]>
Commit | Line | Data |
---|---|---|
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 | */ | |
36 | struct 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; | |
43 | }; | |
44 | ||
45 | int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp) | |
46 | { | |
47 | struct iio_event_interface *ev_int = indio_dev->event_interface; | |
2c00193f | 48 | struct iio_event_data ev; |
1b9dc91e | 49 | unsigned long flags; |
2c00193f | 50 | int copied; |
0a769a95 LPC |
51 | |
52 | /* Does anyone care? */ | |
1b9dc91e | 53 | spin_lock_irqsave(&ev_int->wait.lock, flags); |
0a769a95 | 54 | if (test_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) { |
0a769a95 | 55 | |
2c00193f LPC |
56 | ev.id = ev_code; |
57 | ev.timestamp = timestamp; | |
58 | ||
59 | copied = kfifo_put(&ev_int->det_events, &ev); | |
2c00193f | 60 | if (copied != 0) |
e18045ed | 61 | wake_up_locked_poll(&ev_int->wait, POLLIN); |
43ba1100 | 62 | } |
1b9dc91e | 63 | spin_unlock_irqrestore(&ev_int->wait.lock, flags); |
0a769a95 | 64 | |
2c00193f | 65 | return 0; |
0a769a95 LPC |
66 | } |
67 | EXPORT_SYMBOL(iio_push_event); | |
68 | ||
e18045ed LPC |
69 | /** |
70 | * iio_event_poll() - poll the event queue to find out if it has data | |
71 | */ | |
72 | static unsigned int iio_event_poll(struct file *filep, | |
73 | struct poll_table_struct *wait) | |
74 | { | |
cadc2125 LPC |
75 | struct iio_dev *indio_dev = filep->private_data; |
76 | struct iio_event_interface *ev_int = indio_dev->event_interface; | |
e18045ed LPC |
77 | unsigned int events = 0; |
78 | ||
f18e7a06 LPC |
79 | if (!indio_dev->info) |
80 | return -ENODEV; | |
81 | ||
e18045ed LPC |
82 | poll_wait(filep, &ev_int->wait, wait); |
83 | ||
1b9dc91e | 84 | spin_lock_irq(&ev_int->wait.lock); |
e18045ed LPC |
85 | if (!kfifo_is_empty(&ev_int->det_events)) |
86 | events = POLLIN | POLLRDNORM; | |
1b9dc91e | 87 | spin_unlock_irq(&ev_int->wait.lock); |
e18045ed LPC |
88 | |
89 | return events; | |
90 | } | |
91 | ||
0a769a95 LPC |
92 | static ssize_t iio_event_chrdev_read(struct file *filep, |
93 | char __user *buf, | |
94 | size_t count, | |
95 | loff_t *f_ps) | |
96 | { | |
cadc2125 LPC |
97 | struct iio_dev *indio_dev = filep->private_data; |
98 | struct iio_event_interface *ev_int = indio_dev->event_interface; | |
2c00193f | 99 | unsigned int copied; |
0a769a95 LPC |
100 | int ret; |
101 | ||
f18e7a06 LPC |
102 | if (!indio_dev->info) |
103 | return -ENODEV; | |
104 | ||
2c00193f | 105 | if (count < sizeof(struct iio_event_data)) |
0a769a95 LPC |
106 | return -EINVAL; |
107 | ||
1b9dc91e | 108 | spin_lock_irq(&ev_int->wait.lock); |
2c00193f | 109 | if (kfifo_is_empty(&ev_int->det_events)) { |
0a769a95 LPC |
110 | if (filep->f_flags & O_NONBLOCK) { |
111 | ret = -EAGAIN; | |
43ba1100 | 112 | goto error_unlock; |
0a769a95 | 113 | } |
0a769a95 | 114 | /* Blocking on device; waiting for something to be there */ |
1b9dc91e | 115 | ret = wait_event_interruptible_locked_irq(ev_int->wait, |
d2f0a48f LPC |
116 | !kfifo_is_empty(&ev_int->det_events) || |
117 | indio_dev->info == NULL); | |
0a769a95 | 118 | if (ret) |
43ba1100 | 119 | goto error_unlock; |
d2f0a48f LPC |
120 | if (indio_dev->info == NULL) { |
121 | ret = -ENODEV; | |
122 | goto error_unlock; | |
123 | } | |
0a769a95 | 124 | /* Single access device so no one else can get the data */ |
0a769a95 LPC |
125 | } |
126 | ||
2c00193f | 127 | ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied); |
0a769a95 | 128 | |
43ba1100 | 129 | error_unlock: |
1b9dc91e | 130 | spin_unlock_irq(&ev_int->wait.lock); |
43ba1100 | 131 | |
2c00193f | 132 | return ret ? ret : copied; |
0a769a95 LPC |
133 | } |
134 | ||
135 | static int iio_event_chrdev_release(struct inode *inode, struct file *filep) | |
136 | { | |
cadc2125 LPC |
137 | struct iio_dev *indio_dev = filep->private_data; |
138 | struct iio_event_interface *ev_int = indio_dev->event_interface; | |
0a769a95 | 139 | |
1b9dc91e | 140 | spin_lock_irq(&ev_int->wait.lock); |
a046c1e8 | 141 | __clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags); |
0a769a95 LPC |
142 | /* |
143 | * In order to maintain a clean state for reopening, | |
144 | * clear out any awaiting events. The mask will prevent | |
145 | * any new __iio_push_event calls running. | |
146 | */ | |
2c00193f | 147 | kfifo_reset_out(&ev_int->det_events); |
1b9dc91e | 148 | spin_unlock_irq(&ev_int->wait.lock); |
0a769a95 | 149 | |
cadc2125 LPC |
150 | iio_device_put(indio_dev); |
151 | ||
0a769a95 LPC |
152 | return 0; |
153 | } | |
154 | ||
155 | static const struct file_operations iio_event_chrdev_fileops = { | |
156 | .read = iio_event_chrdev_read, | |
e18045ed | 157 | .poll = iio_event_poll, |
0a769a95 LPC |
158 | .release = iio_event_chrdev_release, |
159 | .owner = THIS_MODULE, | |
160 | .llseek = noop_llseek, | |
161 | }; | |
162 | ||
163 | int iio_event_getfd(struct iio_dev *indio_dev) | |
164 | { | |
165 | struct iio_event_interface *ev_int = indio_dev->event_interface; | |
166 | int fd; | |
167 | ||
168 | if (ev_int == NULL) | |
169 | return -ENODEV; | |
170 | ||
1b9dc91e | 171 | spin_lock_irq(&ev_int->wait.lock); |
a046c1e8 | 172 | if (__test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) { |
1b9dc91e | 173 | spin_unlock_irq(&ev_int->wait.lock); |
0a769a95 LPC |
174 | return -EBUSY; |
175 | } | |
1b9dc91e | 176 | spin_unlock_irq(&ev_int->wait.lock); |
cadc2125 LPC |
177 | iio_device_get(indio_dev); |
178 | ||
179 | fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops, | |
e2aad1d5 | 180 | indio_dev, O_RDONLY | O_CLOEXEC); |
0a769a95 | 181 | if (fd < 0) { |
1b9dc91e | 182 | spin_lock_irq(&ev_int->wait.lock); |
a046c1e8 | 183 | __clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags); |
1b9dc91e | 184 | spin_unlock_irq(&ev_int->wait.lock); |
cadc2125 | 185 | iio_device_put(indio_dev); |
0a769a95 LPC |
186 | } |
187 | return fd; | |
188 | } | |
189 | ||
190 | static const char * const iio_ev_type_text[] = { | |
191 | [IIO_EV_TYPE_THRESH] = "thresh", | |
192 | [IIO_EV_TYPE_MAG] = "mag", | |
193 | [IIO_EV_TYPE_ROC] = "roc", | |
194 | [IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive", | |
195 | [IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive", | |
196 | }; | |
197 | ||
198 | static const char * const iio_ev_dir_text[] = { | |
199 | [IIO_EV_DIR_EITHER] = "either", | |
200 | [IIO_EV_DIR_RISING] = "rising", | |
201 | [IIO_EV_DIR_FALLING] = "falling" | |
202 | }; | |
203 | ||
204 | static ssize_t iio_ev_state_store(struct device *dev, | |
205 | struct device_attribute *attr, | |
206 | const char *buf, | |
207 | size_t len) | |
208 | { | |
e53f5ac5 | 209 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
0a769a95 LPC |
210 | struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); |
211 | int ret; | |
212 | bool val; | |
213 | ||
214 | ret = strtobool(buf, &val); | |
215 | if (ret < 0) | |
216 | return ret; | |
217 | ||
218 | ret = indio_dev->info->write_event_config(indio_dev, | |
219 | this_attr->address, | |
220 | val); | |
221 | return (ret < 0) ? ret : len; | |
222 | } | |
223 | ||
224 | static ssize_t iio_ev_state_show(struct device *dev, | |
225 | struct device_attribute *attr, | |
226 | char *buf) | |
227 | { | |
e53f5ac5 | 228 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
0a769a95 LPC |
229 | struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); |
230 | int val = indio_dev->info->read_event_config(indio_dev, | |
231 | this_attr->address); | |
232 | ||
233 | if (val < 0) | |
234 | return val; | |
235 | else | |
236 | return sprintf(buf, "%d\n", val); | |
237 | } | |
238 | ||
239 | static ssize_t iio_ev_value_show(struct device *dev, | |
240 | struct device_attribute *attr, | |
241 | char *buf) | |
242 | { | |
e53f5ac5 | 243 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
0a769a95 LPC |
244 | struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); |
245 | int val, ret; | |
246 | ||
247 | ret = indio_dev->info->read_event_value(indio_dev, | |
248 | this_attr->address, &val); | |
249 | if (ret < 0) | |
250 | return ret; | |
251 | ||
252 | return sprintf(buf, "%d\n", val); | |
253 | } | |
254 | ||
255 | static ssize_t iio_ev_value_store(struct device *dev, | |
256 | struct device_attribute *attr, | |
257 | const char *buf, | |
258 | size_t len) | |
259 | { | |
e53f5ac5 | 260 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
0a769a95 | 261 | struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); |
948ad205 | 262 | int val; |
0a769a95 LPC |
263 | int ret; |
264 | ||
265 | if (!indio_dev->info->write_event_value) | |
266 | return -EINVAL; | |
267 | ||
948ad205 | 268 | ret = kstrtoint(buf, 10, &val); |
0a769a95 LPC |
269 | if (ret) |
270 | return ret; | |
271 | ||
272 | ret = indio_dev->info->write_event_value(indio_dev, this_attr->address, | |
273 | val); | |
274 | if (ret < 0) | |
275 | return ret; | |
276 | ||
277 | return len; | |
278 | } | |
279 | ||
280 | static int iio_device_add_event_sysfs(struct iio_dev *indio_dev, | |
281 | struct iio_chan_spec const *chan) | |
282 | { | |
283 | int ret = 0, i, attrcount = 0; | |
284 | u64 mask = 0; | |
285 | char *postfix; | |
286 | if (!chan->event_mask) | |
287 | return 0; | |
288 | ||
289 | for_each_set_bit(i, &chan->event_mask, sizeof(chan->event_mask)*8) { | |
290 | postfix = kasprintf(GFP_KERNEL, "%s_%s_en", | |
291 | iio_ev_type_text[i/IIO_EV_DIR_MAX], | |
292 | iio_ev_dir_text[i%IIO_EV_DIR_MAX]); | |
293 | if (postfix == NULL) { | |
294 | ret = -ENOMEM; | |
295 | goto error_ret; | |
296 | } | |
297 | if (chan->modified) | |
2b0774df | 298 | mask = IIO_MOD_EVENT_CODE(chan->type, 0, chan->channel2, |
0a769a95 LPC |
299 | i/IIO_EV_DIR_MAX, |
300 | i%IIO_EV_DIR_MAX); | |
301 | else if (chan->differential) | |
302 | mask = IIO_EVENT_CODE(chan->type, | |
303 | 0, 0, | |
304 | i%IIO_EV_DIR_MAX, | |
305 | i/IIO_EV_DIR_MAX, | |
306 | 0, | |
307 | chan->channel, | |
308 | chan->channel2); | |
309 | else | |
310 | mask = IIO_UNMOD_EVENT_CODE(chan->type, | |
311 | chan->channel, | |
312 | i/IIO_EV_DIR_MAX, | |
313 | i%IIO_EV_DIR_MAX); | |
314 | ||
315 | ret = __iio_add_chan_devattr(postfix, | |
316 | chan, | |
317 | &iio_ev_state_show, | |
318 | iio_ev_state_store, | |
319 | mask, | |
320 | 0, | |
321 | &indio_dev->dev, | |
322 | &indio_dev->event_interface-> | |
323 | dev_attr_list); | |
324 | kfree(postfix); | |
325 | if (ret) | |
326 | goto error_ret; | |
327 | attrcount++; | |
328 | postfix = kasprintf(GFP_KERNEL, "%s_%s_value", | |
329 | iio_ev_type_text[i/IIO_EV_DIR_MAX], | |
330 | iio_ev_dir_text[i%IIO_EV_DIR_MAX]); | |
331 | if (postfix == NULL) { | |
332 | ret = -ENOMEM; | |
333 | goto error_ret; | |
334 | } | |
335 | ret = __iio_add_chan_devattr(postfix, chan, | |
336 | iio_ev_value_show, | |
337 | iio_ev_value_store, | |
338 | mask, | |
339 | 0, | |
340 | &indio_dev->dev, | |
341 | &indio_dev->event_interface-> | |
342 | dev_attr_list); | |
343 | kfree(postfix); | |
344 | if (ret) | |
345 | goto error_ret; | |
346 | attrcount++; | |
347 | } | |
348 | ret = attrcount; | |
349 | error_ret: | |
350 | return ret; | |
351 | } | |
352 | ||
0a769a95 LPC |
353 | static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev) |
354 | { | |
355 | int j, ret, attrcount = 0; | |
356 | ||
0a769a95 LPC |
357 | /* Dynically created from the channels array */ |
358 | for (j = 0; j < indio_dev->num_channels; j++) { | |
359 | ret = iio_device_add_event_sysfs(indio_dev, | |
360 | &indio_dev->channels[j]); | |
361 | if (ret < 0) | |
e3db9ef6 | 362 | return ret; |
0a769a95 LPC |
363 | attrcount += ret; |
364 | } | |
365 | return attrcount; | |
0a769a95 LPC |
366 | } |
367 | ||
368 | static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev) | |
369 | { | |
370 | int j; | |
371 | ||
372 | for (j = 0; j < indio_dev->num_channels; j++) | |
373 | if (indio_dev->channels[j].event_mask != 0) | |
374 | return true; | |
375 | return false; | |
376 | } | |
377 | ||
378 | static void iio_setup_ev_int(struct iio_event_interface *ev_int) | |
379 | { | |
2c00193f | 380 | INIT_KFIFO(ev_int->det_events); |
0a769a95 LPC |
381 | init_waitqueue_head(&ev_int->wait); |
382 | } | |
383 | ||
384 | static const char *iio_event_group_name = "events"; | |
385 | int iio_device_register_eventset(struct iio_dev *indio_dev) | |
386 | { | |
387 | struct iio_dev_attr *p; | |
388 | int ret = 0, attrcount_orig = 0, attrcount, attrn; | |
389 | struct attribute **attr; | |
390 | ||
391 | if (!(indio_dev->info->event_attrs || | |
392 | iio_check_for_dynamic_events(indio_dev))) | |
393 | return 0; | |
394 | ||
395 | indio_dev->event_interface = | |
396 | kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL); | |
397 | if (indio_dev->event_interface == NULL) { | |
398 | ret = -ENOMEM; | |
399 | goto error_ret; | |
400 | } | |
401 | ||
46b24311 SH |
402 | INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list); |
403 | ||
0a769a95 LPC |
404 | iio_setup_ev_int(indio_dev->event_interface); |
405 | if (indio_dev->info->event_attrs != NULL) { | |
406 | attr = indio_dev->info->event_attrs->attrs; | |
407 | while (*attr++ != NULL) | |
408 | attrcount_orig++; | |
409 | } | |
410 | attrcount = attrcount_orig; | |
411 | if (indio_dev->channels) { | |
412 | ret = __iio_add_event_config_attrs(indio_dev); | |
413 | if (ret < 0) | |
414 | goto error_free_setup_event_lines; | |
415 | attrcount += ret; | |
416 | } | |
417 | ||
418 | indio_dev->event_interface->group.name = iio_event_group_name; | |
419 | indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1, | |
420 | sizeof(indio_dev->event_interface->group.attrs[0]), | |
421 | GFP_KERNEL); | |
422 | if (indio_dev->event_interface->group.attrs == NULL) { | |
423 | ret = -ENOMEM; | |
424 | goto error_free_setup_event_lines; | |
425 | } | |
426 | if (indio_dev->info->event_attrs) | |
427 | memcpy(indio_dev->event_interface->group.attrs, | |
428 | indio_dev->info->event_attrs->attrs, | |
429 | sizeof(indio_dev->event_interface->group.attrs[0]) | |
430 | *attrcount_orig); | |
431 | attrn = attrcount_orig; | |
432 | /* Add all elements from the list. */ | |
433 | list_for_each_entry(p, | |
434 | &indio_dev->event_interface->dev_attr_list, | |
435 | l) | |
436 | indio_dev->event_interface->group.attrs[attrn++] = | |
437 | &p->dev_attr.attr; | |
438 | indio_dev->groups[indio_dev->groupcounter++] = | |
439 | &indio_dev->event_interface->group; | |
440 | ||
441 | return 0; | |
442 | ||
443 | error_free_setup_event_lines: | |
84088ebd | 444 | iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list); |
0a769a95 LPC |
445 | kfree(indio_dev->event_interface); |
446 | error_ret: | |
447 | ||
448 | return ret; | |
449 | } | |
450 | ||
d2f0a48f LPC |
451 | /** |
452 | * iio_device_wakeup_eventset - Wakes up the event waitqueue | |
453 | * @indio_dev: The IIO device | |
454 | * | |
455 | * Wakes up the event waitqueue used for poll() and blocking read(). | |
456 | * Should usually be called when the device is unregistered. | |
457 | */ | |
458 | void iio_device_wakeup_eventset(struct iio_dev *indio_dev) | |
459 | { | |
460 | if (indio_dev->event_interface == NULL) | |
461 | return; | |
462 | wake_up(&indio_dev->event_interface->wait); | |
463 | } | |
464 | ||
0a769a95 LPC |
465 | void iio_device_unregister_eventset(struct iio_dev *indio_dev) |
466 | { | |
467 | if (indio_dev->event_interface == NULL) | |
468 | return; | |
84088ebd | 469 | iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list); |
0a769a95 LPC |
470 | kfree(indio_dev->event_interface->group.attrs); |
471 | kfree(indio_dev->event_interface); | |
472 | } |