xref: /linux/include/linux/iio/iio.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 
2 /* The industrial I/O core
3  *
4  * Copyright (c) 2008 Jonathan Cameron
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 as published by
8  * the Free Software Foundation.
9  */
10 #ifndef _INDUSTRIAL_IO_H_
11 #define _INDUSTRIAL_IO_H_
12 
13 #include <linux/device.h>
14 #include <linux/cdev.h>
15 #include <linux/iio/types.h>
16 #include <linux/of.h>
17 /* IIO TODO LIST */
18 /*
19  * Provide means of adjusting timer accuracy.
20  * Currently assumes nano seconds.
21  */
22 
23 enum iio_chan_info_enum {
24 	IIO_CHAN_INFO_RAW = 0,
25 	IIO_CHAN_INFO_PROCESSED,
26 	IIO_CHAN_INFO_SCALE,
27 	IIO_CHAN_INFO_OFFSET,
28 	IIO_CHAN_INFO_CALIBSCALE,
29 	IIO_CHAN_INFO_CALIBBIAS,
30 	IIO_CHAN_INFO_PEAK,
31 	IIO_CHAN_INFO_PEAK_SCALE,
32 	IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW,
33 	IIO_CHAN_INFO_AVERAGE_RAW,
34 	IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY,
35 	IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY,
36 	IIO_CHAN_INFO_SAMP_FREQ,
37 	IIO_CHAN_INFO_FREQUENCY,
38 	IIO_CHAN_INFO_PHASE,
39 	IIO_CHAN_INFO_HARDWAREGAIN,
40 	IIO_CHAN_INFO_HYSTERESIS,
41 	IIO_CHAN_INFO_INT_TIME,
42 	IIO_CHAN_INFO_ENABLE,
43 	IIO_CHAN_INFO_CALIBHEIGHT,
44 	IIO_CHAN_INFO_CALIBWEIGHT,
45 	IIO_CHAN_INFO_DEBOUNCE_COUNT,
46 	IIO_CHAN_INFO_DEBOUNCE_TIME,
47 	IIO_CHAN_INFO_CALIBEMISSIVITY,
48 	IIO_CHAN_INFO_OVERSAMPLING_RATIO,
49 };
50 
51 enum iio_shared_by {
52 	IIO_SEPARATE,
53 	IIO_SHARED_BY_TYPE,
54 	IIO_SHARED_BY_DIR,
55 	IIO_SHARED_BY_ALL
56 };
57 
58 enum iio_endian {
59 	IIO_CPU,
60 	IIO_BE,
61 	IIO_LE,
62 };
63 
64 struct iio_chan_spec;
65 struct iio_dev;
66 
67 /**
68  * struct iio_chan_spec_ext_info - Extended channel info attribute
69  * @name:	Info attribute name
70  * @shared:	Whether this attribute is shared between all channels.
71  * @read:	Read callback for this info attribute, may be NULL.
72  * @write:	Write callback for this info attribute, may be NULL.
73  * @private:	Data private to the driver.
74  */
75 struct iio_chan_spec_ext_info {
76 	const char *name;
77 	enum iio_shared_by shared;
78 	ssize_t (*read)(struct iio_dev *, uintptr_t private,
79 			struct iio_chan_spec const *, char *buf);
80 	ssize_t (*write)(struct iio_dev *, uintptr_t private,
81 			 struct iio_chan_spec const *, const char *buf,
82 			 size_t len);
83 	uintptr_t private;
84 };
85 
86 /**
87  * struct iio_enum - Enum channel info attribute
88  * @items:	An array of strings.
89  * @num_items:	Length of the item array.
90  * @set:	Set callback function, may be NULL.
91  * @get:	Get callback function, may be NULL.
92  *
93  * The iio_enum struct can be used to implement enum style channel attributes.
94  * Enum style attributes are those which have a set of strings which map to
95  * unsigned integer values. The IIO enum helper code takes care of mapping
96  * between value and string as well as generating a "_available" file which
97  * contains a list of all available items. The set callback will be called when
98  * the attribute is updated. The last parameter is the index to the newly
99  * activated item. The get callback will be used to query the currently active
100  * item and is supposed to return the index for it.
101  */
102 struct iio_enum {
103 	const char * const *items;
104 	unsigned int num_items;
105 	int (*set)(struct iio_dev *, const struct iio_chan_spec *, unsigned int);
106 	int (*get)(struct iio_dev *, const struct iio_chan_spec *);
107 };
108 
109 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
110 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
111 ssize_t iio_enum_read(struct iio_dev *indio_dev,
112 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
113 ssize_t iio_enum_write(struct iio_dev *indio_dev,
114 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
115 	size_t len);
116 
117 /**
118  * IIO_ENUM() - Initialize enum extended channel attribute
119  * @_name:	Attribute name
120  * @_shared:	Whether the attribute is shared between all channels
121  * @_e:		Pointer to an iio_enum struct
122  *
123  * This should usually be used together with IIO_ENUM_AVAILABLE()
124  */
125 #define IIO_ENUM(_name, _shared, _e) \
126 { \
127 	.name = (_name), \
128 	.shared = (_shared), \
129 	.read = iio_enum_read, \
130 	.write = iio_enum_write, \
131 	.private = (uintptr_t)(_e), \
132 }
133 
134 /**
135  * IIO_ENUM_AVAILABLE() - Initialize enum available extended channel attribute
136  * @_name:	Attribute name ("_available" will be appended to the name)
137  * @_e:		Pointer to an iio_enum struct
138  *
139  * Creates a read only attribute which lists all the available enum items in a
140  * space separated list. This should usually be used together with IIO_ENUM()
141  */
142 #define IIO_ENUM_AVAILABLE(_name, _e) \
143 { \
144 	.name = (_name "_available"), \
145 	.shared = IIO_SHARED_BY_TYPE, \
146 	.read = iio_enum_available_read, \
147 	.private = (uintptr_t)(_e), \
148 }
149 
150 /**
151  * struct iio_event_spec - specification for a channel event
152  * @type:		    Type of the event
153  * @dir:		    Direction of the event
154  * @mask_separate:	    Bit mask of enum iio_event_info values. Attributes
155  *			    set in this mask will be registered per channel.
156  * @mask_shared_by_type:    Bit mask of enum iio_event_info values. Attributes
157  *			    set in this mask will be shared by channel type.
158  * @mask_shared_by_dir:	    Bit mask of enum iio_event_info values. Attributes
159  *			    set in this mask will be shared by channel type and
160  *			    direction.
161  * @mask_shared_by_all:	    Bit mask of enum iio_event_info values. Attributes
162  *			    set in this mask will be shared by all channels.
163  */
164 struct iio_event_spec {
165 	enum iio_event_type type;
166 	enum iio_event_direction dir;
167 	unsigned long mask_separate;
168 	unsigned long mask_shared_by_type;
169 	unsigned long mask_shared_by_dir;
170 	unsigned long mask_shared_by_all;
171 };
172 
173 /**
174  * struct iio_chan_spec - specification of a single channel
175  * @type:		What type of measurement is the channel making.
176  * @channel:		What number do we wish to assign the channel.
177  * @channel2:		If there is a second number for a differential
178  *			channel then this is it. If modified is set then the
179  *			value here specifies the modifier.
180  * @address:		Driver specific identifier.
181  * @scan_index:		Monotonic index to give ordering in scans when read
182  *			from a buffer.
183  * @scan_type:		Sign:		's' or 'u' to specify signed or unsigned
184  *			realbits:	Number of valid bits of data
185  *			storage_bits:	Realbits + padding
186  *			shift:		Shift right by this before masking out
187  *					realbits.
188  *			endianness:	little or big endian
189  *			repeat:		Number of times real/storage bits
190  *					repeats. When the repeat element is
191  *					more than 1, then the type element in
192  *					sysfs will show a repeat value.
193  *					Otherwise, the number of repetitions is
194  *					omitted.
195  * @info_mask_separate: What information is to be exported that is specific to
196  *			this channel.
197  * @info_mask_shared_by_type: What information is to be exported that is shared
198  *			by all channels of the same type.
199  * @info_mask_shared_by_dir: What information is to be exported that is shared
200  *			by all channels of the same direction.
201  * @info_mask_shared_by_all: What information is to be exported that is shared
202  *			by all channels.
203  * @event_spec:		Array of events which should be registered for this
204  *			channel.
205  * @num_event_specs:	Size of the event_spec array.
206  * @ext_info:		Array of extended info attributes for this channel.
207  *			The array is NULL terminated, the last element should
208  *			have its name field set to NULL.
209  * @extend_name:	Allows labeling of channel attributes with an
210  *			informative name. Note this has no effect codes etc,
211  *			unlike modifiers.
212  * @datasheet_name:	A name used in in-kernel mapping of channels. It should
213  *			correspond to the first name that the channel is referred
214  *			to by in the datasheet (e.g. IND), or the nearest
215  *			possible compound name (e.g. IND-INC).
216  * @modified:		Does a modifier apply to this channel. What these are
217  *			depends on the channel type.  Modifier is set in
218  *			channel2. Examples are IIO_MOD_X for axial sensors about
219  *			the 'x' axis.
220  * @indexed:		Specify the channel has a numerical index. If not,
221  *			the channel index number will be suppressed for sysfs
222  *			attributes but not for event codes.
223  * @output:		Channel is output.
224  * @differential:	Channel is differential.
225  */
226 struct iio_chan_spec {
227 	enum iio_chan_type	type;
228 	int			channel;
229 	int			channel2;
230 	unsigned long		address;
231 	int			scan_index;
232 	struct {
233 		char	sign;
234 		u8	realbits;
235 		u8	storagebits;
236 		u8	shift;
237 		u8	repeat;
238 		enum iio_endian endianness;
239 	} scan_type;
240 	long			info_mask_separate;
241 	long			info_mask_shared_by_type;
242 	long			info_mask_shared_by_dir;
243 	long			info_mask_shared_by_all;
244 	const struct iio_event_spec *event_spec;
245 	unsigned int		num_event_specs;
246 	const struct iio_chan_spec_ext_info *ext_info;
247 	const char		*extend_name;
248 	const char		*datasheet_name;
249 	unsigned		modified:1;
250 	unsigned		indexed:1;
251 	unsigned		output:1;
252 	unsigned		differential:1;
253 };
254 
255 
256 /**
257  * iio_channel_has_info() - Checks whether a channel supports a info attribute
258  * @chan: The channel to be queried
259  * @type: Type of the info attribute to be checked
260  *
261  * Returns true if the channels supports reporting values for the given info
262  * attribute type, false otherwise.
263  */
264 static inline bool iio_channel_has_info(const struct iio_chan_spec *chan,
265 	enum iio_chan_info_enum type)
266 {
267 	return (chan->info_mask_separate & BIT(type)) |
268 		(chan->info_mask_shared_by_type & BIT(type)) |
269 		(chan->info_mask_shared_by_dir & BIT(type)) |
270 		(chan->info_mask_shared_by_all & BIT(type));
271 }
272 
273 #define IIO_CHAN_SOFT_TIMESTAMP(_si) {					\
274 	.type = IIO_TIMESTAMP,						\
275 	.channel = -1,							\
276 	.scan_index = _si,						\
277 	.scan_type = {							\
278 		.sign = 's',						\
279 		.realbits = 64,					\
280 		.storagebits = 64,					\
281 		},							\
282 }
283 
284 /**
285  * iio_get_time_ns() - utility function to get a time stamp for events etc
286  **/
287 static inline s64 iio_get_time_ns(void)
288 {
289 	return ktime_get_real_ns();
290 }
291 
292 /* Device operating modes */
293 #define INDIO_DIRECT_MODE		0x01
294 #define INDIO_BUFFER_TRIGGERED		0x02
295 #define INDIO_BUFFER_SOFTWARE		0x04
296 #define INDIO_BUFFER_HARDWARE		0x08
297 
298 #define INDIO_ALL_BUFFER_MODES					\
299 	(INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE | INDIO_BUFFER_SOFTWARE)
300 
301 #define INDIO_MAX_RAW_ELEMENTS		4
302 
303 struct iio_trigger; /* forward declaration */
304 struct iio_dev;
305 
306 /**
307  * struct iio_info - constant information about device
308  * @driver_module:	module structure used to ensure correct
309  *			ownership of chrdevs etc
310  * @event_attrs:	event control attributes
311  * @attrs:		general purpose device attributes
312  * @read_raw:		function to request a value from the device.
313  *			mask specifies which value. Note 0 means a reading of
314  *			the channel in question.  Return value will specify the
315  *			type of value returned by the device. val and val2 will
316  *			contain the elements making up the returned value.
317  * @read_raw_multi:	function to return values from the device.
318  *			mask specifies which value. Note 0 means a reading of
319  *			the channel in question.  Return value will specify the
320  *			type of value returned by the device. vals pointer
321  *			contain the elements making up the returned value.
322  *			max_len specifies maximum number of elements
323  *			vals pointer can contain. val_len is used to return
324  *			length of valid elements in vals.
325  * @write_raw:		function to write a value to the device.
326  *			Parameters are the same as for read_raw.
327  * @write_raw_get_fmt:	callback function to query the expected
328  *			format/precision. If not set by the driver, write_raw
329  *			returns IIO_VAL_INT_PLUS_MICRO.
330  * @read_event_config:	find out if the event is enabled.
331  * @write_event_config:	set if the event is enabled.
332  * @read_event_value:	read a configuration value associated with the event.
333  * @write_event_value:	write a configuration value for the event.
334  * @validate_trigger:	function to validate the trigger when the
335  *			current trigger gets changed.
336  * @update_scan_mode:	function to configure device and scan buffer when
337  *			channels have changed
338  * @debugfs_reg_access:	function to read or write register value of device
339  * @of_xlate:		function pointer to obtain channel specifier index.
340  *			When #iio-cells is greater than '0', the driver could
341  *			provide a custom of_xlate function that reads the
342  *			*args* and returns the appropriate index in registered
343  *			IIO channels array.
344  * @hwfifo_set_watermark: function pointer to set the current hardware
345  *			fifo watermark level; see hwfifo_* entries in
346  *			Documentation/ABI/testing/sysfs-bus-iio for details on
347  *			how the hardware fifo operates
348  * @hwfifo_flush_to_buffer: function pointer to flush the samples stored
349  *			in the hardware fifo to the device buffer. The driver
350  *			should not flush more than count samples. The function
351  *			must return the number of samples flushed, 0 if no
352  *			samples were flushed or a negative integer if no samples
353  *			were flushed and there was an error.
354  **/
355 struct iio_info {
356 	struct module			*driver_module;
357 	struct attribute_group		*event_attrs;
358 	const struct attribute_group	*attrs;
359 
360 	int (*read_raw)(struct iio_dev *indio_dev,
361 			struct iio_chan_spec const *chan,
362 			int *val,
363 			int *val2,
364 			long mask);
365 
366 	int (*read_raw_multi)(struct iio_dev *indio_dev,
367 			struct iio_chan_spec const *chan,
368 			int max_len,
369 			int *vals,
370 			int *val_len,
371 			long mask);
372 
373 	int (*write_raw)(struct iio_dev *indio_dev,
374 			 struct iio_chan_spec const *chan,
375 			 int val,
376 			 int val2,
377 			 long mask);
378 
379 	int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
380 			 struct iio_chan_spec const *chan,
381 			 long mask);
382 
383 	int (*read_event_config)(struct iio_dev *indio_dev,
384 				 const struct iio_chan_spec *chan,
385 				 enum iio_event_type type,
386 				 enum iio_event_direction dir);
387 
388 	int (*write_event_config)(struct iio_dev *indio_dev,
389 				  const struct iio_chan_spec *chan,
390 				  enum iio_event_type type,
391 				  enum iio_event_direction dir,
392 				  int state);
393 
394 	int (*read_event_value)(struct iio_dev *indio_dev,
395 				const struct iio_chan_spec *chan,
396 				enum iio_event_type type,
397 				enum iio_event_direction dir,
398 				enum iio_event_info info, int *val, int *val2);
399 
400 	int (*write_event_value)(struct iio_dev *indio_dev,
401 				 const struct iio_chan_spec *chan,
402 				 enum iio_event_type type,
403 				 enum iio_event_direction dir,
404 				 enum iio_event_info info, int val, int val2);
405 
406 	int (*validate_trigger)(struct iio_dev *indio_dev,
407 				struct iio_trigger *trig);
408 	int (*update_scan_mode)(struct iio_dev *indio_dev,
409 				const unsigned long *scan_mask);
410 	int (*debugfs_reg_access)(struct iio_dev *indio_dev,
411 				  unsigned reg, unsigned writeval,
412 				  unsigned *readval);
413 	int (*of_xlate)(struct iio_dev *indio_dev,
414 			const struct of_phandle_args *iiospec);
415 	int (*hwfifo_set_watermark)(struct iio_dev *indio_dev, unsigned val);
416 	int (*hwfifo_flush_to_buffer)(struct iio_dev *indio_dev,
417 				      unsigned count);
418 };
419 
420 /**
421  * struct iio_buffer_setup_ops - buffer setup related callbacks
422  * @preenable:		[DRIVER] function to run prior to marking buffer enabled
423  * @postenable:		[DRIVER] function to run after marking buffer enabled
424  * @predisable:		[DRIVER] function to run prior to marking buffer
425  *			disabled
426  * @postdisable:	[DRIVER] function to run after marking buffer disabled
427  * @validate_scan_mask: [DRIVER] function callback to check whether a given
428  *			scan mask is valid for the device.
429  */
430 struct iio_buffer_setup_ops {
431 	int (*preenable)(struct iio_dev *);
432 	int (*postenable)(struct iio_dev *);
433 	int (*predisable)(struct iio_dev *);
434 	int (*postdisable)(struct iio_dev *);
435 	bool (*validate_scan_mask)(struct iio_dev *indio_dev,
436 				   const unsigned long *scan_mask);
437 };
438 
439 /**
440  * struct iio_dev - industrial I/O device
441  * @id:			[INTERN] used to identify device internally
442  * @modes:		[DRIVER] operating modes supported by device
443  * @currentmode:	[DRIVER] current operating mode
444  * @dev:		[DRIVER] device structure, should be assigned a parent
445  *			and owner
446  * @event_interface:	[INTERN] event chrdevs associated with interrupt lines
447  * @buffer:		[DRIVER] any buffer present
448  * @buffer_list:	[INTERN] list of all buffers currently attached
449  * @scan_bytes:		[INTERN] num bytes captured to be fed to buffer demux
450  * @mlock:		[INTERN] lock used to prevent simultaneous device state
451  *			changes
452  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
453  * @masklength:		[INTERN] the length of the mask established from
454  *			channels
455  * @active_scan_mask:	[INTERN] union of all scan masks requested by buffers
456  * @scan_timestamp:	[INTERN] set if any buffers have requested timestamp
457  * @scan_index_timestamp:[INTERN] cache of the index to the timestamp
458  * @trig:		[INTERN] current device trigger (buffer modes)
459  * @pollfunc:		[DRIVER] function run on trigger being received
460  * @channels:		[DRIVER] channel specification structure table
461  * @num_channels:	[DRIVER] number of channels specified in @channels.
462  * @channel_attr_list:	[INTERN] keep track of automatically created channel
463  *			attributes
464  * @chan_attr_group:	[INTERN] group for all attrs in base directory
465  * @name:		[DRIVER] name of the device.
466  * @info:		[DRIVER] callbacks and constant info from driver
467  * @info_exist_lock:	[INTERN] lock to prevent use during removal
468  * @setup_ops:		[DRIVER] callbacks to call before and after buffer
469  *			enable/disable
470  * @chrdev:		[INTERN] associated character device
471  * @groups:		[INTERN] attribute groups
472  * @groupcounter:	[INTERN] index of next attribute group
473  * @flags:		[INTERN] file ops related flags including busy flag.
474  * @debugfs_dentry:	[INTERN] device specific debugfs dentry.
475  * @cached_reg_addr:	[INTERN] cached register address for debugfs reads.
476  */
477 struct iio_dev {
478 	int				id;
479 
480 	int				modes;
481 	int				currentmode;
482 	struct device			dev;
483 
484 	struct iio_event_interface	*event_interface;
485 
486 	struct iio_buffer		*buffer;
487 	struct list_head		buffer_list;
488 	int				scan_bytes;
489 	struct mutex			mlock;
490 
491 	const unsigned long		*available_scan_masks;
492 	unsigned			masklength;
493 	const unsigned long		*active_scan_mask;
494 	bool				scan_timestamp;
495 	unsigned			scan_index_timestamp;
496 	struct iio_trigger		*trig;
497 	struct iio_poll_func		*pollfunc;
498 
499 	struct iio_chan_spec const	*channels;
500 	int				num_channels;
501 
502 	struct list_head		channel_attr_list;
503 	struct attribute_group		chan_attr_group;
504 	const char			*name;
505 	const struct iio_info		*info;
506 	struct mutex			info_exist_lock;
507 	const struct iio_buffer_setup_ops	*setup_ops;
508 	struct cdev			chrdev;
509 #define IIO_MAX_GROUPS 6
510 	const struct attribute_group	*groups[IIO_MAX_GROUPS + 1];
511 	int				groupcounter;
512 
513 	unsigned long			flags;
514 #if defined(CONFIG_DEBUG_FS)
515 	struct dentry			*debugfs_dentry;
516 	unsigned			cached_reg_addr;
517 #endif
518 };
519 
520 const struct iio_chan_spec
521 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si);
522 int iio_device_register(struct iio_dev *indio_dev);
523 void iio_device_unregister(struct iio_dev *indio_dev);
524 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev);
525 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev);
526 int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
527 
528 extern struct bus_type iio_bus_type;
529 
530 /**
531  * iio_device_put() - reference counted deallocation of struct device
532  * @indio_dev: 		IIO device structure containing the device
533  **/
534 static inline void iio_device_put(struct iio_dev *indio_dev)
535 {
536 	if (indio_dev)
537 		put_device(&indio_dev->dev);
538 }
539 
540 /**
541  * dev_to_iio_dev() - Get IIO device struct from a device struct
542  * @dev: 		The device embedded in the IIO device
543  *
544  * Note: The device must be a IIO device, otherwise the result is undefined.
545  */
546 static inline struct iio_dev *dev_to_iio_dev(struct device *dev)
547 {
548 	return container_of(dev, struct iio_dev, dev);
549 }
550 
551 /**
552  * iio_device_get() - increment reference count for the device
553  * @indio_dev: 		IIO device structure
554  *
555  * Returns: The passed IIO device
556  **/
557 static inline struct iio_dev *iio_device_get(struct iio_dev *indio_dev)
558 {
559 	return indio_dev ? dev_to_iio_dev(get_device(&indio_dev->dev)) : NULL;
560 }
561 
562 
563 /**
564  * iio_device_set_drvdata() - Set device driver data
565  * @indio_dev: IIO device structure
566  * @data: Driver specific data
567  *
568  * Allows to attach an arbitrary pointer to an IIO device, which can later be
569  * retrieved by iio_device_get_drvdata().
570  */
571 static inline void iio_device_set_drvdata(struct iio_dev *indio_dev, void *data)
572 {
573 	dev_set_drvdata(&indio_dev->dev, data);
574 }
575 
576 /**
577  * iio_device_get_drvdata() - Get device driver data
578  * @indio_dev: IIO device structure
579  *
580  * Returns the data previously set with iio_device_set_drvdata()
581  */
582 static inline void *iio_device_get_drvdata(struct iio_dev *indio_dev)
583 {
584 	return dev_get_drvdata(&indio_dev->dev);
585 }
586 
587 /* Can we make this smaller? */
588 #define IIO_ALIGN L1_CACHE_BYTES
589 struct iio_dev *iio_device_alloc(int sizeof_priv);
590 
591 static inline void *iio_priv(const struct iio_dev *indio_dev)
592 {
593 	return (char *)indio_dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
594 }
595 
596 static inline struct iio_dev *iio_priv_to_dev(void *priv)
597 {
598 	return (struct iio_dev *)((char *)priv -
599 				  ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
600 }
601 
602 void iio_device_free(struct iio_dev *indio_dev);
603 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv);
604 void devm_iio_device_free(struct device *dev, struct iio_dev *indio_dev);
605 struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
606 						const char *fmt, ...);
607 void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig);
608 
609 /**
610  * iio_buffer_enabled() - helper function to test if the buffer is enabled
611  * @indio_dev:		IIO device structure for device
612  **/
613 static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
614 {
615 	return indio_dev->currentmode
616 		& (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE |
617 		   INDIO_BUFFER_SOFTWARE);
618 }
619 
620 /**
621  * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry
622  * @indio_dev:		IIO device structure for device
623  **/
624 #if defined(CONFIG_DEBUG_FS)
625 static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
626 {
627 	return indio_dev->debugfs_dentry;
628 }
629 #else
630 static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
631 {
632 	return NULL;
633 }
634 #endif
635 
636 int iio_str_to_fixpoint(const char *str, int fract_mult, int *integer,
637 	int *fract);
638 
639 /**
640  * IIO_DEGREE_TO_RAD() - Convert degree to rad
641  * @deg: A value in degree
642  *
643  * Returns the given value converted from degree to rad
644  */
645 #define IIO_DEGREE_TO_RAD(deg) (((deg) * 314159ULL + 9000000ULL) / 18000000ULL)
646 
647 /**
648  * IIO_RAD_TO_DEGREE() - Convert rad to degree
649  * @rad: A value in rad
650  *
651  * Returns the given value converted from rad to degree
652  */
653 #define IIO_RAD_TO_DEGREE(rad) \
654 	(((rad) * 18000000ULL + 314159ULL / 2) / 314159ULL)
655 
656 /**
657  * IIO_G_TO_M_S_2() - Convert g to meter / second**2
658  * @g: A value in g
659  *
660  * Returns the given value converted from g to meter / second**2
661  */
662 #define IIO_G_TO_M_S_2(g) ((g) * 980665ULL / 100000ULL)
663 
664 /**
665  * IIO_M_S_2_TO_G() - Convert meter / second**2 to g
666  * @ms2: A value in meter / second**2
667  *
668  * Returns the given value converted from meter / second**2 to g
669  */
670 #define IIO_M_S_2_TO_G(ms2) (((ms2) * 100000ULL + 980665ULL / 2) / 980665ULL)
671 
672 #endif /* _INDUSTRIAL_IO_H_ */
673