xref: /linux/include/linux/iio/iio.h (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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_SAMP_FREQ,
36 	IIO_CHAN_INFO_FREQUENCY,
37 	IIO_CHAN_INFO_PHASE,
38 	IIO_CHAN_INFO_HARDWAREGAIN,
39 	IIO_CHAN_INFO_HYSTERESIS,
40 	IIO_CHAN_INFO_INT_TIME,
41 	IIO_CHAN_INFO_ENABLE,
42 	IIO_CHAN_INFO_CALIBHEIGHT,
43 	IIO_CHAN_INFO_CALIBWEIGHT,
44 	IIO_CHAN_INFO_DEBOUNCE_COUNT,
45 	IIO_CHAN_INFO_DEBOUNCE_TIME,
46 };
47 
48 enum iio_shared_by {
49 	IIO_SEPARATE,
50 	IIO_SHARED_BY_TYPE,
51 	IIO_SHARED_BY_DIR,
52 	IIO_SHARED_BY_ALL
53 };
54 
55 enum iio_endian {
56 	IIO_CPU,
57 	IIO_BE,
58 	IIO_LE,
59 };
60 
61 struct iio_chan_spec;
62 struct iio_dev;
63 
64 /**
65  * struct iio_chan_spec_ext_info - Extended channel info attribute
66  * @name:	Info attribute name
67  * @shared:	Whether this attribute is shared between all channels.
68  * @read:	Read callback for this info attribute, may be NULL.
69  * @write:	Write callback for this info attribute, may be NULL.
70  * @private:	Data private to the driver.
71  */
72 struct iio_chan_spec_ext_info {
73 	const char *name;
74 	enum iio_shared_by shared;
75 	ssize_t (*read)(struct iio_dev *, uintptr_t private,
76 			struct iio_chan_spec const *, char *buf);
77 	ssize_t (*write)(struct iio_dev *, uintptr_t private,
78 			 struct iio_chan_spec const *, const char *buf,
79 			 size_t len);
80 	uintptr_t private;
81 };
82 
83 /**
84  * struct iio_enum - Enum channel info attribute
85  * @items:	An array of strings.
86  * @num_items:	Length of the item array.
87  * @set:	Set callback function, may be NULL.
88  * @get:	Get callback function, may be NULL.
89  *
90  * The iio_enum struct can be used to implement enum style channel attributes.
91  * Enum style attributes are those which have a set of strings which map to
92  * unsigned integer values. The IIO enum helper code takes care of mapping
93  * between value and string as well as generating a "_available" file which
94  * contains a list of all available items. The set callback will be called when
95  * the attribute is updated. The last parameter is the index to the newly
96  * activated item. The get callback will be used to query the currently active
97  * item and is supposed to return the index for it.
98  */
99 struct iio_enum {
100 	const char * const *items;
101 	unsigned int num_items;
102 	int (*set)(struct iio_dev *, const struct iio_chan_spec *, unsigned int);
103 	int (*get)(struct iio_dev *, const struct iio_chan_spec *);
104 };
105 
106 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
107 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
108 ssize_t iio_enum_read(struct iio_dev *indio_dev,
109 	uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
110 ssize_t iio_enum_write(struct iio_dev *indio_dev,
111 	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
112 	size_t len);
113 
114 /**
115  * IIO_ENUM() - Initialize enum extended channel attribute
116  * @_name:	Attribute name
117  * @_shared:	Whether the attribute is shared between all channels
118  * @_e:		Pointer to an iio_enum struct
119  *
120  * This should usually be used together with IIO_ENUM_AVAILABLE()
121  */
122 #define IIO_ENUM(_name, _shared, _e) \
123 { \
124 	.name = (_name), \
125 	.shared = (_shared), \
126 	.read = iio_enum_read, \
127 	.write = iio_enum_write, \
128 	.private = (uintptr_t)(_e), \
129 }
130 
131 /**
132  * IIO_ENUM_AVAILABLE() - Initialize enum available extended channel attribute
133  * @_name:	Attribute name ("_available" will be appended to the name)
134  * @_e:		Pointer to an iio_enum struct
135  *
136  * Creates a read only attribute which lists all the available enum items in a
137  * space separated list. This should usually be used together with IIO_ENUM()
138  */
139 #define IIO_ENUM_AVAILABLE(_name, _e) \
140 { \
141 	.name = (_name "_available"), \
142 	.shared = IIO_SHARED_BY_TYPE, \
143 	.read = iio_enum_available_read, \
144 	.private = (uintptr_t)(_e), \
145 }
146 
147 /**
148  * struct iio_event_spec - specification for a channel event
149  * @type:		    Type of the event
150  * @dir:		    Direction of the event
151  * @mask_separate:	    Bit mask of enum iio_event_info values. Attributes
152  *			    set in this mask will be registered per channel.
153  * @mask_shared_by_type:    Bit mask of enum iio_event_info values. Attributes
154  *			    set in this mask will be shared by channel type.
155  * @mask_shared_by_dir:	    Bit mask of enum iio_event_info values. Attributes
156  *			    set in this mask will be shared by channel type and
157  *			    direction.
158  * @mask_shared_by_all:	    Bit mask of enum iio_event_info values. Attributes
159  *			    set in this mask will be shared by all channels.
160  */
161 struct iio_event_spec {
162 	enum iio_event_type type;
163 	enum iio_event_direction dir;
164 	unsigned long mask_separate;
165 	unsigned long mask_shared_by_type;
166 	unsigned long mask_shared_by_dir;
167 	unsigned long mask_shared_by_all;
168 };
169 
170 /**
171  * struct iio_chan_spec - specification of a single channel
172  * @type:		What type of measurement is the channel making.
173  * @channel:		What number do we wish to assign the channel.
174  * @channel2:		If there is a second number for a differential
175  *			channel then this is it. If modified is set then the
176  *			value here specifies the modifier.
177  * @address:		Driver specific identifier.
178  * @scan_index:		Monotonic index to give ordering in scans when read
179  *			from a buffer.
180  * @scan_type:		Sign:		's' or 'u' to specify signed or unsigned
181  *			realbits:	Number of valid bits of data
182  *			storage_bits:	Realbits + padding
183  *			shift:		Shift right by this before masking out
184  *					realbits.
185  *			endianness:	little or big endian
186  *			repeat:		Number of times real/storage bits
187  *					repeats. When the repeat element is
188  *					more than 1, then the type element in
189  *					sysfs will show a repeat value.
190  *					Otherwise, the number of repetitions is
191  *					omitted.
192  * @info_mask_separate: What information is to be exported that is specific to
193  *			this channel.
194  * @info_mask_shared_by_type: What information is to be exported that is shared
195  *			by all channels of the same type.
196  * @info_mask_shared_by_dir: What information is to be exported that is shared
197  *			by all channels of the same direction.
198  * @info_mask_shared_by_all: What information is to be exported that is shared
199  *			by all channels.
200  * @event_spec:		Array of events which should be registered for this
201  *			channel.
202  * @num_event_specs:	Size of the event_spec array.
203  * @ext_info:		Array of extended info attributes for this channel.
204  *			The array is NULL terminated, the last element should
205  *			have its name field set to NULL.
206  * @extend_name:	Allows labeling of channel attributes with an
207  *			informative name. Note this has no effect codes etc,
208  *			unlike modifiers.
209  * @datasheet_name:	A name used in in-kernel mapping of channels. It should
210  *			correspond to the first name that the channel is referred
211  *			to by in the datasheet (e.g. IND), or the nearest
212  *			possible compound name (e.g. IND-INC).
213  * @modified:		Does a modifier apply to this channel. What these are
214  *			depends on the channel type.  Modifier is set in
215  *			channel2. Examples are IIO_MOD_X for axial sensors about
216  *			the 'x' axis.
217  * @indexed:		Specify the channel has a numerical index. If not,
218  *			the channel index number will be suppressed for sysfs
219  *			attributes but not for event codes.
220  * @output:		Channel is output.
221  * @differential:	Channel is differential.
222  */
223 struct iio_chan_spec {
224 	enum iio_chan_type	type;
225 	int			channel;
226 	int			channel2;
227 	unsigned long		address;
228 	int			scan_index;
229 	struct {
230 		char	sign;
231 		u8	realbits;
232 		u8	storagebits;
233 		u8	shift;
234 		u8	repeat;
235 		enum iio_endian endianness;
236 	} scan_type;
237 	long			info_mask_separate;
238 	long			info_mask_shared_by_type;
239 	long			info_mask_shared_by_dir;
240 	long			info_mask_shared_by_all;
241 	const struct iio_event_spec *event_spec;
242 	unsigned int		num_event_specs;
243 	const struct iio_chan_spec_ext_info *ext_info;
244 	const char		*extend_name;
245 	const char		*datasheet_name;
246 	unsigned		modified:1;
247 	unsigned		indexed:1;
248 	unsigned		output:1;
249 	unsigned		differential:1;
250 };
251 
252 
253 /**
254  * iio_channel_has_info() - Checks whether a channel supports a info attribute
255  * @chan: The channel to be queried
256  * @type: Type of the info attribute to be checked
257  *
258  * Returns true if the channels supports reporting values for the given info
259  * attribute type, false otherwise.
260  */
261 static inline bool iio_channel_has_info(const struct iio_chan_spec *chan,
262 	enum iio_chan_info_enum type)
263 {
264 	return (chan->info_mask_separate & BIT(type)) |
265 		(chan->info_mask_shared_by_type & BIT(type)) |
266 		(chan->info_mask_shared_by_dir & BIT(type)) |
267 		(chan->info_mask_shared_by_all & BIT(type));
268 }
269 
270 #define IIO_CHAN_SOFT_TIMESTAMP(_si) {					\
271 	.type = IIO_TIMESTAMP,						\
272 	.channel = -1,							\
273 	.scan_index = _si,						\
274 	.scan_type = {							\
275 		.sign = 's',						\
276 		.realbits = 64,					\
277 		.storagebits = 64,					\
278 		},							\
279 }
280 
281 /**
282  * iio_get_time_ns() - utility function to get a time stamp for events etc
283  **/
284 static inline s64 iio_get_time_ns(void)
285 {
286 	return ktime_get_real_ns();
287 }
288 
289 /* Device operating modes */
290 #define INDIO_DIRECT_MODE		0x01
291 #define INDIO_BUFFER_TRIGGERED		0x02
292 #define INDIO_BUFFER_SOFTWARE		0x04
293 #define INDIO_BUFFER_HARDWARE		0x08
294 
295 #define INDIO_ALL_BUFFER_MODES					\
296 	(INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE | INDIO_BUFFER_SOFTWARE)
297 
298 #define INDIO_MAX_RAW_ELEMENTS		4
299 
300 struct iio_trigger; /* forward declaration */
301 struct iio_dev;
302 
303 /**
304  * struct iio_info - constant information about device
305  * @driver_module:	module structure used to ensure correct
306  *			ownership of chrdevs etc
307  * @event_attrs:	event control attributes
308  * @attrs:		general purpose device attributes
309  * @read_raw:		function to request a value from the device.
310  *			mask specifies which value. Note 0 means a reading of
311  *			the channel in question.  Return value will specify the
312  *			type of value returned by the device. val and val2 will
313  *			contain the elements making up the returned value.
314  * @read_raw_multi:	function to return values from the device.
315  *			mask specifies which value. Note 0 means a reading of
316  *			the channel in question.  Return value will specify the
317  *			type of value returned by the device. vals pointer
318  *			contain the elements making up the returned value.
319  *			max_len specifies maximum number of elements
320  *			vals pointer can contain. val_len is used to return
321  *			length of valid elements in vals.
322  * @write_raw:		function to write a value to the device.
323  *			Parameters are the same as for read_raw.
324  * @write_raw_get_fmt:	callback function to query the expected
325  *			format/precision. If not set by the driver, write_raw
326  *			returns IIO_VAL_INT_PLUS_MICRO.
327  * @read_event_config:	find out if the event is enabled.
328  * @write_event_config:	set if the event is enabled.
329  * @read_event_value:	read a configuration value associated with the event.
330  * @write_event_value:	write a configuration value for the event.
331  * @validate_trigger:	function to validate the trigger when the
332  *			current trigger gets changed.
333  * @update_scan_mode:	function to configure device and scan buffer when
334  *			channels have changed
335  * @debugfs_reg_access:	function to read or write register value of device
336  * @of_xlate:		function pointer to obtain channel specifier index.
337  *			When #iio-cells is greater than '0', the driver could
338  *			provide a custom of_xlate function that reads the
339  *			*args* and returns the appropriate index in registered
340  *			IIO channels array.
341  * @hwfifo_set_watermark: function pointer to set the current hardware
342  *			fifo watermark level; see hwfifo_* entries in
343  *			Documentation/ABI/testing/sysfs-bus-iio for details on
344  *			how the hardware fifo operates
345  * @hwfifo_flush_to_buffer: function pointer to flush the samples stored
346  *			in the hardware fifo to the device buffer. The driver
347  *			should not flush more than count samples. The function
348  *			must return the number of samples flushed, 0 if no
349  *			samples were flushed or a negative integer if no samples
350  *			were flushed and there was an error.
351  **/
352 struct iio_info {
353 	struct module			*driver_module;
354 	struct attribute_group		*event_attrs;
355 	const struct attribute_group	*attrs;
356 
357 	int (*read_raw)(struct iio_dev *indio_dev,
358 			struct iio_chan_spec const *chan,
359 			int *val,
360 			int *val2,
361 			long mask);
362 
363 	int (*read_raw_multi)(struct iio_dev *indio_dev,
364 			struct iio_chan_spec const *chan,
365 			int max_len,
366 			int *vals,
367 			int *val_len,
368 			long mask);
369 
370 	int (*write_raw)(struct iio_dev *indio_dev,
371 			 struct iio_chan_spec const *chan,
372 			 int val,
373 			 int val2,
374 			 long mask);
375 
376 	int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
377 			 struct iio_chan_spec const *chan,
378 			 long mask);
379 
380 	int (*read_event_config)(struct iio_dev *indio_dev,
381 				 const struct iio_chan_spec *chan,
382 				 enum iio_event_type type,
383 				 enum iio_event_direction dir);
384 
385 	int (*write_event_config)(struct iio_dev *indio_dev,
386 				  const struct iio_chan_spec *chan,
387 				  enum iio_event_type type,
388 				  enum iio_event_direction dir,
389 				  int state);
390 
391 	int (*read_event_value)(struct iio_dev *indio_dev,
392 				const struct iio_chan_spec *chan,
393 				enum iio_event_type type,
394 				enum iio_event_direction dir,
395 				enum iio_event_info info, int *val, int *val2);
396 
397 	int (*write_event_value)(struct iio_dev *indio_dev,
398 				 const struct iio_chan_spec *chan,
399 				 enum iio_event_type type,
400 				 enum iio_event_direction dir,
401 				 enum iio_event_info info, int val, int val2);
402 
403 	int (*validate_trigger)(struct iio_dev *indio_dev,
404 				struct iio_trigger *trig);
405 	int (*update_scan_mode)(struct iio_dev *indio_dev,
406 				const unsigned long *scan_mask);
407 	int (*debugfs_reg_access)(struct iio_dev *indio_dev,
408 				  unsigned reg, unsigned writeval,
409 				  unsigned *readval);
410 	int (*of_xlate)(struct iio_dev *indio_dev,
411 			const struct of_phandle_args *iiospec);
412 	int (*hwfifo_set_watermark)(struct iio_dev *indio_dev, unsigned val);
413 	int (*hwfifo_flush_to_buffer)(struct iio_dev *indio_dev,
414 				      unsigned count);
415 };
416 
417 /**
418  * struct iio_buffer_setup_ops - buffer setup related callbacks
419  * @preenable:		[DRIVER] function to run prior to marking buffer enabled
420  * @postenable:		[DRIVER] function to run after marking buffer enabled
421  * @predisable:		[DRIVER] function to run prior to marking buffer
422  *			disabled
423  * @postdisable:	[DRIVER] function to run after marking buffer disabled
424  * @validate_scan_mask: [DRIVER] function callback to check whether a given
425  *			scan mask is valid for the device.
426  */
427 struct iio_buffer_setup_ops {
428 	int (*preenable)(struct iio_dev *);
429 	int (*postenable)(struct iio_dev *);
430 	int (*predisable)(struct iio_dev *);
431 	int (*postdisable)(struct iio_dev *);
432 	bool (*validate_scan_mask)(struct iio_dev *indio_dev,
433 				   const unsigned long *scan_mask);
434 };
435 
436 /**
437  * struct iio_dev - industrial I/O device
438  * @id:			[INTERN] used to identify device internally
439  * @modes:		[DRIVER] operating modes supported by device
440  * @currentmode:	[DRIVER] current operating mode
441  * @dev:		[DRIVER] device structure, should be assigned a parent
442  *			and owner
443  * @event_interface:	[INTERN] event chrdevs associated with interrupt lines
444  * @buffer:		[DRIVER] any buffer present
445  * @buffer_list:	[INTERN] list of all buffers currently attached
446  * @scan_bytes:		[INTERN] num bytes captured to be fed to buffer demux
447  * @mlock:		[INTERN] lock used to prevent simultaneous device state
448  *			changes
449  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
450  * @masklength:		[INTERN] the length of the mask established from
451  *			channels
452  * @active_scan_mask:	[INTERN] union of all scan masks requested by buffers
453  * @scan_timestamp:	[INTERN] set if any buffers have requested timestamp
454  * @scan_index_timestamp:[INTERN] cache of the index to the timestamp
455  * @trig:		[INTERN] current device trigger (buffer modes)
456  * @pollfunc:		[DRIVER] function run on trigger being received
457  * @channels:		[DRIVER] channel specification structure table
458  * @num_channels:	[DRIVER] number of channels specified in @channels.
459  * @channel_attr_list:	[INTERN] keep track of automatically created channel
460  *			attributes
461  * @chan_attr_group:	[INTERN] group for all attrs in base directory
462  * @name:		[DRIVER] name of the device.
463  * @info:		[DRIVER] callbacks and constant info from driver
464  * @info_exist_lock:	[INTERN] lock to prevent use during removal
465  * @setup_ops:		[DRIVER] callbacks to call before and after buffer
466  *			enable/disable
467  * @chrdev:		[INTERN] associated character device
468  * @groups:		[INTERN] attribute groups
469  * @groupcounter:	[INTERN] index of next attribute group
470  * @flags:		[INTERN] file ops related flags including busy flag.
471  * @debugfs_dentry:	[INTERN] device specific debugfs dentry.
472  * @cached_reg_addr:	[INTERN] cached register address for debugfs reads.
473  */
474 struct iio_dev {
475 	int				id;
476 
477 	int				modes;
478 	int				currentmode;
479 	struct device			dev;
480 
481 	struct iio_event_interface	*event_interface;
482 
483 	struct iio_buffer		*buffer;
484 	struct list_head		buffer_list;
485 	int				scan_bytes;
486 	struct mutex			mlock;
487 
488 	const unsigned long		*available_scan_masks;
489 	unsigned			masklength;
490 	const unsigned long		*active_scan_mask;
491 	bool				scan_timestamp;
492 	unsigned			scan_index_timestamp;
493 	struct iio_trigger		*trig;
494 	struct iio_poll_func		*pollfunc;
495 
496 	struct iio_chan_spec const	*channels;
497 	int				num_channels;
498 
499 	struct list_head		channel_attr_list;
500 	struct attribute_group		chan_attr_group;
501 	const char			*name;
502 	const struct iio_info		*info;
503 	struct mutex			info_exist_lock;
504 	const struct iio_buffer_setup_ops	*setup_ops;
505 	struct cdev			chrdev;
506 #define IIO_MAX_GROUPS 6
507 	const struct attribute_group	*groups[IIO_MAX_GROUPS + 1];
508 	int				groupcounter;
509 
510 	unsigned long			flags;
511 #if defined(CONFIG_DEBUG_FS)
512 	struct dentry			*debugfs_dentry;
513 	unsigned			cached_reg_addr;
514 #endif
515 };
516 
517 const struct iio_chan_spec
518 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si);
519 int iio_device_register(struct iio_dev *indio_dev);
520 void iio_device_unregister(struct iio_dev *indio_dev);
521 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev);
522 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev);
523 int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
524 
525 extern struct bus_type iio_bus_type;
526 
527 /**
528  * iio_device_put() - reference counted deallocation of struct device
529  * @indio_dev: 		IIO device structure containing the device
530  **/
531 static inline void iio_device_put(struct iio_dev *indio_dev)
532 {
533 	if (indio_dev)
534 		put_device(&indio_dev->dev);
535 }
536 
537 /**
538  * dev_to_iio_dev() - Get IIO device struct from a device struct
539  * @dev: 		The device embedded in the IIO device
540  *
541  * Note: The device must be a IIO device, otherwise the result is undefined.
542  */
543 static inline struct iio_dev *dev_to_iio_dev(struct device *dev)
544 {
545 	return container_of(dev, struct iio_dev, dev);
546 }
547 
548 /**
549  * iio_device_get() - increment reference count for the device
550  * @indio_dev: 		IIO device structure
551  *
552  * Returns: The passed IIO device
553  **/
554 static inline struct iio_dev *iio_device_get(struct iio_dev *indio_dev)
555 {
556 	return indio_dev ? dev_to_iio_dev(get_device(&indio_dev->dev)) : NULL;
557 }
558 
559 
560 /**
561  * iio_device_set_drvdata() - Set device driver data
562  * @indio_dev: IIO device structure
563  * @data: Driver specific data
564  *
565  * Allows to attach an arbitrary pointer to an IIO device, which can later be
566  * retrieved by iio_device_get_drvdata().
567  */
568 static inline void iio_device_set_drvdata(struct iio_dev *indio_dev, void *data)
569 {
570 	dev_set_drvdata(&indio_dev->dev, data);
571 }
572 
573 /**
574  * iio_device_get_drvdata() - Get device driver data
575  * @indio_dev: IIO device structure
576  *
577  * Returns the data previously set with iio_device_set_drvdata()
578  */
579 static inline void *iio_device_get_drvdata(struct iio_dev *indio_dev)
580 {
581 	return dev_get_drvdata(&indio_dev->dev);
582 }
583 
584 /* Can we make this smaller? */
585 #define IIO_ALIGN L1_CACHE_BYTES
586 struct iio_dev *iio_device_alloc(int sizeof_priv);
587 
588 static inline void *iio_priv(const struct iio_dev *indio_dev)
589 {
590 	return (char *)indio_dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
591 }
592 
593 static inline struct iio_dev *iio_priv_to_dev(void *priv)
594 {
595 	return (struct iio_dev *)((char *)priv -
596 				  ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
597 }
598 
599 void iio_device_free(struct iio_dev *indio_dev);
600 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv);
601 void devm_iio_device_free(struct device *dev, struct iio_dev *indio_dev);
602 struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
603 						const char *fmt, ...);
604 void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig);
605 
606 /**
607  * iio_buffer_enabled() - helper function to test if the buffer is enabled
608  * @indio_dev:		IIO device structure for device
609  **/
610 static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
611 {
612 	return indio_dev->currentmode
613 		& (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE |
614 		   INDIO_BUFFER_SOFTWARE);
615 }
616 
617 /**
618  * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry
619  * @indio_dev:		IIO device structure for device
620  **/
621 #if defined(CONFIG_DEBUG_FS)
622 static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
623 {
624 	return indio_dev->debugfs_dentry;
625 }
626 #else
627 static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
628 {
629 	return NULL;
630 }
631 #endif
632 
633 int iio_str_to_fixpoint(const char *str, int fract_mult, int *integer,
634 	int *fract);
635 
636 /**
637  * IIO_DEGREE_TO_RAD() - Convert degree to rad
638  * @deg: A value in degree
639  *
640  * Returns the given value converted from degree to rad
641  */
642 #define IIO_DEGREE_TO_RAD(deg) (((deg) * 314159ULL + 9000000ULL) / 18000000ULL)
643 
644 /**
645  * IIO_G_TO_M_S_2() - Convert g to meter / second**2
646  * @g: A value in g
647  *
648  * Returns the given value converted from g to meter / second**2
649  */
650 #define IIO_G_TO_M_S_2(g) ((g) * 980665ULL / 100000ULL)
651 
652 #endif /* _INDUSTRIAL_IO_H_ */
653