/drivers/staging/iio/iio.h

  1/* The industrial I/O core
  2 *
  3 * Copyright (c) 2008 Jonathan Cameron
  4 *
  5 * This program is free software; you can redistribute it and/or modify it
  6 * under the terms of the GNU General Public License version 2 as published by
  7 * the Free Software Foundation.
  8 */
  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/irq.h>
 16#include "sysfs.h"
 17#include "chrdev.h"
 18
 19/* IIO TODO LIST */
 20/*
 21 * Provide means of adjusting timer accuracy.
 22 * Currently assumes nano seconds.
 23 */
 24
 25/* Event interface flags */
 26#define IIO_BUSY_BIT_POS 1
 27
 28/* naughty temporary hack to match these against the event version
 29   - need to flattern these together */
 30enum iio_chan_type {
 31	/* real channel types */
 32	IIO_IN,
 33	IIO_CURRENT,
 34	IIO_POWER,
 35	IIO_ACCEL,
 36	IIO_IN_DIFF,
 37	IIO_GYRO,
 38	IIO_MAGN,
 39	IIO_LIGHT,
 40	IIO_INTENSITY,
 41	IIO_PROXIMITY,
 42	IIO_TEMP,
 43	IIO_INCLI,
 44	IIO_ROT,
 45	IIO_ANGL,
 46	IIO_TIMESTAMP,
 47};
 48
 49#define IIO_MOD_X			0
 50#define IIO_MOD_LIGHT_BOTH		0
 51#define IIO_MOD_Y			1
 52#define IIO_MOD_LIGHT_IR		1
 53#define IIO_MOD_Z			2
 54#define IIO_MOD_X_AND_Y			3
 55#define IIO_MOD_X_ANX_Z			4
 56#define IIO_MOD_Y_AND_Z			5
 57#define IIO_MOD_X_AND_Y_AND_Z		6
 58#define IIO_MOD_X_OR_Y			7
 59#define IIO_MOD_X_OR_Z			8
 60#define IIO_MOD_Y_OR_Z			9
 61#define IIO_MOD_X_OR_Y_OR_Z		10
 62
 63/* Could add the raw attributes as well - allowing buffer only devices */
 64enum iio_chan_info_enum {
 65	IIO_CHAN_INFO_SCALE_SHARED,
 66	IIO_CHAN_INFO_SCALE_SEPARATE,
 67	IIO_CHAN_INFO_OFFSET_SHARED,
 68	IIO_CHAN_INFO_OFFSET_SEPARATE,
 69	IIO_CHAN_INFO_CALIBSCALE_SHARED,
 70	IIO_CHAN_INFO_CALIBSCALE_SEPARATE,
 71	IIO_CHAN_INFO_CALIBBIAS_SHARED,
 72	IIO_CHAN_INFO_CALIBBIAS_SEPARATE,
 73	IIO_CHAN_INFO_PEAK_SHARED,
 74	IIO_CHAN_INFO_PEAK_SEPARATE,
 75	IIO_CHAN_INFO_PEAK_SCALE_SHARED,
 76	IIO_CHAN_INFO_PEAK_SCALE_SEPARATE,
 77};
 78
 79/**
 80 * struct iio_chan_spec - specification of a single channel
 81 * @type:		What type of measurement is the channel making.
 82 * @channel:		What number or name do we wish to asign the channel.
 83 * @channel2:		If there is a second number for a differential
 84 *			channel then this is it. If modified is set then the
 85 *			value here specifies the modifier.
 86 * @address:		Driver specific identifier.
 87 * @scan_index:	Monotonic index to give ordering in scans when read
 88 *			from a buffer.
 89 * @scan_type:		Sign:		's' or 'u' to specify signed or unsigned
 90 *			realbits:	Number of valid bits of data
 91 *			storage_bits:	Realbits + padding
 92 *			shift:		Shift right by this before masking out
 93 *					realbits.
 94 * @info_mask:		What information is to be exported about this channel.
 95 *			This includes calibbias, scale etc.
 96 * @event_mask:	What events can this channel produce.
 97 * @extend_name:	Allows labeling of channel attributes with an
 98 *			informative name. Note this has no effect codes etc,
 99 *			unlike modifiers.
100 * @processed_val:	Flag to specify the data access attribute should be
101 *			*_input rather than *_raw.
102 * @modified:		Does a modifier apply to this channel. What these are
103 *			depends on the channel type.  Modifier is set in
104 *			channel2. Examples are IIO_MOD_X for axial sensors about
105 *			the 'x' axis.
106 * @indexed:		Specify the channel has a numerical index. If not,
107 *			the value in channel will be suppressed for attribute
108 *			but not for event codes. Typically set it to 0 when
109 *			the index is false.
110 */
111struct iio_chan_spec {
112	enum iio_chan_type	type;
113	int			channel;
114	int			channel2;
115	unsigned long		address;
116	int			scan_index;
117	struct {
118		char	sign;
119		u8	realbits;
120		u8	storagebits;
121		u8	shift;
122	} scan_type;
123	const long		info_mask;
124	const long		event_mask;
125	const char		*extend_name;
126	unsigned		processed_val:1;
127	unsigned		modified:1;
128	unsigned		indexed:1;
129};
130/* Meant for internal use only */
131void __iio_device_attr_deinit(struct device_attribute *dev_attr);
132int __iio_device_attr_init(struct device_attribute *dev_attr,
133			   const char *postfix,
134			   struct iio_chan_spec const *chan,
135			   ssize_t (*readfunc)(struct device *dev,
136					       struct device_attribute *attr,
137					       char *buf),
138			   ssize_t (*writefunc)(struct device *dev,
139						struct device_attribute *attr,
140						const char *buf,
141						size_t len),
142			   bool generic);
143#define IIO_ST(si, rb, sb, sh)						\
144	{ .sign = si, .realbits = rb, .storagebits = sb, .shift = sh }
145
146#define IIO_CHAN(_type, _mod, _indexed, _proc, _name, _chan, _chan2,	\
147		 _inf_mask, _address, _si, _stype, _event_mask)		\
148	{ .type = _type,						\
149	  .modified = _mod,						\
150	  .indexed = _indexed,						\
151	  .processed_val = _proc,					\
152	  .extend_name = _name,						\
153	  .channel = _chan,						\
154	  .channel2 = _chan2,						\
155	  .info_mask = _inf_mask,					\
156	  .address = _address,						\
157	  .scan_index = _si,						\
158	  .scan_type = _stype,						\
159	  .event_mask = _event_mask }
160
161#define IIO_CHAN_SOFT_TIMESTAMP(_si)					\
162	{ .type = IIO_TIMESTAMP, .channel = -1,				\
163			.scan_index = _si, .scan_type = IIO_ST('s', 64, 64, 0) }
164
165int __iio_add_chan_devattr(const char *postfix,
166			   const char *group,
167			   struct iio_chan_spec const *chan,
168			   ssize_t (*func)(struct device *dev,
169					   struct device_attribute *attr,
170					   char *buf),
171			   ssize_t (*writefunc)(struct device *dev,
172						struct device_attribute *attr,
173						const char *buf,
174						size_t len),
175			   int mask,
176			   bool generic,
177			   struct device *dev,
178			   struct list_head *attr_list);
179/**
180 * iio_get_time_ns() - utility function to get a time stamp for events etc
181 **/
182static inline s64 iio_get_time_ns(void)
183{
184	struct timespec ts;
185	/*
186	 * calls getnstimeofday.
187	 * If hrtimers then up to ns accurate, if not microsecond.
188	 */
189	ktime_get_real_ts(&ts);
190
191	return timespec_to_ns(&ts);
192}
193
194/* Device operating modes */
195#define INDIO_DIRECT_MODE		0x01
196#define INDIO_RING_TRIGGERED		0x02
197#define INDIO_RING_HARDWARE_BUFFER	0x08
198
199#define INDIO_ALL_RING_MODES (INDIO_RING_TRIGGERED | INDIO_RING_HARDWARE_BUFFER)
200
201/* Vast majority of this is set by the industrialio subsystem on a
202 * call to iio_device_register. */
203#define IIO_VAL_INT 1
204#define IIO_VAL_INT_PLUS_MICRO 2
205
206/**
207 * struct iio_info - constant information about device
208 * @driver_module:	module structure used to ensure correct
209 *			ownership of chrdevs etc
210 * @num_interrupt_lines:number of physical interrupt lines from device
211 * @event_attrs:	event control attributes
212 * @attrs:		general purpose device attributes
213 * @read_raw:		function to request a value from the device.
214 *			mask specifies which value. Note 0 means a reading of
215 *			the channel in question.  Return value will specify the
216 *			type of value returned by the device. val and val2 will
217 *			contain the elements making up the returned value.
218 * @write_raw:		function to write a value to the device.
219 *			Parameters are the same as for read_raw.
220 * @read_event_config:	find out if the event is enabled.
221 * @write_event_config:	set if the event is enabled.
222 * @read_event_value:	read a value associated with the event. Meaning
223 *			is event dependant. event_code specifies which event.
224 * @write_event_value:	write the value associate with the event.
225 *			Meaning is event dependent.
226 **/
227struct iio_info {
228	struct module			*driver_module;
229	int				num_interrupt_lines;
230	struct attribute_group		*event_attrs;
231	const struct attribute_group	*attrs;
232
233	int (*read_raw)(struct iio_dev *indio_dev,
234			struct iio_chan_spec const *chan,
235			int *val,
236			int *val2,
237			long mask);
238
239	int (*write_raw)(struct iio_dev *indio_dev,
240			 struct iio_chan_spec const *chan,
241			 int val,
242			 int val2,
243			 long mask);
244
245	int (*read_event_config)(struct iio_dev *indio_dev,
246				 int event_code);
247
248	int (*write_event_config)(struct iio_dev *indio_dev,
249				  int event_code,
250				  int state);
251
252	int (*read_event_value)(struct iio_dev *indio_dev,
253				int event_code,
254				int *val);
255	int (*write_event_value)(struct iio_dev *indio_dev,
256				 int event_code,
257				 int val);
258};
259
260/**
261 * struct iio_dev - industrial I/O device
262 * @id:			[INTERN] used to identify device internally
263 * @dev_data:		[DRIVER] device specific data
264 * @modes:		[DRIVER] operating modes supported by device
265 * @currentmode:	[DRIVER] current operating mode
266 * @dev:		[DRIVER] device structure, should be assigned a parent
267 *			and owner
268 * @event_interfaces:	[INTERN] event chrdevs associated with interrupt lines
269 * @ring:		[DRIVER] any ring buffer present
270 * @mlock:		[INTERN] lock used to prevent simultaneous device state
271 *			changes
272 * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
273 * @trig:		[INTERN] current device trigger (ring buffer modes)
274 * @pollfunc:		[DRIVER] function run on trigger being received
275 * @channels:		[DRIVER] channel specification structure table
276 * @num_channels:	[DRIVER] number of chanels specified in @channels.
277 * @channel_attr_list:	[INTERN] keep track of automatically created channel
278 *			attributes.
279 * @name:		[DRIVER] name of the device.
280 **/
281struct iio_dev {
282	int				id;
283	void				*dev_data;
284	int				modes;
285	int				currentmode;
286	struct device			dev;
287
288	struct iio_event_interface	*event_interfaces;
289
290	struct iio_ring_buffer		*ring;
291	struct mutex			mlock;
292
293	u32				*available_scan_masks;
294	struct iio_trigger		*trig;
295	struct iio_poll_func		*pollfunc;
296
297	struct iio_chan_spec const *channels;
298	int num_channels;
299
300	struct list_head channel_attr_list;
301	const char *name;
302	const struct iio_info *info;
303};
304
305/**
306 * iio_device_register() - register a device with the IIO subsystem
307 * @dev_info:		Device structure filled by the device driver
308 **/
309int iio_device_register(struct iio_dev *dev_info);
310
311/**
312 * iio_device_unregister() - unregister a device from the IIO subsystem
313 * @dev_info:		Device structure representing the device.
314 **/
315void iio_device_unregister(struct iio_dev *dev_info);
316
317/**
318 * iio_push_event() - try to add event to the list for userspace reading
319 * @dev_info:		IIO device structure
320 * @ev_line:		Which event line (hardware interrupt)
321 * @ev_code:		What event
322 * @timestamp:		When the event occurred
323 **/
324int iio_push_event(struct iio_dev *dev_info,
325		  int ev_line,
326		  int ev_code,
327		  s64 timestamp);
328
329/* Used to distinguish between bipolar and unipolar scan elemenents.
330 * Whilst this may seem obvious, we may well want to change the representation
331 * in the future!*/
332#define IIO_SIGNED(a) -(a)
333#define IIO_UNSIGNED(a) (a)
334
335extern dev_t iio_devt;
336extern struct bus_type iio_bus_type;
337
338/**
339 * iio_put_device() - reference counted deallocation of struct device
340 * @dev: the iio_device containing the device
341 **/
342static inline void iio_put_device(struct iio_dev *dev)
343{
344	if (dev)
345		put_device(&dev->dev);
346};
347
348/**
349 * to_iio_dev() - get iio_dev for which we have the struct device
350 * @d: the struct device
351 **/
352static inline struct iio_dev *to_iio_dev(struct device *d)
353{
354	return container_of(d, struct iio_dev, dev);
355};
356
357/**
358 * iio_dev_get_devdata() - helper function gets device specific data
359 * @d: the iio_dev associated with the device
360 **/
361static inline void *iio_dev_get_devdata(struct iio_dev *d)
362{
363	return d->dev_data;
364}
365
366
367/* Can we make this smaller? */
368#define IIO_ALIGN L1_CACHE_BYTES
369/**
370 * iio_allocate_device() - allocate an iio_dev from a driver
371 * @sizeof_priv: Space to allocate for private structure.
372 **/
373struct iio_dev *iio_allocate_device(int sizeof_priv);
374
375static inline void *iio_priv(const struct iio_dev *dev)
376{
377	return (char *)dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
378}
379
380static inline struct iio_dev *iio_priv_to_dev(void *priv)
381{
382	return (struct iio_dev *)((char *)priv -
383				  ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
384}
385
386/**
387 * iio_free_device() - free an iio_dev from a driver
388 * @dev: the iio_dev associated with the device
389 **/
390void iio_free_device(struct iio_dev *dev);
391
392/**
393 * iio_put() - internal module reference count reduce
394 **/
395void iio_put(void);
396
397/**
398 * iio_get() - internal module reference count increase
399 **/
400void iio_get(void);
401
402/**
403 * iio_device_get_chrdev_minor() - get an unused minor number
404 **/
405int iio_device_get_chrdev_minor(void);
406void iio_device_free_chrdev_minor(int val);
407
408/**
409 * iio_ring_enabled() - helper function to test if any form of ring is enabled
410 * @dev_info:		IIO device info structure for device
411 **/
412static inline bool iio_ring_enabled(struct iio_dev *dev_info)
413{
414	return dev_info->currentmode
415		& (INDIO_RING_TRIGGERED
416		   | INDIO_RING_HARDWARE_BUFFER);
417};
418
419struct ida;
420
421int iio_get_new_ida_val(struct ida *this_ida);
422void iio_free_ida_val(struct ida *this_ida, int id);
423#endif /* _INDUSTRIAL_IO_H_ */