summaryrefslogtreecommitdiffstats
path: root/include/linux/iio/iio.h
blob: 75a8a20c8179130871dac93a9655d7ecfdbb360f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603

/* The industrial I/O core
 *
 * Copyright (c) 2008 Jonathan Cameron
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */
#ifndef _INDUSTRIAL_IO_H_
#define _INDUSTRIAL_IO_H_

#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/iio/types.h>
/* IIO TODO LIST */
/*
 * Provide means of adjusting timer accuracy.
 * Currently assumes nano seconds.
 */

enum iio_chan_info_enum {
	IIO_CHAN_INFO_RAW = 0,
	IIO_CHAN_INFO_PROCESSED,
	IIO_CHAN_INFO_SCALE,
	IIO_CHAN_INFO_OFFSET,
	IIO_CHAN_INFO_CALIBSCALE,
	IIO_CHAN_INFO_CALIBBIAS,
	IIO_CHAN_INFO_PEAK,
	IIO_CHAN_INFO_PEAK_SCALE,
	IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW,
	IIO_CHAN_INFO_AVERAGE_RAW,
	IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY,
	IIO_CHAN_INFO_SAMP_FREQ,
	IIO_CHAN_INFO_FREQUENCY,
	IIO_CHAN_INFO_PHASE,
	IIO_CHAN_INFO_HARDWAREGAIN,
	IIO_CHAN_INFO_HYSTERESIS,
	IIO_CHAN_INFO_INT_TIME,
};

enum iio_shared_by {
	IIO_SEPARATE,
	IIO_SHARED_BY_TYPE,
	IIO_SHARED_BY_DIR,
	IIO_SHARED_BY_ALL
};

enum iio_endian {
	IIO_CPU,
	IIO_BE,
	IIO_LE,
};

struct iio_chan_spec;
struct iio_dev;

/**
 * struct iio_chan_spec_ext_info - Extended channel info attribute
 * @name:	Info attribute name
 * @shared:	Whether this attribute is shared between all channels.
 * @read:	Read callback for this info attribute, may be NULL.
 * @write:	Write callback for this info attribute, may be NULL.
 * @private:	Data private to the driver.
 */
struct iio_chan_spec_ext_info {
	const char *name;
	enum iio_shared_by shared;
	ssize_t (*read)(struct iio_dev *, uintptr_t private,
			struct iio_chan_spec const *, char *buf);
	ssize_t (*write)(struct iio_dev *, uintptr_t private,
			 struct iio_chan_spec const *, const char *buf,
			 size_t len);
	uintptr_t private;
};

/**
 * struct iio_enum - Enum channel info attribute
 * @items:	An array of strings.
 * @num_items:	Length of the item array.
 * @set:	Set callback function, may be NULL.
 * @get:	Get callback function, may be NULL.
 *
 * The iio_enum struct can be used to implement enum style channel attributes.
 * Enum style attributes are those which have a set of strings which map to
 * unsigned integer values. The IIO enum helper code takes care of mapping
 * between value and string as well as generating a "_available" file which
 * contains a list of all available items. The set callback will be called when
 * the attribute is updated. The last parameter is the index to the newly
 * activated item. The get callback will be used to query the currently active
 * item and is supposed to return the index for it.
 */
struct iio_enum {
	const char * const *items;
	unsigned int num_items;
	int (*set)(struct iio_dev *, const struct iio_chan_spec *, unsigned int);
	int (*get)(struct iio_dev *, const struct iio_chan_spec *);
};

ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
	uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
ssize_t iio_enum_read(struct iio_dev *indio_dev,
	uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
ssize_t iio_enum_write(struct iio_dev *indio_dev,
	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
	size_t len);

/**
 * IIO_ENUM() - Initialize enum extended channel attribute
 * @_name:	Attribute name
 * @_shared:	Whether the attribute is shared between all channels
 * @_e:		Pointer to an iio_enum struct
 *
 * This should usually be used together with IIO_ENUM_AVAILABLE()
 */
#define IIO_ENUM(_name, _shared, _e) \
{ \
	.name = (_name), \
	.shared = (_shared), \
	.read = iio_enum_read, \
	.write = iio_enum_write, \
	.private = (uintptr_t)(_e), \
}

/**
 * IIO_ENUM_AVAILABLE() - Initialize enum available extended channel attribute
 * @_name:	Attribute name ("_available" will be appended to the name)
 * @_e:		Pointer to an iio_enum struct
 *
 * Creates a read only attribute which lists all the available enum items in a
 * space separated list. This should usually be used together with IIO_ENUM()
 */
#define IIO_ENUM_AVAILABLE(_name, _e) \
{ \
	.name = (_name "_available"), \
	.shared = IIO_SHARED_BY_TYPE, \
	.read = iio_enum_available_read, \
	.private = (uintptr_t)(_e), \
}

/**
 * struct iio_event_spec - specification for a channel event
 * @type:		    Type of the event
 * @dir:		    Direction of the event
 * @mask_separate:	    Bit mask of enum iio_event_info values. Attributes
 *			    set in this mask will be registered per channel.
 * @mask_shared_by_type:    Bit mask of enum iio_event_info values. Attributes
 *			    set in this mask will be shared by channel type.
 * @mask_shared_by_dir:	    Bit mask of enum iio_event_info values. Attributes
 *			    set in this mask will be shared by channel type and
 *			    direction.
 * @mask_shared_by_all:	    Bit mask of enum iio_event_info values. Attributes
 *			    set in this mask will be shared by all channels.
 */
struct iio_event_spec {
	enum iio_event_type type;
	enum iio_event_direction dir;
	unsigned long mask_separate;
	unsigned long mask_shared_by_type;
	unsigned long mask_shared_by_dir;
	unsigned long mask_shared_by_all;
};

/**
 * struct iio_chan_spec - specification of a single channel
 * @type:		What type of measurement is the channel making.
 * @channel:		What number do we wish to assign the channel.
 * @channel2:		If there is a second number for a differential
 *			channel then this is it. If modified is set then the
 *			value here specifies the modifier.
 * @address:		Driver specific identifier.
 * @scan_index:		Monotonic index to give ordering in scans when read
 *			from a buffer.
 * @scan_type:		Sign:		's' or 'u' to specify signed or unsigned
 *			realbits:	Number of valid bits of data
 *			storage_bits:	Realbits + padding
 *			shift:		Shift right by this before masking out
 *					realbits.
 *			endianness:	little or big endian
 * @info_mask_separate: What information is to be exported that is specific to
 *			this channel.
 * @info_mask_shared_by_type: What information is to be exported that is shared
 *			by all channels of the same type.
 * @info_mask_shared_by_dir: What information is to be exported that is shared
 *			by all channels of the same direction.
 * @info_mask_shared_by_all: What information is to be exported that is shared
 *			by all channels.
 * @event_spec:		Array of events which should be registered for this
 *			channel.
 * @num_event_specs:	Size of the event_spec array.
 * @ext_info:		Array of extended info attributes for this channel.
 *			The array is NULL terminated, the last element should
 *			have its name field set to NULL.
 * @extend_name:	Allows labeling of channel attributes with an
 *			informative name. Note this has no effect codes etc,
 *			unlike modifiers.
 * @datasheet_name:	A name used in in-kernel mapping of channels. It should
 *			correspond to the first name that the channel is referred
 *			to by in the datasheet (e.g. IND), or the nearest
 *			possible compound name (e.g. IND-INC).
 * @modified:		Does a modifier apply to this channel. What these are
 *			depends on the channel type.  Modifier is set in
 *			channel2. Examples are IIO_MOD_X for axial sensors about
 *			the 'x' axis.
 * @indexed:		Specify the channel has a numerical index. If not,
 *			the channel index number will be suppressed for sysfs
 *			attributes but not for event codes.
 * @output:		Channel is output.
 * @differential:	Channel is differential.
 */
struct iio_chan_spec {
	enum iio_chan_type	type;
	int			channel;
	int			channel2;
	unsigned long		address;
	int			scan_index;
	struct {
		char	sign;
		u8	realbits;
		u8	storagebits;
		u8	shift;
		enum iio_endian endianness;
	} scan_type;
	long			info_mask_separate;
	long			info_mask_shared_by_type;
	long			info_mask_shared_by_dir;
	long			info_mask_shared_by_all;
	const struct iio_event_spec *event_spec;
	unsigned int		num_event_specs;
	const struct iio_chan_spec_ext_info *ext_info;
	const char		*extend_name;
	const char		*datasheet_name;
	unsigned		modified:1;
	unsigned		indexed:1;
	unsigned		output:1;
	unsigned		differential:1;
};


/**
 * iio_channel_has_info() - Checks whether a channel supports a info attribute
 * @chan: The channel to be queried
 * @type: Type of the info attribute to be checked
 *
 * Returns true if the channels supports reporting values for the given info
 * attribute type, false otherwise.
 */
static inline bool iio_channel_has_info(const struct iio_chan_spec *chan,
	enum iio_chan_info_enum type)
{
	return (chan->info_mask_separate & BIT(type)) |
		(chan->info_mask_shared_by_type & BIT(type)) |
		(chan->info_mask_shared_by_dir & BIT(type)) |
		(chan->info_mask_shared_by_all & BIT(type));
}

#define IIO_ST(si, rb, sb, sh)						\
	{ .sign = si, .realbits = rb, .storagebits = sb, .shift = sh }

#define IIO_CHAN_SOFT_TIMESTAMP(_si)					\
	{ .type = IIO_TIMESTAMP, .channel = -1,				\
			.scan_index = _si, .scan_type = IIO_ST('s', 64, 64, 0) }

/**
 * iio_get_time_ns() - utility function to get a time stamp for events etc
 **/
static inline s64 iio_get_time_ns(void)
{
	struct timespec ts;
	/*
	 * calls getnstimeofday.
	 * If hrtimers then up to ns accurate, if not microsecond.
	 */
	ktime_get_real_ts(&ts);

	return timespec_to_ns(&ts);
}

/* Device operating modes */
#define INDIO_DIRECT_MODE		0x01
#define INDIO_BUFFER_TRIGGERED		0x02
#define INDIO_BUFFER_HARDWARE		0x08

#define INDIO_ALL_BUFFER_MODES					\
	(INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE)

struct iio_trigger; /* forward declaration */
struct iio_dev;

/**
 * struct iio_info - constant information about device
 * @driver_module:	module structure used to ensure correct
 *			ownership of chrdevs etc
 * @event_attrs:	event control attributes
 * @attrs:		general purpose device attributes
 * @read_raw:		function to request a value from the device.
 *			mask specifies which value. Note 0 means a reading of
 *			the channel in question.  Return value will specify the
 *			type of value returned by the device. val and val2 will
 *			contain the elements making up the returned value.
 * @write_raw:		function to write a value to the device.
 *			Parameters are the same as for read_raw.
 * @write_raw_get_fmt:	callback function to query the expected
 *			format/precision. If not set by the driver, write_raw
 *			returns IIO_VAL_INT_PLUS_MICRO.
 * @read_event_config:	find out if the event is enabled.
 * @write_event_config:	set if the event is enabled.
 * @read_event_value:	read a configuration value associated with the event.
 * @write_event_value:	write a configuration value for the event.
 * @validate_trigger:	function to validate the trigger when the
 *			current trigger gets changed.
 * @update_scan_mode:	function to configure device and scan buffer when
 *			channels have changed
 * @debugfs_reg_access:	function to read or write register value of device
 **/
struct iio_info {
	struct module			*driver_module;
	struct attribute_group		*event_attrs;
	const struct attribute_group	*attrs;

	int (*read_raw)(struct iio_dev *indio_dev,
			struct iio_chan_spec const *chan,
			int *val,
			int *val2,
			long mask);

	int (*write_raw)(struct iio_dev *indio_dev,
			 struct iio_chan_spec const *chan,
			 int val,
			 int val2,
			 long mask);

	int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
			 struct iio_chan_spec const *chan,
			 long mask);

	int (*read_event_config)(struct iio_dev *indio_dev,
				 const struct iio_chan_spec *chan,
				 enum iio_event_type type,
				 enum iio_event_direction dir);

	int (*write_event_config)(struct iio_dev *indio_dev,
				  const struct iio_chan_spec *chan,
				  enum iio_event_type type,
				  enum iio_event_direction dir,
				  int state);

	int (*read_event_value)(struct iio_dev *indio_dev,
				const struct iio_chan_spec *chan,
				enum iio_event_type type,
				enum iio_event_direction dir,
				enum iio_event_info info, int *val, int *val2);

	int (*write_event_value)(struct iio_dev *indio_dev,
				 const struct iio_chan_spec *chan,
				 enum iio_event_type type,
				 enum iio_event_direction dir,
				 enum iio_event_info info, int val, int val2);

	int (*validate_trigger)(struct iio_dev *indio_dev,
				struct iio_trigger *trig);
	int (*update_scan_mode)(struct iio_dev *indio_dev,
				const unsigned long *scan_mask);
	int (*debugfs_reg_access)(struct iio_dev *indio_dev,
				  unsigned reg, unsigned writeval,
				  unsigned *readval);
};

/**
 * struct iio_buffer_setup_ops - buffer setup related callbacks
 * @preenable:		[DRIVER] function to run prior to marking buffer enabled
 * @postenable:		[DRIVER] function to run after marking buffer enabled
 * @predisable:		[DRIVER] function to run prior to marking buffer
 *			disabled
 * @postdisable:	[DRIVER] function to run after marking buffer disabled
 * @validate_scan_mask: [DRIVER] function callback to check whether a given
 *			scan mask is valid for the device.
 */
struct iio_buffer_setup_ops {
	int (*preenable)(struct iio_dev *);
	int (*postenable)(struct iio_dev *);
	int (*predisable)(struct iio_dev *);
	int (*postdisable)(struct iio_dev *);
	bool (*validate_scan_mask)(struct iio_dev *indio_dev,
				   const unsigned long *scan_mask);
};

/**
 * struct iio_dev - industrial I/O device
 * @id:			[INTERN] used to identify device internally
 * @modes:		[DRIVER] operating modes supported by device
 * @currentmode:	[DRIVER] current operating mode
 * @dev:		[DRIVER] device structure, should be assigned a parent
 *			and owner
 * @event_interface:	[INTERN] event chrdevs associated with interrupt lines
 * @buffer:		[DRIVER] any buffer present
 * @buffer_list:	[INTERN] list of all buffers currently attached
 * @scan_bytes:		[INTERN] num bytes captured to be fed to buffer demux
 * @mlock:		[INTERN] lock used to prevent simultaneous device state
 *			changes
 * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
 * @masklength:		[INTERN] the length of the mask established from
 *			channels
 * @active_scan_mask:	[INTERN] union of all scan masks requested by buffers
 * @scan_timestamp:	[INTERN] set if any buffers have requested timestamp
 * @scan_index_timestamp:[INTERN] cache of the index to the timestamp
 * @trig:		[INTERN] current device trigger (buffer modes)
 * @pollfunc:		[DRIVER] function run on trigger being received
 * @channels:		[DRIVER] channel specification structure table
 * @num_channels:	[DRIVER] number of channels specified in @channels.
 * @channel_attr_list:	[INTERN] keep track of automatically created channel
 *			attributes
 * @chan_attr_group:	[INTERN] group for all attrs in base directory
 * @name:		[DRIVER] name of the device.
 * @info:		[DRIVER] callbacks and constant info from driver
 * @info_exist_lock:	[INTERN] lock to prevent use during removal
 * @setup_ops:		[DRIVER] callbacks to call before and after buffer
 *			enable/disable
 * @chrdev:		[INTERN] associated character device
 * @groups:		[INTERN] attribute groups
 * @groupcounter:	[INTERN] index of next attribute group
 * @flags:		[INTERN] file ops related flags including busy flag.
 * @debugfs_dentry:	[INTERN] device specific debugfs dentry.
 * @cached_reg_addr:	[INTERN] cached register address for debugfs reads.
 */
struct iio_dev {
	int				id;

	int				modes;
	int				currentmode;
	struct device			dev;

	struct iio_event_interface	*event_interface;

	struct iio_buffer		*buffer;
	struct list_head		buffer_list;
	int				scan_bytes;
	struct mutex			mlock;

	const unsigned long		*available_scan_masks;
	unsigned			masklength;
	const unsigned long		*active_scan_mask;
	bool				scan_timestamp;
	unsigned			scan_index_timestamp;
	struct iio_trigger		*trig;
	struct iio_poll_func		*pollfunc;

	struct iio_chan_spec const	*channels;
	int				num_channels;

	struct list_head		channel_attr_list;
	struct attribute_group		chan_attr_group;
	const char			*name;
	const struct iio_info		*info;
	struct mutex			info_exist_lock;
	const struct iio_buffer_setup_ops	*setup_ops;
	struct cdev			chrdev;
#define IIO_MAX_GROUPS 6
	const struct attribute_group	*groups[IIO_MAX_GROUPS + 1];
	int				groupcounter;

	unsigned long			flags;
#if defined(CONFIG_DEBUG_FS)
	struct dentry			*debugfs_dentry;
	unsigned			cached_reg_addr;
#endif
};

const struct iio_chan_spec
*iio_find_channel_from_si(struct iio_dev *indio_dev, int si);
int iio_device_register(struct iio_dev *indio_dev);
void iio_device_unregister(struct iio_dev *indio_dev);
int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev);
void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev);
int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);

extern struct bus_type iio_bus_type;

/**
 * iio_device_put() - reference counted deallocation of struct device
 * @indio_dev: 		IIO device structure containing the device
 **/
static inline void iio_device_put(struct iio_dev *indio_dev)
{
	if (indio_dev)
		put_device(&indio_dev->dev);
}

/**
 * dev_to_iio_dev() - Get IIO device struct from a device struct
 * @dev: 		The device embedded in the IIO device
 *
 * Note: The device must be a IIO device, otherwise the result is undefined.
 */
static inline struct iio_dev *dev_to_iio_dev(struct device *dev)
{
	return container_of(dev, struct iio_dev, dev);
}

/**
 * iio_device_get() - increment reference count for the device
 * @indio_dev: 		IIO device structure
 *
 * Returns: The passed IIO device
 **/
static inline struct iio_dev *iio_device_get(struct iio_dev *indio_dev)
{
	return indio_dev ? dev_to_iio_dev(get_device(&indio_dev->dev)) : NULL;
}


/**
 * iio_device_set_drvdata() - Set device driver data
 * @indio_dev: IIO device structure
 * @data: Driver specific data
 *
 * Allows to attach an arbitrary pointer to an IIO device, which can later be
 * retrieved by iio_device_get_drvdata().
 */
static inline void iio_device_set_drvdata(struct iio_dev *indio_dev, void *data)
{
	dev_set_drvdata(&indio_dev->dev, data);
}

/**
 * iio_device_get_drvdata() - Get device driver data
 * @indio_dev: IIO device structure
 *
 * Returns the data previously set with iio_device_set_drvdata()
 */
static inline void *iio_device_get_drvdata(struct iio_dev *indio_dev)
{
	return dev_get_drvdata(&indio_dev->dev);
}

/* Can we make this smaller? */
#define IIO_ALIGN L1_CACHE_BYTES
struct iio_dev *iio_device_alloc(int sizeof_priv);

static inline void *iio_priv(const struct iio_dev *indio_dev)
{
	return (char *)indio_dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
}

static inline struct iio_dev *iio_priv_to_dev(void *priv)
{
	return (struct iio_dev *)((char *)priv -
				  ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
}

void iio_device_free(struct iio_dev *indio_dev);
struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv);
void devm_iio_device_free(struct device *dev, struct iio_dev *indio_dev);
struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
						const char *fmt, ...);
void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig);

/**
 * iio_buffer_enabled() - helper function to test if the buffer is enabled
 * @indio_dev:		IIO device structure for device
 **/
static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
{
	return indio_dev->currentmode
		& (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE);
}

/**
 * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry
 * @indio_dev:		IIO device structure for device
 **/
#if defined(CONFIG_DEBUG_FS)
static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
{
	return indio_dev->debugfs_dentry;
}
#else
static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
{
	return NULL;
}
#endif

int iio_str_to_fixpoint(const char *str, int fract_mult, int *integer,
	int *fract);

/**
 * IIO_DEGREE_TO_RAD() - Convert degree to rad
 * @deg: A value in degree
 *
 * Returns the given value converted from degree to rad
 */
#define IIO_DEGREE_TO_RAD(deg) (((deg) * 314159ULL + 9000000ULL) / 18000000ULL)

/**
 * IIO_G_TO_M_S_2() - Convert g to meter / second**2
 * @g: A value in g
 *
 * Returns the given value converted from g to meter / second**2
 */
#define IIO_G_TO_M_S_2(g) ((g) * 980665ULL / 100000ULL)

#endif /* _INDUSTRIAL_IO_H_ */
OpenPOWER on IntegriCloud