staging:iio:buffer: pull computation of scan length into a utility function.
[linux-2.6-block.git] / drivers / staging / iio / iio.h
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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 */
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10#ifndef _INDUSTRIAL_IO_H_
11#define _INDUSTRIAL_IO_H_
12
13#include <linux/device.h>
14#include <linux/cdev.h>
af5046af 15#include "types.h"
847ec80b 16/* IIO TODO LIST */
751a3700 17/*
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18 * Provide means of adjusting timer accuracy.
19 * Currently assumes nano seconds.
20 */
21
1d892719 22enum iio_chan_info_enum {
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23 IIO_CHAN_INFO_RAW = 0,
24 IIO_CHAN_INFO_PROCESSED,
25 IIO_CHAN_INFO_SCALE,
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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,
df94aba8 33 IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY,
ce85a1cb 34 IIO_CHAN_INFO_SAMP_FREQ,
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35};
36
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37#define IIO_CHAN_INFO_SHARED_BIT(type) BIT(type*2)
38#define IIO_CHAN_INFO_SEPARATE_BIT(type) BIT(type*2 + 1)
39
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40#define IIO_CHAN_INFO_RAW_SEPARATE_BIT \
41 IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_RAW)
42#define IIO_CHAN_INFO_PROCESSED_SEPARATE_BIT \
43 IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_PROCESSED)
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44#define IIO_CHAN_INFO_SCALE_SEPARATE_BIT \
45 IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_SCALE)
46#define IIO_CHAN_INFO_SCALE_SHARED_BIT \
47 IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_SCALE)
48#define IIO_CHAN_INFO_OFFSET_SEPARATE_BIT \
49 IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_OFFSET)
50#define IIO_CHAN_INFO_OFFSET_SHARED_BIT \
51 IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_OFFSET)
52#define IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT \
53 IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_CALIBSCALE)
54#define IIO_CHAN_INFO_CALIBSCALE_SHARED_BIT \
55 IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_CALIBSCALE)
56#define IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT \
57 IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_CALIBBIAS)
58#define IIO_CHAN_INFO_CALIBBIAS_SHARED_BIT \
59 IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_CALIBBIAS)
60#define IIO_CHAN_INFO_PEAK_SEPARATE_BIT \
61 IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_PEAK)
62#define IIO_CHAN_INFO_PEAK_SHARED_BIT \
63 IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_PEAK)
64#define IIO_CHAN_INFO_PEAKSCALE_SEPARATE_BIT \
65 IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_PEAKSCALE)
66#define IIO_CHAN_INFO_PEAKSCALE_SHARED_BIT \
67 IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_PEAKSCALE)
68#define IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SEPARATE_BIT \
69 IIO_CHAN_INFO_SEPARATE_BIT( \
70 IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW)
71#define IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW_SHARED_BIT \
72 IIO_CHAN_INFO_SHARED_BIT( \
73 IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW)
74#define IIO_CHAN_INFO_AVERAGE_RAW_SEPARATE_BIT \
75 IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_AVERAGE_RAW)
76#define IIO_CHAN_INFO_AVERAGE_RAW_SHARED_BIT \
77 IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_AVERAGE_RAW)
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78#define IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY_SHARED_BIT \
79 IIO_CHAN_INFO_SHARED_BIT( \
80 IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY)
81#define IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY_SEPARATE_BIT \
82 IIO_CHAN_INFO_SEPARATE_BIT( \
83 IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY)
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84#define IIO_CHAN_INFO_SAMP_FREQ_SEPARATE_BIT \
85 IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_SAMP_FREQ)
86#define IIO_CHAN_INFO_SAMP_FREQ_SHARED_BIT \
87 IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_SAMP_FREQ)
c8a9f805 88
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89enum iio_endian {
90 IIO_CPU,
91 IIO_BE,
92 IIO_LE,
93};
94
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95struct iio_chan_spec;
96struct iio_dev;
97
98/**
99 * struct iio_chan_spec_ext_info - Extended channel info attribute
100 * @name: Info attribute name
101 * @shared: Whether this attribute is shared between all channels.
102 * @read: Read callback for this info attribute, may be NULL.
103 * @write: Write callback for this info attribute, may be NULL.
104 */
105struct iio_chan_spec_ext_info {
106 const char *name;
107 bool shared;
108 ssize_t (*read)(struct iio_dev *, struct iio_chan_spec const *,
109 char *buf);
110 ssize_t (*write)(struct iio_dev *, struct iio_chan_spec const *,
111 const char *buf, size_t len);
112};
113
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114/**
115 * struct iio_chan_spec - specification of a single channel
116 * @type: What type of measurement is the channel making.
4abf6f8b 117 * @channel: What number or name do we wish to assign the channel.
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118 * @channel2: If there is a second number for a differential
119 * channel then this is it. If modified is set then the
120 * value here specifies the modifier.
121 * @address: Driver specific identifier.
122 * @scan_index: Monotonic index to give ordering in scans when read
123 * from a buffer.
124 * @scan_type: Sign: 's' or 'u' to specify signed or unsigned
125 * realbits: Number of valid bits of data
126 * storage_bits: Realbits + padding
127 * shift: Shift right by this before masking out
128 * realbits.
8310b86c 129 * endianness: little or big endian
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130 * @info_mask: What information is to be exported about this channel.
131 * This includes calibbias, scale etc.
132 * @event_mask: What events can this channel produce.
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133 * @ext_info: Array of extended info attributes for this channel.
134 * The array is NULL terminated, the last element should
135 * have it's name field set to NULL.
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136 * @extend_name: Allows labeling of channel attributes with an
137 * informative name. Note this has no effect codes etc,
138 * unlike modifiers.
6c63dded 139 * @datasheet_name: A name used in in kernel mapping of channels. It should
4abf6f8b 140 * correspond to the first name that the channel is referred
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141 * to by in the datasheet (e.g. IND), or the nearest
142 * possible compound name (e.g. IND-INC).
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143 * @modified: Does a modifier apply to this channel. What these are
144 * depends on the channel type. Modifier is set in
145 * channel2. Examples are IIO_MOD_X for axial sensors about
146 * the 'x' axis.
147 * @indexed: Specify the channel has a numerical index. If not,
148 * the value in channel will be suppressed for attribute
149 * but not for event codes. Typically set it to 0 when
150 * the index is false.
ade7ef7b 151 * @differential: Channel is differential.
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152 */
153struct iio_chan_spec {
154 enum iio_chan_type type;
155 int channel;
156 int channel2;
157 unsigned long address;
158 int scan_index;
159 struct {
160 char sign;
161 u8 realbits;
162 u8 storagebits;
163 u8 shift;
8310b86c 164 enum iio_endian endianness;
1d892719 165 } scan_type;
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166 long info_mask;
167 long event_mask;
5f420b42 168 const struct iio_chan_spec_ext_info *ext_info;
344692b1 169 const char *extend_name;
6c63dded 170 const char *datasheet_name;
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171 unsigned modified:1;
172 unsigned indexed:1;
c6fc8062 173 unsigned output:1;
ade7ef7b 174 unsigned differential:1;
1d892719 175};
df9c1c42 176
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177#define IIO_ST(si, rb, sb, sh) \
178 { .sign = si, .realbits = rb, .storagebits = sb, .shift = sh }
179
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180#define IIO_CHAN_SOFT_TIMESTAMP(_si) \
181 { .type = IIO_TIMESTAMP, .channel = -1, \
182 .scan_index = _si, .scan_type = IIO_ST('s', 64, 64, 0) }
183
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184/**
185 * iio_get_time_ns() - utility function to get a time stamp for events etc
186 **/
187static inline s64 iio_get_time_ns(void)
188{
189 struct timespec ts;
190 /*
191 * calls getnstimeofday.
192 * If hrtimers then up to ns accurate, if not microsecond.
193 */
194 ktime_get_real_ts(&ts);
195
196 return timespec_to_ns(&ts);
197}
198
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199/* Device operating modes */
200#define INDIO_DIRECT_MODE 0x01
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201#define INDIO_BUFFER_TRIGGERED 0x02
202#define INDIO_BUFFER_HARDWARE 0x08
847ec80b 203
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204#define INDIO_ALL_BUFFER_MODES \
205 (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE)
847ec80b 206
43a4360e 207struct iio_trigger; /* forward declaration */
7ae8cf62 208struct iio_dev;
43a4360e 209
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210/**
211 * struct iio_info - constant information about device
212 * @driver_module: module structure used to ensure correct
213 * ownership of chrdevs etc
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214 * @event_attrs: event control attributes
215 * @attrs: general purpose device attributes
216 * @read_raw: function to request a value from the device.
217 * mask specifies which value. Note 0 means a reading of
218 * the channel in question. Return value will specify the
219 * type of value returned by the device. val and val2 will
220 * contain the elements making up the returned value.
221 * @write_raw: function to write a value to the device.
222 * Parameters are the same as for read_raw.
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223 * @write_raw_get_fmt: callback function to query the expected
224 * format/precision. If not set by the driver, write_raw
225 * returns IIO_VAL_INT_PLUS_MICRO.
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226 * @read_event_config: find out if the event is enabled.
227 * @write_event_config: set if the event is enabled.
228 * @read_event_value: read a value associated with the event. Meaning
229 * is event dependant. event_code specifies which event.
4abf6f8b 230 * @write_event_value: write the value associated with the event.
6fe8135f 231 * Meaning is event dependent.
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232 * @validate_trigger: function to validate the trigger when the
233 * current trigger gets changed.
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234 **/
235struct iio_info {
236 struct module *driver_module;
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237 struct attribute_group *event_attrs;
238 const struct attribute_group *attrs;
239
240 int (*read_raw)(struct iio_dev *indio_dev,
241 struct iio_chan_spec const *chan,
242 int *val,
243 int *val2,
244 long mask);
245
246 int (*write_raw)(struct iio_dev *indio_dev,
247 struct iio_chan_spec const *chan,
248 int val,
249 int val2,
250 long mask);
251
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252 int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
253 struct iio_chan_spec const *chan,
254 long mask);
255
6fe8135f 256 int (*read_event_config)(struct iio_dev *indio_dev,
330c6c57 257 u64 event_code);
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258
259 int (*write_event_config)(struct iio_dev *indio_dev,
330c6c57 260 u64 event_code,
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261 int state);
262
263 int (*read_event_value)(struct iio_dev *indio_dev,
330c6c57 264 u64 event_code,
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265 int *val);
266 int (*write_event_value)(struct iio_dev *indio_dev,
330c6c57 267 u64 event_code,
6fe8135f 268 int val);
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269 int (*validate_trigger)(struct iio_dev *indio_dev,
270 struct iio_trigger *trig);
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271 int (*update_scan_mode)(struct iio_dev *indio_dev,
272 const unsigned long *scan_mask);
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273 int (*debugfs_reg_access)(struct iio_dev *indio_dev,
274 unsigned reg, unsigned writeval,
275 unsigned *readval);
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276};
277
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278/**
279 * struct iio_buffer_setup_ops - buffer setup related callbacks
280 * @preenable: [DRIVER] function to run prior to marking buffer enabled
281 * @postenable: [DRIVER] function to run after marking buffer enabled
282 * @predisable: [DRIVER] function to run prior to marking buffer
283 * disabled
284 * @postdisable: [DRIVER] function to run after marking buffer disabled
285 */
286struct iio_buffer_setup_ops {
287 int (*preenable)(struct iio_dev *);
288 int (*postenable)(struct iio_dev *);
289 int (*predisable)(struct iio_dev *);
290 int (*postdisable)(struct iio_dev *);
291};
292
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293/**
294 * struct iio_dev - industrial I/O device
295 * @id: [INTERN] used to identify device internally
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296 * @modes: [DRIVER] operating modes supported by device
297 * @currentmode: [DRIVER] current operating mode
298 * @dev: [DRIVER] device structure, should be assigned a parent
299 * and owner
5aa96188 300 * @event_interface: [INTERN] event chrdevs associated with interrupt lines
14555b14 301 * @buffer: [DRIVER] any buffer present
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302 * @mlock: [INTERN] lock used to prevent simultaneous device state
303 * changes
e5c003ae 304 * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
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305 * @masklength: [INTERN] the length of the mask established from
306 * channels
959d2952 307 * @active_scan_mask: [INTERN] union of all scan masks requested by buffers
14555b14 308 * @trig: [INTERN] current device trigger (buffer modes)
25985edc 309 * @pollfunc: [DRIVER] function run on trigger being received
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310 * @channels: [DRIVER] channel specification structure table
311 * @num_channels: [DRIVER] number of chanels specified in @channels.
312 * @channel_attr_list: [INTERN] keep track of automatically created channel
1a25e592 313 * attributes
26d25ae3 314 * @chan_attr_group: [INTERN] group for all attrs in base directory
1d892719 315 * @name: [DRIVER] name of the device.
1a25e592 316 * @info: [DRIVER] callbacks and constant info from driver
ac917a81 317 * @info_exist_lock: [INTERN] lock to prevent use during removal
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318 * @setup_ops: [DRIVER] callbacks to call before and after buffer
319 * enable/disable
1a25e592 320 * @chrdev: [INTERN] associated character device
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321 * @groups: [INTERN] attribute groups
322 * @groupcounter: [INTERN] index of next attribute group
bb01443e 323 * @flags: [INTERN] file ops related flags including busy flag.
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324 * @debugfs_dentry: [INTERN] device specific debugfs dentry.
325 * @cached_reg_addr: [INTERN] cached register address for debugfs reads.
326 */
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327struct iio_dev {
328 int id;
4024bc73 329
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330 int modes;
331 int currentmode;
332 struct device dev;
847ec80b 333
5aa96188 334 struct iio_event_interface *event_interface;
847ec80b 335
14555b14 336 struct iio_buffer *buffer;
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337 struct mutex mlock;
338
cd4361c7 339 const unsigned long *available_scan_masks;
32b5eeca 340 unsigned masklength;
cd4361c7 341 const unsigned long *active_scan_mask;
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342 struct iio_trigger *trig;
343 struct iio_poll_func *pollfunc;
1d892719 344
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345 struct iio_chan_spec const *channels;
346 int num_channels;
1d892719 347
1a25e592 348 struct list_head channel_attr_list;
26d25ae3 349 struct attribute_group chan_attr_group;
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350 const char *name;
351 const struct iio_info *info;
ac917a81 352 struct mutex info_exist_lock;
1612244f 353 const struct iio_buffer_setup_ops *setup_ops;
1a25e592 354 struct cdev chrdev;
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355#define IIO_MAX_GROUPS 6
356 const struct attribute_group *groups[IIO_MAX_GROUPS + 1];
357 int groupcounter;
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358
359 unsigned long flags;
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360#if defined(CONFIG_DEBUG_FS)
361 struct dentry *debugfs_dentry;
362 unsigned cached_reg_addr;
363#endif
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364};
365
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366/**
367 * iio_find_channel_from_si() - get channel from its scan index
368 * @indio_dev: device
369 * @si: scan index to match
370 */
371const struct iio_chan_spec
372*iio_find_channel_from_si(struct iio_dev *indio_dev, int si);
373
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374/**
375 * iio_device_register() - register a device with the IIO subsystem
f8c6f4e9 376 * @indio_dev: Device structure filled by the device driver
847ec80b 377 **/
f8c6f4e9 378int iio_device_register(struct iio_dev *indio_dev);
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379
380/**
381 * iio_device_unregister() - unregister a device from the IIO subsystem
f8c6f4e9 382 * @indio_dev: Device structure representing the device.
847ec80b 383 **/
f8c6f4e9 384void iio_device_unregister(struct iio_dev *indio_dev);
847ec80b 385
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386/**
387 * iio_push_event() - try to add event to the list for userspace reading
f8c6f4e9 388 * @indio_dev: IIO device structure
847ec80b 389 * @ev_code: What event
4c572605 390 * @timestamp: When the event occurred
847ec80b 391 **/
f8c6f4e9 392int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
847ec80b 393
5aaaeba8 394extern struct bus_type iio_bus_type;
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395
396/**
4c572605 397 * iio_put_device() - reference counted deallocation of struct device
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398 * @dev: the iio_device containing the device
399 **/
f8c6f4e9 400static inline void iio_put_device(struct iio_dev *indio_dev)
847ec80b 401{
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402 if (indio_dev)
403 put_device(&indio_dev->dev);
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404};
405
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406/* Can we make this smaller? */
407#define IIO_ALIGN L1_CACHE_BYTES
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408/**
409 * iio_allocate_device() - allocate an iio_dev from a driver
6f7c8ee5 410 * @sizeof_priv: Space to allocate for private structure.
847ec80b 411 **/
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412struct iio_dev *iio_allocate_device(int sizeof_priv);
413
f8c6f4e9 414static inline void *iio_priv(const struct iio_dev *indio_dev)
6f7c8ee5 415{
f8c6f4e9 416 return (char *)indio_dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
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417}
418
419static inline struct iio_dev *iio_priv_to_dev(void *priv)
420{
421 return (struct iio_dev *)((char *)priv -
422 ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
423}
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424
425/**
426 * iio_free_device() - free an iio_dev from a driver
4c572605 427 * @dev: the iio_dev associated with the device
847ec80b 428 **/
f8c6f4e9 429void iio_free_device(struct iio_dev *indio_dev);
847ec80b 430
847ec80b 431/**
14555b14 432 * iio_buffer_enabled() - helper function to test if the buffer is enabled
f8c6f4e9 433 * @indio_dev: IIO device info structure for device
847ec80b 434 **/
f8c6f4e9 435static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
847ec80b 436{
f8c6f4e9 437 return indio_dev->currentmode
ec3afa40 438 & (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE);
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439};
440
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441/**
442 * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry
443 * @indio_dev: IIO device info structure for device
444 **/
445#if defined(CONFIG_DEBUG_FS)
446static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
447{
448 return indio_dev->debugfs_dentry;
449};
450#else
451static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
452{
453 return NULL;
454};
455#endif
456
847ec80b 457#endif /* _INDUSTRIAL_IO_H_ */