buffer position for reader
122 * @cur_chan:		current position in chanlist for scan (for those
123 *			drivers that use it)
124 * @scans_done:		the number of scans completed (COMEDI_CB_EOS)
125 * @scan_progress:	amount received or sent for current scan (in bytes)
126 * @munge_chan:		current position in chanlist for "munging"
127 * @munge_count:	"munge" count (in bytes, modulo 2**32)
128 * @munge_ptr:		buffer position for "munging"
129 * @events:		bit-vector of events that have occurred
130 * @cmd:		details of comedi command in progress
131 * @wait_head:		task wait queue for file reader or writer
132 * @cb_mask:		bit-vector of events that should wake waiting tasks
133 * @inttrig:		software trigger function for command, or NULL
134 *
135 * Note about the ..._count and ..._ptr members:
136 *
137 * Think of the _Count values being integers of unlimited size, indexing
138 * into a buffer of infinite length (though only an advancing portion
139 * of the buffer of fixed length prealloc_bufsz is accessible at any time).
140 * Then:
141 *
142 *   Buf_Read_Count <= Buf_Read_Alloc_Count <= Munge_Count <=
143 *   Buf_Write_Count <= Buf_Write_Alloc_Count <=
144 *   (Buf_Read_Count + prealloc_bufsz)
145 *
146 * (Those aren't the actual members, apart from prealloc_bufsz.) When
147 * the buffer is reset, those _Count values start at 0 and only increase
148 * in value, maintaining the above inequalities until the next time the
149 * buffer is reset.  The buffer is divided into the following regions by
150 * the inequalities:
151 *
152 *   [0, Buf_Read_Count):
153 *     old region no longer accessible
154 *   [Buf_Read_Count, Buf_Read_Alloc_Count):
155 *     filled and munged region allocated for reading but not yet read
156 *   [Buf_Read_Alloc_Count, Munge_Count):
157 *     filled and munged region not yet allocated for reading
158 *   [Munge_Count, Buf_Write_Count):
159 *     filled region not yet munged
160 *   [Buf_Write_Count, Buf_Write_Alloc_Count):
161 *     unfilled region allocated for writing but not yet written
162 *   [Buf_Write_Alloc_Count, Buf_Read_Count + prealloc_bufsz):
163 *     unfilled region not yet allocated for writing
164 *   [Buf_Read_Count + prealloc_bufsz, infinity):
165 *     unfilled region not yet accessible
166 *
167 * Data needs to be written into the buffer before it can be read out,
168 * and may need to be converted (or "munged") between the two
169 * operations.  Extra unfilled buffer space may need to allocated for
170 * writing (advancing Buf_Write_Alloc_Count) before new data is written.
171 * After writing new data, the newly filled space needs to be released
172 * (advancing Buf_Write_Count).  This also results in the new data being
173 * "munged" (advancing Munge_Count).  Before data is read out of the
174 * buffer, extra space may need to be allocated for reading (advancing
175 * Buf_Read_Alloc_Count).  After the data has been read out, the space
176 * needs to be released (advancing Buf_Read_Count).
177 *
178 * The actual members, buf_read_count, buf_read_alloc_count,
179 * munge_count, buf_write_count, and buf_write_alloc_count take the
180 * value of the corresponding capitalized _Count values modulo 2^32
181 * (UINT_MAX+1).  Subtracting a "higher" _count value from a "lower"
182 * _count value gives the same answer as subtracting a "higher" _Count
183 * value from a lower _Count value because prealloc_bufsz < UINT_MAX+1.
184 * The modulo operation is done implicitly.
185 *
186 * The buf_read_ptr, munge_ptr, and buf_write_ptr members take the value
187 * of the corresponding capitalized _Count values modulo prealloc_bufsz.
188 * These correspond to byte indices in the physical buffer.  The modulo
189 * operation is done by subtracting prealloc_bufsz when the value
190 * exceeds prealloc_bufsz (assuming prealloc_bufsz plus the increment is
191 * less than or equal to UINT_MAX).
192 */
193struct comedi_async {
194	void *prealloc_buf;
195	unsigned int prealloc_bufsz;
196	struct comedi_buf_map *buf_map;
197	unsigned int max_bufsize;
198	unsigned int buf_write_count;
199	unsigned int buf_write_alloc_count;
200	unsigned int buf_read_count;
201	unsigned int buf_read_alloc_count;
202	unsigned int buf_write_ptr;
203	unsigned int buf_read_ptr;
204	unsigned int cur_chan;
205	unsigned int scans_done;
206	unsigned int scan_progress;
207	unsigned int munge_chan;
208	unsigned int munge_count;
209	unsigned int munge_ptr;
210	unsigned int events;
211	struct comedi_cmd cmd;
212	wait_queue_head_t wait_head;
213	unsigned int cb_mask;
214	int (*inttrig)(struct comedi_device *dev, struct comedi_subdevice *s,
215		       unsigned int x);
216};
217
218/**
219 * comedi_async callback "events"
220 * @COMEDI_CB_EOS:		end-of-scan
221 * @COMEDI_CB_EOA:		end-of-acquisition/output
222 * @COMEDI_CB_BLOCK:		data has arrived, wakes up read() / write()
223 * @COMEDI_CB_EOBUF:		DEPRECATED: end of buffer
224 * @COMEDI_CB_ERROR:		card error during acquisition
225 * @COMEDI_CB_OVERFLOW:		buffer overflow/underflow
226 *
227 * @COMEDI_CB_ERROR_MASK:	events that indicate an error has occurred
228 * @COMEDI_CB_CANCEL_MASK:	events that will cancel an async command
229 */
230#define COMEDI_CB_EOS		(1 << 0)
231#define COMEDI_CB_EOA		(1 << 1)
232#define COMEDI_CB_BLOCK		(1 << 2)
233#define COMEDI_CB_EOBUF		(1 << 3)
234#define COMEDI_CB_ERROR		(1 << 4)
235#define COMEDI_CB_OVERFLOW	(1 << 5)
236
237#define COMEDI_CB_ERROR_MASK	(COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW)
238#define COMEDI_CB_CANCEL_MASK	(COMEDI_CB_EOA | COMEDI_CB_ERROR_MASK)
239
240struct comedi_driver {
241	struct comedi_driver *next;
242
243	const char *driver_name;
244	struct module *module;
245	int (*attach)(struct comedi_device *, struct comedi_devconfig *);
246	void (*detach)(struct comedi_device *);
247	int (*auto_attach)(struct comedi_device *, unsigned long);
248
249	/* number of elements in board_name and board_id arrays */
250	unsigned int num_names;
251	const char *const *board_name;
252	/* offset in bytes from one board name pointer to the next */
253	int offset;
254};
255
256struct comedi_device {
257	int use_count;
258	struct comedi_driver *driver;
259	struct comedi_8254 *pacer;
260	void *private;
261
262	struct device *class_dev;
263	int minor;
264	unsigned int detach_count;
265	/* hw_dev is passed to dma_alloc_coherent when allocating async buffers
266	 * for subdevices that have async_dma_dir set to something other than
267	 * DMA_NONE */
268	struct device *hw_dev;
269
270	const char *board_name;
271	const void *board_ptr;
272	bool attached:1;
273	bool ioenabled:1;
274	spinlock_t spinlock;
275	struct mutex mutex;
276	struct rw_semaphore attach_lock;
277	struct kref refcount;
278
279	int n_subdevices;
280	struct comedi_subdevice *subdevices;
281
282	/* dumb */
283	void __iomem *mmio;
284	unsigned long iobase;
285	unsigned long iolen;
286	unsigned int irq;
287
288	struct comedi_subdevice *read_subdev;
289	struct comedi_subdevice *write_subdev;
290
291	struct fasync_struct *async_queue;
292
293	int (*open)(struct comedi_device *dev);
294	void (*close)(struct comedi_device *dev);
295};
296
297/*
298 * function prototypes
299 */
300
301void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s);
302
303struct comedi_device *comedi_dev_get_from_minor(unsigned minor);
304int comedi_dev_put(struct comedi_device *dev);
305
306/**
307 * comedi_subdevice "runflags"
308 * @COMEDI_SRF_RT:		DEPRECATED: command is running real-time
309 * @COMEDI_SRF_ERROR:		indicates an COMEDI_CB_ERROR event has occurred
310 *				since the last command was started
311 * @COMEDI_SRF_RUNNING:		command is running
312 * @COMEDI_SRF_FREE_SPRIV:	free s->private on detach
313 *
314 * @COMEDI_SRF_BUSY_MASK:	runflags that indicate the subdevice is "busy"
315 */
316#define COMEDI_SRF_RT		BIT(1)
317#define COMEDI_SRF_ERROR	BIT(2)
318#define COMEDI_SRF_RUNNING	BIT(27)
319#define COMEDI_SRF_FREE_SPRIV	BIT(31)
320
321#define COMEDI_SRF_BUSY_MASK	(COMEDI_SRF_ERROR | COMEDI_SRF_RUNNING)
322
323bool comedi_is_subdevice_running(struct comedi_subdevice *s);
324
325void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size);
326
327int comedi_check_chanlist(struct comedi_subdevice *s,
328			  int n,
329			  unsigned int *chanlist);
330
331/* range stuff */
332
333#define RANGE(a, b)		{(a)*1e6, (b)*1e6, 0}
334#define RANGE_ext(a, b)		{(a)*1e6, (b)*1e6, RF_EXTERNAL}
335#define RANGE_mA(a, b)		{(a)*1e6, (b)*1e6, UNIT_mA}
336#define RANGE_unitless(a, b)	{(a)*1e6, (b)*1e6, 0}
337#define BIP_RANGE(a)		{-(a)*1e6, (a)*1e6, 0}
338#define UNI_RANGE(a)		{0, (a)*1e6, 0}
339
340extern const struct comedi_lrange range_bipolar10;
341extern const struct comedi_lrange range_bipolar5;
342extern const struct comedi_lrange range_bipolar2_5;
343extern const struct comedi_lrange range_unipolar10;
344extern const struct comedi_lrange range_unipolar5;
345extern const struct comedi_lrange range_unipolar2_5;
346extern const struct comedi_lrange range_0_20mA;
347extern const struct comedi_lrange range_4_20mA;
348extern const struct comedi_lrange range_0_32mA;
349extern const struct comedi_lrange range_unknown;
350
351#define range_digital		range_unipolar5
352
353#if __GNUC__ >= 3
354#define GCC_ZERO_LENGTH_ARRAY
355#else
356#define GCC_ZERO_LENGTH_ARRAY 0
357#endif
358
359struct comedi_lrange {
360	int length;
361	struct comedi_krange range[GCC_ZERO_LENGTH_ARRAY];
362};
363
364static inline bool comedi_range_is_bipolar(struct comedi_subdevice *s,
365					   unsigned int range)
366{
367	return s->range_table->range[range].min < 0;
368}
369
370static inline bool comedi_range_is_unipolar(struct comedi_subdevice *s,
371					    unsigned int range)
372{
373	return s->range_table->range[range].min >= 0;
374}
375
376static inline bool comedi_range_is_external(struct comedi_subdevice *s,
377					    unsigned int range)
378{
379	return !!(s->range_table->range[range].flags & RF_EXTERNAL);
380}
381
382static inline bool comedi_chan_range_is_bipolar(struct comedi_subdevice *s,
383						unsigned int chan,
384						unsigned int range)
385{
386	return s->range_table_list[chan]->range[range].min < 0;
387}
388
389static inline bool comedi_chan_range_is_unipolar(struct comedi_subdevice *s,
390						 unsigned int chan,
391						 unsigned int range)
392{
393	return s->range_table_list[chan]->range[range].min >= 0;
394}
395
396static inline bool comedi_chan_range_is_external(struct comedi_subdevice *s,
397						 unsigned int chan,
398						 unsigned int range)
399{
400	return !!(s->range_table_list[chan]->range[range].flags & RF_EXTERNAL);
401}
402
403/* munge between offset binary and two's complement values */
404static inline unsigned int comedi_offset_munge(struct comedi_subdevice *s,
405					       unsigned int val)
406{
407	return val ^ s->maxdata ^ (s->maxdata >> 1);
408}
409
410/**
411 * comedi_bytes_per_sample - determine subdevice sample size
412 * @s:		comedi_subdevice struct
413 *
414 * The sample size will be 4 (sizeof int) or 2 (sizeof short) depending on
415 * whether the SDF_LSAMPL subdevice flag is set or not.
416 *
417 * Returns the subdevice sample size.
418 */
419static inline unsigned int comedi_bytes_per_sample(struct comedi_subdevice *s)
420{
421	return s->subdev_flags & SDF_LSAMPL ? sizeof(int) : sizeof(short);
422}
423
424/**
425 * comedi_sample_shift - determine log2 of subdevice sample size
426 * @s:		comedi_subdevice struct
427 *
428 * The sample size will be 4 (sizeof int) or 2 (sizeof short) depending on
429 * whether the SDF_LSAMPL subdevice flag is set or not.  The log2 of the
430 * sample size will be 2 or 1 and can be used as the right operand of a
431 * bit-shift operator to multiply or divide something by the sample size.
432 *
433 * Returns log2 of the subdevice sample size.
434 */
435static inline unsigned int comedi_sample_shift(struct comedi_subdevice *s)
436{
437	return s->subdev_flags & SDF_LSAMPL ? 2 : 1;
438}
439
440/**
441 * comedi_bytes_to_samples - converts a number of bytes to a number of samples
442 * @s:		comedi_subdevice struct
443 * @nbytes:	number of bytes
444 *
445 * Returns the number of bytes divided by the subdevice sample size.
446 */
447static inline unsigned int comedi_bytes_to_samples(struct comedi_subdevice *s,
448						   unsigned int nbytes)
449{
450	return nbytes >> comedi_sample_shift(s);
451}
452
453/**
454 * comedi_samples_to_bytes - converts a number of samples to a number of bytes
455 * @s:		comedi_subdevice struct
456 * @nsamples:	number of samples
457 *
458 * Returns the number of samples multiplied by the subdevice sample size.
459 * Does not check for arithmetic overflow.
460 */
461static inline unsigned int comedi_samples_to_bytes(struct comedi_subdevice *s,
462						   unsigned int nsamples)
463{
464	return nsamples << comedi_sample_shift(s);
465}
466
467/**
468 * comedi_check_trigger_src() - trivially validate a comedi_cmd trigger source
469 * @src: pointer to the trigger source to validate
470 * @flags: bitmask of valid TRIG_* for the trigger
471 *
472 * This is used in "step 1" of the do_cmdtest functions of comedi drivers
473 * to vaildate the comedi_cmd triggers. The mask of the @src against the
474 * @flags allows the userspace comedilib to pass all the comedi_cmd
475 * triggers as TRIG_ANY and get back a bitmask of the valid trigger sources.
476 */
477static inline int comedi_check_trigger_src(unsigned int *src,
478					   unsigned int flags)
479{
480	unsigned int orig_src = *src;
481
482	*src = orig_src & flags;
483	if (*src == TRIG_INVALID || *src != orig_src)
484		return -EINVAL;
485	return 0;
486}
487
488/**
489 * comedi_check_trigger_is_unique() - make sure a trigger source is unique
490 * @src: the trigger source to check
491 */
492static inline int comedi_check_trigger_is_unique(unsigned int src)
493{
494	/* this test is true if more than one _src bit is set */
495	if ((src & (src - 1)) != 0)
496		return -EINVAL;
497	return 0;
498}
499
500/**
501 * comedi_check_trigger_arg_is() - trivially validate a trigger argument
502 * @arg: pointer to the trigger arg to validate
503 * @val: the value the argument should be
504 */
505static inline int comedi_check_trigger_arg_is(unsigned int *arg,
506					      unsigned int val)
507{
508	if (*arg != val) {
509		*arg = val;
510		return -EINVAL;
511	}
512	return 0;
513}
514
515/**
516 * comedi_check_trigger_arg_min() - trivially validate a trigger argument
517 * @arg: pointer to the trigger arg to validate
518 * @val: the minimum value the argument should be
519 */
520static inline int comedi_check_trigger_arg_min(unsigned int *arg,
521					       unsigned int val)
522{
523	if (*arg < val) {
524		*arg = val;
525		return -EINVAL;
526	}
527	return 0;
528}
529
530/**
531 * comedi_check_trigger_arg_max() - trivially validate a trigger argument
532 * @arg: pointer to the trigger arg to validate
533 * @val: the maximum value the argument should be
534 */
535static inline int comedi_check_trigger_arg_max(unsigned int *arg,
536					       unsigned int val)
537{
538	if (*arg > val) {
539		*arg = val;
540		return -EINVAL;
541	}
542	return 0;
543}
544
545/*
546 * Must set dev->hw_dev if you wish to dma directly into comedi's buffer.
547 * Also useful for retrieving a previously configured hardware device of
548 * known bus type.  Set automatically for auto-configured devices.
549 * Automatically set to NULL when detaching hardware device.
550 */
551int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev);
552
553static inline unsigned int comedi_buf_n_bytes_ready(struct comedi_subdevice *s)
554{
555	return s->async->buf_write_count - s->async->buf_read_count;
556}
557
558unsigned int comedi_buf_write_alloc(struct comedi_subdevice *s, unsigned int n);
559unsigned int comedi_buf_write_free(struct comedi_subdevice *s, unsigned int n);
560
561unsigned int comedi_buf_read_n_available(struct comedi_subdevice *s);
562unsigned int comedi_buf_read_alloc(struct comedi_subdevice *s, unsigned int n);
563unsigned int comedi_buf_read_free(struct comedi_subdevice *s, unsigned int n);
564
565unsigned int comedi_buf_write_samples(struct comedi_subdevice *s,
566				      const void *data, unsigned int nsamples);
567unsigned int comedi_buf_read_samples(struct comedi_subdevice *s,
568				     void *data, unsigned int nsamples);
569
570/* drivers.c - general comedi driver functions */
571
572#define COMEDI_TIMEOUT_MS	1000
573
574int comedi_timeout(struct comedi_device *, struct comedi_subdevice *,
575		   struct comedi_insn *,
576		   int (*cb)(struct comedi_device *, struct comedi_subdevice *,
577			     struct comedi_insn *, unsigned long context),
578		   unsigned long context);
579
580unsigned int comedi_handle_events(struct comedi_device *dev,
581				  struct comedi_subdevice *s);
582
583int comedi_dio_insn_config(struct comedi_device *, struct comedi_subdevice *,
584			   struct comedi_insn *, unsigned int *data,
585			   unsigned int mask);
586unsigned int comedi_dio_update_state(struct comedi_subdevice *,
587				     unsigned int *data);
588unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s);
589unsigned int comedi_nscans_left(struct comedi_subdevice *s,
590				unsigned int nscans);
591unsigned int comedi_nsamples_left(struct comedi_subdevice *s,
592				  unsigned int nsamples);
593void comedi_inc_scan_progress(struct comedi_subdevice *s,
594			      unsigned int num_bytes);
595
596void *comedi_alloc_devpriv(struct comedi_device *, size_t);
597int comedi_alloc_subdevices(struct comedi_device *, int);
598int comedi_alloc_subdev_readback(struct comedi_subdevice *);
599
600int comedi_readback_insn_read(struct comedi_device *, struct comedi_subdevice *,
601			      struct comedi_insn *, unsigned int *data);
602
603int comedi_load_firmware(struct comedi_device *, struct device *,
604			 const char *name,
605			 int (*cb)(struct comedi_device *,
606				   const u8 *data, size_t size,
607				   unsigned long context),
608			 unsigned long context);
609
610int __comedi_request_region(struct comedi_device *,
611			    unsigned long start, unsigned long len);
612int comedi_request_region(struct comedi_device *,
613			  unsigned long start, unsigned long len);
614void comedi_legacy_detach(struct comedi_device *);
615
616int comedi_auto_config(struct device *, struct comedi_driver *,
617		       unsigned long context);
618void comedi_auto_unconfig(struct device *);
619
620int comedi_driver_register(struct comedi_driver *);
621void comedi_driver_unregister(struct comedi_driver *);
622
623/**
624 * module_comedi_driver() - Helper macro for registering a comedi driver
625 * @__comedi_driver: comedi_driver struct
626 *
627 * Helper macro for comedi drivers which do not do anything special in module
628 * init/exit. This eliminates a lot of boilerplate. Each module may only use
629 * this macro once, and calling it replaces module_init() and module_exit().
630 */
631#define module_comedi_driver(__comedi_driver) \
632	module_driver(__comedi_driver, comedi_driver_register, \
633			comedi_driver_unregister)
634
635#endif /* _COMEDIDEV_H */
636