xref: /linux/include/linux/iio/iio.h (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
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_mount_matrix - iio mounting matrix
152  * @rotation: 3 dimensional space rotation matrix defining sensor alignment with
153  *            main hardware
154  */
155 struct iio_mount_matrix {
156 	const char *rotation[9];
157 };
158 
159 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
160 			      const struct iio_chan_spec *chan, char *buf);
161 int of_iio_read_mount_matrix(const struct device *dev, const char *propname,
162 			     struct iio_mount_matrix *matrix);
163 
164 typedef const struct iio_mount_matrix *
165 	(iio_get_mount_matrix_t)(const struct iio_dev *indio_dev,
166 				 const struct iio_chan_spec *chan);
167 
168 /**
169  * IIO_MOUNT_MATRIX() - Initialize mount matrix extended channel attribute
170  * @_shared:	Whether the attribute is shared between all channels
171  * @_get:	Pointer to an iio_get_mount_matrix_t accessor
172  */
173 #define IIO_MOUNT_MATRIX(_shared, _get) \
174 { \
175 	.name = "mount_matrix", \
176 	.shared = (_shared), \
177 	.read = iio_show_mount_matrix, \
178 	.private = (uintptr_t)(_get), \
179 }
180 
181 /**
182  * struct iio_event_spec - specification for a channel event
183  * @type:		    Type of the event
184  * @dir:		    Direction of the event
185  * @mask_separate:	    Bit mask of enum iio_event_info values. Attributes
186  *			    set in this mask will be registered per channel.
187  * @mask_shared_by_type:    Bit mask of enum iio_event_info values. Attributes
188  *			    set in this mask will be shared by channel type.
189  * @mask_shared_by_dir:	    Bit mask of enum iio_event_info values. Attributes
190  *			    set in this mask will be shared by channel type and
191  *			    direction.
192  * @mask_shared_by_all:	    Bit mask of enum iio_event_info values. Attributes
193  *			    set in this mask will be shared by all channels.
194  */
195 struct iio_event_spec {
196 	enum iio_event_type type;
197 	enum iio_event_direction dir;
198 	unsigned long mask_separate;
199 	unsigned long mask_shared_by_type;
200 	unsigned long mask_shared_by_dir;
201 	unsigned long mask_shared_by_all;
202 };
203 
204 /**
205  * struct iio_chan_spec - specification of a single channel
206  * @type:		What type of measurement is the channel making.
207  * @channel:		What number do we wish to assign the channel.
208  * @channel2:		If there is a second number for a differential
209  *			channel then this is it. If modified is set then the
210  *			value here specifies the modifier.
211  * @address:		Driver specific identifier.
212  * @scan_index:		Monotonic index to give ordering in scans when read
213  *			from a buffer.
214  * @scan_type:		sign:		's' or 'u' to specify signed or unsigned
215  *			realbits:	Number of valid bits of data
216  *			storagebits:	Realbits + padding
217  *			shift:		Shift right by this before masking out
218  *					realbits.
219  *			repeat:		Number of times real/storage bits
220  *					repeats. When the repeat element is
221  *					more than 1, then the type element in
222  *					sysfs will show a repeat value.
223  *					Otherwise, the number of repetitions is
224  *					omitted.
225  *			endianness:	little or big endian
226  * @info_mask_separate: What information is to be exported that is specific to
227  *			this channel.
228  * @info_mask_shared_by_type: What information is to be exported that is shared
229  *			by all channels of the same type.
230  * @info_mask_shared_by_dir: What information is to be exported that is shared
231  *			by all channels of the same direction.
232  * @info_mask_shared_by_all: What information is to be exported that is shared
233  *			by all channels.
234  * @event_spec:		Array of events which should be registered for this
235  *			channel.
236  * @num_event_specs:	Size of the event_spec array.
237  * @ext_info:		Array of extended info attributes for this channel.
238  *			The array is NULL terminated, the last element should
239  *			have its name field set to NULL.
240  * @extend_name:	Allows labeling of channel attributes with an
241  *			informative name. Note this has no effect codes etc,
242  *			unlike modifiers.
243  * @datasheet_name:	A name used in in-kernel mapping of channels. It should
244  *			correspond to the first name that the channel is referred
245  *			to by in the datasheet (e.g. IND), or the nearest
246  *			possible compound name (e.g. IND-INC).
247  * @modified:		Does a modifier apply to this channel. What these are
248  *			depends on the channel type.  Modifier is set in
249  *			channel2. Examples are IIO_MOD_X for axial sensors about
250  *			the 'x' axis.
251  * @indexed:		Specify the channel has a numerical index. If not,
252  *			the channel index number will be suppressed for sysfs
253  *			attributes but not for event codes.
254  * @output:		Channel is output.
255  * @differential:	Channel is differential.
256  */
257 struct iio_chan_spec {
258 	enum iio_chan_type	type;
259 	int			channel;
260 	int			channel2;
261 	unsigned long		address;
262 	int			scan_index;
263 	struct {
264 		char	sign;
265 		u8	realbits;
266 		u8	storagebits;
267 		u8	shift;
268 		u8	repeat;
269 		enum iio_endian endianness;
270 	} scan_type;
271 	long			info_mask_separate;
272 	long			info_mask_shared_by_type;
273 	long			info_mask_shared_by_dir;
274 	long			info_mask_shared_by_all;
275 	const struct iio_event_spec *event_spec;
276 	unsigned int		num_event_specs;
277 	const struct iio_chan_spec_ext_info *ext_info;
278 	const char		*extend_name;
279 	const char		*datasheet_name;
280 	unsigned		modified:1;
281 	unsigned		indexed:1;
282 	unsigned		output:1;
283 	unsigned		differential:1;
284 };
285 
286 
287 /**
288  * iio_channel_has_info() - Checks whether a channel supports a info attribute
289  * @chan: The channel to be queried
290  * @type: Type of the info attribute to be checked
291  *
292  * Returns true if the channels supports reporting values for the given info
293  * attribute type, false otherwise.
294  */
295 static inline bool iio_channel_has_info(const struct iio_chan_spec *chan,
296 	enum iio_chan_info_enum type)
297 {
298 	return (chan->info_mask_separate & BIT(type)) |
299 		(chan->info_mask_shared_by_type & BIT(type)) |
300 		(chan->info_mask_shared_by_dir & BIT(type)) |
301 		(chan->info_mask_shared_by_all & BIT(type));
302 }
303 
304 #define IIO_CHAN_SOFT_TIMESTAMP(_si) {					\
305 	.type = IIO_TIMESTAMP,						\
306 	.channel = -1,							\
307 	.scan_index = _si,						\
308 	.scan_type = {							\
309 		.sign = 's',						\
310 		.realbits = 64,					\
311 		.storagebits = 64,					\
312 		},							\
313 }
314 
315 /**
316  * iio_get_time_ns() - utility function to get a time stamp for events etc
317  **/
318 static inline s64 iio_get_time_ns(void)
319 {
320 	return ktime_get_real_ns();
321 }
322 
323 /* Device operating modes */
324 #define INDIO_DIRECT_MODE		0x01
325 #define INDIO_BUFFER_TRIGGERED		0x02
326 #define INDIO_BUFFER_SOFTWARE		0x04
327 #define INDIO_BUFFER_HARDWARE		0x08
328 #define INDIO_EVENT_TRIGGERED		0x10
329 
330 #define INDIO_ALL_BUFFER_MODES					\
331 	(INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE | INDIO_BUFFER_SOFTWARE)
332 
333 #define INDIO_MAX_RAW_ELEMENTS		4
334 
335 struct iio_trigger; /* forward declaration */
336 struct iio_dev;
337 
338 /**
339  * struct iio_info - constant information about device
340  * @driver_module:	module structure used to ensure correct
341  *			ownership of chrdevs etc
342  * @event_attrs:	event control attributes
343  * @attrs:		general purpose device attributes
344  * @read_raw:		function to request a value from the device.
345  *			mask specifies which value. Note 0 means a reading of
346  *			the channel in question.  Return value will specify the
347  *			type of value returned by the device. val and val2 will
348  *			contain the elements making up the returned value.
349  * @read_raw_multi:	function to return values from the device.
350  *			mask specifies which value. Note 0 means a reading of
351  *			the channel in question.  Return value will specify the
352  *			type of value returned by the device. vals pointer
353  *			contain the elements making up the returned value.
354  *			max_len specifies maximum number of elements
355  *			vals pointer can contain. val_len is used to return
356  *			length of valid elements in vals.
357  * @write_raw:		function to write a value to the device.
358  *			Parameters are the same as for read_raw.
359  * @write_raw_get_fmt:	callback function to query the expected
360  *			format/precision. If not set by the driver, write_raw
361  *			returns IIO_VAL_INT_PLUS_MICRO.
362  * @read_event_config:	find out if the event is enabled.
363  * @write_event_config:	set if the event is enabled.
364  * @read_event_value:	read a configuration value associated with the event.
365  * @write_event_value:	write a configuration value for the event.
366  * @validate_trigger:	function to validate the trigger when the
367  *			current trigger gets changed.
368  * @update_scan_mode:	function to configure device and scan buffer when
369  *			channels have changed
370  * @debugfs_reg_access:	function to read or write register value of device
371  * @of_xlate:		function pointer to obtain channel specifier index.
372  *			When #iio-cells is greater than '0', the driver could
373  *			provide a custom of_xlate function that reads the
374  *			*args* and returns the appropriate index in registered
375  *			IIO channels array.
376  * @hwfifo_set_watermark: function pointer to set the current hardware
377  *			fifo watermark level; see hwfifo_* entries in
378  *			Documentation/ABI/testing/sysfs-bus-iio for details on
379  *			how the hardware fifo operates
380  * @hwfifo_flush_to_buffer: function pointer to flush the samples stored
381  *			in the hardware fifo to the device buffer. The driver
382  *			should not flush more than count samples. The function
383  *			must return the number of samples flushed, 0 if no
384  *			samples were flushed or a negative integer if no samples
385  *			were flushed and there was an error.
386  **/
387 struct iio_info {
388 	struct module			*driver_module;
389 	struct attribute_group		*event_attrs;
390 	const struct attribute_group	*attrs;
391 
392 	int (*read_raw)(struct iio_dev *indio_dev,
393 			struct iio_chan_spec const *chan,
394 			int *val,
395 			int *val2,
396 			long mask);
397 
398 	int (*read_raw_multi)(struct iio_dev *indio_dev,
399 			struct iio_chan_spec const *chan,
400 			int max_len,
401 			int *vals,
402 			int *val_len,
403 			long mask);
404 
405 	int (*write_raw)(struct iio_dev *indio_dev,
406 			 struct iio_chan_spec const *chan,
407 			 int val,
408 			 int val2,
409 			 long mask);
410 
411 	int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
412 			 struct iio_chan_spec const *chan,
413 			 long mask);
414 
415 	int (*read_event_config)(struct iio_dev *indio_dev,
416 				 const struct iio_chan_spec *chan,
417 				 enum iio_event_type type,
418 				 enum iio_event_direction dir);
419 
420 	int (*write_event_config)(struct iio_dev *indio_dev,
421 				  const struct iio_chan_spec *chan,
422 				  enum iio_event_type type,
423 				  enum iio_event_direction dir,
424 				  int state);
425 
426 	int (*read_event_value)(struct iio_dev *indio_dev,
427 				const struct iio_chan_spec *chan,
428 				enum iio_event_type type,
429 				enum iio_event_direction dir,
430 				enum iio_event_info info, int *val, int *val2);
431 
432 	int (*write_event_value)(struct iio_dev *indio_dev,
433 				 const struct iio_chan_spec *chan,
434 				 enum iio_event_type type,
435 				 enum iio_event_direction dir,
436 				 enum iio_event_info info, int val, int val2);
437 
438 	int (*validate_trigger)(struct iio_dev *indio_dev,
439 				struct iio_trigger *trig);
440 	int (*update_scan_mode)(struct iio_dev *indio_dev,
441 				const unsigned long *scan_mask);
442 	int (*debugfs_reg_access)(struct iio_dev *indio_dev,
443 				  unsigned reg, unsigned writeval,
444 				  unsigned *readval);
445 	int (*of_xlate)(struct iio_dev *indio_dev,
446 			const struct of_phandle_args *iiospec);
447 	int (*hwfifo_set_watermark)(struct iio_dev *indio_dev, unsigned val);
448 	int (*hwfifo_flush_to_buffer)(struct iio_dev *indio_dev,
449 				      unsigned count);
450 };
451 
452 /**
453  * struct iio_buffer_setup_ops - buffer setup related callbacks
454  * @preenable:		[DRIVER] function to run prior to marking buffer enabled
455  * @postenable:		[DRIVER] function to run after marking buffer enabled
456  * @predisable:		[DRIVER] function to run prior to marking buffer
457  *			disabled
458  * @postdisable:	[DRIVER] function to run after marking buffer disabled
459  * @validate_scan_mask: [DRIVER] function callback to check whether a given
460  *			scan mask is valid for the device.
461  */
462 struct iio_buffer_setup_ops {
463 	int (*preenable)(struct iio_dev *);
464 	int (*postenable)(struct iio_dev *);
465 	int (*predisable)(struct iio_dev *);
466 	int (*postdisable)(struct iio_dev *);
467 	bool (*validate_scan_mask)(struct iio_dev *indio_dev,
468 				   const unsigned long *scan_mask);
469 };
470 
471 /**
472  * struct iio_dev - industrial I/O device
473  * @id:			[INTERN] used to identify device internally
474  * @modes:		[DRIVER] operating modes supported by device
475  * @currentmode:	[DRIVER] current operating mode
476  * @dev:		[DRIVER] device structure, should be assigned a parent
477  *			and owner
478  * @event_interface:	[INTERN] event chrdevs associated with interrupt lines
479  * @buffer:		[DRIVER] any buffer present
480  * @buffer_list:	[INTERN] list of all buffers currently attached
481  * @scan_bytes:		[INTERN] num bytes captured to be fed to buffer demux
482  * @mlock:		[DRIVER] lock used to prevent simultaneous device state
483  *			changes
484  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
485  * @masklength:		[INTERN] the length of the mask established from
486  *			channels
487  * @active_scan_mask:	[INTERN] union of all scan masks requested by buffers
488  * @scan_timestamp:	[INTERN] set if any buffers have requested timestamp
489  * @scan_index_timestamp:[INTERN] cache of the index to the timestamp
490  * @trig:		[INTERN] current device trigger (buffer modes)
491  * @pollfunc:		[DRIVER] function run on trigger being received
492  * @pollfunc_event:	[DRIVER] function run on events trigger being received
493  * @channels:		[DRIVER] channel specification structure table
494  * @num_channels:	[DRIVER] number of channels specified in @channels.
495  * @channel_attr_list:	[INTERN] keep track of automatically created channel
496  *			attributes
497  * @chan_attr_group:	[INTERN] group for all attrs in base directory
498  * @name:		[DRIVER] name of the device.
499  * @info:		[DRIVER] callbacks and constant info from driver
500  * @info_exist_lock:	[INTERN] lock to prevent use during removal
501  * @setup_ops:		[DRIVER] callbacks to call before and after buffer
502  *			enable/disable
503  * @chrdev:		[INTERN] associated character device
504  * @groups:		[INTERN] attribute groups
505  * @groupcounter:	[INTERN] index of next attribute group
506  * @flags:		[INTERN] file ops related flags including busy flag.
507  * @debugfs_dentry:	[INTERN] device specific debugfs dentry.
508  * @cached_reg_addr:	[INTERN] cached register address for debugfs reads.
509  */
510 struct iio_dev {
511 	int				id;
512 
513 	int				modes;
514 	int				currentmode;
515 	struct device			dev;
516 
517 	struct iio_event_interface	*event_interface;
518 
519 	struct iio_buffer		*buffer;
520 	struct list_head		buffer_list;
521 	int				scan_bytes;
522 	struct mutex			mlock;
523 
524 	const unsigned long		*available_scan_masks;
525 	unsigned			masklength;
526 	const unsigned long		*active_scan_mask;
527 	bool				scan_timestamp;
528 	unsigned			scan_index_timestamp;
529 	struct iio_trigger		*trig;
530 	struct iio_poll_func		*pollfunc;
531 	struct iio_poll_func		*pollfunc_event;
532 
533 	struct iio_chan_spec const	*channels;
534 	int				num_channels;
535 
536 	struct list_head		channel_attr_list;
537 	struct attribute_group		chan_attr_group;
538 	const char			*name;
539 	const struct iio_info		*info;
540 	struct mutex			info_exist_lock;
541 	const struct iio_buffer_setup_ops	*setup_ops;
542 	struct cdev			chrdev;
543 #define IIO_MAX_GROUPS 6
544 	const struct attribute_group	*groups[IIO_MAX_GROUPS + 1];
545 	int				groupcounter;
546 
547 	unsigned long			flags;
548 #if defined(CONFIG_DEBUG_FS)
549 	struct dentry			*debugfs_dentry;
550 	unsigned			cached_reg_addr;
551 #endif
552 };
553 
554 const struct iio_chan_spec
555 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si);
556 int iio_device_register(struct iio_dev *indio_dev);
557 void iio_device_unregister(struct iio_dev *indio_dev);
558 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev);
559 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev);
560 int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
561 int iio_device_claim_direct_mode(struct iio_dev *indio_dev);
562 void iio_device_release_direct_mode(struct iio_dev *indio_dev);
563 
564 extern struct bus_type iio_bus_type;
565 
566 /**
567  * iio_device_put() - reference counted deallocation of struct device
568  * @indio_dev: 		IIO device structure containing the device
569  **/
570 static inline void iio_device_put(struct iio_dev *indio_dev)
571 {
572 	if (indio_dev)
573 		put_device(&indio_dev->dev);
574 }
575 
576 /**
577  * dev_to_iio_dev() - Get IIO device struct from a device struct
578  * @dev: 		The device embedded in the IIO device
579  *
580  * Note: The device must be a IIO device, otherwise the result is undefined.
581  */
582 static inline struct iio_dev *dev_to_iio_dev(struct device *dev)
583 {
584 	return container_of(dev, struct iio_dev, dev);
585 }
586 
587 /**
588  * iio_device_get() - increment reference count for the device
589  * @indio_dev: 		IIO device structure
590  *
591  * Returns: The passed IIO device
592  **/
593 static inline struct iio_dev *iio_device_get(struct iio_dev *indio_dev)
594 {
595 	return indio_dev ? dev_to_iio_dev(get_device(&indio_dev->dev)) : NULL;
596 }
597 
598 
599 /**
600  * iio_device_set_drvdata() - Set device driver data
601  * @indio_dev: IIO device structure
602  * @data: Driver specific data
603  *
604  * Allows to attach an arbitrary pointer to an IIO device, which can later be
605  * retrieved by iio_device_get_drvdata().
606  */
607 static inline void iio_device_set_drvdata(struct iio_dev *indio_dev, void *data)
608 {
609 	dev_set_drvdata(&indio_dev->dev, data);
610 }
611 
612 /**
613  * iio_device_get_drvdata() - Get device driver data
614  * @indio_dev: IIO device structure
615  *
616  * Returns the data previously set with iio_device_set_drvdata()
617  */
618 static inline void *iio_device_get_drvdata(struct iio_dev *indio_dev)
619 {
620 	return dev_get_drvdata(&indio_dev->dev);
621 }
622 
623 /* Can we make this smaller? */
624 #define IIO_ALIGN L1_CACHE_BYTES
625 struct iio_dev *iio_device_alloc(int sizeof_priv);
626 
627 static inline void *iio_priv(const struct iio_dev *indio_dev)
628 {
629 	return (char *)indio_dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
630 }
631 
632 static inline struct iio_dev *iio_priv_to_dev(void *priv)
633 {
634 	return (struct iio_dev *)((char *)priv -
635 				  ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
636 }
637 
638 void iio_device_free(struct iio_dev *indio_dev);
639 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv);
640 void devm_iio_device_free(struct device *dev, struct iio_dev *indio_dev);
641 struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
642 						const char *fmt, ...);
643 void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig);
644 
645 /**
646  * iio_buffer_enabled() - helper function to test if the buffer is enabled
647  * @indio_dev:		IIO device structure for device
648  **/
649 static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
650 {
651 	return indio_dev->currentmode
652 		& (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE |
653 		   INDIO_BUFFER_SOFTWARE);
654 }
655 
656 /**
657  * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry
658  * @indio_dev:		IIO device structure for device
659  **/
660 #if defined(CONFIG_DEBUG_FS)
661 static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
662 {
663 	return indio_dev->debugfs_dentry;
664 }
665 #else
666 static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
667 {
668 	return NULL;
669 }
670 #endif
671 
672 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals);
673 
674 int iio_str_to_fixpoint(const char *str, int fract_mult, int *integer,
675 	int *fract);
676 
677 /**
678  * IIO_DEGREE_TO_RAD() - Convert degree to rad
679  * @deg: A value in degree
680  *
681  * Returns the given value converted from degree to rad
682  */
683 #define IIO_DEGREE_TO_RAD(deg) (((deg) * 314159ULL + 9000000ULL) / 18000000ULL)
684 
685 /**
686  * IIO_RAD_TO_DEGREE() - Convert rad to degree
687  * @rad: A value in rad
688  *
689  * Returns the given value converted from rad to degree
690  */
691 #define IIO_RAD_TO_DEGREE(rad) \
692 	(((rad) * 18000000ULL + 314159ULL / 2) / 314159ULL)
693 
694 /**
695  * IIO_G_TO_M_S_2() - Convert g to meter / second**2
696  * @g: A value in g
697  *
698  * Returns the given value converted from g to meter / second**2
699  */
700 #define IIO_G_TO_M_S_2(g) ((g) * 980665ULL / 100000ULL)
701 
702 /**
703  * IIO_M_S_2_TO_G() - Convert meter / second**2 to g
704  * @ms2: A value in meter / second**2
705  *
706  * Returns the given value converted from meter / second**2 to g
707  */
708 #define IIO_M_S_2_TO_G(ms2) (((ms2) * 100000ULL + 980665ULL / 2) / 980665ULL)
709 
710 #endif /* _INDUSTRIAL_IO_H_ */
711