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