iio: core : events ABI for specifying period
[deliverable/linux.git] / drivers / iio / industrialio-event.c
CommitLineData
0a769a95
LPC
1/* Industrial I/O event handling
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 * Based on elements of hwmon and input subsystems.
10 */
11
12#include <linux/anon_inodes.h>
13#include <linux/device.h>
14#include <linux/fs.h>
15#include <linux/kernel.h>
2c00193f 16#include <linux/kfifo.h>
0a769a95 17#include <linux/module.h>
e18045ed 18#include <linux/poll.h>
0a769a95
LPC
19#include <linux/sched.h>
20#include <linux/slab.h>
21#include <linux/uaccess.h>
22#include <linux/wait.h>
06458e27 23#include <linux/iio/iio.h>
0a769a95 24#include "iio_core.h"
06458e27
JC
25#include <linux/iio/sysfs.h>
26#include <linux/iio/events.h>
0a769a95 27
0a769a95
LPC
28/**
29 * struct iio_event_interface - chrdev interface for an event line
30 * @wait: wait queue to allow blocking reads of events
0a769a95 31 * @det_events: list of detected events
0a769a95
LPC
32 * @dev_attr_list: list of event interface sysfs attribute
33 * @flags: file operations related flags including busy flag.
34 * @group: event interface sysfs attribute group
35 */
36struct iio_event_interface {
37 wait_queue_head_t wait;
2c00193f
LPC
38 DECLARE_KFIFO(det_events, struct iio_event_data, 16);
39
0a769a95
LPC
40 struct list_head dev_attr_list;
41 unsigned long flags;
42 struct attribute_group group;
b91accaf 43 struct mutex read_lock;
0a769a95
LPC
44};
45
a7e57dce
SK
46/**
47 * iio_push_event() - try to add event to the list for userspace reading
48 * @indio_dev: IIO device structure
49 * @ev_code: What event
50 * @timestamp: When the event occurred
b91accaf
LPC
51 *
52 * Note: The caller must make sure that this function is not running
53 * concurrently for the same indio_dev more than once.
a7e57dce 54 **/
0a769a95
LPC
55int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
56{
57 struct iio_event_interface *ev_int = indio_dev->event_interface;
2c00193f
LPC
58 struct iio_event_data ev;
59 int copied;
0a769a95
LPC
60
61 /* Does anyone care? */
0a769a95 62 if (test_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
0a769a95 63
2c00193f
LPC
64 ev.id = ev_code;
65 ev.timestamp = timestamp;
66
498d319b 67 copied = kfifo_put(&ev_int->det_events, ev);
2c00193f 68 if (copied != 0)
b91accaf 69 wake_up_poll(&ev_int->wait, POLLIN);
43ba1100 70 }
0a769a95 71
2c00193f 72 return 0;
0a769a95
LPC
73}
74EXPORT_SYMBOL(iio_push_event);
75
e18045ed
LPC
76/**
77 * iio_event_poll() - poll the event queue to find out if it has data
78 */
79static unsigned int iio_event_poll(struct file *filep,
80 struct poll_table_struct *wait)
81{
cadc2125
LPC
82 struct iio_dev *indio_dev = filep->private_data;
83 struct iio_event_interface *ev_int = indio_dev->event_interface;
e18045ed
LPC
84 unsigned int events = 0;
85
f18e7a06
LPC
86 if (!indio_dev->info)
87 return -ENODEV;
88
e18045ed
LPC
89 poll_wait(filep, &ev_int->wait, wait);
90
e18045ed
LPC
91 if (!kfifo_is_empty(&ev_int->det_events))
92 events = POLLIN | POLLRDNORM;
e18045ed
LPC
93
94 return events;
95}
96
0a769a95
LPC
97static ssize_t iio_event_chrdev_read(struct file *filep,
98 char __user *buf,
99 size_t count,
100 loff_t *f_ps)
101{
cadc2125
LPC
102 struct iio_dev *indio_dev = filep->private_data;
103 struct iio_event_interface *ev_int = indio_dev->event_interface;
2c00193f 104 unsigned int copied;
0a769a95
LPC
105 int ret;
106
f18e7a06
LPC
107 if (!indio_dev->info)
108 return -ENODEV;
109
2c00193f 110 if (count < sizeof(struct iio_event_data))
0a769a95
LPC
111 return -EINVAL;
112
b91accaf
LPC
113 do {
114 if (kfifo_is_empty(&ev_int->det_events)) {
115 if (filep->f_flags & O_NONBLOCK)
116 return -EAGAIN;
117
118 ret = wait_event_interruptible(ev_int->wait,
d2f0a48f
LPC
119 !kfifo_is_empty(&ev_int->det_events) ||
120 indio_dev->info == NULL);
b91accaf
LPC
121 if (ret)
122 return ret;
123 if (indio_dev->info == NULL)
124 return -ENODEV;
d2f0a48f 125 }
0a769a95 126
b91accaf
LPC
127 if (mutex_lock_interruptible(&ev_int->read_lock))
128 return -ERESTARTSYS;
129 ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
130 mutex_unlock(&ev_int->read_lock);
131
132 if (ret)
133 return ret;
134
135 /*
136 * If we couldn't read anything from the fifo (a different
137 * thread might have been faster) we either return -EAGAIN if
138 * the file descriptor is non-blocking, otherwise we go back to
139 * sleep and wait for more data to arrive.
140 */
141 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
142 return -EAGAIN;
0a769a95 143
b91accaf 144 } while (copied == 0);
43ba1100 145
b91accaf 146 return copied;
0a769a95
LPC
147}
148
149static int iio_event_chrdev_release(struct inode *inode, struct file *filep)
150{
cadc2125
LPC
151 struct iio_dev *indio_dev = filep->private_data;
152 struct iio_event_interface *ev_int = indio_dev->event_interface;
0a769a95 153
b91accaf 154 clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
0a769a95 155
cadc2125
LPC
156 iio_device_put(indio_dev);
157
0a769a95
LPC
158 return 0;
159}
160
161static const struct file_operations iio_event_chrdev_fileops = {
162 .read = iio_event_chrdev_read,
e18045ed 163 .poll = iio_event_poll,
0a769a95
LPC
164 .release = iio_event_chrdev_release,
165 .owner = THIS_MODULE,
166 .llseek = noop_llseek,
167};
168
169int iio_event_getfd(struct iio_dev *indio_dev)
170{
171 struct iio_event_interface *ev_int = indio_dev->event_interface;
172 int fd;
173
174 if (ev_int == NULL)
175 return -ENODEV;
176
b91accaf 177 if (test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags))
0a769a95 178 return -EBUSY;
b91accaf 179
cadc2125
LPC
180 iio_device_get(indio_dev);
181
182 fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops,
e2aad1d5 183 indio_dev, O_RDONLY | O_CLOEXEC);
0a769a95 184 if (fd < 0) {
b91accaf 185 clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
cadc2125 186 iio_device_put(indio_dev);
b91accaf
LPC
187 } else {
188 kfifo_reset_out(&ev_int->det_events);
0a769a95 189 }
b91accaf 190
0a769a95
LPC
191 return fd;
192}
193
194static const char * const iio_ev_type_text[] = {
195 [IIO_EV_TYPE_THRESH] = "thresh",
196 [IIO_EV_TYPE_MAG] = "mag",
197 [IIO_EV_TYPE_ROC] = "roc",
198 [IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
199 [IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
200};
201
202static const char * const iio_ev_dir_text[] = {
203 [IIO_EV_DIR_EITHER] = "either",
204 [IIO_EV_DIR_RISING] = "rising",
205 [IIO_EV_DIR_FALLING] = "falling"
206};
207
b4e3ac0a
LPC
208static const char * const iio_ev_info_text[] = {
209 [IIO_EV_INFO_ENABLE] = "en",
210 [IIO_EV_INFO_VALUE] = "value",
ec6670ae 211 [IIO_EV_INFO_HYSTERESIS] = "hysteresis",
77a533c7 212 [IIO_EV_INFO_PERIOD] = "period",
b4e3ac0a
LPC
213};
214
215static enum iio_event_direction iio_ev_attr_dir(struct iio_dev_attr *attr)
216{
217 return attr->c->event_spec[attr->address & 0xffff].dir;
218}
219
220static enum iio_event_type iio_ev_attr_type(struct iio_dev_attr *attr)
221{
222 return attr->c->event_spec[attr->address & 0xffff].type;
223}
224
225static enum iio_event_info iio_ev_attr_info(struct iio_dev_attr *attr)
226{
227 return (attr->address >> 16) & 0xffff;
228}
229
0a769a95
LPC
230static ssize_t iio_ev_state_store(struct device *dev,
231 struct device_attribute *attr,
232 const char *buf,
233 size_t len)
234{
e53f5ac5 235 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95
LPC
236 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
237 int ret;
238 bool val;
239
240 ret = strtobool(buf, &val);
241 if (ret < 0)
242 return ret;
243
cb955852
LPC
244 ret = indio_dev->info->write_event_config(indio_dev,
245 this_attr->c, iio_ev_attr_type(this_attr),
246 iio_ev_attr_dir(this_attr), val);
b4e3ac0a 247
0a769a95
LPC
248 return (ret < 0) ? ret : len;
249}
250
251static ssize_t iio_ev_state_show(struct device *dev,
252 struct device_attribute *attr,
253 char *buf)
254{
e53f5ac5 255 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 256 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
b4e3ac0a 257 int val;
0a769a95 258
cb955852
LPC
259 val = indio_dev->info->read_event_config(indio_dev,
260 this_attr->c, iio_ev_attr_type(this_attr),
261 iio_ev_attr_dir(this_attr));
0a769a95
LPC
262 if (val < 0)
263 return val;
264 else
265 return sprintf(buf, "%d\n", val);
266}
267
268static ssize_t iio_ev_value_show(struct device *dev,
269 struct device_attribute *attr,
270 char *buf)
271{
e53f5ac5 272 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 273 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
9fbfb4b3 274 int val, val2, val_arr[2];
b4e3ac0a 275 int ret;
0a769a95 276
cb955852
LPC
277 ret = indio_dev->info->read_event_value(indio_dev,
278 this_attr->c, iio_ev_attr_type(this_attr),
279 iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
280 &val, &val2);
281 if (ret < 0)
282 return ret;
9fbfb4b3
SP
283 val_arr[0] = val;
284 val_arr[1] = val2;
285 return iio_format_value(buf, ret, 2, val_arr);
0a769a95
LPC
286}
287
288static ssize_t iio_ev_value_store(struct device *dev,
289 struct device_attribute *attr,
290 const char *buf,
291 size_t len)
292{
e53f5ac5 293 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 294 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
b4e3ac0a 295 int val, val2;
0a769a95
LPC
296 int ret;
297
cb955852 298 if (!indio_dev->info->write_event_value)
0a769a95
LPC
299 return -EINVAL;
300
cb955852
LPC
301 ret = iio_str_to_fixpoint(buf, 100000, &val, &val2);
302 if (ret)
303 return ret;
304 ret = indio_dev->info->write_event_value(indio_dev,
305 this_attr->c, iio_ev_attr_type(this_attr),
306 iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
307 val, val2);
0a769a95
LPC
308 if (ret < 0)
309 return ret;
310
311 return len;
312}
313
b4e3ac0a
LPC
314static int iio_device_add_event(struct iio_dev *indio_dev,
315 const struct iio_chan_spec *chan, unsigned int spec_index,
316 enum iio_event_type type, enum iio_event_direction dir,
317 enum iio_shared_by shared_by, const unsigned long *mask)
318{
319 ssize_t (*show)(struct device *, struct device_attribute *, char *);
320 ssize_t (*store)(struct device *, struct device_attribute *,
321 const char *, size_t);
322 unsigned int attrcount = 0;
323 unsigned int i;
324 char *postfix;
325 int ret;
326
ef4b4856
JC
327 for_each_set_bit(i, mask, sizeof(*mask)*8) {
328 if (i >= ARRAY_SIZE(iio_ev_info_text))
329 return -EINVAL;
b4e3ac0a
LPC
330 postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
331 iio_ev_type_text[type], iio_ev_dir_text[dir],
332 iio_ev_info_text[i]);
333 if (postfix == NULL)
334 return -ENOMEM;
335
336 if (i == IIO_EV_INFO_ENABLE) {
337 show = iio_ev_state_show;
338 store = iio_ev_state_store;
339 } else {
340 show = iio_ev_value_show;
341 store = iio_ev_value_store;
342 }
343
344 ret = __iio_add_chan_devattr(postfix, chan, show, store,
345 (i << 16) | spec_index, shared_by, &indio_dev->dev,
346 &indio_dev->event_interface->dev_attr_list);
347 kfree(postfix);
348
349 if (ret)
350 return ret;
351
352 attrcount++;
353 }
354
355 return attrcount;
356}
357
cb955852 358static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
b4e3ac0a
LPC
359 struct iio_chan_spec const *chan)
360{
361 int ret = 0, i, attrcount = 0;
362 enum iio_event_direction dir;
363 enum iio_event_type type;
364
365 for (i = 0; i < chan->num_event_specs; i++) {
366 type = chan->event_spec[i].type;
367 dir = chan->event_spec[i].dir;
368
369 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
370 IIO_SEPARATE, &chan->event_spec[i].mask_separate);
371 if (ret < 0)
92825ff9 372 return ret;
b4e3ac0a
LPC
373 attrcount += ret;
374
375 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
376 IIO_SHARED_BY_TYPE,
377 &chan->event_spec[i].mask_shared_by_type);
378 if (ret < 0)
92825ff9 379 return ret;
b4e3ac0a
LPC
380 attrcount += ret;
381
382 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
383 IIO_SHARED_BY_DIR,
384 &chan->event_spec[i].mask_shared_by_dir);
385 if (ret < 0)
92825ff9 386 return ret;
b4e3ac0a
LPC
387 attrcount += ret;
388
389 ret = iio_device_add_event(indio_dev, chan, i, type, dir,
390 IIO_SHARED_BY_ALL,
391 &chan->event_spec[i].mask_shared_by_all);
392 if (ret < 0)
92825ff9 393 return ret;
b4e3ac0a
LPC
394 attrcount += ret;
395 }
396 ret = attrcount;
b4e3ac0a
LPC
397 return ret;
398}
399
0a769a95
LPC
400static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
401{
402 int j, ret, attrcount = 0;
403
0a769a95
LPC
404 /* Dynically created from the channels array */
405 for (j = 0; j < indio_dev->num_channels; j++) {
406 ret = iio_device_add_event_sysfs(indio_dev,
407 &indio_dev->channels[j]);
408 if (ret < 0)
e3db9ef6 409 return ret;
0a769a95
LPC
410 attrcount += ret;
411 }
412 return attrcount;
0a769a95
LPC
413}
414
415static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
416{
417 int j;
418
b4e3ac0a 419 for (j = 0; j < indio_dev->num_channels; j++) {
b4e3ac0a
LPC
420 if (indio_dev->channels[j].num_event_specs != 0)
421 return true;
422 }
0a769a95
LPC
423 return false;
424}
425
426static void iio_setup_ev_int(struct iio_event_interface *ev_int)
427{
2c00193f 428 INIT_KFIFO(ev_int->det_events);
0a769a95 429 init_waitqueue_head(&ev_int->wait);
b91accaf 430 mutex_init(&ev_int->read_lock);
0a769a95
LPC
431}
432
433static const char *iio_event_group_name = "events";
434int iio_device_register_eventset(struct iio_dev *indio_dev)
435{
436 struct iio_dev_attr *p;
437 int ret = 0, attrcount_orig = 0, attrcount, attrn;
438 struct attribute **attr;
439
440 if (!(indio_dev->info->event_attrs ||
441 iio_check_for_dynamic_events(indio_dev)))
442 return 0;
443
444 indio_dev->event_interface =
445 kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
92825ff9
HK
446 if (indio_dev->event_interface == NULL)
447 return -ENOMEM;
0a769a95 448
46b24311
SH
449 INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);
450
0a769a95
LPC
451 iio_setup_ev_int(indio_dev->event_interface);
452 if (indio_dev->info->event_attrs != NULL) {
453 attr = indio_dev->info->event_attrs->attrs;
454 while (*attr++ != NULL)
455 attrcount_orig++;
456 }
457 attrcount = attrcount_orig;
458 if (indio_dev->channels) {
459 ret = __iio_add_event_config_attrs(indio_dev);
460 if (ret < 0)
461 goto error_free_setup_event_lines;
462 attrcount += ret;
463 }
464
465 indio_dev->event_interface->group.name = iio_event_group_name;
466 indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1,
467 sizeof(indio_dev->event_interface->group.attrs[0]),
468 GFP_KERNEL);
469 if (indio_dev->event_interface->group.attrs == NULL) {
470 ret = -ENOMEM;
471 goto error_free_setup_event_lines;
472 }
473 if (indio_dev->info->event_attrs)
474 memcpy(indio_dev->event_interface->group.attrs,
475 indio_dev->info->event_attrs->attrs,
476 sizeof(indio_dev->event_interface->group.attrs[0])
477 *attrcount_orig);
478 attrn = attrcount_orig;
479 /* Add all elements from the list. */
480 list_for_each_entry(p,
481 &indio_dev->event_interface->dev_attr_list,
482 l)
483 indio_dev->event_interface->group.attrs[attrn++] =
484 &p->dev_attr.attr;
485 indio_dev->groups[indio_dev->groupcounter++] =
486 &indio_dev->event_interface->group;
487
488 return 0;
489
490error_free_setup_event_lines:
84088ebd 491 iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list);
0a769a95 492 kfree(indio_dev->event_interface);
0a769a95
LPC
493 return ret;
494}
495
d2f0a48f
LPC
496/**
497 * iio_device_wakeup_eventset - Wakes up the event waitqueue
498 * @indio_dev: The IIO device
499 *
500 * Wakes up the event waitqueue used for poll() and blocking read().
501 * Should usually be called when the device is unregistered.
502 */
503void iio_device_wakeup_eventset(struct iio_dev *indio_dev)
504{
505 if (indio_dev->event_interface == NULL)
506 return;
507 wake_up(&indio_dev->event_interface->wait);
508}
509
0a769a95
LPC
510void iio_device_unregister_eventset(struct iio_dev *indio_dev)
511{
512 if (indio_dev->event_interface == NULL)
513 return;
84088ebd 514 iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list);
0a769a95
LPC
515 kfree(indio_dev->event_interface->group.attrs);
516 kfree(indio_dev->event_interface);
517}
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